title: Effects of the timing of initial feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae.
abstract: The effects of delayed first feeding on growth and survival of spotted mandarin fish Siniperca scherzeri larvae were examined under controlled conditions. Morphometric characters [yolk-sac volume, oil globule volume, head depth (H(D)), body depth (B(D)), eye diameter (E(D)), musculature height (M(H)), mouth diameter (M(D)) and total length (L(T))], body mass (M), specific growth rate (S(GR)) and survival were evaluated under different first-feeding time (2, 3, 4 and 5 days after hatching). Larvae began to feed exogenously at 2 days after hatching (DAH) and the point of no return (P(NR)) occurred between 5 and 6 DAH at 23 degrees C, range +/-1.0 degrees C. The yolk volume of larvae first-fed at 2 days had a significant difference compared with that of larvae first-fed at 3, 4 and 5 days on 3 and 4 DAH. The larvae first-fed at 2 days achieved comparatively better growth performance than that of 3, 4 and 5 days. On 5 DAH, all morphometric characters had significant differences between 2 and 5 days and 2 and 4 days initial feeding, respectively. Total mortality was recorded on 9 DAH for the larvae first-fed at 5 days. On 12 DAH, significant differences were observed between 2 and 4 days and 3 and 4 days initial feeding for all morphometric characters. From 16 DAH to the end of experiment, all growth variables of the larvae first-fed at 2 days were significantly higher than those in other treatments. The S(GR) (2-9 DAH) first-fed at 2 and 3 days were significantly higher than 4 and 5 day treatments, and the S(GR) (9-16 DAH) first-fed at 2 days was significantly higher than 3 and 4 day treatments. There was no significant difference, however, of S(GR) (16-28 DAH) among treatments. Survival rate was significantly higher at 2 days initial feeding (27.42%) when compared with 3 (15.96%) and 4 days (7.92%) initial feeding at the end of experiment. The present study suggests that the first feeding of S. scherzeri larvae should be initiated at 2 days after hatching for achieving good growth and survival.
authors.affiliation: College of Fishery, Huazhong Agricultural University, Wuhan, Hubei 430070, China.
authors.forename: L
authors.initials: L
authors.lastname: Zhang
authors.forename: Y J
authors.initials: YJ
authors.lastname: Wang
authors.forename: M H
authors.initials: MH
authors.lastname: Hu
authors.forename: Q X
authors.initials: QX
authors.lastname: Fan
authors.forename: S G
authors.initials: SG
authors.lastname: Chenung
authors.forename: P K S
authors.initials: PK
authors.lastname: Shin
authors.forename: H
authors.initials: H
authors.lastname: Li
authors.forename: L
authors.initials: L
authors.lastname: Cao
mesh_terms: D000818:Animals; D005248:Feeding Methods / Q000662:veterinary*; D005398:Fisheries / Q000379:methods*; D010473:Perciformes / Q000254:growth & development / Q000502:physiology*; D016019:Survival Analysis; D013997:Time Factors; D015017:Yolk Sac / Q000378:metabolism