Spottedblackgrouper are true groupers belonging to the family Serranidae, subfamily Epinephrine. Although commonly called ‘groper’ in New Zealand, the haiku (Poly prion oxygenate) and bass (P. Americans) are actually ‘wreck fishes’ belonging to the family Polyprionidae.
Spottedblackgrouper are only found in southeast Australia (Spencer Gulf to southern Queensland, excluding Tasmania), Elizabeth and Middleton Reefs, Lord Howe and Norfolk Islands, and northern New Zealand. In New Zealand the largest and possibly only breeding population is found in the Germanic Islands Marine Reserve.
Around mainland New Zealand spottedblackgrouper are relatively common on shallow reefs at Three Kings Islands and along Northland’s rocky east coast. Small juveniles have been recorded as far south as Dominika on the west coast, and Palmier Bay in the east.
Spottedblackgrouper inhabit rocky reefs in estuaries and on the open coast to at least 50 m depth. At the Germanic Islands small juvenile spottedblackgrouper are found in large intertidal rock pools as well as amongst boulders at 20 to 30 m depth.
Spottedblackgrouper appear to have had very little fishing pressure anywhere in New Zealand, however those in eastern Australia are considered to be heavily depleted by line, set net and spear fishers. Spottedblackgrouper are opportunistic predators of smaller reef fishes and crustaceans (shrimps, crabs and rock lobster).
Spottedblackgrouper are vulnerable to a variety of fishing methods due to their large size, territorial behavior and natural curiosity. Populations in eastern Australia are considered to be overfished and their estuaries nursery habitats are threatened by coastal development and pollution.
Spotted black groupers may suffer internal damage from hooks and over-expansion of their swim bladder if caught by accident. Like whales, large filter-feeding sharks and rays can accidentally ingest these, and all species suffer from entanglement in marine debris.
It is found off the coastline of southeastern Australia and northern New Zealand, generally inhabiting near-shore rock and coral reefs at depths down to 50 meters. Its main range comprises the southeast coastline of Australia, in the state of New South Wales ; New Zealand populations are suspected to be nonbreeding, so are a result of drifting larvae.
The species is a protogynous hermaphrodite, with individuals starting as females and changing to males at an estimated 100–110 cm in length and 29–30 years of age. Drastic but localized declines in saddle tail grouper stocks due to line fishing were first noted around heavily populated areas in the early 1900s.
However, in the 1950s, 1960s and 1970s, E. Amelia populations suffered a severe decline due to the rise in popularity of spear fishing. Due to the species' large size, slowness, curiosity, territorial habits, and use of inshore habitats, it was extremely vulnerable to spear fishing.
After more than two decades of severe spear fishing-driven decline, the New South Wales fishery department belatedly banned the spearing or taking of black cod in 1983, and subsequently listed the species as vulnerable under New South Wales fisheries legislation. Remarks on Fishes, with Descriptions of new Species in the British Museum, chiefly from Southern Seas.
Here at the Germanic Islands, one finds the fascinating spottedblackgrouper (Epimetheus Amelia) in sufficient numbers to guarantee an encounter. Miraculously, these impressive, intelligent and inquisitive fish have been spared their extinction, their fate almost everywhere else in the world, and regrettably also around the main islands of New Zealand.
Now they are fully protected, their human visitors behave in friendly ways, bringing a welcome change to the boredom of their fishy lives. In New Zealand known as spotted black groupers (Epimetheus Amelia) these large fish are limited to the subtropical waters of northern New Zealand, Three Kings Islands, Norfolk Island and the Pervades, eastern Australia, Elizabeth Reef and Middleton Reef, which amounts to a very small habitat area on the globe.
Groupers are usually found where the sandy bottom meets the rocky shore, and where a cave or sheltering canyon is nearby. Several times each day, they patrol their huge territories in search of easy prey, usually sick animals.
The spotted black groper has huge jaws with sharp conical teeth, suitable for holding prey animals. Like other groupers, this fish can change its coloring while you watch, from black to gray to brown to white and spotted with five clear oblique bands.
The other fish in the picture are Germanic (northern) Hawaii.f031607: White-lip is not at all afraid of people and sets the scene by sniffing at some food we brought. Living near Fishing Rock, these groupers are used to a long-lived tradition of being fed scraps and seeing people in the water.
His jaws are big and his teeth sharp, and it is rather daunting to give him an outstretched hand for a cuddle.f031703: White-lip has given a clear signal, and one of his females comes close for a good look.f031704: One lady of White-lip's harem is encouraged by his casual behavior, and decides to come in for the scraps of food offered. Striped made dart furiously around to pick at the crumbs.f031706: The female grouper turns out to be insistent on grabbing the plastic box, not afraid of a bit of a jostle with the diver.
More groupers appear on the scene.f031608: A large female allows herself to be stroked, not at all in a hurry to leave. Because visitors to Raoul are relatively rare, and snorkel divers rarer still, such encounters are not an everyday event, and both species have to get used to one another, which involves trust.f031701: Close-up of a large female which has just changed color.
He is easily identified by some white spots on his bottom lip and left gill cover, as these blemishes fail to change color.f031700: female groupers.f031709: A female grouper shows interest in the photographer's camera and quietly hangs stationary in front of him. At 40 cm still too young to join a large male, she looks entirely after herself.f031717: A snorkel diver has dived to meet one of the female groupers.f031718: The small grouper has mustered all her courage to allow skin contact with the much larger diver.
In return, the diver must have enough courage to approach her least sensitive spot: the dangerous mouth.f031719: Two young groupers have come to learn the ropes, but they are much more wary than the older ones.f031612: White-lip opens his formidable cheeks to suck up a morsel of food. So he came up from behind and gave the shutterbug a good thump with his lower jaw; then rubbed his large body all over the photographer's shoulder and neck.
The bottom of the lower jaw feels like a hard bony plate, which groupers apparently use for thumping. Realized he sought attention and I began stroking his massive body with coarse scales.
For good measure I dropped my camera on the 6 m deep sandy bottom. The females who watched all this, hurried closer in excitement, demanding their turns while also becoming mostly white. While I was kneeling on the sandy bottom and fanning the sand to study what it is made of, White-lip suddenly approached frontally.
Inhabit caves, gutters and crevices usually to depths of 50 m, although individuals have been collected from below 100 m. Juveniles are found inshore, often in coastal rock pools and estuaries. Black Rock cod are very territorial and individuals have relatively small home ranges.
Smaller individuals are regularly seen in caves and gutters around Lord Howe Island. Large individuals over a length of 50 cm have distinct canine teeth on both sides of the upper and lower jaws.
Grows to about 1.6 m and a weight of 81 kg in Australian waters, and to about 2 m in New Zealand. Highly variable, and able to rapidly change from a uniform dark grayish- black to a blotched or banded pattern.
Young fish usually have a distinct black spot or saddle on the upper tail base, and five sloping grayish to black bars which break up and fade towards the belly. Fish in estuaries are uniformly dark, whereas those on coastal reefs are usually banded.
Like many groupers (family Serranidae), the Black Rock cod is a protogynous hermaphrodite, meaning that individuals change sex from females to males during their life cycle. In New Zealand, females change sex at 100 to 110 cm in length.
Once common in New South Wales, including the Sydney region, the Black Rock cod was considered a valuable food fish. Declining numbers due to angling and spearfishing resulted in protection of the Black Rock cod.
It is illegal to sell the species in New South Wales. IUCN Red List: Near ThreatenedEPBC Act 1999: Vulnerable NSW: Vulnerable (NSW Fisheries Management Act 1994 – August 2013 list)In the past, Black Rock cod were heavily targeted by anglers and spearfishes, resulting in the decline of this specie sand its 1983 protection in New South Wales waters.
A recent study (Harass & Malcolm 2013) found that numbers of Black Rock cod remain low despite being protected for about 30 years in New South Wales. Roughley (1916) reported that “at one time it was fairly plentiful in the vicinity of Port Jackson, but has become very scarce in recent years, owing to the havoc wrought by fishermen…” Black Rock cod are secretive and usually retreat into caves and crevices when approached.
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Unpublished Report to the Northern Rivers Catchment Management Authority. Monitoring distribution and abundance of Black Cod (Epimetheus Amelia) within the Port Stephens-Great Lakes Marine Park (PSG LMP).
Final Report to NSW Department of Primary Industries and Hunter-Central Rivers Catchment Management Authority. NSW DPI (2011) Black Cod (Epimetheus Amelia) Recovery Plan.
Marine Surveys undertaken in the Elizabeth and Middleton Reefs Marine National Nature Reserve, December 2003. Report produced for Department of the Environment and Heritage.
Australian Institute of Marine Science, Townsville. Revision of the Indo-Pacific groupers: (Performed: Serranidae: Epinephrine): with descriptions of five new species.
A Field Guide to the Common Sea and Estuary Fishes of Non-tropical Australia. Van Heerlen L, Klan ten OS, Coat Jr, Jerry DR and Robbins WD (2009).
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Molecular Ecology and Evolutionary Laboratory, School of Marine and Tropical Biology, James Cook University, Townsville, Queensland. The Middleton and Elizabeth Reefs, South Pacific Ocean.