Geometric morphometric analysis of the freshwater prawn Macrobrachium borellii (Decapoda: Palaemonidae) at a microgeographical scale in a floodplain system

TORRES MV; GIRI F; COLLINS PA

ECOLOGICAL RESEARCH

SPRINGER TOKYO

Lugar: Tokyo; Año: 2014

0912-3814

The hydrologic regime of a floodplain system tends to homogenise populations between water bodies in high water periods, decreasing the differences between the populations of nearby sites. The movements of some species are related to the spatial and temporal dynamics of the environment in the context of a floodplain system. Hydrological fluctuations in a floodplain system modulate the dispersal and presence of decapods among habitats. Morphological variations among populations of the freshwater prawn Macrobrachium borellii in a floodplain system at a microgeographical scale were studied. Geometric morphometrics were used to compare the shapes of prawns. The cephalothorax structure was represented using 16 digitised landmarks. Environmental variables were also measured to characterise each site. The average cephalothorax shape was different between sexes in all sites. Populations that were near each other in terms of hydrological distance had similar shapes, but all of the populations differed in shape from the farthest population. The environmental variables were not good predictors of the average cephalothorax shape. Instead, the average cephalothorax shape was strongly related to the hydrologic distance and geographical location. The swimming characteristics of these prawns and their passive movements, together with the dynamics of a floodplain system, explain the low morphological variation between populations in this study. The dynamic characteristics of the system influence the dispersal of the prawns and allow populations to remain connected.