The development of pharyngeal taste buds in Hucho taimen (Pallas, 1773) larvae

This study aims to investigate the relationship between the development of pharyngeal taste buds (TBs) and first feeding of Hucho taimen. Larvae were fed with live food (water flea and tubifex) for 8 weeks. TBs of larval pharynx were histologically examined using light microscopy during the rearing experiment. The results showed that the first few TBs primordia were visible within the pharynx 27 days after hatch (DAH), which coincides with the onset of feeding, and the first few TBs with open receptor areas appear 45 DAH. TBs of pharynx were well developed 76 DAH. The number and size of TBs were quantified during larval development. The average number of pharynx was 8.63±1.15, 11.29±0.50, 14.50±1.06, and 17.78±0.47 TBs at 27, 36, 45, and 76 DAH, respectively. The number of TBs increased in both the upper and lower pharynx. The ratio of height to width of TBs showed an increase tendency, ranging from 0.81 to 1.11. The height of TBs showed an increase tendency after 29 DAH during the development. However, the width of TBs exhibited a low at 35 DAH. In conclusion, the development of pharyngeal TBs coincides with the first feeding, and this should lead to a better understanding of improvement of larval rearing in H. taimen hatcheries.