Spawning period and ontogenic stages of some teleost species in the Lebanese seawaters.

Sami Lakkis ⁽¹⁾⁽²⁾ and Raymonde Zeidane ^(2)
(1)Faculty of Sciences, Lebanese University, Beirut, Lebanon.
⁽²⁾ Laboratory of Marine Ecology & Plankton, NCMS/LNCSR
P.O.Box 138, Byblos-Jbeil Lebanon; e-mail:slakkis@inco.com.lb

Abstract

Amongst the 300 species of Teleost fishes inhabiting the Levantine Basin, including 59 lessepsian migrants of indo-Pacific origin, 95 types of eggs and larvae were identified from the Lebanese seawaters. From those a dozen of species are not mentioned as adult stages in the area. The major group species contributing to the abundance of ichtyoplankton are: larvae of Coris julis, Engraulis encrasicolis, and eggs of Sparidae and Serranidae. The best known ontogenic stages of lessepsian migrants are: Siganus rivulatus, Sargocentrum rubrumand Stephanolepis diaspros. Spawning period of the majority of fish species is situated between March and November, with a peak from May and September. In winter (December, January,February) Ichtyoplankton is poor in eggs. The average size of eggs in the Levantine Basin is smaller than that of the western basin; while the spawning period of most of the species is at least one month earlier than that of the western Mediterranean. The development stages of several fish species is still unknown either from experimental study and from field work. Complete ontogenic stages from hatching till juvenile stage of only 30% of the adult species is known; as for the embryonic and larval development stages of the majority of species need to be studied particularly for the exotic and lessepsian species in the Levantine Basin.