Patterns Of Fish Species Richness Research Articles

Biogeographic patterns of fish species richness in Ontario lakes in relation to historical and environmental factors

Fish species richness in Ontario lakes was summarized for 80 equal-area quadrats and ranged from 59 species per quadrat in southwestern Ontario to 17 species per quadrat in northern Ontario. Correlograms based on Moran's I coefficient indicated the spatial structure of lake species richness was anisotropic and exhibited a strong south–north gradient of decreasing richness. Relationships among Euclidean distance matrices based on richness, postglacial dispersal, climate, elevation, lake chemistry, and lake morphometry were identified with the aid of the Mantel test and principal coordinates analysis. The presence of spatial autocorrelation may bias matrix correlations; therefore, spatial autocorrelation was removed using the partial Mantel test. The results of the partial Mantel test indicated regional lake species richness was significantly correlated with postglacial dispersal and climate. In particular, the results of principal coordinates analysis identified length of time since deglaciation, length of time covered by glacial lakes, distance from dispersal corridor, and mean annual air temperature as the dominant variables in these data sets.

Patterns of fish species richness and abundance in coastal marshes and other nearshore habitats in Green Bay, Lake Michigan

Patterns of fish species richness and abundance in coastal marshes and other nearshore habitats in Green Bay, Lake Michigan

Patterns of fish species richness in the Seine River basin, France

Variation in fish assemblage structure was examined in different rivers of the Seine Basin. Factor analysis was used to identify similarities among samples and species, and to show ichtyological changes along an upstream-downstream gradient. Fish species richness was correlated with catchment area, distance from the source and number of individuals. Relationships between species richness and number of individuals in a sample were largely an artifact of sampling. Species richness increased with river size, reached a maximum in midsize rivers, then decreased in large rivers. This species richness pattern was consistent with the model of the River Continuum Concept. However, possible causes could include greater pollution effects in large rivers. Distribution of feeding guilds was related to river size. Species richness and proportion of omnivores and piscivores increased with river size, whereas species richness and proportion of invertivores declined downstream. These patterns suggest that trophic diversity of fish assemblages may be related to food availability.