REPRODUCTIVE BIOLOGY OF Trigla lucerna AND Trigloporus lastoviza IN THE EGYPTIAN MEDITERRANEAN WATERS

REPRODUCTIVE BIOLOGY OF Trigla lucerna AND Trigloporus lastoviza
IN THE EGYPTIAN MEDITERRANEAN WATERS
BY
M. ABDALLAH* AND S. N. FALTAS
*Nationallnstitute ofOceanography and Fisheries, Alexandria, Egypt.
Key words: Reproductive Biology, Trigla lucerna, Trigloporus lastoviza,
Mediterranean.
ABSTRACT
Study of reproductive biology of gumards Trigla’ lucerna,
Linnaeus 1758 and Trigloporus lastoviza (Brtinnich 1768) are based
on specimens caught by bottom trawlers operating in the Egyptian
Mediterranean waters, off Alexandria during the period extending
from October 1996 to Septelnber 1997. The results are summarized as
follows:
1- Sex ratio (Males: Females) was 1: 1.28 for T. lucerna and 1: 1.01
for T. lastoviza.
2- Size at first sexual maturity Vlas 15.6 cm for males & 17 em for
females of T. lucerna and 14.5 cm for males & 15.3 cm for
females of T. lastoviza.
3- Spawning season extended from December to April for both T.
lucerna and T. l’astov;za.
4- Ova diameter distribution revealed that both of T. lucerna and T.
lastoviza are fractional spawners.
5- The average fecundity estimates of T. lucerna ranged from 7078 to
121 700 eggs for the size range 16-30 cm while for T. lastoviza, it
varied between 3462 -and 26640 eggs for the size range 15-24 em.