General Ecology
Found from inshore to about 100 m in reef, mangrove, seagrass, and estuarine habitats (Sadovy and Eklund 1999).

Juveniles live in shallow bays, holes, below undercut ledges in swift tidal creeks draining mangrove swamp, rivers and estuaries while adults live around structures in, near, and offshore (Bullock et al. 1992, Gerber et al. 2005, Koenig et al. 2007). Juveniles exhibit high site fidelity to mangrove habitat for 5-6 years, then emigrate to offshore reefs at body length of about 1 m TL (Koenig et al. 2007).

Juvenile distribution in mangroves depends on local water quality, particularly dissolved oxygen content (>4 ppm) and mid-range salinities (>10 ppt) (www.bio.fsu.edu/coleman_lab/goliath_grouper.html, accessed on 31st Dec 2005).

During a survey of the freshwater fish of southern Florida from 1976 to 1983, no E. itajara was collected although the salinity-tolerant juveniles could be found in shallow, costal waters (Loftus and Kushlan 1987). In 181 sites, presence of mangrove areas appears to be important for juveniles (Sadovy and Eklund 1999). Koenig et al. (2007) demonstrated the high nursery value of mangrove to juveniles.

Diet
The species feeds on a wide diversity of fishes and invertebrates (Sadovy and Eklund 1999). It is a classic apex predator, large, rare and only a few individuals occur on any given reef unit (Huntsman et al. 1999)

Reproduction
Up to 100, sometimes more, individuals aggregate to spawn at specific times and locations. The aggregations last only a few weeks each year and represent most of the total annual reproductive effort (Sadovy and Eklund 1999). Its reproductive season occurs between June and December, with peak activity indicated from July through September in the eastern Gulf of Mexico (Bullock et al. 1992). The species is one of the few groupers that aggregate in relatively shallow (10-50 m) water (Coleman et al. 2002).

Possible courtship activities (without spawning) were observed on a wreck in the eastern Gulf of Mexico at 33 m depth in August 1990 (Colin 1994). Wrecks are often noted to be spawning areas for this species.

A study indicated that a 1,322 mm standard length (SL) and a 1,397 mm SL female had a batch fecundity of 38,922,168 ±1,518,283 and 56,599,306 ±1,866,130 oocytes, respectively (Bullock and Smith 1991).

According to a conceptual model for the role of dispersal in a simple life history model of E. itajara, such groupers exhibit a positive response to the establishment of a marine reserve. Apart from inducing an increase in population growth rate, implementation of a reserve could increase population recovery rates by increasing reproductive output (Gerber et al. 2005).

Age, growth and longevity
Epinephelus itajara grow slowly relative to their potential maximum size. Growth rates for male and female are similar, averaging >100 mm per year through age 6, then slowing to about 30 mm per year by age 15, and finally declining to <10 mm per year after age 25. Von Bertalanffy growth model was found to be TL (mm) = 206[1-e^{(-0.126(Age+0.49)}] (Bullock et al. 1992).

Maximum size and age recorded were 2,000-2,500 mm TL (Heemstra and Randall 1993), 37 years (female) and 26 years (male) (Bullock et al. 1992), respectively.