In tropical regions, temperature is the fundamental environmental factor controlling the reproduction-related physiological activities of fish. Tropical fish are particularly sensitive to climate change since they develop in a relatively stable thermal environment. A review was done to assess the potential effect of temperature rise on reproduction and population structure in the commercially important hermaphrodite grouper and wrasse species, and in gonochoric snapper species in the southern Gulf of Mexico. Temperature increase can disturb the aromatase synthesis and/or activity, which can affect the reproductive cycle and sexual differentiation in all studied species and the sexual inversion process in sequential hermaphrodites. Moreover, a mistiming or discontinuity in spawning seasonality could occur, with an alteration in the sex ratio in favor of males and a consequent reduction in populations’ fecundity. Furthermore, if the level of fishing exploitation enhances species’ sensitivity to environmental changes, then the stock of red grouper Epinephelus morio would be more affected by temperature increases than other species because it is the only fish population in the Campeche Bank currently assessed as overexploited.

Snappers exhibit reproductive trait plasticity in response to habitat distribution. Lutjanus griseus is among the most economically important snappers in the western Central Atlantic but has received limited study in the region. Data on the reproductive biology of the L. griseus population were collected on the continental shelf of the Yucatan Peninsula, Mexico. Over a nineteen-month period, 1236 specimens were captured monthly in three Yucatan artisanal fishing fleet operational areas. Data were grouped by month to generate an annual analysis. Individual sex and maturation status were identified by gonad histology. Median size did not differ between females (33.2 cm fork length [FL]) and males (33.3 cm FL), and the sex ratio was balanced (F:M=0.98:1.00). Size at maturity was 24.2 cm FL for females (38% of maximum size reported for the species) and 22.8 cm FL for males (36% of maximum size), and the spawning season ran from May to September. The results confirm that this population exhibits the typical reproductive pattern of snappers distributed on continental shelves or in shallow water areas and provide critical data for stock assessment and implementation of management measures for L. griseus stock in the southern Gulf of Mexico.

Lane snapper Lutjanus synagris is an important species that supports both commercial and recreational fisheries. In the southern Gulf of Mexico, lane snapper is one of the snapper species with the highest annual catch volumes. Nevertheless, information on several life-history traits such as longevity, natural mortality and age at maturity is lacking, which are important for providing appropriate management options. From the total captured lane snapper (n = 1150), 367 were used to estimate the age-life history. Specimens were captured through the small-scale fleet of Yucatan from 2008 to 2009 in southern Gulf of Mexico with total lengths from 14.50–45.90 cm and whole weights from 0.05–1.10 kg. Thin otolith sections were used to determine the age of lane snapper. Left sagittae were embedded in clear epoxy resin, thin sectioned (300 µm thickness), and analyzed using a stereomicroscope, counting opaque zones (white) deposited annually during late spring to early summer. Estimated ages ranged from 0 ⁺ to 16 years for females (n = 189) and from 0 ⁺ to 15 years for males (n = 164). In the growth modeling process, three candidate models were fitted to improve the plausibility of growth estimates under conditions where both small/young and large/old individuals are poorly represented, and the observed length-at-age data show high variability. A Bayesian approach based on the Markov Chain Monte Carlo was used, with informative priors on the growth parameters. During model fitting, three‑parameter versions were used: k, L _∞ , and a third parameter based on length-at-birth, L ₀ ; among these, the last two parameters have the same interpretation across all models. The best growth model by sex was selected based on the Leave-one-out cross-validation technique. The von Bertalanffy growth model was the best-fitting model for growth in both females and males. Growth parameters for females were for maximum mean length or asymptotic length ( L _∞ ) = 32.21 cm total length; growth coefficient ( k ₁ ) = 0.27 year ^-1 ; size-at-age-zero ( L ₀ ) = 2.06 cm and for males L _∞ = 28.32 cm total length; k ₁ = 0.41 year ^-1 ; L ₀ = 2.03 cm. Natural mortality was estimated at 0.39 year ^-1 for females and 0.41 year ^-1 for males. Age at maturity in which 50% of the females and males have reached maturity was A ₅₀ = 3.11 years for females and 1.68 years for males. The reference points of the optimal size (L _opt ) and optimal age (A _opt ) to harvest the specimens to achieve maximum yield were 26.17 cm total length, 6.20 years for females and 21.24 cm total length, 3.38 years for males. These results on the age-based life history and growth of lane snapper are novel for the southern Gulf of Mexico population. This information forms the basis for developing appropriate management measures, as catch volumes and exploitation levels are steadily increasing.

Overexploitation is the main anthropogenic threat to groupers (Epinephelidae) that aggregate to spawn. Fishing negatively affects their reproductive success and indirectly harms fishery economic yield. In the southern Gulf of Mexico, grouper catches, which include thirteen species, are in decline. A lack of biological information on each exploited species prevents optimising fishery management. Using histological examination of the gonads, the reproductive traits of red hind Epinephelus guttatus and yellowfin grouper Mycteroperca venenosa were studied from January 2008 to October 2009. Collections were made at two reef systems (Alacranes Reef and Bajos del Norte) on the continental shelf of the Yucatan Peninsula, Mexico, where these species form transient spawning aggregations. The results confirmed that previously identified spawning aggregation sites at both reefs constitute productive seasonal and perennial “hotspots” for both groupers; they spawn annually between January and April. Females of these protogynous hermaphroditic species exhibit a reproductive strategy characterised by asynchronous ovarian development organisation and ovulation. Sex ratios and maximum sizes at each reef suggest that populations of both groupers had a good conservation status as of the late 2000s. Both reefs are now marine protected areas, and a discussion is made of the consequent possible benefits to grouper population conservation and sustainability in the southern Gulf of Mexico.