Marine Betta (Calloplesiops altivelis) Care Guide
Calloplesiops altivelis, the comet or marine betta, is a nocturnal Indo-Pacific fish that mimics a moray eel when threatened.
Overview
Calloplesiops altivelis (Steindachner, 1903), the comet or marine betta, is a reef-associated marine fish of the family Plesiopidae. FishBase records a maximum total length of 20 cm. It is a nocturnal species best known for its defensive mimicry of the moray eel.
Taxonomy
- Family: Plesiopidae (roundheads)
- Genus: Calloplesiops
- Scientific name: Calloplesiops altivelis (Steindachner, 1903)
Habitat
According to FishBase the species ranges across the Indo-Pacific, from the Red Sea and East Africa to Tonga and the Line Islands, at depths of 3 to 110 m, most often between 3 and 45 m. By day it hides under ledges and in holes.
Tank requirements
- Minimum tank volume: 250 L (about 66 gal) (KB record)
- Temperature: 24-26 °C (75-79 °F)
- pH: 8.1-8.4
- Carbonate hardness range (record): 8-12 °dGH
- Lifespan: 5-10 years (KB record)
Diet
FishBase classifies the species as carnivorous, with a trophic level near 4.0. In aquaria it accepts meaty foods offered a couple of times daily, consistent with the feeding frequency noted in the record.
Compatibility
It is a generally peaceful but predatory fish that will eat very small tankmates. Suitable companions include clownfish, tangs, cardinalfish and wrasses, while small dottybacks in confined tanks and other predators such as lionfish should be avoided.
Behaviour and defence
FishBase describes a distinctive antipredator behaviour: the fish has a false eye formed by an ocellus on the dorsal fin, and when threatened it pokes its head into a hole and exposes its tail end, which mimics the head of a moray eel. Males guard the eggs.
Conservation status
IUCN Red List: Least Concern, assessed 12 August 2019.