Shrimps of an ancient Balkan lake: Bionomy and conservation

Abstract

In order to have a comprehensive evaluation and classification of the natural biota of Lake Pamvotis, the present study aims at investigating shrimps' bionomic traits. Information on shrimps' habitat preferences, abundances, and syntopic species in relation to the physicochemical profile of the lake's water are investigated for the first time. The study was carried out on a bi-monthly base, at six littoral sites of the lake. Samples' study from different habitats and seasons revealed that the freshwater shrimp Atyaephyra thyamisensis was the most abundant species, accounting for 44.76% of the total taxa catch, while the grass shrimp Palaemonetes antennarius was less abundant (7.54%). Syntopic fish species in the littoral zone of Lake Pamvotis such as Economidichthys pygmaeus, Gambusia holbrooki, Knipowitschia caucasica and Rutillus panosi showed interannual differences with abundances of 24.12%, 19.13%, 4.26% and 0.20%, respectively. Correspondence analysis revealed clear patterns between species and stations. A. thyamisensis was predominant in shallow, well oxygenated water bodies rich with aquatic vegetation, but it was absent from deeper habitats. P. antennarius was found mainly in lentic water bodies, rocky substratum and deeper habitats. Taking into account the high ecological importance of the freshwater shrimps in ecosystems' energy flow, ecological and biological data of lake's shrimps are discussed and presented thoroughly. Threats and conservation measures for both shrimp species are debated also in detail.

An integrative approach challenges species hypotheses and provides hints for evolutionary history of two Mediterranean freshwater palaemonid shrimps (Decapoda: Caridea)

“…One example concerning Palaemonidae is the study by Cartaxana (2015), who on the basis of measurements of the body parts and genetic data suggested the fusion of two Palaemon species. Similar linear distance-based morphometric studies of Palaemon antennarius in north-western Greece by Anastasiadou et al (2009Anastasiadou et al ( , 2014Anastasiadou et al ( , 2017 showed some phenotypic plasticity connected with sex and the type of habitat, although their studies were not supported by genetic analyses.…”