Journal articles: 'Rostrum'

1

Hansen, M. J., S. Krause, M. Breuker, R. H. J. M. Kurvers, F. Dhellemmes, P. E. Viblanc, J. Müller, et al. "Linking hunting weaponry to attack strategies in sailfish and striped marlin." Proceedings of the Royal Society B: Biological Sciences 287, no. 1918 (January 15, 2020): 20192228. http://dx.doi.org/10.1098/rspb.2019.2228.

Full text

Abstract:

Linking morphological differences in foraging adaptations to prey choice and feeding strategies has provided major evolutionary insights across taxa. Here, we combine behavioural and morphological approaches to explore and compare the role of the rostrum (bill) and micro-teeth in the feeding behaviour of sailfish ( Istiophorus platypterus ) and striped marlin ( Kajikia audax ) when attacking schooling sardine prey. Behavioural results from high-speed videos showed that sailfish and striped marlin both regularly made rostrum contact with prey but displayed distinct strategies. Marlin used high-speed dashes, breaking schools apart, often contacting prey incidentally or tapping at isolated prey with their rostra; while sailfish used their rostra more frequently and tended to use a slower, less disruptive approach with more horizontal rostral slashes on cohesive prey schools. Capture success per attack was similar between species, but striped marlin had higher capture rates per minute. The rostra of both species are covered with micro-teeth, and micro-CT imaging showed that species did not differ in average micro-tooth length, but sailfish had a higher density of micro-teeth on the dorsal and ventral sides of their rostra and a higher amount of micro-teeth regrowth, suggesting a greater amount of rostrum use is associated with more investment in micro-teeth. Our analysis shows that the rostra of billfish are used in distinct ways and we discuss our results in the broader context of relationships between morphological and behavioural feeding adaptations across species.

APA, Harvard, Vancouver, ISO, and other styles

2

Ermilov, Sergey G. "New Galumnidae (Acari, Oribatida) from Ecuador." Systematic and Applied Acarology 24, no. 3 (March 4, 2019): 348. http://dx.doi.org/10.11158/saa.24.3.2.

Full text

Abstract:

Two new species of the oribatid mite family Galumnidae are described from Ecuador. Galumna napoensis sp. nov. differs from Galumna nonoensis Balogh, 1988 by the pointed rostrum and rostral setae distinctly longer than rostral setae, and the presence of tubercles posterior to dorsosejugal suture. Pergalumna finnamorei sp. nov. differs from Pergalumna lenticulata Ermilov & Friedrich, 2016 by the pointed rostrum, long interlamellar setae, stria forming reticulate pattern in anterior parts of prodorsum, notogaster and pteromorphs, rostral setae distinctly longer than rostral setae, localization of porose area Aa between la and lm, postanal porose area and reticulate epimere I, and the absence of foveoles on notogaster, pteromorphs and in anogenital region.

APA, Harvard, Vancouver, ISO, and other styles

3

Huang, Jiandong, Xia Wang, Yuanchao Hu, Jia Liu, Jennifer A. Peteya, and Julia A. Clarke. "A new ornithurine from the Early Cretaceous of China sheds light on the evolution of early ecological and cranial diversity in birds." PeerJ 4 (March 15, 2016): e1765. http://dx.doi.org/10.7717/peerj.1765.

Full text

Abstract:

Despite the increasing number of exceptional feathered fossils discovered in the Late Jurassic and Cretaceous of northeastern China, representatives of Ornithurae, a clade that includes comparatively-close relatives of crown clade Aves (extant birds) and that clade, are still comparatively rare. Here, we report a new ornithurine speciesChangzuiornis ahgmifrom the Early Cretaceous Jiufotang Formation. The new species shows an extremely elongate rostrum so far unknown in basal ornithurines and changes our understanding of the evolution of aspects of extant avian ecology and cranial evolution. Most of this elongate rostrum inChangzuiornis ahgmiis made up of maxilla, a characteristic not present in the avian crown clade in which most of the rostrum and nearly the entire facial margin is made up by premaxilla. The only other avialans known to exhibit an elongate rostrum with the facial margin comprised primarily of maxilla are derived ornithurines previously placed phylogenetically as among the closest outgroups to the avian crown clade as well as one derived enantiornithine clade. We find that, consistent with a proposed developmental shift in cranial ontogeny late in avialan evolution, that this elongate rostrum is achieved through elongation of the maxilla while the premaxilla remains only a small part of rostral length. Thus, only in Late Cretaceous ornithurine taxa does the premaxilla begin to play a larger role. The rostral and postcranial proportions ofChangzuiornissuggest an ecology not previously reported in Ornithurae; the only other species with an elongate rostrum are two marine Late Cretacous taxa interpreted as showing a derived picivorous diet.

APA, Harvard, Vancouver, ISO, and other styles

4

Liasko, Roman, Chryssa Anastasiadou, and Alexandros Ntakis. "Eco-morphological consequences of the ‘rostral loss’ in the intertidal marine shrimp Hippolyte sapphica morphotypes." Journal of the Marine Biological Association of the United Kingdom 98, no. 7 (October 26, 2017): 1667–73. http://dx.doi.org/10.1017/s0025315417000960.

Full text

Abstract:

The shrimp Hippolyte sapphica has a unique and sharp rostral dimorphism: morphotype A with a well-developed dentate rostrum, and morphotype B with a short, juvenile-like toothless rostrum. Previous research has shown that both morphotypes/forms belong to the same species and co-occur in the same habitat. Both forms occur in both sexes; however, form B individuals have a higher tendency to become males. Moreover, form A females are characterized by prolonged viability. The present comparative morphometric study concentrates on the changes induced by the rostral dimorphism and interprets them in terms of eco-morphological adaptations. Results showed that (i) the rostral length was the most isometric among the studied morphometric variables; (ii) males of A and B forms were not significantly different morphometrically; (iii) unexpectedly, form A non-ovigerous females had more developed carapace, abdominal somites and appendages in comparison with form B and, finally (iv), form B ovigerous females had higher tail and scaphocerite lengths, suggesting that they overcome higher turbulent force during the rapid backward movements and that the long rostrum improves hydrodynamic streamlining and stability. In conclusion, the previous finding that form B individuals tend to become males receives an adaptational explanation. The gene(s) responsible for the short rostrum accumulate in males, where their micro-evolutionary disadvantage is minimal or even absent.

APA, Harvard, Vancouver, ISO, and other styles

5

Boessenecker, Robert W., Danielle Fraser, Morgan Churchill, and Jonathan H. Geisler. "A toothless dwarf dolphin (Odontoceti: Xenorophidae) points to explosive feeding diversification of modern whales (Neoceti)." Proceedings of the Royal Society B: Biological Sciences 284, no. 1861 (August 23, 2017): 20170531. http://dx.doi.org/10.1098/rspb.2017.0531.

Full text

Abstract:

Toothed whales (Odontoceti) are adapted for catching prey underwater and possess some of the most derived feeding specializations of all mammals, including the loss of milk teeth (monophyodonty), high tooth count (polydonty), and the loss of discrete tooth classes (homodonty). Many extant odontocetes possess some combination of short, broad rostra, reduced tooth counts, fleshy lips, and enlarged hyoid bones—all adaptations for suction feeding upon fishes and squid. We report a new fossil odontocete from the Oligocene (approx. 30 Ma) of South Carolina ( Inermorostrum xenops , gen. et sp. nov.) that possesses adaptations for suction feeding: toothlessness and a shortened rostrum (brevirostry). Enlarged foramina on the rostrum suggest the presence of enlarged lips or perhaps vibrissae. Phylogenetic analysis firmly places Inermorostrum within the Xenorophidae, an early diverging odontocete clade typified by long-snouted, heterodont dolphins. Inermorostrum is the earliest obligate suction feeder within the Odontoceti, a feeding mode that independently evolved several times within the clade. Analysis of macroevolutionary trends in rostral shape indicate stabilizing selection around an optimum rostral shape over the course of odontocete evolution, and a post-Eocene explosion in feeding morphology, heralding the diversity of feeding behaviour among modern Odontoceti.

APA, Harvard, Vancouver, ISO, and other styles

6

Dhellemmes, F., M. J. Hansen, S. D. Bouet, J. J. Videler, P. Domenici, J. F. Steffensen, T. Hildebrandt, et al. "Oil gland and oil pores in billfishes: in search of a function." Journal of Experimental Biology 223, no. 19 (August 13, 2020): jeb224956. http://dx.doi.org/10.1242/jeb.224956.

Full text

Abstract:

ABSTRACTBillfishes are well known for their distinctive elongated rostra, i.e. bills. The functional significance of billfish rostra has been frequently discussed and the recent discovery of an oil gland (glandula oleofera) at the base of the rostrum in swordfish, Xiphias gladius, has added an interesting facet to this discussion regarding the potential co-evolution of gland and rostra. Here, we investigated the oil gland and oil pores (through which the oil is brought to the skin surface) of four billfish species – swordfish, Atlantic blue marlin (Makaira nigricans), Indo-Pacific sailfish (Istiophorus platypterus) and striped marlin (Kajikia audax) – and provide detailed evidence for the presence of an oil gland in the last three. All four species had a high density of oil pores on the forehead which is consistent with the hypothesis of hydrodynamic benefits of the oil. The extension of the pores onto the front half of the rostrum in sailfish and striped marlin, but not in swordfish or blue marlin, suggests that the oil may have additional functions. One such function could be linked to the antibacterial and anti-inflammatory properties of the oil. However, the available evidence on predatory rostrum use (and hence the likelihood of tissue damage) is only partly consistent with the extension of pores on rostra across species. We conclude that the oil gland probably serves multiple, non-mutually exclusive functions. More detailed information on rostrum use in blue marlin and swordfish is needed to better link behavioural and morphological data with the aim of accomplishing a full comparative analysis.

APA, Harvard, Vancouver, ISO, and other styles

7

ASHELBY, CHRISTOPHER W., and SAMMY DE GRAVE. "A new species of Palaemon (Crustacea, Decapoda, Palaemonidae) from West Africa, with a re-description of Palaemon maculatus (Thallwitz, 1892)." Zootaxa 2085, no. 1 (April 29, 2009): 27–44. http://dx.doi.org/10.11646/zootaxa.2085.1.3.

Full text

Abstract:

A new species of Palaemon, P. powelli sp. nov., is described from tropical West Africa. The new species is characterised by the shape and proportions of its chelae, the shape of the rostrum, spacing between dorsal rostral teeth and a poorly developed grooming brush on the fifth pereiopod. Palaemon maculatus (Thallwitz, 1892) is redescribed and can be separated from other eastern Atlantic members of the genus by the form of the rostrum, the proportions of the segments of pereiopod 2 and the large number of rows of setae in the grooming brush on the fifth pereiopod.

APA, Harvard, Vancouver, ISO, and other styles

8

Welten, Monique, Moya Meredith Smith, Charlie Underwood, and Zerina Johanson. "Evolutionary origins and development of saw-teeth on the sawfish and sawshark rostrum (Elasmobranchii; Chondrichthyes)." Royal Society Open Science 2, no. 9 (September 2015): 150189. http://dx.doi.org/10.1098/rsos.150189.

Full text

Abstract:

A well-known characteristic of chondrichthyans (e.g. sharks, rays) is their covering of external skin denticles (placoid scales), but less well understood is the wide morphological diversity that these skin denticles can show. Some of the more unusual of these are the tooth-like structures associated with the elongate cartilaginous rostrum ‘saw’ in three chondrichthyan groups: Pristiophoridae (sawsharks; Selachii), Pristidae (sawfish; Batoidea) and the fossil Sclerorhynchoidea (Batoidea). Comparative topographic and developmental studies of the ‘saw-teeth’ were undertaken in adults and embryos of these groups, by means of three-dimensional-rendered volumes from X-ray computed tomography. This provided data on development and relative arrangement in embryos, with regenerative replacement in adults. Saw-teeth are morphologically similar on the rostra of the Pristiophoridae and the Sclerorhynchoidea, with the same replacement modes, despite the lack of a close phylogenetic relationship. In both, tooth-like structures develop under the skin of the embryos, aligned with the rostrum surface, before rotating into lateral position and then attaching through a pedicel to the rostrum cartilage. As well, saw-teeth are replaced and added to as space becomes available. By contrast, saw-teeth in Pristidae insert into sockets in the rostrum cartilage, growing continuously and are not replaced. Despite superficial similarity to oral tooth developmental organization, saw-tooth spatial initiation arrangement is associated with rostrum growth. Replacement is space-dependent and more comparable to that of dermal skin denticles. We suggest these saw-teeth represent modified dermal denticles and lack the ‘many-for-one’ replacement characteristic of elasmobranch oral dentitions.

APA, Harvard, Vancouver, ISO, and other styles

9

Rieppel, Olivier, Johannes Müller, and Jun Liu. "Rostral structure in Thalattosauria (Reptilia, Diapsida)." Canadian Journal of Earth Sciences 42, no. 12 (December 1, 2005): 2081–86. http://dx.doi.org/10.1139/e05-076.

Full text

Abstract:

The rostral structure of thalattosaurs is reviewed on the basis of a re-investigation of the holotype of Nectosaurus halius and Thalattosaurus alexandrae. The askeptosaurid genera Askeptosaurus and Anshunsaurus share an elongated, parallel-sided rostrum that terminates in a blunt tip. A diastema separating the premaxillary from the maxillary teeth is absent. The claraziid genera Clarazia and Thalattosaurus share a relatively shorter rostrum that has convergent lateral margins and that terminates in a pointed tip. A diastema separating the premaxillary from the maxillary teeth is present. The well-preserved holotype of Nectosaurus halius shows a highly derived rostral structure. The maxilla is short with an anteriorly truncated (vertical) margin, a narrow but high ascending process, and a dorsally curving medial flange that is in natural articulation with the ventrally deflected vomer. These findings corroborate Peyer's original reconstruction of Hescheleria with a nearly vertically placed premaxilla.

APA, Harvard, Vancouver, ISO, and other styles

10

Pendrey, R. C., N. R. Loneragan, R. A. Kenyon, and D. J. Vance. "Simple morphometric characters, confirmed by gel electrophoresis, separate small juvenile banana prawns (Penaeus indicus and P. merguiensis)." Marine and Freshwater Research 50, no. 7 (1999): 677. http://dx.doi.org/10.1071/mf99038.

Full text

Abstract:

The juveniles of red-legged banana prawns Penaeus indicus and white banana prawns P. merguiensis are difficult to distinguish. Gel electrophoresis, with the enzyme malate dehydrogenase, clearly separated into species both large and small prawns. Four morphological characters were measured from juvenile prawns (identified using electrophoresis): three of these provided reliable separation into species. The mean ratio of the distance from the anterior-most dorsal rostral tooth (first tooth) to the tip of the rostrum (L 1 ): to the distance between this tooth and the second tooth (L 1,2 ) was higher for P. indicus (3.16) than P. merguiensis (1.56). All juvenile P. indicus had the first tooth posterior to the antennular peduncle, while it was anterior for all P. merguiensis. More than 90% of P. indicus had six rostral teeth behind the eye, while over 90% of P. merguiensis had five teeth behind the eye. Damage to the rostrum prevented measurements of the position of the first tooth in 20 to 30% of juvenile prawns. Combining the measurements of the ratio of L 1 : L 1,2 and the count of the number of rostral teeth behind the eye meant that all prawns could be unambiguously identified.

APA, Harvard, Vancouver, ISO, and other styles

11

Pendrey, R. C., N. R. Loneragan, R. A. Kenyon, and D. J. Vance. "Short Communication: Simple morphometric characters, confirmed by gel electrophoresis, separate small juvenile banana prawns (Penaeus indicus and P. merguiensis)." Marine and Freshwater Research 51, no. 4 (2000): 379. http://dx.doi.org/10.1071/mf99038_co.

Full text

Abstract:

The juveniles of red-legged banana prawns Penaeus indicus and white banana prawns P. merguiensis are difficult to distinguish. Gel electrophoresis, with the enzyme malate dehydrogenase, clearly separated into species both large and small prawns. Four morphological characters were measured from juvenile prawns (identified using electrophoresis): three of these provided reliable separation into species. The mean ratio of the distance from the anterior-most dorsal rostral tooth (first tooth) to the tip of the rostrum (L 1 ): to the distance between this tooth and the second tooth (L 1,2 ) was higher for P. indicus (3.16) than P. merguiensis (1.56). All juvenile P. indicus had the first tooth posterior to the antennular peduncle, while it was anterior for all P. merguiensis. More than 90% of P. indicus had six rostral teeth behind the eye, while over 90% of P. merguiensis had five teeth behind the eye. Damage to the rostrum prevented measurements of the position of the first tooth in 20 to 30% of juvenile prawns. Combining the measurements of the ratio of L 1 : L 1,2 and the count of the number of rostral teeth behind the eye meant that all prawns could be unambiguously identified.

APA, Harvard, Vancouver, ISO, and other styles

12

Keupp, Helmut, and Dirk Fuchs. "Enigmabelus n. gen. (Enigmabelitidae n. f.), an Early Jurassic (Late Pliensbachian) belemnite with an outstanding rostrum morphology." Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 298, no. 1 (October 1, 2020): 55–66. http://dx.doi.org/10.1127/njgpa/2020/0933.

Full text

Abstract:

The Subboreal marly facies of the Lower Jurassic (Upper Pliensbachian) Amaltheenton Formation in southern Germany contains a reduced association of belemnite species. Based on their rostra, we here describe three new taxa, Enigmabelus doppelsteini n. g. n. sp., E. micros n. sp., and ? E. leptos n. sp. included in a new family Enigmabelitidae, which is assigned to the suborder Belemnitina. All specimens come from the few centimetres thick echinid-pectinid horizon, uppermost Pliensbachian, of the clay pit south of Buttenheim (Germany, northern Bavaria). The moderately slender to slender and small rostra (between 8 and about 25 mm) exhibit uncommon and unique features, for instance the reduction of the ventral part of the rostrum resulting in an open alveolus. Most unusual is the apical line of the Enigmabelitidae n. f., which runs along the ventral surface of the rostrum solidum causing a fan-like arrangement of calcite crystals (instead of a concentric arrangement). We therefore introduce the perilineate apical line.

APA, Harvard, Vancouver, ISO, and other styles

13

Li, Longhai, Ce Guo, Shun Xu, Yaopeng Ma, and Zhiwei Yu. "Nanoindentation Properties and Finite Element Analysis of the Rostrum of Cyrtotrachelus buqueti Guer (Coleoptera: Curculionidae)." Microscopy and Microanalysis 25, no. 3 (March 22, 2019): 786–97. http://dx.doi.org/10.1017/s1431927619000242.

Full text

Abstract:

AbstractThis work focuses on the application of nanoindentation measurements and the finite element method for analyzing the mechanical properties of the rostrum of the outstanding driller Cyrtotrachelus buqueti Guer. Nanoindentation tests were carried out to measure the Young's modulus and hardness of the rostrum, with the results for the “dry” samples being 13.886 ± 0.75 and 0.368 ± 0.0445 GPa, respectively. The values for the “fresh” samples showed no clear difference from those of the “dry” ones. Moreover, field observation was conducted to determine the motion behaviors of the rostrum on the weevil. Micro-computed tomography technology was employed to obtain structural information about the rostrum, using 9 µm slices. A real three-dimensional model of the rostrum was created using the MIMICS application. Finally, the mechanical properties of the rostrum were determined by finite element analysis. It was concluded that the rostrum provides an ideal biological template for the design of biocomposite materials and lightweight tube-shaped structures. The properties determined in this study can potentially be applied in different fields, such as in the design of automotive hybrid transmission shafts, helicopter tail drive shafts, robotic arms, and other sandwich structures in aerospace engineering.

APA, Harvard, Vancouver, ISO, and other styles

14

McCurry, Matthew R., and Nicholas D. Pyenson. "Hyper-longirostry and kinematic disparity in extinct toothed whales." Paleobiology 45, no. 1 (November 6, 2018): 21–29. http://dx.doi.org/10.1017/pab.2018.33.

Full text

Abstract:

AbstractToothed cetacean (Odontoceti) lineages in the Miocene and Pliocene evolved rostra that are proportionally more elongate than any other aquatic mammal or reptile, living or extinct. Their similarities in cranial proportions to billfish may suggest a convergent feeding style, where the rostrum is swept through the water to hit and stun prey. Here we calculated second moment of area from rostral cross sections of these fossil odontocete taxa, as well as from extant ecological analogues, to infer variation in feeding behavior. Our results show that the extremely long rostra of extinct toothed whales vary considerably in functionally relevant measures of shape and likely exhibited a diversity of feeding behaviors, ranging from those similar to modern odontocetes to those convergent with billfish. Eustatic sea-level and temperature maxima of the Miocene likely led to changes in prey characteristics or abundance that enabled the repeated evolution of this extreme morphotype, which later went extinct during late Pliocene climatic deterioration.

APA, Harvard, Vancouver, ISO, and other styles

15

Ullmann, Clemens Vinzenz, and Philip A. E. Pogge von Strandmann. "The effect of shell secretion rate on Mg / Ca and Sr / Ca ratios in biogenic calcite as observed in a belemnite rostrum." Biogeosciences 14, no. 1 (January 9, 2017): 89–97. http://dx.doi.org/10.5194/bg-14-89-2017.

Full text

Abstract:

Abstract. Isotopic ratios and concentrations of the alkaline earth metals Mg and Sr in biogenic calcite are of great importance as proxies for environmental parameters. In particular, the Mg / Ca ratio as a temperature proxy has had considerable success. It is often hard to determine, however, which parameter ultimately controls the concentration of these elements in calcite. Here, multiple Mg / Ca and Sr / Ca transects through a belemnite rostrum of Passaloteuthis bisulcata (Blainville, 1827) are used to isolate the effect of calcite secretion rate on incorporation of Mg and Sr into the calcite. With increasing calcite secretion rate Mg / Ca ratios decrease and Sr / Ca ratios in the rostrum increase. In the studied specimen this effect is found to be linear for both element ratios over a calcite secretion rate increase of ca. 150 %. Mg / Ca ratios and Sr / Ca ratios show a linear co-variation with increasing relative growth rate, where a 100 % increase in growth rate leads to a (8.1 ± 0.9) % depletion in Mg and a (5.9 ± 0.7) % enrichment in Sr. The magnitude of the calcite secretion rate effect on Mg is (37 ± 4) % greater than that on Sr. These findings are qualitatively confirmed by a geochemical transect through a second rostrum of Passaloteuthis sp. Growth rate effects are well defined in rostra of Passaloteuthis, but only account for a minor part of chemical heterogeneity. Biasing effects on palaeoenvironmental studies can be minimized by informed sampling, whereby the apex and apical line of the rostrum are avoided.

APA, Harvard, Vancouver, ISO, and other styles

16

THORBURN, DEAN C., DAVID L. MORGAN, ANDREW J. ROWLAND, and HOWARD S. GILL. "Freshwater Sawfish Pristis microdon Latham, 1794 (Chondrichthyes : Pristidae) in the Kimberley region of Western Australia." Zootaxa 1471, no. 1 (May 10, 2007): 27. http://dx.doi.org/10.11646/zootaxa.1471.1.3.

Full text

Abstract:

The Freshwater Sawfish Pristis microdon was captured in marine waters of King Sound, and estuarine and fresh waters of the Fitzroy and Robinson rivers, in the Kimberley region of Western Australia. In light of the IUCN listing of the species as critically endangered, non-destructive means, including tagging-recapture data and information from specimens found dead on the banks, were utilised. Observations of sexual maturity, annuli present on vertebrae, recaptures of tagged individuals and length-frequency data suggested that the freshwaters of the Fitzroy River are a nursery for this species where immature individuals (up to 2800 mm total length) remain for a maximum of four or five years. Morphology and counts of the number of rostral teeth indicated that, in most cases, the rostral tooth morphology can be used to differentiate male and female P. microdon and also are useful in distinguishing this species from the congeneric and sympatric Pristis clavata. Furthermore, differences in the relationship between rostrum length and total length between the sexes may provide an effective diagnostic tool for the collation of historical distribution and sex ratio data from rostrums held in private collections. Rostral tooth counts and length at age data also suggest that the synonymisation of P. microdon, Pristis zephyreus and Pristis perotteti is not warranted.

APA, Harvard, Vancouver, ISO, and other styles

17

Allen, Jeffrey B., and Guillermo Riveros. "Hydrodynamic Characterization of thePolyodon spathulaRostrum Using CFD." Journal of Applied Mathematics 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/346173.

Full text

Abstract:

Among the various functions of the paddlefish rostrum, it is also believed to serve as a stabilizer to counteract the downward force that would otherwise occur during the process of filter feeding. From its unique shape, it is hypothesized that the paddlefish rostrum serves to generate a substantial amount of lift that naturally occurs as the rostrum is elevated at the same time the fish opens its mouth. The present, numerical study is an attempt to quantify the amount of lift (and drag) that is generated by the rostrum of a juvenile paddlefish. Additionally, this data is compared with other hydrofoils. The results suggest that the paddlefish rostrum does indeed produce substantial lift at certain angles of attack. In fact, the results indicate that the amount of lift is comparable to that produced by a symmetric foil (NACA 0012).

APA, Harvard, Vancouver, ISO, and other styles

18

Ermilov, Sergey G., and Leonila Corpuz-raros. "New Trizetoidea (Acari, Oribatida) from the Philippines." Systematic and Applied Acarology 22, no. 8 (August 4, 2017): 1243. http://dx.doi.org/10.11158/saa.22.8.8.

Full text

Abstract:

Two new species of oribatid mites of the superfamily Trizetoidea (Acari, Oribatida) are described from the Philippines. Eurhynchoribates (Eurhynchoribates) nuevavizcayaensis sp. nov. (Rhynchoribatidae) is similar to E. (E.) pocsi (Mahunka, 1986) in having the interlamellar setae the longest of the setae on the prodorsum, setiform, thickened; mostly long notogastral setae; setiform, thickened aggenital and adanal setae; and localization of ad3 in paraanal and adanal lyrifissures in inverse apoanal positions. It differs by the pointed rostrum, h1 longest of the setae on the notogaster, and the absence of lateral teeth on the rostrum. Suctobelbila trifasciata sp. nov. (Suctobelbidae) is similar to S. baderi Mahunka, 1988 in having two lateral longitudinally oriented ridges on the notogaster, but differs by its larger body size, in having two or three pairs of rostral teeth, three longitudinal notogastral ridges, six pairs of genital setae and the absence of humeral tubercles.

APA, Harvard, Vancouver, ISO, and other styles

19

Barros, Olga Alcântara, Maria Somália Sales Viana, Bartolomeu Cruz Viana, João Hermínio da Silva, Alexandre Rocha Paschoal, and Paulo Victor de Oliveira. "New data on Beurlenia araripensis Martins-Neto & Mezzalira, 1991, a lacustrine shrimp from Crato Formation, and its morphological variations based on the shape and the number of rostral spines." PLOS ONE 16, no. 3 (March 17, 2021): e0247497. http://dx.doi.org/10.1371/journal.pone.0247497.

Full text

Abstract:

Fossil freshwater carideans are very rare worldwide. Here, we present new taxonomic remarks about Beurlenia araripensis from the Early Cretaceous laminated limestones of the Crato Formation, Araripe Basin, northeastern Brazil. We analyzed five fossil samples, testing the morphological variations such as, rostrum with 5 to 14 supra-rostral spines and 2 to 3 sub-rostral spines, which appears as serrate for Caridea. This variation demonstrates a morphologic plasticity also seen in extant species of the group, such as those of the genera Macrobrachium and Palaemon.

APA, Harvard, Vancouver, ISO, and other styles

20

Rita, Patrícia, Kenneth De Baets, and Martina Schlott. "Rostrum size differences between Toarcian belemnite battlefields." Fossil Record 21, no. 1 (June 7, 2018): 171–82. http://dx.doi.org/10.5194/fr-21-171-2018.

Full text

Abstract:

Abstract. Body size changes have been reported across crisis intervals. Belemnites – now considered extinct stem-decabrachians – have rarely been investigated for this purpose, and the few studies have resulted in ambiguous outcomes. Here we investigate two Toarcian belemnite accumulations in southern Germany from a morphometric point of view with the support of computed tomography data. The aim of this study is to test whether a difference in size can be observed between the rostra of the two studied samples, from individual lineage to community, and which proxy is more reliable. A significant decrease in median size from the Early Toarcian (Dactylioceras tenuicostatum Zone) to the Middle Toarcian (Haugia variabilis Zone) is recognized. This is observed at the community level of organization, considering the whole assemblage, but also within Passaloteuthis–Acrocoelites lineage, at the genus level. It is also demonstrated that diameter-based measurements or maximum preserved length are not reliable proxies for size, and therefore apical length or three-dimensional approximations, such as the geometric mean or the post-phragmocone volume, are more advisable. This is especially important when comparing specimens with markedly different rostrum shapes. Further studies are, however, still necessary to disentangle the mechanisms behind the reduction in rostrum size within the Toarcian and their putative environmental causes.

APA, Harvard, Vancouver, ISO, and other styles

21

Barreto, Marliton Rocha, and Germano Henrique Rosado-Neto. "Dimorfismo Sexual de Onchoscelis germari (Boheman) (Coleoptera: Curculionidae)." EntomoBrasilis 5, no. 3 (December 13, 2012): 242–45. http://dx.doi.org/10.12741/ebrasilis.v5i3.203.

Full text

Abstract:

Onchoscelis germari (Boheman) é uma espécie de gorgulho associada com Simarouba amara Aubl. (Simaroubaceae), popularmente conhecida como “caixeta”. Sessenta e três exemplares adultos foram coletados e examinados em laboratório para determinação do dimorfismo sexual. As seguintes diferenças morfológicas foram observadas e ilustradas: 1) rostro, nos machos, mais rugoso, com pontuação maior e mais densa, tricarenado dorsalmente nos 2/3 basais, e revestido por cerdas eretas semelhantes a escamas e que se estendem até perto do meio; rostro, na fêmea, mais liso, com pontuação fina e mais esparsa, apenas a carena mediana distinta, e com revestimento denso mais concentrado na base; 2) inserção da antena, nos machos, mais próxima do ápice; e nas fêmeas mais ou menos no meio do rostro; 3) sulco esternal, nos machos, mais raso e com suas margens laterais apenas indicadas ou ausentes no prosterno; nas fêmeas o sulco é mais profundo e as margens laterais mais acentuadas no prosterno; 4) último tergito abdominal visível e distinto nos machos, enquanto que nas fêmeas é encoberto pelo penúltimo tergito. Sexual Dimorphism in Onchoscelis germari (Boheman) (Coleoptera: Curculionidae) Abstract. Onchoscelis germari (Boheman) is a weevil species associated with Simarouba amara Aubl (Simaroubaceae), commonly named “caixeta”. Sixty three specimens were collected and observed in laboratory for sexual dimorphism differences. The following morphological aspects were observed and illustrated: 1) rostrum of males more rough, coarse and with more dense punctures, tricarinate at the basal 2/3, and covered with erect scales from its base to near middle; rostrum of females smoother, with fine and sparse punctures, only the median longitudinal distinct, and only the base covered by erect scales; 2) males with antenna inserted near the apex of rostrum; and near the middle in females; 3) sternal channel of males flatter, with its lateral margins only indicated or absent in the prosternum; the sternal channel of the females deeper, with its lateral margins more prominent; 4) the eighth abdominal tergite of males visible and distinct; while in the females covered by the seventh abdominal tergite.

APA, Harvard, Vancouver, ISO, and other styles

22

Smith, Moya Meredith, Alex Riley, Gareth J. Fraser, Charlie Underwood, Monique Welten, Jürgen Kriwet, Cathrin Pfaff, and Zerina Johanson. "Early development of rostrum saw-teeth in a fossil ray tests classical theories of the evolution of vertebrate dentitions." Proceedings of the Royal Society B: Biological Sciences 282, no. 1816 (October 7, 2015): 20151628. http://dx.doi.org/10.1098/rspb.2015.1628.

Full text

Abstract:

In classical theory, teeth of vertebrate dentitions evolved from co-option of external skin denticles into the oral cavity. This hypothesis predicts that ordered tooth arrangement and regulated replacement in the oral dentition were also derived from skin denticles. The fossil batoid ray Schizorhiza stromeri (Chondrichthyes; Cretaceous) provides a test of this theory. Schizorhiza preserves an extended cartilaginous rostrum with closely spaced, alternating saw-teeth, different from sawfish and sawsharks today. Multiple replacement teeth reveal unique new data from micro-CT scanning, showing how the ‘cone-in-cone’ series of ordered saw-teeth sets arrange themselves developmentally, to become enclosed by the roots of pre-existing saw-teeth. At the rostrum tip, newly developing saw-teeth are present, as mineralized crown tips within a vascular, cartilaginous furrow; these reorient via two 90° rotations then relocate laterally between previously formed roots. Saw-tooth replacement slows mid-rostrum where fewer saw-teeth are regenerated. These exceptional developmental data reveal regulated order for serial self-renewal, maintaining the saw edge with ever-increasing saw-tooth size. This mimics tooth replacement in chondrichthyans, but differs in the crown reorientation and their enclosure directly between roots of predecessor saw-teeth. Schizorhiza saw-tooth development is decoupled from the jaw teeth and their replacement, dependent on a dental lamina. This highly specialized rostral saw, derived from diversification of skin denticles, is distinct from the dentition and demonstrates the potential developmental plasticity of skin denticles.

APA, Harvard, Vancouver, ISO, and other styles

23

Jawad, Laith A., Kristiaan Hoedemakers, Ana L. Ibáñez, Yassin A. Ahmed, Mohamed A. Abu El-Regal, and Sahar F. Mehanna. "Morphology study of the otoliths of the parrotfish,Chlorurus sordidus(Forsskål, 1775) andHipposcarus harid(Forsskål, 1775) from the Red Sea coast of Egypt (Family: Scaridae)." Journal of the Marine Biological Association of the United Kingdom 98, no. 4 (February 6, 2017): 819–28. http://dx.doi.org/10.1017/s0025315416002034.

Full text

Abstract:

In the present study a comparison of the otolith morphology of two species of parrotfish, family Scaridae, collected from the Red Sea coast of Egypt, is conducted to identify the most appropriate taxonomic characters that separate these species. Ontogenetic changes in the otoliths of the two scarid fishes become evident. In the otoliths ofChlorurus sordidus, the following characters are comparable in small-sized adult fishes: otolith width, otolith depth, mesial surface shape, lateral surface shape, shape of sulcus acusticus, column, rostrum and size of rostrum. The otoliths of young adults (GI)C. sordidusdiffer from the adult ones in 14 out of the 22 characteristics studied. In the otoliths ofHipposcarus harid, the following characters are comparable in small and large fish: otolith width, otolith depth, mesial and lateral surface shapes, shape of sulcus acusticus, rostrum and size of rostrum.

APA, Harvard, Vancouver, ISO, and other styles

24

ERMILOV, SERGEY G., and JOCHEN MARTENS. "A new genus and two new species of Galumnidae (Acari, Oribatida) from Nepal." Zootaxa 5039, no. 2 (September 15, 2021): 277–90. http://dx.doi.org/10.11646/zootaxa.5039.2.8.

Full text

Abstract:

One new genus and two new species of oribatid mites (Oribatida) of the family Galumnidae are described from soil in Nepal. Anomalogalumna gen. nov. (with type species Anomalogalumna dungeri sp. nov.) differs from Flagellozetes Balogh, 1970 by the absence of octotaxic system, and the presence of short, notogastral setae and areolate-reticulate surface of the notogaster and anogenital region. Allogalumna beateae sp. nov. differs from all other species of the genus by the presence of thickened rostral, lamellar and interlamellar setae, and the position of rostral seta (close to lamellar seta and distant from the rostrum).

APA, Harvard, Vancouver, ISO, and other styles

25

Guinot, D., and B. Richer De Forges. "REVISION OF THE INDO-PACIFIC SPHENOCARCINUS WITH A SINGLE ROSTRUM AND DESCRIPTION OF TWO NEW SPECIES (CRUSTACEA, DECAPODA, BRACHYURA, MAJIDAE)." Marine Research in Indonesia 24 (May 10, 2018): 49–71. http://dx.doi.org/10.14203/mri.v24i0.400.

Full text

Abstract:

Two species of the genus Sphenocarcinus A. Milne Edwards 1876, with a single rostrum exist in the Indo-Pacific and they are principally only known by their original description: S. cuneus (Wood-Mason 1891) and S. aurorae Alcock 1899. Each species is herewith redescribed, based on the examination of the types. Two new species are established. S. difficilis sp. nov., represented by numerous specimens from Madagascar (ORSTOM collection), proved to be an intermediate species between S. cuneus and S. aurorae. S. pinocchio sp. nov., (collected in the Makassar Strait, Indonesia (mission Corindon II), is characterized by its very Jong and strongly curved rostrum. One male specimen, also collected in the Makassar Strait, probably modified by a sacculinid parasite, and with a more curved, snub rostrum, can be regarded as an unusual form of S. pinocchio sp. nov. A key of the four Indo-Pacific Sphenocarcinus with a single rostrum is presented.

APA, Harvard, Vancouver, ISO, and other styles

26

BROWN, SAMUEL D. J. "A new species of Proterhinus Sharp, 1878 (Coleoptera: Curculionoidea: Belidae) from Miti‘aro, Cook Islands, South Paciﬁc." Zootaxa 4664, no. 4 (September 5, 2019): 481–96. http://dx.doi.org/10.11646/zootaxa.4664.4.2.

Full text

Abstract:

Proterhinus tauai Brown, new species is described from specimens collected on the island of Miti‘aro in the Cook Islands, South Paciﬁc. It differs from congeners by the combination of having a dorsal vestiture of decumbent brown clavate scales, lacking erect elongate setae, anterior pronotal angles projecting forwards, and having short antennae that do not reach the posterior margin of the pronotum. This species shows strong sexual dimorphism in the shape of the rostrum, with males having a large semicircular rostrum, compared with a stout subrectangular rostrum in females. Fitting allometric models to the relationship of morphometric variables with body length show that rostrum width and area have signiﬁcantly different allometric relationships between the sexes, consistent with hypotheses of sexual selection. Proterhinus tauai was collected from coastal scrub vegetation. Collection data and observation of captive specimens indicate a host relationship with the parasitic vine Cassytha ﬁliformis L. (Lauraceae).

APA, Harvard, Vancouver, ISO, and other styles

27

Benito, M., and Matías Reolid. "Comparison of the Calcareous Shells of Belemnitida and Sepiida: Is the Cuttlebone Prong an Analogue of the Belemnite Rostrum Solidum?" Minerals 10, no. 8 (August 12, 2020): 713. http://dx.doi.org/10.3390/min10080713.

Full text

Abstract:

The microstructure of the rostrum solidum of Jurassic belemnites is compared with that of Sepia cuttlebones, in order to examine possible convergences in their style of growth. For this study, transmitted and polarized light, cathodoluminescence, epifluorescence, scanning electron and backscattered electron microscopy have been employed. Despite differences in the primary mineralogy of the studied belemnites and sepiids, calcite and aragonite, respectively, many similarities have been observed between the microstructure of the belemnite rostra and the prong of Sepia cuttlebone: (1) In both, crystals start growing from successive spherulites, from which crystals emerge radially towards the apex and the external walls, displaying internally micro-fibrous texture. (2) Both display concentric growth layering, comprising an alternation of organic-rich and organic-poor layers, which, in turn, is traverse by the radially-arranged micro-fibrous crystals. (3) The highest organic matter content and porosity have been observed along the apical area of the Sepia prong, similarly to that interpreted for belemnite rostra. The strong convergences observed suggest that the growth of belemnites occurred similarly to that of the prong of sepiids and that the Sepia prong is the analog of the belemnite rostrum. Additionally, non-classical crystallization processes are proposed to be involved in the formation Sepia endoskeleton.

APA, Harvard, Vancouver, ISO, and other styles

28

Buchy, Marie-Céline, Wolfgang Stinnesbeck, Eberhard Frey, and Arturo H. Gonzalez Gonzalez. "First occurrence of the genus Dakosaurus (Crocodyliformes, Thalattosuchia) in the Late Jurassic of Mexico." Bulletin de la Société Géologique de France 178, no. 5 (September 1, 2007): 391–97. http://dx.doi.org/10.2113/gssgfbull.178.5.391.

Full text

Abstract:

Abstract The fragmentary rostrum of a thalattosuchian is described. The specimen comes from the vicinity of the village of San Juan de los Dolores, next to Los Lirios, Coahuila, northeastern Mexico. Associated ammonites allow to assign the specimen to the Kimmeridgian section (Upper Jurassic) of the La Casita Formation. Because of its massiveness, its cranial architecture and the morphology of its teeth, the specimen is referred to the genus Dakosaurus, but is too incomplete for further determination. The genus is known by few specimens from the Late Jurassic of Europe and Argentina, and was until now unknown from North and Central America. It represents a new but expected element of the assemblage of marine reptiles populating the Mexican Gulf during the Late Jurassic. The specimen is one of the few members of the group preserving in 3 dimensions and visible, the preorbital portion of the rostrum, and especially of the nasopharyngeal canal; it confirms the existence of a large space possibly housing salt glands rostral to the orbits.

APA, Harvard, Vancouver, ISO, and other styles

29

Schnurr, Sarah, and Marina V. Malyutina. "Two New Species of The Genus Eurycope (Isopoda, Munnopsidae) from Icelandic Waters." Polish Polar Research 35, no. 2 (July 29, 2014): 361–88. http://dx.doi.org/10.2478/popore-2014-0013.

Full text

Abstract:

AbstractCollections of munnopsid isopods of the BIOICE (Benthic Invertebrates of Icelandic Waters; 1991–2004) and the IceAGE1 (Icelandic Marine Animals: Genetics and Ecology; since 2011) expeditions included ten species of the genusEurycopeG.O. Sars, 1864, thereof are two species new to science. Thus, the descriptions of the two new species are presented herein.Eurycope elianaesp. n. is distinguished from the other species of the genus mainly by two long, slightly robust, simple setae on the tip of the rostrum in combination with the size and shape of the rostrum itself.E elianaesp. n. shares the presence of two long, slightly robust, simple seta on the tip of the rostrum withE. tumidicarpus. The shape of the rostrum itself is more similar toE. inermisand species of theE. complanatacomplex.E. aculeatasp. n. is characterized by possessing dorsomedial acute projections on pereo-nites 5–7, which is unusual for the genus.E. aculeatasp. n. is most similar toE. cornuta. Both new species are, so far, known only from localities south of the Greenland-Scotland Ridge.

APA, Harvard, Vancouver, ISO, and other styles

30

Riveros, Guillermo A., Felipe J. Acosta, Reena R. Patel, and Wayne Hodo. "Computational mechanics of the paddlefish rostrum." Engineering Computations 37, no. 4 (December 9, 2019): 1317–40. http://dx.doi.org/10.1108/ec-12-2018-0567.

Full text

Abstract:

Purpose The rostrum of a paddlefish provides hydrodynamic stability during feeding process in addition to detect the food using receptors that are randomly distributed in the rostrum. The exterior tissue of the rostrum covers the cartilage that surrounds the bones forming interlocking star shaped bones. Design/methodology/approach The aim of this work is to assess the mechanical behavior of four finite element models varying the type of formulation as follows: linear-reduced integration, linear-full integration, quadratic-reduced integration and quadratic-full integration. The paper also presents the load transfer mechanisms of the bone structure of the rostrum. The base material used in the study was steel with elastic–plastic behavior as a homogeneous material before applying materials properties that represents the behavior of bones, cartilages and tissues. Findings Conclusions are based on comparison among the four models. There is no significant difference between integration orders for similar type of elements. Quadratic-reduced integration formulation resulted in lower structural stiffness compared with linear formulation as seen by higher displacements and stresses than using linearly formulated elements. It is concluded that second-order elements with reduced integration are the alternative to analyze biological structures as they can better adapt to the complex natural contours and can model accurately stress concentrations and distributions without over stiffening their general response. Originality/value The use of advanced computational mechanics techniques to analyze the complex geometry and components of the paddlefish rostrum provides a viable avenue to gain fundamental understanding of the proper finite element formulation needed to successfully obtain the system behavior and hot spot locations.

APA, Harvard, Vancouver, ISO, and other styles

31

MacLeod, Colin D. "Possible functions of the ultradense bone in the rostrum of Blainville's beaked whale (Mesoplodon densirostris)." Canadian Journal of Zoology 80, no. 1 (January 1, 2002): 178–84. http://dx.doi.org/10.1139/z01-188.

Full text

Abstract:

The rostrum of Blainville's beaked whale, Mesoplodon densirostris, becomes secondarily ossified, particularly in males, as individuals mature. This mesorostral ossification forms the densest bone currently known and represents a considerable investment of resources for this species. Three functions for this mesorostral ossification have been proposed: prevention of damage to the rostrum during aggressive malemale interactions, ballast to aid deep diving, and sound transmission. These functions were assessed using data from museum specimens and observations of this species in the wild. Prevention of damage to the rostrum during aggressive malemale interactions was found to be the most likely function, based on the currently available data.

APA, Harvard, Vancouver, ISO, and other styles

32

Ermilov, Sergey G., and Josef Starý. "TAXONOMIC CONTRIBUTION TO THE KNOWLEDGE OF GALUMNA (ACARI, ORIBATIDA, GALUMNIDAE) OF THE NEOTROPICAL REGION: DESCRIPTION OF A NEW SPECIES FROM BOLIVIA AND A KEY TO KNOWN SPECIES OF THE GENUS." Acarina 29, no. 1 (2021): 105–14. http://dx.doi.org/10.21684/0132-8077-2021-29-1-105-114.

Full text

Abstract:

A new species of Galumna (Oribatida, Galumnidae) is described from Bolivian rainforest leaf litter. Galumna parareticulata sp. n. differs from Galumna reticulata Hammer, 1958 in longer body, pointed rostrum, the presence of a median rostral ridge, longer lamellar seta, and slightly developed head of bothridial seta. The species Galumna lyrica is transferred from the subgenus Galumna to Neogalumna: Galumna (Neogalumna) lyrica (Jacot, 1935) comb. nov. An identification key to the known species/subspecies of the genus from the Neotropical region is presented.

APA, Harvard, Vancouver, ISO, and other styles

33

Eviatar, E., Y. Golan, and H. Gavriel. "Fronto-septal rostrum: prevalence, classification and clinical implications." Journal of Laryngology & Otology 132, no. 5 (May 2018): 423–28. http://dx.doi.org/10.1017/s0022215118000130.

Full text

Abstract:

AbstractObjective:To describe a newly observed frontal sinus anatomical variant, the fronto-septal rostrum.Methods:Consecutive sinus computed tomography scans performed during 2013 were reviewed. The fronto-septal rostrum was defined as a mucosa-lined air space formed in the attachment of the most upper bony nasal septum and the central floor of the frontal sinuses.Results:The study included 400 computed tomography scans from 189 women (47.3 per cent) and 211 men (52.8 per cent), with a mean age of 46.8 years. A fronto-septal rostrum was observed in 122 patients (30.5 per cent), with a mean length of 10.63 mm, width of 4.52 mm, height of 2.18 mm and volume of 63.52 mm3. There was no statistically significant difference related to gender (p = 0.343), and no association between the side of the fronto-septal rostrum and age (p = 0.811) or volume (p = 0.203).Conclusion:The newly described fronto-septal rostrum has possible clinical and surgical implications. It is suggested that this aerated space is used in specific surgical indications and its presence evaluated in cases of septal infection.

APA, Harvard, Vancouver, ISO, and other styles

34

Tang, Lingyi, Li Zhang, Michael Yue, Da Tian, Mu Su, and Zhen Li. "New Insights into the Ultrastructure of Bioapatite After Partial Dissolution: Based on Whale Rostrum, the Densest Bone." Microscopy and Microanalysis 25, no. 6 (October 10, 2019): 1323–30. http://dx.doi.org/10.1017/s1431927619015022.

Full text

Abstract:

AbstractMineral particles in bone are interlaced with collagen fibrils, hindering the investigation of bioapatite crystallites (BAp). This study utilized a special whale rostrum (the most highly mineralized bone ever recorded) to measure the crystallites of bone BAp via long-term dissolution in water. The BAp in the rostrum has a low solubility (6.7 ppm Ca and 3.8 ppm P after 150 days dissolution) as well as in normal bones, which leads to its Ksp value of ~10−53. Atomic force microscopy results show tightly compacted mineral crystallites and confirm the low amount of collagen in the rostrum. Additionally, the mineral crystallites demonstrate irregular plate-like shapes with variable sizes. The small crystallites (~11 × 24 nm) are easily detached from BAp prisms, compared with the large crystallites (~50 nm). Moreover, various orientations of crystallites are observed on the edge of the prisms, which suggest a random direction of mineral growth. Furthermore, these plate-like crystallites prefer to be stacked layer by layer under weak regulation from collagen. The morphology of rostrum after dissolution provides new insights into the actual morphology of BAp crystallites.

APA, Harvard, Vancouver, ISO, and other styles

35

Toju, Hirokazu, and Teiji Sota. "Adaptive divergence of scaling relationships mediates the arms race between a weevil and its host plant." Biology Letters 2, no. 4 (July 18, 2006): 539–42. http://dx.doi.org/10.1098/rsbl.2006.0514.

Full text

Abstract:

Coevolution of exaggerated morphologies between insects and plants is a well-known but poorly understood phenomenon in evolutionary biology. In the antagonistic interaction between a seed-predatory insect, the camellia weevil ( Curculio camelliae ), and its host plant, Japanese camellia ( Camellia japonica ), we examined the evolutionary trajectory of an exaggerated offensive trait of the weevil (rostrum length) in terms of scaling relationship. Sampling throughout Japan revealed that the ratio of the rostrum length to overall body size was correlated with the ratio of the pericarp thickness to overall fruit size across the localities. We found a geographical interpopulation divergence in a parameter pertaining to the allometric equation of rostrum length (the coefficient a in y = ax b , where y and x denote rostrum and body lengths, respectively), and the pattern of geographical differentiation in the allometric coefficient was closely correlated with the variation in the pericarp thickness of Japanese camellia. Our results provide a novel example of a geographically diverged scaling relationship in an insect morphology resulting from a coevolutionary arms race with its host plant.

APA, Harvard, Vancouver, ISO, and other styles

36

Sarda, F., and M. Demestre. "Shortening of the Rostrum and Rostral Variability in Aristeus antennatus (Risso, 1816) (Decapoda: Aristeidae)." Journal of Crustacean Biology 9, no. 4 (November 1989): 570. http://dx.doi.org/10.2307/1548588.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

PESSACQ, PABLO, LUIS B. EPELE, and D. CHRISTOPHER ROGERS. "A new species of Lynceus (Crustacea: Branchiopoda: Laevicaudata) from Patagonia, with comments on laevicaudatan systematics." Zootaxa 3043, no. 1 (September 28, 2011): 25. http://dx.doi.org/10.11646/zootaxa.3043.1.2.

Full text

Abstract:

Lynceus mallinensis, a new species of laevicaudatan clam shrimp is described from a single temporary pool in Chubut province, Patagonia, Argentina. The form of the male rostrum necessitates a reevaluation of rostral characters for the genus. This species differs from L. rotundirostris, the only known Lynceus from Patagonia, by the absence of a distinct umbo. L. mallinensis is the fourth species of this genus and the fifth laevicaudatan to be reported from South America. The systematical position of the Laevicaudata is discussed in the Introduction.

APA, Harvard, Vancouver, ISO, and other styles

38

WANG, YAN-RONG, and ZHONG-LI SHA. "Description of two new species of Lysmata Risso, 1816 (Decapoda, Lysmatidae) from the China seas, with remarks on Lysmata vittata (Stimpson 1860)." Zootaxa 4392, no. 1 (March 7, 2018): 28. http://dx.doi.org/10.11646/zootaxa.4392.1.2.

Full text

Abstract:

Two new species of Lysmata Risso, 1816 are described and illustrated from the China seas. L. brevrostrus sp. nov. is characterized by the short rostrum not reaching the distal margin of the eyes, and the rostral ventral margin unarmed with tooth; L. parvispinosus sp. nov. is characterized by the dactylus of posterior three pereiopods tapering (not biunguiculate) and the flexor margin of the dactylus bearing two basal inconspicuous spinules. A morphologically variable species, L. vittata (Stimpson 1860), is discussed based on specimens collected from the China seas.

APA, Harvard, Vancouver, ISO, and other styles

39

Patel, Reena, Guillermo Riveros, David Thompson, Edward Perkins, Jan Jeffery Hoover, John Peters, and Antoinette Tordesillas. "A Transdisciplinary Approach for Analyzing Stress Flow Patterns in Biostructures." Mathematical and Computational Applications 24, no. 2 (April 26, 2019): 47. http://dx.doi.org/10.3390/mca24020047.

Full text

Abstract:

This work presents a transdisciplinary, integrated approach that uses computational mechanics experiments with a flow network strategy to gain fundamental insights into the stress flow of high-performance, lightweight, structured composites by investigating the rostrum of paddlefish. Although computational mechanics experiments give an overall distribution of stress in the structural systems, stress flow patterns formed at nascent stages of loading a biostructure are hard to determine. Computational mechanics experiments on a complex model will involve a high degree of freedom thereby making the extraction of finer details computationally expensive. To address this challenge, the evolution of the stress in the rostrum is formulated as a network flow problem generated by extracting the node and connectivity information from the numerical model of the rostrum. The flow network is weighted based on the parameter of interest, which is stress in the current research. The changing kinematics of the system is provided as input to the mathematical algorithm that computes the minimum cut of the flow network. The flow network approach is verified using two simple classical problems. When applied to the model of the rostrum, the flow network approach identifies strain localization in tensile regions, and buckling/crushing in compressive regions.

APA, Harvard, Vancouver, ISO, and other styles

40

BRUCE, A. J., J. OKUNO, and XINZHENG LI. "Manipontonia gen. nov., a new pontoniine shrimp genus for Periclimenes psamathe (De Man) (Crustacea: Decapoda: Palaemonidae)." Zootaxa 926, no. 1 (March 31, 2005): 1. http://dx.doi.org/10.11646/zootaxa.926.1.1.

Full text

Abstract:

A new genus, Manipontonia, is designated to include Periclimenes psamathe (De Man, 1902), on account of its peculiar morphology, with the combination of a long and slender rostrum with ventral margin unarmed, the proximal rostral dorsal teeth and epigastric tooth having fine ventral denticulations and endopod of male first pleopod with the appendix interna terminally with few terminal cincinnuli, which distinguishes this genus from all other species of Periclimenes, and the other genera of the Pontoniinae. The report includes some new host records: Acabaria robusta (Shann) [Gorgonacea]; Dendronephthya cf. decussata Utinomi [Alcyonacea].

APA, Harvard, Vancouver, ISO, and other styles

41

Ermilov, Sergey G., Elizabeth A. Hugo-Coetzee, and Alexander A. Khaustov. "Two new species of the genus Ausoribula (Acari, Oribatida, Oribatulidae) from termitaries of South Africa." Acarologia 57, no. 3 (May 16, 2017): 643–50. http://dx.doi.org/10.24349/acarologia/20174183.

Full text

Abstract:

Two new species of oribatid mites of the previously monotypic genus Ausoribula Lee, 1992 (Oribatulidae) are described from termite nests of South Africa. Ausoribula termitophila n. sp. has a pointed rostrum, elongately fusiform, bothridial setae, a weak anterior notogastral margin which only slightly protrudes into the prodorsum, notogastral setae c2 similar in length to other setae (except shorter c1) and three or four pairs of genital setae. In contrast, A. quagesetosa Lee, 1992 has a rounded rostrum, bothridial setae clavate, and the anterior notogastral margin interrupted and strongly protruding into the prodorsum. Ausoribula bloemfonteinensis n. sp. has a pointed rostrum, clavate bothridial setae, the anterior notogastral margin distinct and only slightly protruding, notogastral setae c2 shorter than other setae (except the shorter c1) and three pairs of genital setae. The genus Ausoribula is recorded in the Ethiopian region for the first time.

APA, Harvard, Vancouver, ISO, and other styles

42

Makarov, A. A. "On the Rostrum of the RAS Presidium." Herald of the Russian Academy of Sciences 79, no. 2 (April 2009): 150–66. http://dx.doi.org/10.1134/s1019331609020129.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Danilov-Danil’yan, V. I., and A. N. Gel’fan. "On the rostrum of the RAS presidium." Herald of the Russian Academy of Sciences 84, no. 5 (September 2014): 335–43. http://dx.doi.org/10.1134/s1019331614050013.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Petrov, Yu A., and V. V. Trepavlov. "On the rostrum of the RAS presidium." Herald of the Russian Academy of Sciences 84, no. 5 (September 2014): 344–56. http://dx.doi.org/10.1134/s1019331614050098.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

CARUSO, F., M. L. SALADINO, A. SPINELLA, C. DI STEFANO, P. TISSEYRE, S. TUSA, and E. CAPONETTI. "PHYSICO-CHEMICAL CHARACTERIZATION OF THE ACQUALADRONE ROSTRUM." Archaeometry 53, no. 3 (March 8, 2011): 547–62. http://dx.doi.org/10.1111/j.1475-4754.2010.00567.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Nevatte, R. J., B. E. Wueringer, D. E. Jacob, J. M. Park, and J. E. Williamson. "First insights into the function of the sawshark rostrum through examination of rostral tooth microwear." Journal of Fish Biology 91, no. 6 (October 16, 2017): 1582–602. http://dx.doi.org/10.1111/jfb.13467.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Niemi, Ritva, and Piotr Skubała. "New species of Moritzoppia and Medioppia from the Beskidy Mountains, Poland (Acarina, Oribatida, Oppiidae)." Entomologica Fennica 4, no. 3 (September 1, 1993): 195–200. http://dx.doi.org/10.33338/ef.83767.

Full text

Abstract:

Moritzoppia sharipovi sp. n. and Medioppia beskidyensis sp. n. are described from Poland. M. sharipovi is distinguished from other species by the rostrum, sensilli, the crista and the large size. M. beskidyensis differs from all other species by the tubercles in the posterior margin of the prodorsum, the form of the rostrum, the number of genital hairs and the fusiform sensilli. A new combination, Medioppia ordunensis (Iturrondobeitia & Salona, 1988) comb. n. is presented.

APA, Harvard, Vancouver, ISO, and other styles

48

OKUNO, JUNJI. "Palaemonella shirakawai, a new species of shrimp (Crustacea: Decapoda: Palaemonidae), associated with burrow dwelling opistognathid fish from the Ryukyu Islands, Japan." Zootaxa 4299, no. 4 (July 31, 2017): 521. http://dx.doi.org/10.11646/zootaxa.4299.4.3.

Full text

Abstract:

A new palaemonid shrimp, Palaemonella shirakawai sp. nov., is described and illustrated on the basis of a single ovigerous female specimen captured from the Ryukyu Islands, Japan. It appears closest to P. aliska Marin by sharing the median carina of the carapace armed with dorsal rostral teeth extending posterior to the level of the hepatic tooth, but is immediately differentiated by the shorter rostrum, a rounded posterior margin of the telson, an elongate antennal scaphocerite with a truncate distal margin of lamella, and the longer second pereiopod. The present new species is an associate of burrow dwelling fishes belonging to the family Opistognathidae.

APA, Harvard, Vancouver, ISO, and other styles

49

FRIEDMAN, ARIEL-LEIB-LEONID. "Indophyes yaromi, a new genus and species of Nanophyidae (Curculionoidea) from southern India." Zootaxa 3219, no. 1 (March 2, 2012): 54. http://dx.doi.org/10.11646/zootaxa.3219.1.2.

Full text

Abstract:

A new monobasic genus of Nanophyidae, Indophyes, and a new species, I. yaromi, are described from southern India (type locality: Karnataka, Bilukoppa, 800 m, 40 km W Mudigere). The new genus is characterized by 5-segmented antennal funicle, strong sexual dimorphism of the rostrum, dentate femora, male tibiae unarmed, abdominal suture IV distinct in both sexes, male pygidium not foveate and 8th elytral interstria not crenulate. The subulate form of rostrum—abruptly narrowed apically—is unusual among the Nanophyidae.

APA, Harvard, Vancouver, ISO, and other styles

50

MOLLEN, FREDERIK H., SABINE P. WINTNER, SAMUEL P. IGLÉSIAS, SEAN R. VAN SOMMERAN, and JOHN W. M. JAGT. "Comparative morphology of rostral cartilages in extant mackerel sharks (Chondrichthyes, Lamniformes, Lamnidae) using CT scanning." Zootaxa 3340, no. 1 (June 8, 2012): 29. http://dx.doi.org/10.11646/zootaxa.3340.1.2.

Full text

Abstract:

A comparative study of rostral morphology of extant mackerel sharks (Lamniformes, Lamnidae) is presented. Based oncomputed tomography (CT) scans of fresh specimens, 3D reconstructions, dried museum chondrocrania and the availableliterature, detailed morphological descriptions of the rostral cartilages are provided for the type species of all three extantlamnid genera, namely Carcharodon carcharias (Linnaeus, 1758), Isurus oxyrinchus Rafinesque, 1810 and Lamna nasus(Bonnaterre, 1788), and compared with those of I. paucus Guitart Manday, 1966 and L. ditropis Hubbs & Follett, 1947.Despite intraspecific variation, the rostral cartilages of all extant lamnids present significant differences that allow genus-and species-level identification, which is especially of use to identify fossil rostral nodes of these particular taxa. The maindifferences were found to be in overall calcification of the rostrum (Lamna > Isurus > Carcharodon), general configura-tion of the rostral open space, position of the base of the lateral rostral cartilages, (non-)abutting lateral cartilages, (absent)rostral keels and shape of the rostral node. In cross section, the base of the rostral node is rounded in Lamna, Y-shaped in Isurus and uncalcified in juvenile and subadult Carcharodon (tesserae absent).

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Rostrum'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles