The Israeli Journal of Aquaculture - Bamidgeh 55(4), 2003
The 7th Annual Dan Popper Symposium


GONAD MATURATION AND VITELLOGENESIS IN A MARINE
SHRIMP (LITOPENAEUS VANNAMEI ) GROWN IN
GEOTHERMAL BRACKISH WATER


Shmuel Parnes, Carmen Segall, Shaul Raviv, Dudu Azulay, Tal Goshen, Claytus Davis and Amir Sagi*

Department of Life Sciences and the Institute for Applied Biosciences, Ben Gurion University of the Negev, P.O.Box 653, Beer Sheva 84105, Israel


Abstract

A unique case of the full development of female gonads was discovered during a routine check of Litopenaeus vannamei shrimp broodstock grown in geothermal brackish water at a commercial shrimp farm in the Negev. The gonads of the female were vitellogenic, based on morphological and physiological examinations. Using PCR and specific vitellogenin primers, we found that the vitellogenin gene, which was partially sequenced in our laboratory, was expressed in the female. We therefore decided to probe the issues of gonad maturation and the timing of vitellogenin gene expression in this marine shrimp when it is grown in geothermal brackish water from the Negev in southern Israel. Female shrimp were sampled from the farm at various times. Vg gene expression was not detected in young previtellogenic females using the same set of primers, however, it was detected after the females reached a certain size and age threshold, without clear signs of secondary vitellogenesis. Older female shrimp that grew in brackish water (2-3 ppt) and were fed a commercial pelleted diet could be manipulated to start vitellogenic processes by transferring them to a marine-like environment (30 ppt, enriched diet). Most of these females developed a full vitellogenic ovary with clear expression of the vitellogenin gene in both the hepatopancreas and the ovary.

*email: sagia@bgumail.bgu.ac.il

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