Length–weight relations of selected species of the family Gerreidae (Actinopterygii: Perciformes) from the Mexican coast

Abstract

Abstract. In this study, parameters of the length-weight relation (LWR) were estimated for fifteen species of Gerreidae (mojarras) caught from the Pacific-and Atlantic coast of Mexico, including the Gulf of California. The Pacific species were: Diapterus aureolus, Diapterus brevirostris, Eucinostomus currani, Eucinostomus dowii, Eucinostomus entomelas, Eucinostomus gracilis, Eugerres axillaris, Eugerres lineatus, and Gerres cinereus. The Atlantic species were: Diapterus auratus, Eucinostomus argenteus, Eucinostomus gula, Eucinostomus jonesi, Eucinostomus melanopterus, and Eugerres plumieri.The values of the exponent b of the length-weight relation ranged from 2.58 to 3.79. To the best of our knowledge, these are the first parameter estimates for nine species for the Mexican coast and for four on a worldwide scale.Keywords: fish, length-weight relation, Gerreidae, Mexico (CI) of the Centro Interdisciplinario de Ciencias Marinas in La Paz, Baja California Sur, Mexico. In the CI laboratory, total length (TL) to the nearest 1 mm and gross weight to the nearest 0.01 g, of all fish were measured. For the analysis of LWR, we excluded very small specimens (< 1.0 cm TL) in order to avoid unreasonable values for LWR parameters. The allometric equation W = aL b (see below) was fitted to the length-weight data. The a and b parameters of the model were estimated by the least-squares method applied to the log-transformed data according to the formula: In this study, 5052 specimens belonging to fifteen species of Gerreidae were analyzed. Sample size ranged from 17 for the striped mojarra (Eugerres plumieri) to 1956 for the dark-spot mojarra (Eucinostomus entomelas). All sample sizes (n), minimum and maximum length and weight, parameters of LWR (a and b), 95% confidence limits of b, and the coefficient of determination (r 2 ) by species, are presented in Table 1.According to Koutrakis and Tsikliras (2003), the parameter b varies between 2 and 4, but in the present study it ranged from a minimum of 2.58 for the Black axillary mojarra (Eugerres axillaris) to a maximum of 3.79 for the Irish mojarra (Diapterus auratus). These values can be considered within the expected range for fish (Froese 1998). The average value of b was 3.06; nearly 90% of b-values were between 2.5 and 3.2, with coefficients of determination (r 2 ) ≥ 0.94 in thirteen species. In consequence, current parameters can be used at least to derive weight estimates from a given value of length or vice versa, although limited to the size ranges used to estimate the parameters.Several artefacts and biological factors are known to affect fish LWR. The differences in the values of b have been attributed in other studies to several factors: sex, gonad maturity, growth phase, health, food availability, stomach fullness, season, water temperature, salinity, and even preservation techniques (Yığın and Ismen 2009, Robinson et al. 2010). Although we did not take any of these into account, in the present work these differences can also be attributed in part to the number of sp...

Length–weight relationships of four fish species from Fatala estuary, Guinea, West Africa

“…Therefore, our study provides a significant baseline study on the LWRs of four fish species from Fatala estuary. These results are useful for further studies or for other key parameters needed for fisheries management (De La Cruz Agüero et al, 2011; Fromentin & Fonteneau, 2001; Gonçalves et al, 1997; Moutopoulos & Stergiou, 2002; Saberi et al, 2017). The results presented here are reliable and can enrich length‐weight relationships and maximum lengths in FishBase (Froese & Pauly, 2021).…”

Untitled

“…We found that prediction of the length and weight of Gerreidae species based on sagittal length may be performed with an acceptable prediction error. Additionally, these models in combination with published length/mass relationships for mojarras (De La Cruz-Agüero et al 2011) can be used to estimate both the length and mass of ingested gerreids. Furthermore, these data improve our understanding of the potential role of gerreid fish in the trophic ecology of piscivorous species in the coastal areas of Mexico.…”

“…Fish of the family Gerreidae, known as mojarras or silver biddies, live in shallow coastal waters of tropical and sub-temperate regions, preferentially in areas with sandy and muddy bottoms, and often show a sympatric distribution (De La Cruz-Agüero et al 2011). In Mexico, although they are not exploited on a large scale, mojarras are a valuable resource among local fishermen as food or bait, with catches reaching approximately 1200 t per year (CONAPESCA 2012).…”

Length–weight relationships of 5 fish species from the Sine Saloum estuary, Senegal, West Africa

“…sex ratio, age of first maturity, fecundity, recruitment, natural and fishing mortality, growth patterns, estimation of biomass, population dynamics) to the required stock assessment for proper population management (Le Cren, 1951; Froese, 2006; Fromentin & Fonteneau, 2001; Hampton, 2000). They help to describe a specific population, to compare fish species populations or fish life histories between seasons, years, zones and regions, provided all investigators use the same standardized sampling methodology (De La Cruz Agüero et al., 2011; Gonçalves et al., 1997; Moutopoulos & Stergiou, 2002). In this study, we assessed length‐weight relationships for 5 fish species from the Sine Saloum estuary.…”