Platax pinnatus, also known as the longfin batfish, pinnate spadefish, pinnate batfish, pinnatus batfish, dusky batfish, shaded batfish, or red-faced batfish is a species of marine ray-finned fish belonging to the family Ephippidae, the spadefishes and batfishes. This species is found in the western Pacific Ocean and occasionally is kept in .
Taxonomy
Platax pinnatus was first formally described as
Chaetodon pinnatus in 1758 by
Carl Linnaeus in the 10th edition of Systema Naturae with its type locality given as "
East Indies".
This species is classified within the
genus Platax which belongs to the family Ephippidae
in the order
Moroniformes.
The specific name,
pinnatus, means "finned" and is an allusion to the very long
dorsal fin and
, particularly in juveniles.
Description
Platax pinnatus adults have a round, strongly compressed body which has a depth of twice the length of the head. This species reaches a maximum published
total length of .
Larger adults, with a
standard length in excess of have a protruding snout and a concave dorsal profile of the head. Both jaws have bands of thin, flattened, tricuspid teeth with the central cusp being around two times as long as the lateral cusps. There are vomerine teeth but no palatine teeth. The
dorsal fin is supported by 5 or 6 spines and between 34 and 37 soft rays while the
anal fin contains 3 spines and 24 to 28 soft rays.
The overall colour is silvery with a dusky or dark vertical bar running through the eye and a second similar bar running through the base of the
pectoral fin. The dorsal, anal and
are yellow.
The juveniles are mainly black with the body and median fins outlined in orange and the dorsal and anal fins are greatly elongated.
Distribution and habitat
Platax pinnatus is found in the Indo-West Pacific although
FishBase notes that records from the
Indian Ocean, other than
Australia, are subject to some doubt. The confirmed range is in the western Pacific from the
Ryukyu Islands south to Australia.
In Australia, it has been recorded from off the central coast of Western Australia, around the tropical northern coasts and south along the east coast to the central coast of New South Wales.
The adults are found under the overhangs of steep outer reef slopes down to depths greater than . The juveniles are found among
Mangrove or sheltering in caves and under ledges in inner protected
Reef.
Biology
Platax pinnatus adults are normally solitary but will gather in large schools to move over open substrates.
[ The juveniles are Batesian mimicry of a toxic species of flatworm by colour and shape.][ They feed on algae as well as jellyfish and other gelatinous zooplankton.][ This species has been observed to significantly reduce algal growths on coral in studies simulating the effects of overfishing on the Great Barrier Reef.]
Utilisation
Platax pinnatus is kept in Fish keeping but is difficult to maintain.
Gallery
File:Dusky Batfish (Platax pinnatus) (6096549191).jpg
File:Dusky Batfish (Platax pinnatus) (6135858057).jpg
File:Platax pinnatus (2).JPG
File:Boulogne sur mer.- Nausicaà Platax pinnatus.jpg
File:Pinnate Batfish (Platax pinnatus) (46722837661).jpg|With cleaner wrasse
External links
