Morphometric Growth Patterns and Seasonal Variations in Mass of Cymbium glans (Gmelin, 1791) in the EEZ of Côte d’Ivoire
Diomandé LOUA *
University of San Pedro, Marine Sciences Training and Research Unit, San Pedro, BP1800 San Pedro, Côte d'Ivoire.
Abdoulaye KONE
University of San Pedro, Marine Sciences Training and Research Unit, San Pedro, BP1800 San Pedro, Côte d'Ivoire.
Christian Bernard TIA
University of San Pedro, Marine Sciences Training and Research Unit, San Pedro, BP1800 San Pedro, Côte d'Ivoire.
Atcho OTCHOUMOU
Université Nangui Abrogoua, Animal Biology and Cytology Laboratory, Abidjan, 02 BP 801Abidjan, Côte d’Ivoire.
*Author to whom correspondence should be addressed.
Abstract
Cymbium glans is an increasingly important fishery resource in Côte d'Ivoire, although it is mainly exploited as a by-catch by trawlers. However, biological data on this species are still limited, particularly with regard to its growth and seasonal variations in biomass. The aim of this study is to analyse the relative growth and seasonal variation in the mass of C. glans in the Côte d'Ivoire Exclusive Economic Zone. In this study 361 specimens were collected monthly from January 2018 to December 2018 in order to measure the morphometric dimensions and mass of individuals. Allometric relationships between length, width, shell height and mass were studied using logarithmic regression models. The results reveal negative allometric growth in width and height relative to length, reflecting a more elongated shell shape as size increases. In addition, a significant increase in mass was observed during the warm season, probably linked to better food availability and environmental conditions favourable to the accumulation of energy reserves. These results contribute to a better understanding of the growth mechanisms of C. glans in the wild.
Keywords: Cymbium glans, relative growth, seasonal variation, fisheries management