Student Stuff

Red Indianfish
Pataecus fronto Richardson, 1844

Red Indianfish and sponge. View larger image.

Common name

Red Indianfish

Scientific name

Pataecus fronto
Pataeco - A dwarf-like Phoenician god (Greek). Refers to the likeness of this species to the images of gods on the bows of ancient sailing vessels.
fronto - brow, fore part of anything (Latin). Refers to the high first dorsal fin.

Family name

Pataecidae
Pataeco - A dwarf-like Phoenician god (Greek)
idae - suffix meaning that this a family name. All animal family names end in -idae.

Size

The Red Indianfish reaches a maximum length of 35cm.

Number of species

Fishes of the family Pataecidae are collectively known as prowfishes. This is one of the few families that is endemic to (only found in) Australia. Three species are known; the Red Indianfish, Pataecus fronto, the Warty Prowfish, Aetapcus maculatus, and the Whiskered Prowfish, Neopataecus waterhousii. The Red Indianfish is the only species in the genus Pataecus.

The Red Indianfish is related to the Scorpionfishes, family Scorpaenidae.

Distribution

The Red Indianfish occurs in temperate and subtropical coastal marine waters from Moreton Bay, Queensland, 27^o25'S to Durras, NSW, 35^o10'S, and from South Australia to Shark Bay, Western Australia, 25^o21'S.

Red Indianfish photographed at Bare Island, La Perouse, NSW.

Habitat requirements

Red Indianfish are found primarily in sponge beds, in rocky reefs and estuaries. The species is reported to live in water of 20-80m depth, however, the fish in the images on this page was photographed in only 10m of water. They are sometimes accidentally captured in commercial trawl nets, but are of no commercial importance.

Structural, physiological and behavioural adaptations

The Red Indian fish is an uncommon species with a compressed body and a long-based dorsal fin. It is known to periodically shed its skin in one complete piece. This rids the fish of the encrusting algae and bryozoans that grow on the fish's skin and improve its camouflage. Little is known of the biology of this species. View an x-ray image of the skeleton of a Red Indianfish.

Red Indianfish modified from McCulloch, 1934.

Dorsal fin

The common name of the Red Indianfish comes from the long dorsal fin which resembles the popular image of a native North American chief's headdress. The dorsal fin stretches the entire length of the body, and comprises an elevated spiny section joined with a lower, soft-rayed section. This is in turn joined to the caudal (tail) fin.

View movie showing a White Ear (view fact sheet) biting the dorsal fin of a Red Indianfish. View a low resolution movie clip (122k) of this species swimming. Go to the movies page for high and low resolution versions.

Colouration

Red Indianfish are often scarlet, brick red or orange. Occasionally they may be pale (view image) or have black and/or white spots, mainly on the upper half of the fish. This colouration, combined with the distinctive shape of the fish, results in this species being camouflaged near sponges (see below).

A Red Indianfish blending in with a sponge.

Sponge mimicry

Red Indianfish are often found associated with the sponges that they resemble. Divers also observe them on cracks in reef walls and lying on bare rocky bottoms. In all cases, the fish is very sedentary and looks sponge-like. Red Indianfish are an underwater photographers' delight because, unlike most fishes, they do not swim off when discovered, but stay motionless during the photographic session.

The Red Indianfish has also been observed to rock back and forth with the surge of passing waves. This also helps to make the fish look less "fish-like".

A Red Indianfish in a crack on a reef wall.

Swimming

Red Indianfish have an unusual swimming "style". If a Red Indianfish is removed from a sponge and released above the bottom it will twist and fall and spin back to its position on the sponge. Whilst it is doing so, it resembles a large dead leaf sinking through the water. The remarkable thing about this behaviour is that the fish is in complete control of the "fall", and can "fall" against a current to land back in the spot from which it was removed, but all the time it looks nothing like a fish.

Follow-up questions

The long dorsal fin is an impressive adaptation. Can you think of how it might benefit the fish?
The Warty Prowfish is another strange looking member of the family Pataecidae. This fish has an unusual self-defense mechanism. What is it?
The Red Indianfish has no scales. It also lacks a pair of fins found in many other fishes. Which pair?