Ontogenetic Otolith Development in an Endemic Tooth-Carp, Aphanius vladykovi (Teleostei: Aphaniidae)

Abstract

Otolith morphology in the tooth-carp/killifish genus Aphanius is an important source of taxonomic information. However, little is known about the range of ontogenetic variation in otolith morphology. In this study, the development of otolith morphology during the early life stages of the Zagros tooth-carp, Aphanius vladykovi is described and discussed. The study material comprises 15 larvae and early juveniles representing nine different developmental stages (0–120 days post hatching), all reared under the same laboratory conditions. The results reveal (i) clear ontogenetic differences in otolith morphology during larval and early juvenile growth phases, (ii) a developmental progression in otolith morphology, which is similar to that described for A. farsicus in a previous study, and (iii) a more rapid rate of otolith development during the larval phase in A. vladykovi than in A. farsicus. It can be hypothesized that the shared pattern of overall development seen in A. vladykovi and A. farsicus reflects their close phylogenetic relationship.