International Journal Of Biology and Biological Sciences Vol. 3(5), pp. 053-066, December 2014 ISSN 2327-3062 ©2014 Academe Research Journals

Full Length Research Paper

Energy storage and allocation of pearl oyster Pinctada radiata (Leach, 1814) in relation to timing of pearl seeding

Moussa R. M.¹*, ElSalhia M.² and Khalifa A.²

¹Aquaculture Division, Invertebrate Aquaculture Laboratory, National Institute of Oceanography and Fisheries, Alexandria, Egypt.

²Fisheries Division, Fish Physiology Laboratory, National Institute of Oceanography and Fisheries, Alexandria, Egypt.

*Corresponding author. E-mail: ragiamoussa@yahoo.com.au.  Tel: +201120020346, +2012 08 40 40 47.

Accepted 4 December, 2014

Abstract

Seasonal and monthly changes in biochemical components and condition indices of the gonadal-visceral mass (GVM), gill, mantle, and adductor muscle of pearl oyster Pinctada radiata were analyzed from May 2012 to May 2013 in Eastern Egyptian Mediterranean coast in relation to reproductive cycle to provide information about the suitable time for implantation surgery. Protein was the major structural part of GVM and adductor muscle which was utilized to supply energy for late gonad development and spawning. Glycogen in adductor muscle might be for meeting the energy demands for spawning and gonad rebuilding, while accumulated gill glycogen was considered a major energy source for spawning and maintenance. Energy requirements were met by proteins and glycogen to a greater extent as compared to lipid. Year could be divided into three phases: somatic growth and maintenance, gametogenesis, and spawning phase. High condition index (CI) and fatness values were observed in May and June, whereas the lowest were observed after spawning (August). Contrarily, the shell component index minimum value was recorded in May then it increased till it reached the maximum value in August. The suitable time for pearl implantation surgery was October as oysters would be more energetic.

Key words: Protein, lipid, glycogen, condition index, shell component index, fatness, pearl oyster Pinctada radiata.