Academic literature on the topic 'Palaemon serratus'

The three lobed paragnath of Palaemon serratus (Pennant) contains numerous rosette-type tegumental glands often arranged in clusters of up to ten glands. Each gland is made up of around ten cells most of which stain deeply with toluidine blue and whose contents have a reticulate appearance in electron micrographs. One, or occasionally two, cells stain faintly and have a fine granular appearance in electron micrographs. The central region of each gland contains the main drainage duct together with feeder canals from the vesicular storage areas. The actively secreting region of each cell is peripheral and typified by abundant rough endoplasmic reticulum and Golgi apparatus. There are nerves adjacent to the glands and their contents are probably discharged in response to a food stimulus. The structure and possible function of the glands are discussed in relation to those of other species The secretions could act as a lubricant and as a binding agent to aid in the ingestion of particulate food. There is no evidence for any direct digestive function.

AbstractDiel activity rhythms of the prawn Palaemon serratus from Alfacs Bay, Ebro Delta, Spain, were studied under laboratory conditions by time-lapse video recording. The activity pattern showed endogenous rhythmicity of a circadian period with maximum activity at night. The feeding habits of P. serratus were studied using the frequency-of-occurrence method and the points method. The food of this species mainly consists of molluscs and crustaceans, and the remains of gastropods, amphipods, isopods, bivalves, mysids, copepods, and decapods were identified. The remaining items consisted of cnidarians, polychaetes, ophiuroids, plant material, sand, and unidentified organic debris. Results indicate that P. serratus is a predator of benthic invertebrates rather than a scavenger or detritus feeder. Diet composition changes with the size of the prawn.

Recordings from the muscles of the pyloric chamber of the shrimp Palaemon display a rhythmic pattern which is either monophasic or biphasic, and is different from the triphasic pyloric pattern of large decapods. Identification of the pyloric neurones in the stomatogastric ganglion and study of their synaptic relationships indicate that the pyloric circuit of Palaemon is very similar to the pyloric circuit of large decapods. It is concluded that homologous neuronal circuits in related species, although similar in terms of their ‘wiring diagram’, are able to produce significantly different patterned outputs.

Mestrado em Biologia Aplicada - Toxicologia e Ecotoxicologia
O principal objectivo deste estudo foi investigar os efeitos agúdos do fenitrotião, um pesticida organofosforado, e da deltametrina, um pesticida piretróide, no camarão branco legítimo, Palaemon serratus, utilizando parâmetros a diferentes níveis de organização biológica. O estado antioxidante do fígado, o metabolismo energético e a neurotransmissão foram utilizados para avaliar os efeitos do fenitrotião e da deltametrina ao nível sub-individual. A velocidade de natação foi utilizada para avaliar os efeitos de ambos os pesticidas ao nível individual. No caso dos ensaios realizados com o fenitrotião, foi, ainda, realizado um teste de evitamento, para determinar a capacidade do camarão legítimo escapar do pesticida. Neste contexto, também se pretendia desenvolver testes de comportamento com este organismo marinho e perceber se estas alterações comportamentais são sensíveis e se podem ser usadas como um indicador de efeitos em bioensaios ecotoxicológicos. Os resultados demonstraram que o pesticida deltametrina foi mais tóxico para o camarão legítimo do que o fenitrotião, uma vez que o valor de CL50 estimado foi 20 vezes inferior ao do fenitrotião. Verificou-se que os dois pesticidas induzidem efeitos opostos nas actividades de AChE no olho e de ChE no musculo e que apenas o pesticida deltametrina induziu stress oxidativo na glândula digestiva do camarão legítimo. Contudo, a velocidade de natação foi reduzida tanto no camarão legítimo exposto a fenitrotião como no exposto a deltametrina, provando que este comportamento pode e deve ser usado como critério de efeito em bioensaios ecotoxicológicos. Para além disso, a velocidade de natação foi tão sensível como a actividade da AchE no olho do camarão legítimo, no caso da exposição ao pesticida deltametrina. No presente trabalho também foi observado que o camarão legítimo consegue evitar baixas concentrações do pesticida fenitrotião. Porém o camarão legítimo perde esta capacidade para escapar quando é exposto a concentrações mais elevadas do fenitrotião, o que poder ser um problema para o teste. Apesar disso, este trabalho mostra que o comportamento do camarão legítimo pode ser usado como critério em bioensaios, uma vez que ambos os pesticidas induzem efeitos a este nível.
The main purpose of this study was to investigate the acute effects of fenitrothion, an organophosphate pesticide, and deltamethrin, a pyrethroid pesticide, in the common prawn, Palaemon serratus, using parameters at different levels of biological organization. Liver antioxidant status, energetic metabolism and neurotransmission were used to assess the effects of fenitrothion and deltamethrin at sub-individual level. Swimming velocity was used to assess the effects of both pesticides at the individual level. To assess the effects of fenitrothion, it was also developed and avoidance behaviour test, to determine the escaping capability of prawns. In this context it was aimed to develop behavioural tests with this marine organism and to understand if those behavioral alterations are sensitive and can be used as an endpoint in ecotoxicology bioassays. Results showed that the pesticide deltamethrin was more toxic to exposed prawn than fenitrothion, since the LC50 value estimated was 20 times lower than the value for fenitrothion. It was also observed that the two pesticides induced opposite effects in the activities of eye AChE and muscle ChE and that only deltamethrin induced oxidative stress in the digestive gland of the common prawn. However, swimming velocity was impaired for prawns exposed to both pesticides, proving that this behaviour can and should be used as effect criteria in bioassays. In addition swimming velocity was as sensitive as eye AChE activity in the case of deltamethrin exposure. In the present work it was also observed that prawn can avoid low concentrations of fenitrothion. However, common prawn lost this ability to avoid the toxic when it was exposed to high concentrations of fenitrothion, which may be a problem for the avoidance test itself. Despite that, the present work shows that the common prawn behaviour can be used as effect criteria in bioassays, since both pesticides induce effects at this level of biological organization.

Tolerance to low temperature and high pressure may allow shallow-water species to extend bathymetric range in response to changing climate, but adaptation to contrasting shallow-water environments may affect tolerance to these factors. The brackish shallow-water shrimp Palaemon varians demonstrates remarkable tolerance to elevated hydrostatic pressure and low temperature, but inhabits a highly variable environment: environmental adaptation may therefore make P. varians tolerances unrepresentative of other shallow-water species. Critical thermal maximum (CTmax), critical hydrostatic pressure maximum (CPmax), and acute respiratory response to hydrostatic pressure were assessed in the shallow-water shrimp Palaemon serratus, which inhabits a more stable intertidal habitat. P. serratus’ CTmax was 22.3°C when acclimated at 10°C, and CPmax was 5.9, 10.1, and 14.1 MPa when acclimated at 5, 10, and 15°C respectively: these critical tolerances were consistently lower than P. varians. Respiratory responses to acute hyperbaric exposures similarly indicated lower tolerance to hydrostatic pressure in P. serratus than in P. varians. Contrasting tolerances likely reflect physiological adaptation to differing environments and reveal that the capacity for depth-range extension may vary among species from different habitats.

Etude des effets letaux (taux de mortalite, stades auxquels surviennent les mortalites), subletaux (frequence des mues, metamorphose, croissance, alterations morphologiques. . . ) et de la bioaccumulation du zinc et du cadmium au cours du developpement larvaire de l. Serratus. L'action de chacun des metaux a ete consideree soit separement, soit pour des surcharges combinees

La fitness et a fortiori la survie d'une population dépendent de la stratégie et des performances de reproduction façonnées par son environnement. Par conséquent, les biomarqueurs traduisant une altération de la fonction de reproduction présentent un intérêt particulier. L'atteinte de la fertilité mâle au sein de la faune sauvage a notamment été adressée comme une problématique majeure susceptible de représenter une menace pour le maintien des populations. Toutefois, peu de méthodologies sont aujourd'hui disponibles chez des espèces pertinentes pour aborder cette problématique dans le cadre de programmes de biosurveillance environnementale, notamment chez les crustacés en dépit de leur représentativité au sein du règne animal et de leurs indispensables fonctions au sein des écosystèmes. Dans ce contexte, les présents travaux avaient pour objectif de proposer une ou plusieurs méthodologies basées sur la mesure de marqueurs de fonctionnalité et d'intégrité spermatique chez des crevettes Palaemonidae. Les investigations se sont portées sur deux espèces, une estuarienne, Palaemon longirostris, et une côtière, Palaemon serratus, pour leur complémentarité vis-à-vis du continuum estuaire - littoral. Compte tenu des nombreuses spécificités structurelles et fonctionnelles des spermatozoïdes de crustacés, I nombre de marqueurs transposables vers ces espèces s'est finalement avéré limité. Aussi, après une brève prospection, l'effort de recherche a rapidement été recentré sur la mesure de l'intégrité de l'ADN. Dès lors, la démarche scientifique a été construite de sorte à évaluer, point par point, la pertinence de la méthodologie développée dans une perspective d'application de l'outil dans le cadre de la surveillance environnementale. Une étape préliminaire d'optimisation et de validation méthodologique du test Cornet a démontré que, contrairement à une grande majorité de type spermatique, l'adaptation de ce test sur les spermatozoïdes de Palaemonidae ne nécessite aucune modification particulière du protocole. La dynamique de la réponse biologique en termes d'apparitions, de rémanence et d'effets possibles sur la fitness a été évaluée en conditions contrôlées au laboratoire. Ainsi, des expositions ex vivo et in vivo ont été conduites en utilisant une variété de génotoxiques modèles présentant différents modes d'actions. Les résultats ont attesté de la sensibilité, de la reproductibilité et du caractère intégrateur de la réponse. En revanche, aucun lien entre un ADN spermatique endommagé et une altération du succès de reproduction pré-éclosion n'a pu être établi. Parallèlement, une approche in situ a été conduite en vue de caractériser la valeur basale de la réponse mesurée. Différentes stratégies ont dû être adoptées en fonction des contraintes propres au milieu de vie de chacune des deux espèces. Un référentiel et une valeur seuil, communs aux deux espèces, ont pu être définis, soulignant le potentiel de transférabilité inter-espèces de l'outil. La méthodologie ainsi finalisée, a été éprouvée dans le cadre de plusieurs campagnes de suivi de différentes populations indigènes de l'estuaire et de la baie de Seine en 2015 et 2016. Les résultats se sont révélés très cohérents au regard de la pression de contamination et de la dynamique hydro-sédimentaire de la baie de Seine. En définitive, l'intégrité de l'ADN spermatique chez les Palaemonidae est opérationnelle en l'état pour un déploiement in situ en tant que biomarqueur d'exposition à un stress génotoxique. De futurs études devront néanmoins être conduites (1) pour mieux discerner les implications de ces dommages spermatiques en termes d'impact sur le recrutement des nouvelles cohortes et (2) éprouver la transférabilité de la méthodologie à d'autres espèces de crevettes et sur une plus large échelle géographique
The environment shapes the reproduction's strategy and performance of a population, influencing its fitness and a fortiori its survival. Therefore, biomarkers that alter reproductive functions represent a great interest in ecotoxicology. The reduction of male fertility in wildlife can represent a threat to the population's survival. Moreover, fcw methodologies are available for species that are relevant to address this issue on envimnmental biomonitoring programs, especially for crustaceans, despite their representativeness in the wildlife and their essential functions within ecosysterns. The present work aimed to propose methodologies based on the measurement of functionality and integrity spermatic biomarkers on Palaemonidae shrimps. We studied two species, an estuarine, Palaemon longirostris, and a coastal species. Palaemon serratus. due to their complementaiity on the continuum estuary-littoral ecosystem. Howevcr, crustaceans' sperm has many structuraI and functional characteristics, the number of transposable markers is limited. Thereafter, the research effort was refocused on the measurement of the DNA integrity and this inethod was evaluated for its adequacy for a biomonitoring study. We optitrtized and validate the Cornet assay for the Palaemonidae species, and the dynamic of the biological response in ternis of appearances, persistence, and possible effects on fitness was evaluated under controlled conditions in the laboratoiy. Furthermore, ex-vivo and in-vivo exposures were conducted using genotoxic models with different modes of action. On the one hand, results attested to the sensibility, the reproducibility and the integrating character of the response, on the other hand, no correlation between damaged sperm DNA and an altération of the pre-hatch stage of development was established. In paralIel, an in-situ approach was conducted to characterize the baseline level of the measured response, taking into consideration the specific constraints of each species' habitat. We were able to define a common baseline level and a threshold value for both species, highlighting the potential of the tool for inter-species transferability. This method was tested with native populations from the estuary and from the Seine Bay in 2015 and 20] 6. And, the results proved to be consistent with the contamination pressure and the hydro-sedimentary dynamics of the Seine Bay. Ultimately, the DNA integrity of sperm in Palaemonidae seems to be functional for in-situ deploytnents as a biomarker of exposure to genotoxic stress. Nevertheless, future studies should be conducted (1) to botter discern the implications of this spermatic damage on the recruitment of new cohorts and, (2) to test the transferability of the methodology to other shrimp species and on a wider geographical scale