---
title: Comet Longfin (Calloplesiops altivelis)
scientific_name: Calloplesiops altivelis
common_name: Comet Longfin
taxon: Longfins
conservation_status: LC - Least Concern
published: 2024-11-07T22:09:24.806Z
updated: 2026-08-23T09:18:53.232Z
tags: Comet Longfin, Calloplesiops altivelis, Longfins, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/longfins/comet-longfin
---

# Comet Longfin (*Calloplesiops altivelis*)

## Quick facts

- **Group:** Longfins (*Plesiopidae*)
- **Size:** 20 cm
- **Depth:** 3-110 m
- **Diet:** Carnivore
- **Activity:** Nocturnal
- **Rarity:** Uncommon
- **Habitat:** Caves, overhangs and reef crevices
- **Reproduction:** Egg layer
- **Conservation status:** LC - Least Concern

## How to recognise it

- black-brown body covered in small white spots, like a night sky
- large ocellus at the rear of the dorsal fin
- enormous rounded fins that double the apparent size of the fish
- up to 20 cm

Frighten this fish and it turns into a moray eel.

The display is precise. It pushes its head into a hole and leaves the back half of its body outside, spreading the dorsal, anal and tail fins into one continuous dark surface. The false eye at the rear of the dorsal fin becomes the eye of the eel; the pale-spotted dark fins become the head and open jaws of a whitemouth moray, right down to the pattern; and the whole assembly is held facing the intruder. What is looking at you is the wrong end of a twenty-centimeter fish, and it looks exactly like the business end of something that will bite.

What makes it convincing is that the model lives in the same holes. A predator working the reef meets real morays in exactly these places, and any hesitation is enough, because the fish only needs a second to be gone into the rock.

The rest of the time it is one of the more beautiful things in a cave: deep black-brown scattered with small white spots, with fins so large and rounded that the animal appears twice its actual size drifting slowly along the ceiling.

It spends the day inside and comes out at night to hunt small fish and crustaceans.

## Also known as

- **English:** comet, Marine Betta
- **Hebrew:** שחמי מפרשן
- **French:** Comète à grandes nageoires, Cométe à Grandes Nageoires, Poisson-comète à grandes nageoires
- **Italian:** Betta marina, Pesce cometa
- **German:** Mirakelfisch
- **Spanish:** Pez cometa de aletas grandes
- **Portuguese:** Assessor-cometa-indiano
- **Dutch:** Rifwachter
- **Czech:** oblohlav divukrásný
- **Japanese:** シモフリタナバタウオ, Shimofuri-tanabata-uo, Shimofuritanabatauo
- **Chinese:** 孔雀七夕魚, 海水鬥魚, 珍珠麗七夕魚
- **Russian:** Белоточечный каллоплезиопс
- **AF:** Komeet
- **DA:** Kometbars, Mirakelfisk
- **ET:** Silmlaik-komeetahven, Silmlaik-ümarpeaahven
- **MSA:** Merakan
- **TH:** ปลากัดทะเล, ปลาครีบยาวจุดขาว
- **VI:** Cá Sao chổi

## Scientific synonyms

- *Barrosia barrosi* Smith, 1952
- *Callopresiops altivelis* (Steindachner, 1903)
- *Plesiops altivelis* Steindachner, 1903

## Range

Indian Ocean, Mozambique, Red Sea, Seychelles

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/longfins/comet-longfin)*
*Updated: August 23, 2026*