Growth and morphological development of laboratory-reared larvae and juveniles of the Laotioan indigenous cyprinid Hypsibarbus malcolmi
Source: Ichthyological Research, Volume 57, Number 4, November 2010 , pp. 389-397(9)
Abstract:The morphological development, including the pigmentation, body proportions, fins, and survival rate for 30 days after hatching, of laboratory-reared larval and juvenile Hypsibarbus malcolmi is described. Body lengths (BL) of larvae and juveniles were 2.0 ± 0.2 (mean ± SD) mm at 1 h after hatching (day 0) and 9.2 ± 0.6 mm on day 16, reaching 12.1 ± 0.9 mm on day 30. Yolk volume decreased linearly, with the yolk being completely absorbed by day 3 in all preflexion larvae (all specimens >3.2 mm BL). Feeding was observed on day 2 in fish which had rapidly undergone complete yolk absorption following mouth and anus opening on day 1, and on day 3 in all remaining fish. Myomere numbers were 20–21 + 11–12 = 31–33, although they were not clearly visible in juveniles. Melanophores were few on the body during days 0–2, but increased with growth and covered the entire upper dorsal body surface during the juvenile stage. Body proportions tended to become constant in juveniles. Notochord flexion began in larvae >5.2 mm BL on day 8, and was completed in larvae >8.4 mm BL on day 14. Specimens with full fin ray complements were initially observed on day 22 (10.4 mm BL in juveniles). All specimens >11.5 mm BL had attained the juvenile stage. A high survival rate of 92.7% was estimated on day 30.
Document Type: Research Article
Affiliations: 1: Laboratory of Global Fisheries Sciences, Department of Global Agricultural Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan 2: Fisheries Division, Japan International Research Center for Agricultural Sciences, 1-1 Owashi, Tsukuba, Ibaraki, 305-8686, Japan, Email: email@example.com 3: Aquaculture Unit, Living Aquatic Resource Research Center, National Agriculture and Forestry Research Institute, Khounta Village, Sikhotabong District, Vientiane, Laos 4: IC Net Ltd., 3rd floor FSK Building, 4-1 Shintoshin, Chuo-ku, Saitama, Saitama, 330-0081, Japan 5: Namxouang Aquaculture Development Center, Aquculture Improvement and Extension Project, Vientiane, Laos
Publication date: November 2010