Comparative Otolith Morphology of Two Morphs of Schizopygopsis thermalis Herzenstein 1891 (Pisces, Cyprinidae) in a Headwater Lake on the Qinghai-Tibet Plateau

Teleost otoliths provide a pivotal medium for studying changes in population structure and population dynamics of fish. Understanding the otolith-fish size relationship and intraspecies variation in otolith morphology is essential for the accurate assessment and management of fishery resources. In our study, we aimed to estimate the relationships between otolith morphological measurements and fish length, and detect differences in the otolith morphology of planktivorous and benthivorous morphs of Schizopygopsis thermalis in Lake Amdo Tsonak Co on the Qinghai-Tibet Plateau (QTP). Both morphs exhibited strong linear otolith-fish size relationships; otolith morphology was sexually dimorphic in each morph; the morphs differed significantly in otolith shape and size (e.g., posterior side, the region between the posterior and ventral otolith, otolith length, circularity, and surface density). In addition, we found that the differences in otolith morphology between morphs are related to habitat preferences, diet, and growth. Basic data on the biology of S. thermalis are essential for poorly studied Lake Amdo Tsonak Co, and our study emphasizes that intraspecific variation in otolith morphology should be taken into consideration when differentiating stocks, populations, and age classes based on otolith morphology.

Automated summary

Teleost otoliths are important for studying changes in fish population structure and dynamics. This study focused on estimating the relationship between otolith morphology and fish length, as well as detecting differences in otolith morphology between planktivorous and benthivorous morphs of Schizopygopsis thermalis in Lake Amdo Tsonak Co on the Qinghai-Tibet Plateau. The results showed that there were significant variations in otolith morphology between the two morphs, and these differences were related to habitat preferences, diet, and growth.