---
title: Cook’s Cardinalfish (Ostorhinchus cookii)
scientific_name: Ostorhinchus cookii
common_name: Cook’s Cardinalfish
taxon: Cardinals
conservation_status: LC - Least Concern
published: 2024-11-08T20:19:25.121Z
updated: 2026-08-15T13:10:39.862Z
tags: Cook’s Cardinalfish, Ostorhinchus cookii, Cardinals, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/cardinals/cooks-cardinalfish
---

# Cook’s Cardinalfish (*Ostorhinchus cookii*)

## Quick facts

- **Group:** Cardinals (*Apogonidae*)
- **Size:** up to 10 cm
- **Depth:** 1-10 m
- **Diet:** Carnivore
- **Activity:** Nocturnal
- **Rarity:** Common
- **Habitat:** Very shallow reef flats and rocky shorelines
- **Reproduction:** Mouthbrooder, Gonochoric
- **Conservation status:** LC - Least Concern

## How to recognise it

- pale body with several fine dark stripes and a dark spot on the tail base
- stripes finer and more numerous than in the five-lined species
- in very shallow water, often under rocks on a reef flat
- length up to 10 cm

A finely striped cardinalfish of very shallow water - reef flats, rock pools, the first couple of meters where surge makes photography difficult and most fish are juveniles.

Ten centimeters (4 in), and it lives there as an adult. Shallow water is a hard address for a small nocturnal fish: it heats, it moves, and everything visible in it is exposed. What it offers is holes, food, and few competitors of this kind, and cardinalfish are equipped for the last part - they only need somewhere dark to spend the day.

It hunts small crustaceans over the flat at night, and males brood the eggs in the mouth like the rest of the family.

For a snorkeler this is one of the more likely cardinalfish to meet, and for a diver one of the least. The family is usually associated with caves and ledges, and this species is a reminder that the same body plan works in a rock pool.

## Also known as

- **English:** Cook's Cardinalfish, Blackbanded Cardinal, Blackbanded Cardinalfish
- **Hebrew:** אפוגון חמש-קו
- **Portuguese:** Cardeal-de-Cook
- **Czech:** parmovec Cookův
- **Japanese:** スジイシモチ, Sujiishimochi
- **Chinese:** 大目側仔, 大面側仔, 庫氏天竺鯛

## Scientific synonyms

- *Amia robusta* Smith & Radcliffe, 1911
- *Apogon cooki* Macleay, 1881
- *Apogon cookie* MacLeay, 1881
- *Apogon cookii* MacLeay, 1881
- *Apogon melanotaenia* Regan, 1905
- *Apogon robusta* (Smith & Radcliffe, 1911)
- *Apogon robustus* (Smith & Radcliffe, 1911)

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/cardinals/cooks-cardinalfish)*
*Updated: August 15, 2026*