Academic literature on the topic 'Fish guild'

Abstract.The functional community is described depends on the function of species in utilization food (guild). The utilization of food is a process of energy transfers in the food chain and it is represented in the pyramid of numbers. The objective of this research was to analyze the structure community of fish and the guild compositions in Sempor Reservoir. This research applied a survey with purposive random sampling technique with four station in Sempor Reservoir. Sampling at each site was taken 4 replication with interval 1 monts. The composition and status of the guild is carried out by mesuring the guild based on the position of the mouth, tooth type, gill filter type, and ratio of body length and intestine. Guilds are composed of compositions depicted by a number pyramid based on the number of species per station. The results of this reserach captured 439 individuals consists of 14 species and belong to 6 families that dominated by Cyprinidae. The number and species of fish caught were the most at the Bangkong river inlet (142 individuals) and the lowest at the center of the reservoir (60 individuals). Comparison of the composition of fish guilds at the four stations in the Sempor Reservoir shows that the number of omnivorous and carnivorous fish is obtained more than herbivorous fish. The composition of the guild at Kalianget river inlet (72.9%) and Central reservoir (42.7%) was dominated by carnivorous fish, while at Pengantalan river inlet (52.9%) and Bangkong (58.9%) were dominated by omnivorous fish. The composition of herbivorous fish is at least at all stations so that in general the composition of fish guilds in the Sempor reservoir has not been balanced.Keywords: species composition, guild, pyramid of number,Sempor reservoir Abstrak. Komunitas secara fungsional menggambarkan fungsi spesies yang ditentukan dengan pemanfaatan sumber makanan (guild). Pemanfaatan makanan dalam rantai makanan merupakan proses transfer energi dan digambarkan dengan piramida jumlah. Tujuan dari penelitian ini adalah mengkaji komposisi dan tingkat status guild komunitas ikan yang tertangkap di perairan waduk Sempor. Penelitian dilakukan dengan metode survei dan teknik purposive random sampling pada 4 stasiun di Waduk Sempor. Sampling dilakukan sebanyak 4 kali tiap bulan. Komposisi dan status guild dengan mengukur guild berdasarkan posisi mulut, tipe gigi, tipe tapis insang, dan rasio panjang tubuh dan usus. Komposisi guild digambarkan dengan piramida jumlah berdasarkan jumlah spesies per stasiun. Hasil penelitian diperoleh 439 individu terdiri dari 8 Familia dan 14 Spesies yang di dominasi familia Cyprinidae. Jumlah dan jenis individu ikan yang tertangkap paling banyak pada inlet sungai Bangkong (142 individu) dan terendah pada bagian tengah waduk (60 individu). Perbandingan komposisi guild ikan pada empat stasiun di waduk Sempor menunjukkan bahwa jumlah ikan omnivora dan karnivora lebih banyak diperoleh daripada ikan herbivora. Komposisi guild pada inlet sungai Kalianget (72,9%) dan Tengah waduk (42,7%) di dominasi oleh ikan karnivora, sedangkan pada inlet sungai Pengantalan (52,9%) dan Bangkong (58,9%) di dominasi ikan omnivora. Komposisi ikan herbivora paling sedikit pada semua stasiun sehingga secara umum komposisi guild ikan di waduk Sempor belum seimbang.Kata kunci: komposisi jenis, guild, piramida jumlah, waduk Sempor

Abstract In coastal South Carolina, many wetlands are impounded and managed as migratory waterfowl habitat. Impoundment effects on fish production and habitat quality largely are unknown. We used the size-frequency method to estimate summer production of fish guilds in three impoundments along the Combahee River, South Carolina. We predicted that guild-specific production would vary with impoundment salinity, which ranged from 3 to 21 practical salinity units. We expected that marine species that use the estuary as nursery habitat would have greatest production in the impoundment with the highest salinity regime, and that species that inhabit the upper reaches of the estuary would have greatest production in the impoundment with the lowest salinity regime. Finally, we expected that estuarine species would be highly productive in all study impoundments, because these species can reproduce within these structures. We found that guild-specific productivity varied both among years and among impoundments, generally following salinity gradients, though to a lesser extent than expected. Our guild-specific estimates of fish productivity fell on the low end of the range of previously published estuarine fish production estimates. Additionally, we observed large mortality events in the study impoundments each summer. The results of our study indicate that during the summer, the study impoundments provided poor-quality fish habitat to all guilds.

Of a total of 101 fish species caught in the Lower Miranda River floodplain, 29 were omnivorous, 16 ichthyophagous, 12 herbivorous, 18 detritivorous, 8 zooplanktophagous, 7 insectivorous, 2 lepidophagous, 4 ichthyophagous/insectivorous and 4 zooplanktophagous/insectivorous. Almost half of the species belong to omnivorous and detritivorous trophic guilds. The same is not true when biomass is considered. The number of fish species by trophic guild didn't change along the year whereas the biomass changed significantly. The frequency of abundant fish species was not the same for the sampled environments.

Southeast Asian riverine fishes are classified into three guilds (‘black’, ‘white’ and ‘grey’ species) based on their reproductive and migration strategies. In this study, we aimed to investigate whether fish morphology could be used to predict the Mekong fish guilds. Nine dimensionless ratios of fish morphological traits were used to describe the locomotion and food acquisition strategies of 121 fish species. The links between morphological traits and fish guilds were assessed using a principal component analysis (PCA) and a variance partitioning analysis, which revealed a strong morphological overlap between the guilds. Despite the high contribution of intra-guild variability to overall morphological variability (~90%), black and white fish significantly differed in terms of locomotion-related traits. Mekong fish guilds were satisfactorily predicted by using a random forest (RF) model, which produced a percentage of successful classification of ca 50% for each of the three guilds. Caudal propulsion efficiency, pectoral fin vertical position and body elongation were the most significant traits in the RF predictive model. Although the present study provides initial insight into the links between Mekong fish morphology and ecological guilds, further research is needed in order to clarify the relationship between species morphology, migratory status and responses to environmental variation.

Over exploitation of consumed fishes causes declining of targeted fish populations that will lead to a cascade effect to the guild compositions. The change of carnivorous, omnivorous and herbivorous fish populations drives to the food chain destructions and unstable ecosystems. The objective of this study was to build fish community modelling based on guild compositions. This study was conducted on fish communities in the Banjaran River. The data collected were species richness, the abundance of fish and the guild composition among carnivore, herbivore, and omnivore. Survey and purposive random sampling technique were applied and Banjaran River was divided into five sites based on the physical characteristics of the environment and fishing activities. Species richness data were analyzed by ANOVA, the composition of the carnivorous, omnivorous and herbivorous fish was analyzed descriptively based on the guild pyramides. About 115 individuals consist of 17 species belong to 5 families were found. The species richness in the five sites in was relatively similar (P > 0.05 (P = 0.269)). The fish community in site 3 had the balanced composition which was composed by 3% carnivores, 21.2% omnivores and 75.8% of herbivores. This fish community modelling could be an an alternative way to manage fish community. By controlling the carnivorous fish population, the natural resource especially fish as food resource will sustain and the species loss will be prevent.

Abstract Aim: This study evaluated the trophic structure of the fish assemblage along the longitudinal gradient of a first-order rural stream. Methods Fish were sampled by electrofishing technique in December 2007, September 2008 and March 2009, at three stretch of the Itiz stream (headwater, middle and mouth). We sampled 1,255 individuals relating to 18 species. The categorization of trophic guilds was based on stomach content data of 1,096 individuals, analyzed according to the volumetric method, except for four species, which were classified according to the literature. To test the hypothesis of differences in the richness, abundance and biomass of trophic guilds along the headwater-mouth gradient, it was performed non-parametric statistical analysis of the dietary data. Was also calculated, the amplitude of trophic niche (Levins's index) for each guild. To summarize the composition and abundance of the trophic guilds along the longitudinal gradient, we applied a non-metric multidimensional scaling (NMDS). Results We registered seven guilds: herbivorous, detritivorous, aquatic insectivorous, terrestrial insectivorous, invertivorous, omnivorous and piscivorous, the latter was exclusive to headwater and middle stretches. The omnivorous guild was not recorded in the headwater. Through PERMANOVA analysis it was found that the species richness of more specialized guilds (detritivorous and insectivorous terrestrial) and of generalist invertivorous increased, while less specialized guilds like aquatic insectivorous and herbivorous, decrease significantly in headwater-mouth direction. Except by the non-expected increase of insectivorous terrestrial and decrease of herbivorous downstream, the non-metric multidimensional scaling (NMDS) identified longitudinal variations in abundance and biomass of the guilds that agree with general patterns of fish guilds distribution along environmental gradients. Conclusion These results suggest that the influence of environmental conditions around the stream (local particularities) also contributed to the formation of the observed patterns of trophic guilds along its longitudinal gradient.

A major strength of the guild approach is its ability to simplify community analysis by aggregating species with similar roles or functions into groups. These groups can be used to study a number of important ecological concepts, including functional diversity, community response to disturbance, and food-web dynamics. Despite increased use, guild membership can be based on subjective criteria that are arbitrarily chosen, leading to inconsistencies across studies. Additionally, studies using the guild approach generally ignore ontogenetic changes in diet and habitat use and therefore do not fully capture the complexity of aquatic communities. Although these issues have been discussed in the literature, much has changed since the last review was published a decade ago. In our examination, we discuss data requirements and consequences of data availability and reliability on guild formation. We identify bootstrapping and permutation techniques developed to address limitations through cluster validation and the identification of ontogenetic shifts prior to guild delineation. Lastly, we provide a step-by-step guide to guild analysis, accompanied by a decision tree, to facilitate objective and informed guild creation.

Abstract Economic developments in Alberta have resulted in widespread changes in land use that may deteriorate river conditions for fish. Fish assemblages were characterized with index of biological integrity metrics for the heavily-developed watershed of the Battle River, Alberta. Metric relationships with human stressors were quantified using regression and information theory methods. Although the fauna comprised 14 native species, 50% of the catch was white sucker (Catostomus commersoni Lacepede, 1803). Five statistically unrelated metrics were identified as being responsive to stressors: two trophic guilds, one habitat guild, one reproductive guild, and one measure of community structure. Regression showed that the cumulative effect of human developments, indexed as road density in the basin, was negatively linked to the relative abundance of lithophils and positively linked to the relative abundance of omnivores. Agriculture also threatened the integrity of fish assemblages. Stream sections with higher cattle densities in their basins had fewer lithophils and benthic invertivores; whereas stream sections with higher nutrient concentrations contained fewer species, as well as fewer top carnivores, but more true omnivores. Understanding effects of human footprints that are expanding in western Canada will be critical to the successful management of aquatic resources.

The variation in river discharge alters habitat heterogeneity with implications for the distribution of fish species with different habitat requirements. Assessments of habitat availability following changes in river discharge are difficult to apply at broad spatial scales and with relevance to multiple species. We used a MesoHABSIM modeling approach to quantify river-wide changes in habitat availability for five fish habitat guilds under three river discharge levels along the Niobrara River, NE, USA. We used a time-series of river discharge (1958–2010) to create uniform continuous under-threshold habitat duration curves that identified habitat conditions that may result in periods of stress for fish communities along the Niobrara River. Habitat availability for each fish habitat guild was dependent on river discharge and location along the river. Habitat availability for fish habitat guilds ranged from 5% to 49% of the total channel area suggesting habitat availability may, at times, be limited. We provide river discharge guidelines for bioperiods that limit the frequency and duration of stressful habitat conditions. Understanding interactions between river discharge and habitat availability through time and at river-wide scales may aid in managing for ecological integrity by including protection of river discharge variability to support multiple fish habitat guilds.