First report on the spawning migration and early life development of a cyprinid species of the genus Telestes

Abstract

Reproductive migration of a Telestes species is reported for the first time for the Balkan endemic Telestes pleurobipunctatus (Stephanidis, 1939) from Louros River (Northwestern Greece), while the embryonic and larval development is also described for the first time for this species and genus. Adult fish migrate in late winter upstream and spawn in a peak of 2–3 nights in the outflow of springs. Embryos at hatching measure approx. 6.0 mm notochord length (NL), flexion starts at 8.1 mm NL and food particles are noted in the digestive tract of larvae at 8.2 mm NL. The larval period is characterized by the sequential formation of fins and the development of scalation. Fin differentiation ends with the completion of pelvic fin rays and the disappearance of the pre-anal finfold at 20.0 mm. First scales appear at 17.0 mm standard length (SL) and scalation completes at 27.8 mm SL. We propose that the size at a specific ontogenetic event, the pigmentation pattern and the pre-anal myomeres' number comprise diagnostic characters that permit distinguishing T. pleurobipunctatus larvae from other sympatric cyprinids. We note the rare pattern of scale scalation and pigmentation pattern of the target species. Parapatric speciation in T. pleurobipunctatus possibly related to its spawning migration pattern, as well as the use of larval identification in monitoring and conservation programmes targeting threatened cyprinids exhibiting this type of reproductive behaviour are also discussed.