The splitfin flashlightfish or two-fin flashlightfish (''Anomalops katoptron'') is a species of
beryciform fish in the family
Anomalopidae
Anomalopidae (lanterneye fishes or flashlight fishes) are a family of fish distinguished by bioluminescent organs located underneath their eyes, for which they are named. These light organs contain luminous bacteria and can be "shut off" by the f ...
. It is found in warm waters in the central and western
Pacific Ocean near shallow
reefs in depth.
It can grow to a length of
TL. It is the only known member of its
genus.
Description
The splitfin flashlightfish is characterized by two bean shaped torch-like organs under its eyes containing
bioluminescent
Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some Fungus, fungi, microorganisms including ...
bacteria, which the fish can turn on and off by blinking. The light organs are embedded in suborbital cavities and are connected at the anterior edge via a cartilaginous rod like attachment. The suborbital light organs are densely settled with luminous symbiotic bacteria that grow in tubular structures and produce a constant bluish light.
[Hellinger, Jens, Peter Jägers, Marcel Donner, Franziska Sutt, Melanie D. Mark, Budiono Senen, Ralph Tollrian, and Stefan Herlitze. "The Flashlight Fish Anomalops Katoptron Uses Bioluminescent Light to Detect Prey in the Dark." PLOS ONE. Public Library of Science, n.d. Web. 03 May 2017] Its body is black with a blue tinge along the
dorsal and
caudal fins. Adults can reach up to
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
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...
, and south to the Great Barrier Reef. It is generally found near drop-offs and caves 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 can be found in large schools during moonless nights in the shallow water of coral reefs and in the open surrounding water.]
In the aquarium
This fish can be found in the aquarium
An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...
trade. It can be kept with other nocturnal fish, including pinecone fish
Pinecone fishes are small and unusual marine fish of the family ''Monocentridae''. The family contains just four species in two genera, one of which is monotypic. Their distribution is limited to tropical and subtropical waters of the Indo-Pacif ...
, glasseye squirrelfish, and cardinalfish. This species requires plenty of hiding places and low lighting in the aquarium. Spawning of the related flashlightfish ''Photoblepharon palpebratum
''Photoblepharon palpebratum'', the eyelight fish or one-fin flashlightfish, is a species of saltwater anomalopid fish of the order Beryciformes. It is native to the western and central Pacific Ocean where it is found along seaward reefs close t ...
'' in an aquarium was observed by Meyer-Rochow in 1976.
References
External links
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{{Taxonbar, from=Q2038050
Anomalopidae
Taxa named by Pieter Bleeker
Fish described in 1856
Fish of the Pacific Ocean