Stud. Mar. 29(1): 7–20 UDC 597.541(262)) Biological characteristics of the round sardinella Sardinella aurita Valenciennes, () off the Lebanese coast Sharif JEMAA * , Myriam LTEIF , Celine MAHFOUZ , Anthony OUBA , Abed Al Rahman HASSOUN , Elissar GEMAYEL ,Gaby KHALAF . National Council for Scientifc Research, National Centre for Marine Sciences, P.B. Batroun, Liban. *E-mail: sharif.jemaa@cnrs.edu.lb ABSTRACT e present study investigates aspects of the biology of round sardinella, Sardinella aurita (Valenciennes, ) collected from Dora and Tripoli (Lebanon) between September and September . A total of specimens were collected from catches of purse seines and gillnets. Data on fsh total length (LT), total weight (WT), sex and maturity were obtained. e length–weight relationships showed positive allometry. An overall sex ratio was calculated to be F/M=.. e L were estimated to be . ± . cm and . ± . cm for males and females, respectively. Keywords: round sardinella; Levantine basin, life history, Mediterranean INTRODUCTION Small pelagic fshes represent about - of the total annual world fsheries catch (ICES ). Clupeidae are key species in the marine food chain and their presence is needed to maintain the balance of ecosystems (Smith et al. ). As plankton, they can exercise control over zooplankton abundance, control "top-down" or that of their own predators control "bottom-up" in different situations (Bakun ). For example, the collapses of populations of sardines and anchovies have been accompanied by declines in the amount of sea birds and marine mammals (Chavez et al. ). erefore, major changes in the abundance of these species may be accompanied by marked changes in the ecosystem structure (Alheit et al. ). Natural predation (mammals, seabirds, fsh) and fshing (artisanal inshore and offshore industry) are the main sources of mortality of adult individuals (Bacha et al. ). e GFCM (General Fisheries Commission for the Mediterranean) Working Group analyzed the variations of several small pelagic stocks across the Mediterranean in (GFCM ). Stock assessments of small pelagics in seven sub-regions in the Mediterranean show that most stocks are fully exploited and about are overfshed (Nieto et al. ).