HISTOLOGICAL ATLAS OF SINIBOTIA REEVESAE BRAIN

Sinibotia reevesae, an endemic fish, lives only in the upper reaches of the Yangtze River. This study explored the structure characteristics of Sinibotia reevesae brain and effects of the ecological habits on the central nervous system. The results showed that S. reevesae brain was composed of five parts of telencephalon, diencephalon, mesencephalon, cerebellum and myelecephalon. The olfactory lobe was a typical spindle shape and the preoptic nucleus of the brain was arranged in a cord-like manner without large preoptic nucleus and small cell group. The corpus mamillare and parasympathetic nucleus were visible in the diencephalon, meanwhile, saccus vasculosus and inferior lobeis were well developed. There were five layers in the tectum opticum of the mesencephalon and three layers in the cerebellum. The myelecephalon located in the end of the brain and differentiated into facial lobes and developed vagal lobes. Histological observations revealed that olfactory, auditory, tactile sensation, taste, motor centers and athletic ability of S. reevesae were well-developed. To sum up, the S. reevesae mainly depend on the sense of smell, hearing, touch, and taste to forage and to evade the natural enemies.