Effect of hatching time on larval mortality and survival of the prawnMacrobrachium idae

✍ Scribed by T. J. Pandian; S. Katre

• Book ID: 104733496
• Publisher: Springer-Verlag
• Year: 1972
• Tongue: English
• Weight: 726 KB
• Volume: 13
• Category: Article
• ISSN: 0025-3162
• DOI: 10.1007/bf00348081

✦ Synopsis

The prawn Macrobrachiura ~ ~rx.wrt oaxries 40 to 160 eggs depending upon the body size of the mother animal. After incubation, 63, 35 and 2 % eggs are batehed on the first, second and third hatching nights, respectively. Meau dry weight of a single larva released on the first night is 429 tag (equivalent to 2.86 cal). Larvae released on the seoond or third hatching nights weighed 380 ~g (-2.56 cal) or 30S (-2.02 cal). The total reserve yolk-energy available in a larva hatched on the first night is I oal. There is a definite sh~ from protein to fat metabolism as hatching is delayed. ~eO~ censumpt-ion of devoloping eggs awaiting release on or seoond hatching night is t.9 g//mg dry weight/h. In comparison to larvae released on the first night, those released on the second night exhibit 2 % inomase in total body-length and 2.4 or 14.3 % decrease in the lengths of the 6th abdominal segment or the orbit. Laxvae released on the first, second or third hatching nights, on exposure to starvation stress, su~vive for 3.8, 2.3 or 1.5 d~ys. The swimming speed of larvae released on the first or seoond night is L0 or 0.6 em/se~ Larvae released on the subsequent hat~hlng nights oornmitted nearly 2 times greater number of mist~es per em distance in the horizontal plane. Since hatching of all developing eggs simultaneously on the first hatching night is possa~ble by means of artifioial teehnique(s), it is possible to "improve" survival rate of decapod larvae.