Length at Maturity, Sex Ratio, and Proportions of Maturity of the Giant Electric Ray, Narcine entemedor, in Its Septentrional Distribution

Abstract

The size at which a certain fraction of a fish population reaches sexual maturity is an important parameter of life history. The estimation of this parameter based on logistic or sigmoid models could provide different ogives and values of length at maturity, which must be analyzed and considered as a basic feature of biological reproduction for the species. A total of 305 individuals of Narcine entemedor (N. entemedor) were obtained from artisanal fisheries in the Bahía de La Paz, Mexico. For the organisms sampled, sexes were determined and total length (TL) in cm was measured from October 2013 to December 2015. The results indicated that the females were larger, ranging from 48.5 cm to 84 cm TL, while males varied from 41.5 cm to 58.5 cm TL. The sex ratio was dominated by males ranging from 45–55 cm TL, while females were more abundant from 60 to 85 cm TL. Mature females were present all year long, exhibiting a continuous annual reproductive cycle. The length at maturity data were described by the Gompertz model with value of 55.87 cm TL. The comparison between models, and the model selection between them, showed that the Gompertz model had maximum likelihood and smaller Akaike information criterion, indicating that this model was a better fit to the maturity proportion data of N. entemedor.

Size at sexual maturity, seasonal variation by maturity stages, and fecundity of the spotted round ray (Urobatis maculatus) and the thorny stingray (Urotrygon rogersi) from the northern tropical eastern Pacific

“…The use of a multi‐model approach and inference assures that the observed results are more reliable than those obtained in previous studies (Alvarez‐Fuentes et al, 2023; García‐Rodríguez et al, 2020; Katsanevakis, 2014). In some species of elasmobranchs, such as Atlantic sharpnose shark Rhizoprionodon terraenovae (Richardson, 1836), bat eagle ray Myliobatis californica Gill 1865, giant electric ray Narcine entemedor Jordan & Starks, 1895, and blotched stingray Urotrygon chilensis (Günther, 1872), the multi‐model approach and inference have also been used to estimate size at sexual maturity (Alvarez‐Fuentes et al, 2023; García‐Rodríguez et al, 2020; Oviedo‐Pérez et al, 2014; Pérez‐Palafox et al, 2022).…”

“…Fuentes et al, 2023;García-Rodríguez et al, 2020;Oviedo-Pérez et al, 2014;Pérez-Palafox et al, 2022).…”

Back to the basics: Neuroendocrine control of reproduction

“…Sexual maturation in fish denotes the developmental phase in their life cycle during which they acquire the ability to reproduce (Sabraha et al, 2017; Palafox et al, 2022) [17,13] . The growth of gonads and the ability to produce viable gametes (sperm and eggs) are important components of their reproductive system.…”

“…The measurement of this distance is a crucial factor in establishing laws on fishing techniques in order to guarantee the sustainable utilization of resources. Sexual maturity is influenced by factors such as age, rate of growth, and hormonal fluctuations (Palafox et al, 2022) [13] . Scientists frequently examine the physiological and morphological alterations linked to sexual maturity in order to gain insights into the reproductive biology of various fish species.…”