Justification:Mycteroperca rosacea is listed as Vulnerable because of its rather narrow range of occurrence and because of observational data that indicate a reduction in population abundance over the past 10 years of approximately 50% of the standing biomass. This reduction is due to intense subsistence, artisinal, and recreational fishing throughout the range of the species. Because the species is one of the most important fishes to the Gulf of California fisheries, there is no indication that this activity (cause for reduction) will cease and, thus the species warrants continued monitoring and further conservation action. As the species is long-lived and also aggregates to spawn, it is particularly vulnerable to overexploitation.

Mycteroperca rosacea is common throughout the Gulf of California. Mycteroperca rosacea is one of the most important fishes to the Gulf of California fisheries. Observational data indicate a reduction in population abundance over the past 10 years of approximately 50% of the standing biomass from intense subsistence, artisinal, and recreational fishing throughout the range of the species. There is no indication that this activity (cause for reduction) has ceased. Data have been provided by M. Buckhorn, J. Rupnow, and J. Torre.

GeneralMycteroperca rosacea is a reef-associated species that prefers rocky areas in shallow water at depths of about 50 m. The species is also found on seamounts (Buckhorn, M.L., pers. Comm.).

FeedingAdults feed on schools of the flatiron herring, Harengula thrissina, and anchoveta, Cetengraulis mysticetus when available; if not, on other schooling or non-schooling fishes. Most individuals feed at dawn and dusk, with a peak in activity about 20 minutes after sunset. Juveniles feed throughout the day on a variety of benthic fishes and crustaceans.

ReproductionIn Loreto, Mexico: Punta Lobos, on the northeast tip (specifically the north facing side of the point) is the “main” aggregation site (see Figure 1). This is considered the “main” site because the size classes and abundances are much higher than the other sites surveyed. Large (60 to 90 cm) leopard grouper on the south facing side have been recorded during the day but not in the afternoons. Surveys of Punta Lobos were conducted 2001, 2004, 2005, 2006. Spawning was observed directly in 2004 to 2006. El Bajo Tijeras is a large, flat sandy seamount to the south of Isla Carmen with a several shallow (45 to 60 ft. depth) rocky pinnacles. Surveys of these pinnacles, in 2001, recorded large leopard groupers in high abundances during the day at one pinnacle in particular. No dives were conducted in the afternoon so it was only presumed that spawning took place at that spot that year. Monitoring in subsequent years failed to record the same size classes and abundances there (COBI surveys) and at other nearby pinnacles. At Punta Coyote, just outside of Puerto Escondido, spawning has been observed directly in 2005 and 2006. Surveys conducted in 2006 recorded another large group (30 to 40 animals) of mature grouper (70 to 90 cm) at Danzante North Punta. Surveys were only conducted in the morning at this site but these grouper exhibited the same pre-courtship behaviour observed during morning surveys at Punta Lobos, so it is only presumed to be a spawning site at this time. (from M. Buckhorn, pers. Comm., University of California, Davis, 1 March 2007).

Follow the link below for Figure 1: Known spawning aggregation sites of Mycteroperca rosacea in the Gulf of California (courtesy of ML Buckhorn, University of California, Davis).

This species was previously listed as a protogynous hermaphrodite, however, upon further study this species is now known to be gonochoric (Erisman and Hastings, In press).

In Loreto, Mexico, Mycteroperca rosacea spawns from April through June. The species is an aggregate, broadcast spawner.

BiologyMaximum age thus far recorded is 17 years in a 69 cm male (see Figure 2 and Table 1).

Follow the link below for:

Figure 2: Age-length (total length, x-axis) relationship for Mycteroperca rosacea taken from the Gulf of California (courtesy of ML Buckhorn, unpublished data, University of California, Davis).

Table 1: Life history table of Mycteroperca rosacea from specimens collected in the Gulf of California (courtesy of ML Buckhorn, unpublished data, University of California, Davis).