Work

Ontogeny of the digestive system and enzymatic activities in redtail botia Yasuhikotakia modesta larvae: A new fish species for freshwater aquaculture

Year: 2025

Type: article

Abstract: The ontogeny of digestive functions of redtail botia Yasuhikotakia modesta was investigated 1–30 days after hatching (DAH) using morphological, histological, and digestive enzyme approaches. One-day-old larvae were nursed in a 15 m² rearing tank containing diverse natural food organisms. The water temperature during the rearing period was 27.7–31.0 °C. Morphological changes in the digestive tract showed that total body length increased from 2.94 ± 0.13 mm to 22.25 ± 3.33 mm, along with relative gut length (RGL) ranged from 0.39 to 0.74, and mouth size increased from 0.21 ± 0.04 mm to 1.87 ± 0.16 mm. The redtail botia larvae started exogenous feeding at 3 DAH (4.13 ± 0.39 mm), and yolk sac absorption occurred between 3–5 DAH (4.13 ± 0.39–4.36 ± 0.17 mm). By 6 DAH (4.61 ± 0.24 mm), the digestive tract differentiated into the oral cavity, esophagus, stomach region, and intestine. The stomach appeared on 7 DAH (4.77 ± 0.28 mm) and gastric glands were identified on 12 DAH (9.79 ± 1.04 mm), indicating a fully functional stomach. By 15 DAH (11.42 ± 0.97 mm), the digestive tract completed its morphological structures with the appearance of the pyloric sphincter, a constriction of the mucosa between the stomach and the intestine. Digestive enzyme analysis detected trypsin, chymotrypsin, and amylase from 1 DAH (2.94 ± 0.13 mm), while pepsin was first detected at 12 DAH (9.79 ± 1.04 mm), coinciding with gastric gland formation. These findings provide information to develop efficient larval feeding strategies in this species. • Study digestive system and enzyme activity in redtail botia larvae (days 1–30). • Exogenous feeding began on day 3 and the digestive tract fully formed on day 15. • Trypsin, chymotrypsin, and amylase detected at hatch while pepsin detected on day 12. • Provide information to develop efficient larval feeding strategies.

Source: Aquaculture Reports

DOI: 10.1016/j.aqrep.2025.103220

Authors: Tran Thi Thanh Hien, Nguyen Thanh Hieu, Ta Anh Thu, Tran Nguyen Duy Khoa, Nguyen Hong Quyet Thang, Pham Thanh Liem

Institution: Can Tho University

Language: English

Topic: Aquaculture Nutrition and Growth

Subfield: Aquatic Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Zero hunger

Open Access status: gold

Estimated APC paid: $2,640