Hatching time effect on the intra‐spawning larval morphology and growth in Northern pike (Esox luciusL.) |
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| Authors: | Awatef Trabelsi Jean‐Noël Gardeur Fabrice Teletchea Jean Brun‐Bellut Pascal Fontaine |
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| Institution: | 1. Unité de Recherche Animal Fonctionnalités des Produits Animaux, Nancy‐Université INRA, , Vandoeuvre‐lès‐Nancy, France;2. Laboratoire d'Ecologie Animale et de Planctonologie, Département des Sciences de la Vie, Faculté des Sciences de Sfax, , Sfax, Tunisia |
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| Abstract: | Based on the analysis of 11 morphometric variables of body (total length, body area and perimeter, myotome height and eye diameter) and yolk sac (length, height, area, perimeter and volume) of pike larvae, the aim of this study was to evaluate how larval size at hatching and growth of larvae hatched from single egg batches vary according to three hatching times: early, mid and late. Hatching time structures strongly pike larval morphometrics. Early hatched larvae have smaller body sizes at hatch, faster growth and higher yolk use efficiency than late hatched ones. Early hatched larvae seem to be premature and hatch at precocious developmental stage whereas late hatched individuals continue their growth within the egg shell and hatch at larger size but with lower reserves (yolk). A compensatory growth phase was observed for the early hatching pike larvae particularly during the first 5 days post hatch. Consequently, no significant difference in body parameters was recorded from day 10 post hatching whatever the hatching time. The higher growth accomplished by early hatched larvae may be related to a particular metabolic activity that converts more efficiently yolk into body tissues. |
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| Keywords: | hatching time
Esox lucius
morphometry body yolk sac growth |
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