Intraspecific morphological variation in shads, Dorosoma anale and D. petenense (Actinopterygii: Clupeiformes: Clupeidae), in the Mexican Grijalva and Usumacinta river basins

Abstract

Historical hydrological changes and the environmental characteristics of northern Middle America have promoted diversification and determined the distribution of fishes in the Grijalva and Usumacinta river basins of Mexico. In several taxa with wide distributions, cryptic diversity has been identified through molecular and morphological analyses. This study evaluated the intraspecific morphological variation of Dorosoma anale Meek, 1904 and Dorosoma petenense (Günther, 1867) along the Grijalva and Usumacinta river basins through geometric morphometric and linear biometric analyses. Little intraspecific differentiation was detected for either species. However, differences were identified between populations in the Grijalva basin and those from the upper Usumacinta River basins with respect to body height, head size, pelvic fin position, and anal fin size. The phenotypic expression of these attributes appears to be closely related to habitat type and geographic isolation. The morphological differences within D. petenense support the molecular hypothesis of two lineages existing in the Usumacinta River basin.

Primeros registros de un pez dorosomátido y de un parásito metazoario de peces en la laguna de Masaya, Nicaragua

“…Por ejemplo, sus congéneros Dorosoma petenense y Dorosoma anale presentan patrones linajes genético-moleculares en diferentes regiones de su rango (Elias et al 2022;Macossay-Cortez et al 2022). Las poblaciones de D. chavesi da cada cuerpo de agua que habita, ameritan comparación morfológica y molecular.…”

Niche overlap between sympatric cichlid species of the genus Rocio (Cichliformes: Cichlidae) in Guatemala

“…Variation within each species is reflected by the differences related to mouth positioning, head shape, and slight differences in fin positioning and the caudal peduncle. This is more evident in spec- show that intraspecific body shape variation is common (Ardón et al, 2022;Macossay-Cortez et al, 2022;McMahan et al, 2017) and might lead to understanding the kinds of habitats where those species are found (Aguilar-Contreras et al, 2021). However, the similarity in closely related species might lead to the perception that morphological similarity could be biased due to the inherent intraspecific variation, limiting any analysis that suggests a pattern similar to that of ecological character displacement (Elmer et al, 2010;Garita-Alvarado et al, 2021).…”