Somatic condition and average catch size of the Mexican barred snapper Hoplopagrus guentherii in the northwestern Gulf of California

The present study aimed to understand the population dynamics of the Mexican barred snapper Hoplopagrus guentherii in Santa Rosalía, Gulf of California. This species is among the most economically important resources of artisanal fisheries. The size structure ranged from 28 cm (female) to 69 cm (male) total length. The weight-length relationship expressed with the equation W = a × Ltb for all specimens and by sex indicated isometric growth. There was a greater number of females than males. The gonadosomatic index showed two maturity peaks in April and June and two spawning periods in May and July. The hepatosomatic index decreased during spawning, reflecting the energy translocation, but the general condition of H. guentherii did not vary significantly during the year. The size at first capture was estimated to be 42.5 cm in total length, constituting basic information for the fisheries management of the species.