Seasonal variation of reproductive traits of the caramote prawn in the Gulf of Tunis

Abstract

The caramote prawn, Melicertus kerathurus, is a Penaeidae species inhabiting the Mediterranean Sea and the Est Atlantic Ocean. Caramote prawn represents a commercially important species in terms of both aquaculture and fishing; however, there is poor information on its reproductive biology in Mediterranean and, particularly, in Tunisian waters. To fulfil such a gap, monthly samples of caramote prawn were collected along the northern Tunisian coast throughout one year. Ovaries maturity data, obtained by histological analysis, together with reproductive and condition indices, indicated the main spawning season extends from April to August, with a clear peak in July-August. However, gonadic production still persists during September-December, although at lower levels. The seasonal patterns of somatic and gonadic conditions suggested that energy reserves, during the main spawning period, were invested both in gonadic and body production; but males and females appeared to devote differently such energy reserves. During the spawning peak, females revealed both good somatic and gonadic conditions simultaneously, while males displayed worse body conditions. Monthly sea surface temperature (SST) showed a high level of pattern correspondence with ovary maturity phase and gonadosomatic index (GSI); but a strong linear relationship between SST and GSI in the study area was observed only for males. Such results increased reproductive biology knowledge, therefore allowing to improve the management quality of both wild caramote prawn stocks and reared populations.

Marine ecosystems and living resources in the Central Mediterranean Sea: an introduction

“…Several documents on life histories of the most important small pelagic and demersal resources have been published (e.g., Ben Meriem, 1993Meriem, , 1995Ben Meriem et al, 1995;Levi et al, 2003;Basilone et al, 2004Basilone et al, , 2006Basilone et al, , 2013Rjeibi et al, 2010;Garofalo et al, 2010;Bonanno et al, 2013Bonanno et al, , 2014bBonanno et al, , 2015Khoufi et al, 2014, Jaziri et al, 2015Lauria et al, 2016), pointing out, inter alia, a great variability depending on the habitat conditions. Information on biological parameters represents fundamental aspects for the proper understanding of population dynamics and for the application of the ecosystem approach to sustainable exploitation of marine resources.…”

“…Both the permanent and non-permanent character of the recognized physical features of the Central Mediterranean, as well as its degree of variability, have been studied (e.g., Olita et al, 2007;Gasparini et al, 2008;Drago et al, 2010;Placenti et al, 2013;Ben Ismail et al, 2014;Bonanno et al, 2014a;Jouini et al, 2016). Some studies singled out the influences of environmental variability on the biological resources in the Central Mediterranean (e.g., Levi et al, 2003;Garofalo et al, 2010;Rjeibi et al, 2010;Basilone et al, 2013Basilone et al, , 2015Basilone et al, , 2017Bonanno et al, 2013Bonanno et al, , 2014bBonanno et al, , 2015Fiorentino et al, 2013;Khoufi et al, 2014;Barra et al, 2015;Jaziri et al, 2015;Lauria et al, 2016;Gargano et al, 2017). However, only part of the main features affecting the ecosystems and living resources in the Central Mediterranean has been fully understood.…”