[ Recent molecular analyses based on five genes show that Cromileptes altivelis is included in the same clade as species of Epinephelus. Consequently, the species should be included in Epinephelus as Epinephelus altivelis.][ ]
Genetics
Genetic research has revealed the species to have missing genes relating to immunity and the MAPK signal pathway, which may affect the species' disease resistance and growth traits.
A hybrid grouper has been formed between this species and a closely related grouper, the giant grouper ( E. lanceolatus). The hybrid had 1.6x faster growth rate than the humpback grouper, 4.7% increased meat yield, yet was more morphologically similar to E. lanceolatus.
Distribution and habitat
It is widely distributed throughout the tropical waters of the central Indo-West Pacific region.
The humpback fish has a preferendum temperature of 24.5 C, similar to other cool, temperate, freshwater fishes.
Non-native distribution
In Florida, the grouper was first recorded to be observed in 1984, with the last recorded observation in 2012. Throughout Florida, it has been spotted in Tampa Bay, Pompano Beach, and West Beach.
The humpback grouper has a short history of being introduced in Hawaii, being first observed in 1991. It has since been Local extinction, with the last observation in 2005.
Description
The humpback grouper is a medium-sized fish which grows up to .
Relating to its coloration, the young are white with round black spots. The adults have a body colouration with variances of grey and beige, with darker blotches variable in size on the body. Small black spots cover the whole body. In comparison, juveniles have fewer of these black spots than adults, but the spots can be larger, or as large, as their eyes.
Biology and ecology
Life cycle and behaviour
This species is a protogynous hermaphrodite; in other words, all individuals are born female, with the ability to transform to males as they grow older. Female humpback groupers start transitioning to males as early as 3 years. By the age of 9, most humpback groupers are male.
Although primarily solitary, they are also known to swim in pairs, or sometimes in groups of 3–6. The purpose of these groups is unknown.
Compared to other closely related groupers, the humpback grouper has a slow growth rate, with female humpback groupers maturing around 1.5 years.
Cryopreservation has been tested with these humpback grouper embryos, with the survival rate of 7.55% and maximum time of viability being 5 days.
The humpback grouper's peak spawning time is between October and January,
Diet
The diet of this grouper is based on small and ,
Because of their carnivorous diet, C. altivepis has been commonly blamed for Ciguatera poisoning throughout their native and non-nonnative distribution.
Disease
With live fish markets potentially acting as a transmitter of disease, this species has been commonly blamed for ciguatera fish poisoning cases. Ciguatera fish poisoning comes from consuming a fish with , and the humpback grouper, amongst many other predatory fish, can easily accumulate ciguatoxins. Because of this, ciguatera 'hotspots' surrounding these markets have been a concern for human health.
The humpback grouper is also known to be able to carry many pathogens, including Hirudinea, Pasteurella, grouper iridoviruses, and more. Iridovirus is a leading cause of mortality in groupers kept in captivity, which causes lethargic swimming, darker body coloration, anemia, and more.
Conservation
The humpback grouper has been given the Data Deficient status by the IUCN. It is a highly valued food fish, especially in Southeast Asia where it is also overexploited. It is bred in aquaculture, but there is no evidence that captive breeding has reduced the fishing pressure on wild populations. Despite this, it is suspected that the population has declined historically.
Australia has put strong conservation measures in place for this species (no take species on the Great Barrier Reef and strict possession limits elsewhere, e.g. Western Australia). Size limits apply in commercial fisheries such as the Torres Strait reef line fishery.
Other potentially effective management techniques to preserve the humpback grouper would be implementing size limits, no-take areas, and increasing effort control.
Aquaculture
Although the mariculture of this species has been regarded to be in a primitive stage, the humpback grouper remains to be a popular fish in US aquariums, live fish markets throughout Asia,
Live fish markets
The humpback grouper is a popular fish amongst live fish markets, mainly throughout Asia, but more so in Hong Kong.
Hatchery-produced groupers are susceptible to having poorly functioning , causing juveniles to circle on the surface until death, with the mortality rate ranging from 20 to 30% from this condition.
Rearing
When collecting eggs from this species for aquaculture, buoyant eggs are selected, and are usually 0.80–0.83 mm in diameter. From the wild, juveniles are often chosen.
Socioeconomic effects
Grouper aquaculture has remained popular throughout Southeast Asia because of the accessibility of materials. In Bali, 'backyard' hatcheries contributed to economic development, with an increased profit compared to more traditional local agricultural paths such as coconut plantations.
Despite this, production is likely to remain low. Because of the slow growing humpback groupers, farmers are likely to mainly focus on faster growth fish.
External links
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http://www.marinespecies.org/aphia.php?p=taxdetails&id=218193
