Reproductive biology of the southern stingray Hypanus americanus (Hildebrand and Schroeder, 1928) and composition of batoid landings from Yucatán (México)

Despite its importance in some Caribbean artisanal fisheries, few published studies have examined the reproductive traits of the southern stingray, Hypanus americanus . In the present study, several traits are described based on a sample of 115 specimens from Yucatán (México), with disk width (DW) ranging from 40 to 113 cm for females (n = 72) and from 48 to 105 cm for males (n = 43). Oocytes of different sizes were recorded in the ovaries, and their quantity increased with female size. The gonadosomatic and hepatosomatic indices were higher from January to May, then decreased in the subsequent months. The sex ratio was estimated at 1:0.6 (females to males), and the histological examination of the reproductive organs showed 37 immature specimens (23 females and 14 males) and an average size at sexual maturity (L 50 ) of 59.12 cm DW for males and 68.54 cm DW for females. Additionally, the composition of batoids during two years of landings was analyzed from a local seafood distributor: landings were on average 205.3 ± 16.8 tons/year (97.14% of H. americanus, 2.61% of Styracura schmardae, and 0.25% of Aetobatus narinari). Based on the intermediate L 50 value for both sexes (64 cm DW) and the size-frequency distributions of H. americanus catches, 55.5% of female specimens in 2022 and 51.3% in 2023 were below this proposed minimum catch size; meanwhile, 34.8% of males in 2022 and 29.4% in 2023 were below this threshold, which it would be necessary to ensure that at least 55-60% of the specimens have reached sexual maturity upon capture for this species. This study underscores the need for further research on biological and fisheries data for H. americanus off the northern coast of the Yucatan Peninsula, given the limited information on its population dynamics and exploitation status.