Distribution, Abundance, and Resource Utilization of Littoral Zone Fishes in Response to a Nutrient/Production Gradient in Lake Memphremagog

1977 ◽  
Vol 34 (8) ◽  
pp. 1105-1117 ◽  
Author(s):  
Dominique Gascon ◽  
William C. Leggett
Keyword(s):  
Interspecific Competition ◽  
Resource Utilization ◽  
Fish Species ◽  
Littoral Zone ◽  
Individual Species ◽  
Food Utilization ◽  
Fish Food ◽  
Gradient Distribution ◽  
Northern Areas ◽  
Fundulus Diaphanus

The abundance and distribution of six littoral zone fish species (Notropis volucellus, Hybognathus nuchalls, Notemigonus crysoleucas, Pimephales notatus, Fundulus diaphanus, and Etheostoma nigrum) in Lake Memphremagog were influenced directly by a nutrient-driven production gradient existing along the long axis of the lake. The biomass of the six littoral zone fish species was approximately 3 times greater in the more productive southern areas than in the less productive northern areas. Interspecific competition for food was more intense in the less productive northern areas than in the more productive southern areas, and strongly influenced the patterns of food utilization. However, interspecific competition did not appear to play the major role in determining the distribution of the species on the gradient. Distribution of individual species was principally governed by the relative abundance of preferred food resources. The distribution of only one species, Fundulus diaphanus, appeared to be determined primarily by direct competition. Key words: littoral zone, Lake Memphremagog, nutrients, production, resource utilization, fish, food availability

scholarly journals Simultaneous absolute quantification and sequencing of fish environmental DNA in a mesocosm by quantitative sequencing technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tatsuhiko Hoshino ◽  
Ryohei Nakao ◽  
Hideyuki Doi ◽  
Toshifumi Minamoto
Keyword(s):  
Fish Species ◽  
High Throughput Sequencing ◽  
Correlation Coefficients ◽  
Environmental Dna ◽  
Digital Pcr ◽  
Absolute Quantification ◽  
Taqman Probe ◽  
Individual Species ◽  
Natural Environments ◽  
Target Sequence

AbstractThe combination of high-throughput sequencing technology and environmental DNA (eDNA) analysis has the potential to be a powerful tool for comprehensive, non-invasive monitoring of species in the environment. To understand the correlation between the abundance of eDNA and that of species in natural environments, we have to obtain quantitative eDNA data, usually via individual assays for each species. The recently developed quantitative sequencing (qSeq) technique enables simultaneous phylogenetic identification and quantification of individual species by counting random tags added to the 5′ end of the target sequence during the first DNA synthesis. Here, we applied qSeq to eDNA analysis to test its effectiveness in biodiversity monitoring. eDNA was extracted from water samples taken over 4 days from aquaria containing five fish species (Hemigrammocypris neglectus, Candidia temminckii, Oryzias latipes, Rhinogobius flumineus, and Misgurnus anguillicaudatus), and quantified by qSeq and microfluidic digital PCR (dPCR) using a TaqMan probe. The eDNA abundance quantified by qSeq was consistent with that quantified by dPCR for each fish species at each sampling time. The correlation coefficients between qSeq and dPCR were 0.643, 0.859, and 0.786 for H. neglectus, O. latipes, and M. anguillicaudatus, respectively, indicating that qSeq accurately quantifies fish eDNA.

scholarly journals Delivering Food to Hungry Fish in the San Francisco Estuary

2021 ◽  
Vol 9 ◽  
Author(s):  
Laura Twardochleb ◽  
Leela Dixit ◽  
Mallory Bedwell ◽  
Brittany Davis ◽  
Jared Frantzich
Keyword(s):  
Invasive Species ◽  
San Francisco ◽  
Fish Species ◽  
San Francisco Estuary ◽  
Fish Food ◽  
Yolo Bypass ◽  
Delta Smelt ◽  
Endangered Fish ◽  
The Past

The San Francisco Estuary is home to an important endangered fish called delta smelt. Delta smelt eat small, nutritious animals called zooplankton to survive and grow. In turn, zooplankton grow by eating microscopic plant-like organisms called phytoplankton. In the past, the Estuary was full of plankton and delta smelt. Because people have removed water from the Estuary and invasive species now live there, the Estuary no longer has enough plankton to feed delta smelt, making it difficult for them to survive. Scientists have found a unique place in the Estuary, the Yolo Bypass, that has lots of fish food. The problem is that delta smelt do not live in the Yolo Bypass year-round. Scientists are working to solve this problem by sending river or farm water through the Yolo Bypass, to move fish food downstream to feed the hungry delta smelt and other fish species.

Atlantic fishes in the Mediterranean: using biological traits to assess the origin of newcomer fishes

2020 ◽  
Vol 643 ◽  
pp. 133-143
Author(s):  
J Evans ◽  
E Arndt ◽  
PJ Schembri
Keyword(s):  
Fish Species ◽  
Global Environmental Change ◽  
The Body ◽  
Individual Species ◽  
Biological Traits ◽  
Depth Range ◽  
Long Distance ◽  
Biological Trait ◽  
The Mediterranean ◽  
Cryptogenic Species

Two important facets of global environmental change are alteration of climatic regimes and the introduction of alien species. From a biogeographical perspective, these 2 processes lead to very similar results: a change in the distribution of species. Here, we considered Atlantic fish species that are recent newcomers in the Mediterranean Sea, using biological traits to assess their origin. For this purpose, we first re-evaluated all records of Atlantic fish species in the Mediterranean (n = 103) to exclude those not considered recent newcomers (n = 33). Based on faunistic data, we classified the true newcomers into 4 origin categories: alien, vagrant, range-expansion or cryptogenic. Then, we compared biological traits of species we characterised as aliens (n = 7), vagrants (n = 14) or range-expanders (n = 23). Finally, we re-assessed the origin of cryptogenic species (n = 26) using multivariate discriminant analysis, measuring the distance of individual species to the centroids of aliens, vagrants or range-expanders, allowing us to infer their probable ‘mode of origin’. The body size, depth range, temperature range, habitat and ability to undertake long-distance migration were the most important traits that could be related to alien, vagrant or range-expanding fishes. It was possible to assign 10 cryptogenic species a specific origin category with reasonable confidence, while the remaining cryptogenic species combined trait values of different origin categories. These results indicate that biological trait analysis can be coupled with faunistic data to help assess the most likely origin of a newcomer species, thus informing management decisions.

Only a few key prey species fuel a temperate coastal fish food web

2020 ◽  
Vol 653 ◽  
pp. 153-166
Author(s):  
SSH Poiesz ◽  
JIJ Witte ◽  
HW van der Veer
Keyword(s):  
Food Web ◽  
Fish Species ◽  
Fish Community ◽  
Prey Species ◽  
Wadden Sea ◽  
Food Web Structure ◽  
Fish Food ◽  
Coastal Fish ◽  
Web Structure ◽  
Sea Fish

The food web structure of a coastal fish community (western Dutch Wadden Sea) was studied based on stomach content data from samples collected between 2010 and 2018. In total, 54 fish species were caught and 72 different prey items were identified. Fish species consumed from only a few up to >30 different prey species, suggesting the presence of both opportunistic and more specialized feeders. We found no significant differences between years or switches in food source with fish size. The trophic positions of the Wadden Sea fish community ranged from 2.0 to 4.7, with most trophic positions above 3.0. In the past, (near)-resident species were the most abundant guild in spring, and juvenile marine migrants in autumn. At present, all guilds are present in similar but low abundances. The (near)-resident community consisted of about 20 species that fed primarily on amphipod crustaceans, brown shrimps and juvenile herring. There was only a slight overlap in diet with the group of juvenile marine migrants (5 species of juvenile flatfishes and clupeids), whose preferred prey were copepods, polychaetes and brown shrimps. About 15 species of marine seasonal visitors showed an overlap in diet with both the (near)-resident and the juvenile marine migrants, especially for brown shrimps and to a lesser extent herring and gobies. Our results illustrate (1) the pivotal position of a few key prey species (amphipod crustaceans, brown shrimps, juvenile herring and gobies) for the coastal Wadden Sea fishes and (2) that the substantial prey overlap in the diet of some predators cannot exclude intra- and inter-specific competition among these predators.

Ichthyofaunal Diversity of River Kapaleswari at Paschim Medinipur District of West Bengal, India

2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Arun Jana ◽  
Godhuli Sit ◽  
Angsuman Chanda
Keyword(s):  
Fish Species ◽  
West Bengal ◽  
Economic Value ◽  
Fish Population ◽  
Individual Species ◽  
Fish Diversity ◽  
Faunal Diversity ◽  
Data Deficient ◽  
Future Policy ◽  
First Time

The present study has been conducted on ichthyofaunal diversity of river Kapaleswari flowing through Paschim Medinipur district of West Bengal, India. Results reveal the existence of 56 indigenous fish species under 22 families of 8 orders and the order Perciformes represents the largest diversity with 8 families and 20 species. Cyprinidae is the most dominant family; contributed 26.79% species. Two species namely Stigmatogobius sadanundio & Gobiopsis macrostoma have been first time recorded from Paschim Medinipur district of West Bengal. Among the recorded fish species of Kapaleswari River, 47.07% were used as food-fish, 1.79% used as ornamental & the remaining 57.14% were used as both food and ornamental. So, maximum fish species have important socio-economic value for the development of local people proximate to the Kapaleswari River. The values of the Shannon-Weaver index (H) range from ‘3.58’ to ‘3.79’ & the Simpson’s index (D) from ‘0.023’ to ‘0.032’ among the sampling sites are indicative to diverse fish population in Kapaleswari River. The result of species evenness has been concluded that individual species are near to disturb condition at Kapaleswari river. According to IUCN ver. 2020.1, status of the fishes in the river depicts, 75% are Least Concern, 3.57% are Vulnerable, 8.93% are Near Threatened, 10.71% are Not Evaluated & 1.71% are Data Deficient. As per local status 71.42% of fishes of this river are under risk and need immediate conservation to protect them from extinction. Hence, the work is a documentation of macro faunal diversity of Kapaleswari river as well as regional level for helpful for future researchers and policy planners and also helpful to formulate the future policy for conservation and management of the fish diversity in the river Kapaleswari.

scholarly journals When does fishing lead to more fish? Community consequences of bottom trawl fisheries in demersal food webs

2013 ◽  
Vol 280 (1769) ◽  
pp. 20131883 ◽  
Author(s):  
P. Daniel van Denderen ◽  
Tobias van Kooten ◽  
Adriaan D. Rijnsdorp
Keyword(s):  
Fish Species ◽  
Benthic Invertebrate ◽  
Maximum Sustainable Yield ◽  
Benthivorous Fish ◽  
Fish Food ◽  
Bottom Up ◽  
Positive Effects ◽  
Controlled Systems ◽  
Target Fish ◽  
Benthic Invertebrate Community

Bottom trawls are a globally used fishing gear that physically disturb the seabed and kill non-target organisms, including those that are food for the targeted fish species. There are indications that ensuing changes to the benthic invertebrate community may increase the availability of food and promote growth and even fisheries yield of target fish species. If and how this occurs is the subject of ongoing debate, with evidence both in favour and against. We model the effects of trawling on a simple ecosystem of benthivorous fish and two food populations (benthos), susceptible and resistant to trawling. We show that the ecosystem response to trawling depends on whether the abundance of benthos is top-down or bottom-up controlled. Fishing may result in higher fish abundance, higher (maximum sustainable) yield and increased persistence of fish when the benthos which is the best-quality fish food is also more resistant to trawling. These positive effects occur in bottom-up controlled systems and systems with limited impact of fish feeding on benthos, resembling bottom-up control. Fishing leads to lower yields and fish persistence in all configurations where susceptible benthos are more profitable prey. Our results highlight the importance of mechanistic ecosystem knowledge as a requirement for successful management.

scholarly journals Effect of food types on competitive interaction between Aedes aegypti (LINNAEUS, 1762) and Ae. albopictus (SKUSE, 1894) (Diptera, Culicidae): a proximate level appraisal

2017 ◽  
Vol 86 (2) ◽  
pp. 99-118 ◽  
Author(s):  
Sampa Banerjee ◽  
Sushree Mohan ◽  
Soujita Pramanik ◽  
Soumyajit Banerjee ◽  
Goutam K. Saha ◽  
...  
Keyword(s):  
Life History ◽  
Aedes Aegypti ◽  
Interspecific Competition ◽  
Food Quality ◽  
Population Characteristics ◽  
Competitive Interactions ◽  
Food Type ◽  
Pupal Weight ◽  
Fish Food ◽  
Larval Habitats

AbstractCompetitive interactions between coexisting Aedes aegypti and Ae. albopictus have been implied as a crucial factor shaping life history traits and population characteristics. The overlap in resource requirements and similarities in the life history strategies of the two Aedes mosquitoes form a basis for competitive interactions. In the present study, the role of the food quality of the larval habitats in influencing the outcome of competition between Ae. aegypti and Ae. albopictus is evaluated to highlight food quality as a basis for asymmetric competitive outcomes. Instar I larvae of the two mosquitoes were reared using conspecifics or heterospecifics of constant size and equal ratio with four different food types: boiled rice, boiled pulses, a mixture of boiled rice and pulses, and fish food. Competitive interactions were evaluated using age at pupation (AP), pupal weight (PW), dry adult weight (AW) and wing length (WL) with respect to intra- and interspecific competition for the two sexes of each mosquito species. The results show that Ae. albopictus developed faster but achieved a smaller size compared to Ae. aegypti under interspecific competition conditions, the extent of the difference varying significantly with the food type. Given the variety of food resources available in the small container larval habitats, the results of the study imply that food quality may act differentially with respect to larval development and adult body size, depending on the conspecifics or heterospecifics and on the sex of the species concerned. The dominance of one species over the other may also be a consequence of the resource utilization pattern that varies in the larval habitats.

scholarly journals Bacteriological profile of selected fish species and water sample from Otuocha River Anambra State

2020 ◽  
Vol 18 (1) ◽  
pp. 11-26
Author(s):  
K.E. Amuneke ◽  
G.C. Igbodiegwu ◽  
P.A. Okeke ◽  
A.C. Adibe
Keyword(s):  
Water Sample ◽  
Fish Species ◽  
Continuous Process ◽  
Landing Site ◽  
Microbial Load ◽  
Anthropogenic Sources ◽  
Microbial Quality ◽  
Fish Food ◽  
Fish Samples

Attempt to ensure fish food security is a continuous process and food safety is a global concern for consumers and food industry. Fish is an  important source of healthy and cheap source of animal protein that among its numerous benefit fish is widely acceptable, across socio-economic, age and religious barrier. However, supply of contaminated free fish is desirable to ensure safe consumption and a healthy consumer public`. The  objective of the study is to provide baseline information on the microbial quality of Otuocha river, hence establish the microbial quality of fish caught in Otuocha river. Five fish species (Aruis gigas, Bagrus bayad, Schilbe mystus, Chrysichthys nigroditatus and Protopterus annectens) and water sample were taken from Otuocha fish landing site and river respectively and transported to laboratory. The fish samples were cleaned with sterile distilled water and 1 g of skin, gills, intestine cut aseptically and labelled along with water sample before microbial analysis following standard method. The result obtained in water and fish samples showed high microbial load in Otuocha river and was attributed to anthropogenic sources. Nine different bacteria were isolated in fish samples while seven were isolated in water sample. The study concluded that Otuocha river has high microbial load, hence recommend that fish from Otuocha river should be properly cooked/smoked before consumption and sanitary standard of Otuocha river and its environs be improved while public enlightenment on waste disposal be undertaken. Key words: Microbial load, fish, water, Otuocha River

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