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The Atlantic goliath grouper, Epinephelus itajara (Lichtenstein, 1822), is considered a critically endangered species. Since 2002, fishing, storage, transport, and marketing of E. itajara has been prohibited in Brazil. However, there are records of fishing of E. itajara in the Brazilian state of Para. This study recorded the illegal sale of E. itajara fillets in the municipality of Braganca, as well as fraud resulting from the substitution of one species for another. Through two distinct molecular procedures, 22 fillet samples sold as Atlantic goliath grouper were investigated. In total, 21 (95.5%) samples were confirmed as belonging to E. itajara and one was not. This demonstrates the weakness in the inspection process, which must be urgently adjusted, and it also revealed the need for a consistent, permanent, and effective program to raise awareness in the community of the damage caused by the illegal purchase and the need to preserve E. itajara.

The Atlantic goliath grouper, Epinephelus itajara (Lichtenstein, 1822), is considered a critically endangered species. In Brazil, the harvesting, transportation, and sale of E. itajara or it’s by products have been prohibited, but illegal harvesting still occurs. This study developed a simple, sensitive and accurate procedure for the safe identification of E. itajara by polymerase chain reaction (PCR). A specific primer (16S-RYOP4) was designed, synthesized and grouped with universal primers. The efficiency of specific amplification of the new set of primers was proven using samples of E. itajara, four species of epinephelids and five other species of fish marketed in northern Brazil. This procedure can be used to inspect products sold in stores, supermarkets and fairs, especially in places of reduced scientific, technological and economic development, where there is a record of illegal fishing and selling of E. itajara.

We evaluated Atlantic Goliath Groupers, Epinephelus itajara, in their nursery habitats via microchemical analyses of fin rays. Juveniles were sampled from known nursery habitats off southwest Florida, and adults were primarily sampled from a spawning aggregation off southeast, Florida. We collected fin rays using a non-lethal technique that is minimally invasive with no known negative effects on growth or survival. Trace metal constituents in the fin rays were quantified with an inductively coupled plasma mass spectrometer via laser ablation (LA-ICP-MS). Two spatial scales were quantified to test the limitations of grouping individuals based on elemental compositions. On a small spatial scale (i.e., 100s of m), individuals were correctly classified within individual watersheds 64% of the time. On a larger spatial scale (i.e., 10s–100s of km), juveniles were classified with 100% accuracy. Trace metals in adults were analyzed by back-tracking across fin ray annuli to a year in which our previous studies have shown these adults occupied their juvenile habitats (i.e., 2006). These fish were grouped using a measure of dissimilarity and then analyzed to test whether we could reclassify them into these same groupings based solely on the chemical components in their fin rays, which was done with over 84% accuracy. Although juvenile habitats of the adults could not be determined due to the lack of baseline data, classifications were driven by similar elements to those that drove the classification of juveniles, suggesting similar physiological mechanisms. The results highlight the importance of spatial scale for interpreting microchemical analyses on calcified structures in fishes.

Goliath grouper Epinephelus itajara suffered significant overfishing in the United States until they were protected from harvest in 1990. As the population recovers, interactions between Goliath grouper and anglers have increased, and are often reported to management agencies as complaints after grouper predation upon hooked fish. Goliath grouper are generally characterized as opportunistic predators capable of consuming a wide variety of prey types; however, minimal data are available regarding the prey capture behavior of this species. Kinematic analyses of adult Goliath grouper feeding events demonstrated the capacity of individuals to modulate feeding behavior based upon the mobility and position of ‘prey’ items. Mobile epibenthic food (tethered swimming fish) elicited larger maximum gapes, faster times to food capture, shorter times to mouth closing, and more rapid total bite durations than food items that were not moving (cut dead bait). Feeding sequences involving mobile food items were characterized by a significantly higher degree of ram feeding behavior, while immobile food elicited primarily suction feeding and were preceded by a slower and closer approach to the food item prior to the onset of mouth opening. The findings are discussed in light of predation upon angled species and demonstrate the ability of Goliath grouper to adjust their feeding strategy based upon prey type and condition. This behavior likely allows for the exploitation of a wide variety of prey and provides an expansive dietary breadth for these opportunistic predators.

The concentrations of mercury, lead, cadmium, and arsenic were evaluated in 96 samples, 12 by each one of the following eight fish species: snook (Centropomus undecimalis), crevalle jack (Caranx hippos), Serra Spanish mackerel (Scomberomorus brasiliensis), southern red snapper (Lutjanus purpureus), blue runner (Caranx crysos), Atlantic tarpon (Megalops atlanticus), ladyfish (Elops saurus), and Atlantic goliath grouper (Epinephelus itajara), which were collected during 1 year in the Atrato River Delta in the Gulf of Uraba, Colombian Caribbean. Three fish were caught from each of the following sites the community usually uses to catch them (known as fishing grounds): Bahia Candelaria, Bahia Marirrio, Bocas del Roto, and Bocas del Atrato. The quantification of metals was performed by microwave-induced plasma-optical emission spectrometry. The Pb concentration fluctuated from 0.672 to 3.110 mg kg−1, surpassing the maximum permissible limit (MPL = 0.3 mg kg−1) for human consumption for all species. The Hg concentration ranged between < Limit of detection and 6.303 mg kg−1, and in the crevalle jack and Atlantic tarpon, concentrations exceeded the MPL (0.5 mg kg−1). The levels of Cd and As were not significant in the studied species and did not exceed the MPL (0.05 mg kg−1).

While juvenile Atlantic goliath grouper, Epinephelus itajara (Lichtenstein, 1822), are known to depend on mangrove root structure, relationships with water properties (e.g., salinity) and depth remain unclear or understudied. Because availability of suitable mangrove habitat has been suggested as the primary bottleneck to the recovery of this threatened species in the US, we investigated habitat associations of juvenile Atlantic goliath grouper with respect to physical water properties within mangrove habitats. Our study was conducted in six coastal rivers and three canals within the Ten Thousand Islands region of southwest Florida. Results suggested that juvenile Atlantic goliath grouper differed in how they associated with specific mangrove habitats based on season and size. We found that smaller juveniles ( 3 mg L−1) within mangrove habitat. For small juveniles, extreme temperatures influenced habitat association; for large juveniles, extreme salinity influenced distribution. We also found evidence that juvenile Atlantic goliath grouper associated more with natural rivers over man-made canals. The present study has utility for delineating suitable mangrove habitats for protection and potentially in the design of sampling surveys that aim to estimate population abundance.

We isolated 40 microsatellite markers for the endangered Atlantic, and Pacific goliath grouper, Epinephelus itajara and E. quinquefasciatus. Loci were characterized using samples of E. itajara (n = 52) and E. quinquefasciatus (n = 10). Twenty-nine loci were polymorphic. For E. itajara and E. quinquefasciatus, respectively, mean numbers of alleles per locus were 5.2 and 4.3 and mean observed heterozygosities were 0.46 and 0.63. Three loci departed from Hardy–Weinberg equilibrium expectations in the E. itajara sample. Allele frequencies differed significantly between the two taxa for each polymorphic locus.

The EPIC strategy was used in the present study in order to develop molecular markers for Epinephelus itajara. Twelve primers were designed for six genomic regions. The results of the study provide a number of appropriate new nuclear DNA markers for future genetic studies in several endangered/overexploited grouper species. The description of these markers will also expand the number of molecular tools available for the reconstruction of the life history of the different grouper species, in particular those in urgent need of effective protection measures.