Reproductive variability of the common snook, Centropomus undecimalis, in environments of contrasting salinities interconnected by the Grijalva–Usumacinta fluvial system

Abstract

The common snook, Centropomus undecimalis, is a migratory euryhaline fish. In the southern Gulf of Mexico, fishing of large snooks occurs mainly in the marine environment (MA), while medium-size adults and juveniles are caught in freshwater environments (FW); however, large-size adults can also be found in FW far away from the sea, and the effect of different environments on their reproductive cycle is unknown. To describe the reproductive cycle of this species in different salinity habitats, we analyzed macroscopic reproductive characteristics during one annual cycle in FW and MA interconnected by the Grijalva–Usumacinta basin. Specimens with full-grown gonads and capable of spawning were found in FW, an unusual condition not reported for this habitat, but active spawning was observed only in MA. Centropomus undecimalis has a biological strategy that allows the use of FW as a juvenile until it reaches sexual maturity as a male and joins the reproductive stock in MA. Adults of both sexes can remain in both FW and MA without affecting their reproductive cycle, suggesting that those that mature in FW migrate to the sea during the spawning season.

Efecto de tres dietas en el cultivo experimental del róbalo (Centropomus undecimalis Bloch, 1792)

“…The results obtained in other studies (11,12) regarding length-weight relationship also suggest an isometric growth as values for this parameter were between b= 2.5 -3.5, indicating that the common snook increases proportionally in length and weight.…”

“…Además, dietas formuladas para especies dulceacuícolas no deberían utilizarse para peces marinos o estuarinos debido a las diferencias fisiológicas que existen entre ellos que hacen que, entre otros, los requerimientos de ácidos grasos sean distintos (9).Los resultados obtenidos por otros investigadores (11,12) para la relación LongitudPeso registraron un crecimiento isométrico, lo cual coincide con el presente estudio, al considerarse que las especies con crecimiento isométrico fluctúan entre los valores de b=2.5 common snook aquaculture, an experimental feeding based on live tilapia (Oreochromis niloticus) obtained acceptable growth results (0.50 g/day), which imply that this species has an interesting potential to be cultured (3). In the present study, the daily weight gain was of 0.65 g/day, which shows that growth can be improved by means of high quality feeding.…”

Temporal changes in the hydrology and nutrient concentrations of a large tropical river: Anthropogenic influence in the Lower Grijalva River, Mexico

“…Although C. undecimalis is still very common in the unregulated Usumacinta River, it is scarce in the Grijalva (Gómez‐González, Velázquez‐Velázquez, Anzueto‐Calvo, & Maza‐Cruz, ). Physical barriers, alteration of seasonal changes in flow that may have acted as cues to migrate, and the modification of river‐floodplain interactions due to dam construction have most likely negatively affected population numbers of snook in the Grijalva (Hernández‐Vidal, Chiappa‐Carrara, & Contreras‐Sánchez, ).…”

Seasonal variability of near-surface zooplankton community structure in the southern Gulf of Mexico

“…Monthly zooplankton samplings were collected from March 2011 to February 2012 near the influence of the González River, as part of the Grijalva-Usumacinta River system. Zooplankton was collected near the surface (2-3 m depth) from three sites in a spawning ground identified by local anglers and reported for two snook species: Centropomus undecimalis and Centropomus parallelus (Hernández-Vidal et al, 2014). These three sampling sites were located at: site A, 18°26'4.10"N, 92°59'47.60"W (7-8 m depth); site B, 18°26'59.16"N, 92°59'59.51"W (7.5-9 m depth); and site C, 18°27'30.71"N, 93°00'5.94"W (8-10 m depth) ( Fig.…”