Age, growth and population dynamics of two congeneric and invasive gobies, Rhinogobius giurinus and R. cliffordpopei (Actinopterygii, Gobiidae) in a plateau lake, southwestern China

摘要

Although many goby species have become widely established outside of their native ranges, little is known yet about invasive population biology. The age, growth and population dynamics of two introduced goby species (Rhinogobius giurinus and Rhinogobius cliffordpopei) were quantified in Lake Erhai (southwest China) with the general aim to improve empirical knowledge and management strategies. The results revealed that their lifespan ranges 2 years. The size and time at sexual maturity for R. cliffordpopei was lower than for R. giurinus. R. cliffordpopei displayed higher total mortality, fishing mortality and exploitation rates than R. giurinus, whereas the natural mortality of R. cliffordpopei was lower than that of R. giurinus. The catch per unit effort of benthic fyke nets was low from April to June in R. cliffordpopei and from July to September in R. giurinus, whereas it was high from July to September in R. cliffordpopei and from April to June in R. giurinus. Thus, several specific strategies are suggested to improve the cost-efficiency of the current management practices related to the mesh size of benthic fyke nets used for physical removals, the timing of deployment of control actions and the use of synergic control methods.