Ecophenotypy in Limnocythere inopinata (Ostracoda) from the late Holocene of Kajemarum Oasis (north-eastern Nigeria)

Previous work on the late Holocene (4000–95 cal. yr BP) palaeolimnology of Kajemarum Oasis (north-eastern Nigeria) allows direct comparisons to be made between limnological variables and temporal morphological variations in successive parthenogenetic populations of the ostracod Limnocythere inopinata (Baird 1843). Morphometric analysis of ostracod shells reveals no directional trends but a significant co-occurrence of peaks in means of morphological variables with those in inferred salinity may indicate a direct response of the organisms to environment (ecophenotypy). Mean roundness index values show significant increase midway through the sequence, but it is argued that ecophenotypy is unlikely, although the underlying reasons for this response remains unclear.