Kingdom Animalia Family Anomalopidae Phylum Chordata Order Beryciformes | Class Actinopterygii Genus Anomalops
Kner, 1868 Rank Species | |
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Similar Anomalopidae, Photoblepharon, Beryciformes, Spotted trunkfish, Ornate butterflyfish | ||
The splitfin flashlightfish or two-fin flashlightfish (Anomalops katoptron) is a species of beryciform fish in the family Anomalopidae. It is found in warm waters in the central and western Pacific Ocean near shallow reefs 200–400 m (660–1,300 ft) in depth. It can grow to a length of 35 cm (14 in) TL. It is the only known member of its genus.
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Description
The splitfin flashlightfish gets its name from the two glowing light organs beneath its eyes containing bioluminescent bacteria, which the fish can turn on and off by blinking. Its body is black with a blue tinge along the dorsal and caudal fins. Adults can reach up to 35 cm (14 in) TL in length.
Distribution and habitat
Splitfin flashlightfish are found in the western and central Pacific Ocean from the Philippines and Indonesia east to the Tuamotus, north to Japan, and south to the Great Barrier Reef. It is generally found near drop-offs and caves 200–400 m (660–1,310 ft) in depth, but will move into shallower waters during the winter months.
Biology and ecology
A nocturnal species, the splitfin flashlightfish avoids sunlight and seeks prey in dark areas. It feeds primarily on zooplankton. Individuals form schools 24-48 in number. While the exact purpose of the flashlightfishes' blink is not known, it has been observed that the fish blink on average five times less frequently when prey is present, leaving their light on for longer intervals. If starved, it slowly loses the ability to emit light.
In the aquarium
This fish can be found in the aquarium trade. It can be kept with other nocturnal fish, including pinecone fish, glasseye squirrelfish, and cardinalfish. This species requires plenty of hiding places and low lighting in the aquarium. Spawning of the related flashlightfish Photoblepharon palpebratum in an aquarium was observed by Meyer-Rochow in 1976.