Nocturnal & Cave Dwellers

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Most nocturnal and cave dwelling fish, such as squirrel and soldier fish, generally feed at night. However, other species, such as the scorpionfish live in crevices in the reef, but do not necessarily wait until nightfall to feed. Apogonids often live in caves, or hide in coral branches during the day.

Some common nocturnal & cave dwellers

Moray eel and banded coral shrimp

Moray eels

Family Muraenidae

Moray eels are normally encountered with their heads sticking out from under a ledge or cave. They have long bodies and lack any pectoral or pelvic fins. Although morays have an aggressive appearance, constantly opening and closing their mouths, they are simply pumping water in through the mouth and out through a small opening on the side of the neck. Eels like all fish, must extract oxygen from water to breath. Most morays have long canine teeth for grabbing fish and octopus which are swallowed whole. In addition, they have teeth in the middle of their throat that also help prevent prey from escaping. A number of small morays have short conical teeth used to crush crustaceans. The tube-like extensions on the nostrils of moray eels provide great sensitivity to scent in the water. The largest species of moray eel is the Giant Moray which may reach lengths of 2.2 metres. Moray eels should not be eaten as they carry a disease called ciguatera.

Whitetip soldierfish

Squirrelfish & soldierfish

Family Holocentridae

Squirrelfish and soldierfish are relatively deep-bodied fish with large eyes and mouths, large, coarse scales, prominent fin spines and a red colouration. Mostly nocturnal, these fish tend to hide in caves or under ledges during the day, coming out at night to forage for fish and crustaceans. Their red colour is ideal for a nocturnal species. Since red is the first colour to be absorbed by water, red fish are practically invisible at night. Squirrelfish and soldierfish are very ancient fish dating back over 50 million years. The heavy spines over their head are considered a primitive feature among fish. Squirrelfish have a large venomous spine at the back of each cheek capable of causing a painful sting.

Scorpionfish, lionfish & stonefish

Family Scorpaenidae

Firefish: Family Scorpaenidae

Like scorpions, this group of fish are armed with venomous spines and give powerful stings. The dorsal fin consists of 7-18 venomous spines. Other characteristics of this group include a bony ridge across the cheek and a large head covered in short spines.

The stonefish has an unlucky number of 13 spines. There is no active method of delivering the venom. Stonefish have a large oblong gland at the base of each spine, and pressure has to be applied for venom to be discharged through a duct in the spine.

Lionfish do not have a venom duct in their spine and the venom is less powerful than the stonefish. Unlike other scorpionfish, the lionfish is an active predator, stalking prey at night and living under ledges and in caves during the day.

Most scorpionfish are well-camouflaged bottom-living predators dwelling in caves and crevices, waiting to ambush small fish and crustaceans. Scorpionfish engulf their prey with lightning speed. They have been timed engulfing prey in just 1/100^th of a second.

The venom of the scorpionfish is denatured by heat. Placing a limb in hot water [NOT BOILING] will relieve pain.

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