Variation of the relationships between lengths and weights applied to 123 fish species observed at Réunion Island (Indian Ocean)
|Author(s)||Roos David1, Taconet Julien1, Gentil Claire1, Brisset Blandine1, Evano Hugues1, Aumond Yoann1, Huet J1, Lepetit C2, Boymond-Morales R2, Rungassamy T2, Elleboode Romain3, Mahé Kelig3|
|Affiliation(s)||1 : Ifremer, Délégation Océan Indien, Le Port, Réunion, France
2 : Réserve Naturelle Marine de La Réunion, Saint-Paul, Réunion, france
3 : Ifremer, Centre Manche-mer du Nord, Laboratoire Ressources Halieutiques, Boulogne-sur-Mer, France
|Source||African Journal Of Marine Science (1814-232X) (National Inquiry Services Center (NISC)), 2022-04 , Vol. 44 , N. 2 , P. 171-180|
|Keyword(s)||generalised linear model, gutted weight, L-W relationship, marine fish, sexual dimorphism, standard length, temporal effect|
Body length–weight (L–W) relationships of 123 fish species (122 Actinopterygii and 1 Elasmobranchii) were studied from 10 218 individuals caught around Réunion Island from 2000 to 2021. All species, except for 4 with a very small number of individuals and limited length range, showed a significant relationship between total length and total weight. For 52 species, the data showed the body becoming more elongated (i.e. b < 3.0) over their lifespan, while for 63 species the individuals became thicker (i.e. b > 3.0); only 4 species had a b-value equal to 3.0, signifying isometric growth. Of 72 species for which macroscopic observation allowed identification of sex, there was sexual dimorphism for only 9 species (12.5%), with a significant difference between the slopes of the length–weight relationships. Temporal effects were also investigated, using the annual component of time of capture for 75 species and the seasonal component for 73 species. A temporal effect was significant for 27 species (36.0%) when the sampling year was taken into account, and for 14 species (19.2%) when the sampling quarter (season) was taken into account. Finally, among 120 species tested, the relationship between total length and standard length was significant, and among 114 species the relationship between total weight and gutted (eviscerated) weight was significant.