Estudo comparando a dieta de três espécies de loricarídeos Eurycheilichthys limulus, Ancistrus brevipinnis e Hemiancistrus punctulatus, em diferentes riachos, com os objetivos de verificar a ocorrência ou não de sobreposição alimentar entre as espécies e entre as classe de tamanho de cada espécie. As coletas foram realizadas bimestralmente, pela técnica de pesca elétrica, a partir de junho / 2012 a junho / 2013, em riachos da bacia do alto Jacuí, Rio Grande do Sul, Brasil. Por meio da análise do conteúdo alimentar, foram identificados 26 itens alimentares. De modo geral, as três espécies apresentaram quatro itens que se destacaram: Detrito orgânico, Bacillariophyta, Sedimento e Material vegetal. Além disso, a espécie Eurycheilichthys limulus consumiu uma elevada proporção de larvas de Simuliidae e Chironomidae, e as espécies Ancistrus brevipinnis e Hemiancistrus punctulatus apresentaram uma composição da dieta semelhante. Ancistrus brevipinnis apresentou como principais itens alimentares consumidos alga Oedogoniophyceae, larva de Chironomidae, Tecameba, alga Zygnemaphyceae e Rotífera, enquanto Hemiancistrus punctulatus apresentou como principais itens alimentares consumidos alga Oedogoniophyceae, alga Zygnemaphyceae, Tecameba, larva de Chironomidae e alga Cyanophyceae. Foram identificados os itens responsáveis por essa diferença. Todas as espécies e classes de tamanho apresentaram um alto valor de amplitude de nicho e, na maioria das interações, um baixo valor de sobreposição alimentar. Algumas interações entre as espécies Eurycheilichthys limulus versus Hemiancistrus punctulatus e Ancistrus brevipinnis versus H. punctulatus apresentaram valores altos de sobreposição alimentar, o que poderia indicar uma competição, porém o modelo nulo mostrou o compartilhamento de recursos entre as espécies e classes de tamanho/espécies. Por fim, constatou-se que há segregação alimentar entre as três espécies de Siluriformes estudadas e que a partilha de recursos entre as espécies está relacionada à utilização diferencial de itens em diferentes fases da vida. / Study comparing the diet of three species of loricariids Eurycheilichthys limulus, Ancistrus brevipinnis, and Hemiancistrus punctulatus in different streams aiming to verify the presence or absence of food overlap between the species and between each species of size. Samples were conducted bimonthly by electrofishing technique from June / 2012 to June / 2013 In streams of high Jacuí basin, Rio Grande do Sul, Brazil. Through the content analysis feeds were identified 26 food items. In general, the three species showed the presence of four items that stood out: Detritus Organic, Bacillariophyta, Sediment, and Plant Material. In addition to these items, other items were representatively consumed differently for each species. The species Eurycheilichthys limulus consumed a high proportion of Simuliidae larvae and Chironomidae larvae, the species A. punctulatus and H. brevipinnis had a similar composition of the diet, Ancistrus brevipinnis presented as the main food items consumed: algae Oedogoniophyceae, larvae Chironomidae, Tecameba, algae Zygnemaphyceae, and Rotifers, while Hemiancistrus punctulatus presented as the main food items consumed algae Oedogoniophyceae, algae Zygnemaphyceae, Tecameba, larvae Chironomidae, and algae Cyanophycea. Species segregation can be observed by Analysis Coordinates Principal (PCoA). The items identified were responsible for this difference. All species and all size classes showed a high value of niche breadth. In general, these species have a low feeding overlap values. Some interactions between the species Eurycheilichthys limulus versus Hemiancistrus punctulatus and between Ancistrus brevipinnis versus Hemiancistrus punctulatus showed the presence of high values of food overlap indicating a competition, but the null model confirmed the niche partitioning between the species and classes size / species. Finally, it was found that there are food segregation between the three species of Siluriformes studied and that the sharing of resources between species is related to differential use of items in different stages of life.

Estudo comparando a dieta de três espécies de loricarídeos Eurycheilichthys limulus, Ancistrus brevipinnis e Hemiancistrus punctulatus, em diferentes riachos, com os objetivos de verificar a ocorrência ou não de sobreposição alimentar entre as espécies e entre as classe de tamanho de cada espécie. As coletas foram realizadas bimestralmente, pela técnica de pesca elétrica, a partir de junho / 2012 a junho / 2013, em riachos da bacia do alto Jacuí, Rio Grande do Sul, Brasil. Por meio da análise do conteúdo alimentar, foram identificados 26 itens alimentares. De modo geral, as três espécies apresentaram quatro itens que se destacaram: Detrito orgânico, Bacillariophyta, Sedimento e Material vegetal. Além disso, a espécie Eurycheilichthys limulus consumiu uma elevada proporção de larvas de Simuliidae e Chironomidae, e as espécies Ancistrus brevipinnis e Hemiancistrus punctulatus apresentaram uma composição da dieta semelhante. Ancistrus brevipinnis apresentou como principais itens alimentares consumidos alga Oedogoniophyceae, larva de Chironomidae, Tecameba, alga Zygnemaphyceae e Rotífera, enquanto Hemiancistrus punctulatus apresentou como principais itens alimentares consumidos alga Oedogoniophyceae, alga Zygnemaphyceae, Tecameba, larva de Chironomidae e alga Cyanophyceae. Foram identificados os itens responsáveis por essa diferença. Todas as espécies e classes de tamanho apresentaram um alto valor de amplitude de nicho e, na maioria das interações, um baixo valor de sobreposição alimentar. Algumas interações entre as espécies Eurycheilichthys limulus versus Hemiancistrus punctulatus e Ancistrus brevipinnis versus H. punctulatus apresentaram valores altos de sobreposição alimentar, o que poderia indicar uma competição, porém o modelo nulo mostrou o compartilhamento de recursos entre as espécies e classes de tamanho/espécies. Por fim, constatou-se que há segregação alimentar entre as três espécies de Siluriformes estudadas e que a partilha de recursos entre as espécies está relacionada à utilização diferencial de itens em diferentes fases da vida. / Study comparing the diet of three species of loricariids Eurycheilichthys limulus, Ancistrus brevipinnis, and Hemiancistrus punctulatus in different streams aiming to verify the presence or absence of food overlap between the species and between each species of size. Samples were conducted bimonthly by electrofishing technique from June / 2012 to June / 2013 In streams of high Jacuí basin, Rio Grande do Sul, Brazil. Through the content analysis feeds were identified 26 food items. In general, the three species showed the presence of four items that stood out: Detritus Organic, Bacillariophyta, Sediment, and Plant Material. In addition to these items, other items were representatively consumed differently for each species. The species Eurycheilichthys limulus consumed a high proportion of Simuliidae larvae and Chironomidae larvae, the species A. punctulatus and H. brevipinnis had a similar composition of the diet, Ancistrus brevipinnis presented as the main food items consumed: algae Oedogoniophyceae, larvae Chironomidae, Tecameba, algae Zygnemaphyceae, and Rotifers, while Hemiancistrus punctulatus presented as the main food items consumed algae Oedogoniophyceae, algae Zygnemaphyceae, Tecameba, larvae Chironomidae, and algae Cyanophycea. Species segregation can be observed by Analysis Coordinates Principal (PCoA). The items identified were responsible for this difference. All species and all size classes showed a high value of niche breadth. In general, these species have a low feeding overlap values. Some interactions between the species Eurycheilichthys limulus versus Hemiancistrus punctulatus and between Ancistrus brevipinnis versus Hemiancistrus punctulatus showed the presence of high values of food overlap indicating a competition, but the null model confirmed the niche partitioning between the species and classes size / species. Finally, it was found that there are food segregation between the three species of Siluriformes studied and that the sharing of resources between species is related to differential use of items in different stages of life.

Estudo comparando a dieta de três espécies de loricarídeos Eurycheilichthys limulus, Ancistrus brevipinnis e Hemiancistrus punctulatus, em diferentes riachos, com os objetivos de verificar a ocorrência ou não de sobreposição alimentar entre as espécies e entre as classe de tamanho de cada espécie. As coletas foram realizadas bimestralmente, pela técnica de pesca elétrica, a partir de junho / 2012 a junho / 2013, em riachos da bacia do alto Jacuí, Rio Grande do Sul, Brasil. Por meio da análise do conteúdo alimentar, foram identificados 26 itens alimentares. De modo geral, as três espécies apresentaram quatro itens que se destacaram: Detrito orgânico, Bacillariophyta, Sedimento e Material vegetal. Além disso, a espécie Eurycheilichthys limulus consumiu uma elevada proporção de larvas de Simuliidae e Chironomidae, e as espécies Ancistrus brevipinnis e Hemiancistrus punctulatus apresentaram uma composição da dieta semelhante. Ancistrus brevipinnis apresentou como principais itens alimentares consumidos alga Oedogoniophyceae, larva de Chironomidae, Tecameba, alga Zygnemaphyceae e Rotífera, enquanto Hemiancistrus punctulatus apresentou como principais itens alimentares consumidos alga Oedogoniophyceae, alga Zygnemaphyceae, Tecameba, larva de Chironomidae e alga Cyanophyceae. Foram identificados os itens responsáveis por essa diferença. Todas as espécies e classes de tamanho apresentaram um alto valor de amplitude de nicho e, na maioria das interações, um baixo valor de sobreposição alimentar. Algumas interações entre as espécies Eurycheilichthys limulus versus Hemiancistrus punctulatus e Ancistrus brevipinnis versus H. punctulatus apresentaram valores altos de sobreposição alimentar, o que poderia indicar uma competição, porém o modelo nulo mostrou o compartilhamento de recursos entre as espécies e classes de tamanho/espécies. Por fim, constatou-se que há segregação alimentar entre as três espécies de Siluriformes estudadas e que a partilha de recursos entre as espécies está relacionada à utilização diferencial de itens em diferentes fases da vida. / Study comparing the diet of three species of loricariids Eurycheilichthys limulus, Ancistrus brevipinnis, and Hemiancistrus punctulatus in different streams aiming to verify the presence or absence of food overlap between the species and between each species of size. Samples were conducted bimonthly by electrofishing technique from June / 2012 to June / 2013 In streams of high Jacuí basin, Rio Grande do Sul, Brazil. Through the content analysis feeds were identified 26 food items. In general, the three species showed the presence of four items that stood out: Detritus Organic, Bacillariophyta, Sediment, and Plant Material. In addition to these items, other items were representatively consumed differently for each species. The species Eurycheilichthys limulus consumed a high proportion of Simuliidae larvae and Chironomidae larvae, the species A. punctulatus and H. brevipinnis had a similar composition of the diet, Ancistrus brevipinnis presented as the main food items consumed: algae Oedogoniophyceae, larvae Chironomidae, Tecameba, algae Zygnemaphyceae, and Rotifers, while Hemiancistrus punctulatus presented as the main food items consumed algae Oedogoniophyceae, algae Zygnemaphyceae, Tecameba, larvae Chironomidae, and algae Cyanophycea. Species segregation can be observed by Analysis Coordinates Principal (PCoA). The items identified were responsible for this difference. All species and all size classes showed a high value of niche breadth. In general, these species have a low feeding overlap values. Some interactions between the species Eurycheilichthys limulus versus Hemiancistrus punctulatus and between Ancistrus brevipinnis versus Hemiancistrus punctulatus showed the presence of high values of food overlap indicating a competition, but the null model confirmed the niche partitioning between the species and classes size / species. Finally, it was found that there are food segregation between the three species of Siluriformes studied and that the sharing of resources between species is related to differential use of items in different stages of life.

Thesis (Ph.D.)--University of Wollongong, 2008. / Typescript. Includes bibliographical references.

No description available.

This study is based on the examinations and analyses of 388 largemouthed black bass (Micropterus salmoides) and 118 spotted black bass (Micropterus puctulatus ssp.) which were collected over a period of three years from 9 lakes in the North-Central and East Texas areas. The results should show the following: (1) the average age of the black bass in each of the nine reservoirs in Texas; (2) the growth rate of the bass in these reservoirs; (3) the feeding habits of the bass in all reservoirs studied; (4) a comparison of the growth rates of the largemouthed and spotted basses; and (5) a comparison of the growth rates of bass from Texas and Oklahoma.

Two species of black bass, smallmouth bass Micropterus dolomieu and spotted bass Micropterus punctulatus, are sympatric in both riverine and impounded sections of the New River, Virginia. Resource use (habitat and diet) by the two species was investigated to determine patterns and extent of resource partitioning between them and how those patterns might differ between lotic and lentic environments. Individual fitness indicators (i.e., growth and body condition factor) were also measured to assess performance of populations of the two species in the study areas. Fitness indicators suggested relatively good performance of both species in both river and impoundment, which implied that competitive pressures were not intense. Diet analyses indicated fairly high overlap in prey types consumed. High fitness combined with considerable diet overlap suggested that food availability was adequate, and that segregation in this impounded river system was not on a trophic basis. The two species were found to segregate spatially, with spotted bass predominant in the impoundment and smallmouth more abundant in the river. Spatial segregation was also apparent within both river and impoundment habitat types. / Master of Science