---
title: Ringtail Cardinalfish (Nectamia annularis)
scientific_name: Nectamia annularis
common_name: Ringtail Cardinalfish
taxon: Cardinals
conservation_status: LC - Least Concern
published: 2024-11-08T19:46:06.340Z
updated: 2026-08-20T16:17:04.161Z
tags: Ringtail Cardinalfish, Nectamia annularis, Cardinals, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/cardinals/ringtail-cardinalfish
---

# Ringtail Cardinalfish (*Nectamia annularis*)

## Quick facts

- **Group:** Cardinals (*Apogonidae*)
- **Size:** up to 7 cm
- **Depth:** 0-17 m
- **Diet:** Carnivore
- **Activity:** Nocturnal
- **Rarity:** Common
- **Habitat:** Shallow lagoon coral heads and rubble
- **Reproduction:** Mouthbrooder, Gonochoric
- **Endemic:** Endemic to the Red Sea
- **Conservation status:** LC - Least Concern

## How to recognise it

- pale fish with a dark ring encircling the tail base, not a spot
- dark bar through the eye
- in small groups deep inside branching coral
- length up to 7 cm

A small pale cardinalfish with a dark ring right around the tail base - a band, not a spot, and the difference is what names the genus.

Seven centimeters (3 in), living deep inside branching coral heads in shallow lagoons and rarely coming out where a camera can see it whole. It shares those colonies with coral gobies, guard crabs and shrimps, all of them relying on the same branches.

At night it works the sand and rubble around the colony for small crustaceans, but it does not go far - unlike the bigger cardinalfish that commute across open bottom, a fish this size stays close to cover.

Males brood in the mouth. In a species this small the clutch is a few dozen eggs, and the male carries them for about a week without eating, which is a serious investment for an animal that has to keep hiding at the same time.

## Also known as

- **English:** Ringtail Cardinalfish, Tailring Cardinalfish
- **Portuguese:** Cardeal-de-cauda-anelada
- **Czech:** parmovec kroužkatý

## Scientific synonyms

- *Apogon annularis* Rüppell, 1829
- *Apogon erdmani* Lachner, 1951
- *Ostorhynchus annularis* (Rüppell, 1829)

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*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/cardinals/ringtail-cardinalfish)*
*Updated: August 20, 2026*