Distribution pattern in Aegla uruguayana Schmitt, 1942 (Decapoda: Anomura: Aeglidae): temporal and spatial approach.

The presence, density, and distribution pattern of a species in a particular space and time result from evolutionary and ecological processes. We evaluated the density and spatial distribution pattern of the freshwater anomuran crab, Aegla uruguayana Schmitt, 1942 , in relation to temporal and spatial scales. The temporal scale followed a seasonal analysis, and the space scale was evaluated from the study of three streams located in different provinces of Argentina. Specimens were collected in four sampling campaigns during spring, summer, autumn, and winter in three temperate freshwater environments of the La Plata Basin, Argentina, using 1 m² sampling units. The density varied according to the studied populations and was not by seasonality. The distribution pattern was not influenced by the evaluated scales. The A. uruguayana populations presented a clumped pattern showing a negative binomial distribution. A possible cause of such a pattern is the strong environmental heterogeneity of the three studied sites. The species presented gregarious behavior that could be associated with the spatial arrangement of the shelters available in the particular habitats as well as ecological strategies for optimal and efficient use of resources in these topographies. Our study is the first on the dynamics of the distribution in terms of temporal and spatial scopes of a species of Aegla Leach, 1820 , an endemic freshwater anomuran. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Crustacean Biology is the property of Oxford University Press / USA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)