Feeding habits of the leopard grouper, Mycteroperca rosacea (Actinopterygii: Perciformes: Epinephelidae), in the central Gulf of California, BCS, Mexico

Abstract

Background. The leopard grouper, Mycteroperca rosacea (Streets, 1877), is endemic to northwestern Mexico and has high commercial value. Although facts of its basic biology are known, information on its trophic ecology, in particular, is scarce. The objective of the presently reported study was to characterize the feeding habits of M. rosacea through the analysis of stomach contents, and to determine possible variations linked to sex (male or female), size (small, medium, or large), or season (spring, summer, autumn, or winter), in order to understand the trophic role that this species plays in the ecosystem where it is found. Materials and methods. Fish were captured monthly, from March 2014 to May 2015 by spearfishing in Santa Rosalía, BCS, Mexico. Percentages by the number, by weight, and frequency of appearance of each food category, the index of relative importance (%IRI), and prey-specific index of relative importance (%PSIRI) were used to determine the importance of each prey item in the leopard grouper diet. Diet breadth was calculated using Levin's index. Possible differences in the diet by sex, size, or season were identified through a multivariate PERMANOVA analysis. Results. A total of 341 leopard grouper specimens were collected, 309 of which had stomachs containing food. A total of 28 prey species were identified. According to the %IRI, the contribution to the diet of the coastal pelagic prey Nyctiphanes simplex and Sardinops sagax (Jenyns, 1842) was 87%, whereas according to the %PSIRI the contribution to the diet of those two prey species was 57%, in addition to several demersal prey species. A PERMANOVA analysis indicated that there were significant differences in the diet of leopard grouper by sex, size, and season, but the interactions sex-size, sex-season, size-season, and sex-size-season, were not significant. Conclusions. Mycteroperca rosacea was identified as a carnivorous predator with narrow trophic width, with significant differences in diet according to the sex, size, season, and size-sex interactions, which could be the result of different energetic requirements, hunting abilities, and food availability. The %PSIRI turned out to be the most adequate index to determine the feeding habits of fish, as it provides a better mean value to determine the most important prey.

Feeding Habits of Sarda chiliensis chiliensis (Cuvier, 1832) in Northern Chile and Southern Perú

“…First, we can observe that on a 100% percentage scale, especially with respect to the IRI suggested by Pinkas et al [ 37 ] and modified by Hacunda [ 61 ], the significance of each prey item with respect to the stomachs that presented content is highlighted [ 62 ].…”

Reduced fish diversity despite increased fish biomass in a Gulf of California Marine Protected Area

“…Although IUCN has classified this species as ''Least Concern'' (Erisman & Craig, 2018), a decline in abundance has been reported from over a decade ago (Sala et al, 2004) because it is one of the most intensely fished groupers in the GC (Sala et al, 2003;TinHan et al, 2014). Given the key ecological role of the leopard grouper in reef ecosystems as a high level carnivore (in adult stages over 36.5 cm TL; Moreno-Sanchez et al, 2019), and its economic importance by representing a high proportion of the annual fishing revenue (78% in combination with snappers; TinHan et al, 2014), enhanced protection strategies are needed for stabilization and recovery of population numbers within the region.…”

Hábitos alimenticios de Caranx vinctus (Perciformes: Carangidae), especie de importancia comercial en la bahía de Acapulco, Guerrero, México

“…El índice de importancia relativa (IIR) (Pinkas, Oliphant, & Iverson, 1971) es uno de los índices más utilizados para determinar hábitos alimentarios de una especie, sin embargo en la actualidad se sabe que este índice conlleva desaciertos matemáticos y metodológicos, que pueden derivar en una interpretación errónea de los resultados. En atención a dicha problemática Brown et al (2012), propusieron el uso del índice de importancia relativa específico de las presas (% PSIRI), mismo que pondera la importancia de cada artículo alimentario únicamente entre los organismos en que se presentó, de esta forma se obtiene mayor precisión de la dieta y se evitan sesgos de sobre o subestimación de presas, contrario a lo que ocurre cuando se opta por el % IIR, ya que pondera la importancia de cada presa con respecto a los estómagos que presentaron contenido (Moreno-Sánchez, et al, 2019).…”

“…Estas curvas se construyeron a partir del valor del índice de diversidad de Shannon-Wiener (H') y el número de estómagos. Dentro del cálculo de las curvas, un coeficiente de variación (CV) igual o inferior a 5 % (0.05) indicó que el número de estómagos fue el adecuado para representar la dieta de acuerdo a trabajos publicados (Jiménez-Valverde & Hortal, 2003;Moreno-Sánchez et al, 2019).…”