Die Besiedlung von Süßwasserlebensräumen durch Palaemonetes argentinus, Nobili 1901 (Decapoda: Caridea; Palaemonidae): Experimentelle und morphologische Untersuchungen zur Larvalentwicklung

Abstract

Palaemonetes argentinus were investigated during larval development for their degree of adaptation to a freshwater environment. This species inhabits both brackish water as well as pure freshwater habitats in northern Argentina. Initially, the individual larval stages were described using morphological features and distinguishing characters. In addition, the response of the larvae to various forage conditions and 14 different temperate-salinity combinations was examined. The goal of the study was to discover to what extent P. argentinus has evolved characteristics over time that may indicate this species in the process of adapting to freshwater environment.P. argentinus larvae exhibited typical characteristics of Palaemonids both in inhabiting marine environments as well as brackish water, and in the large number of larval stages and the described variability during larval development. In contrast, there are traits that suggest adaptation to freshwater environments has already occurred (facultative lecithotrophy, tolerance to starvation periods during zoea I, euryhalinity, vestigial third pereiopod and relatively large zoea I larva).