---
title: Offshore Cardinalfish (Ostorhinchus bryx)
scientific_name: Ostorhinchus bryx
common_name: Offshore Cardinalfish
taxon: Cardinals
conservation_status: LC - Least Concern
published: 2024-11-08T20:13:15.807Z
updated: 2026-08-18T22:21:25.328Z
tags: Offshore Cardinalfish, Ostorhinchus bryx, Cardinals, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/cardinals/offshore-cardinalfish
---

# Offshore Cardinalfish (*Ostorhinchus bryx*)

## Quick facts

- **Group:** Cardinals (*Apogonidae*)
- **Size:** 5.2 cm
- **Depth:** 14-155 m
- **Diet:** Planktivore
- **Activity:** Nocturnal
- **Rarity:** Rare
- **Habitat:** Deep reef slopes below normal diving range
- **Reproduction:** Mouthbrooder
- **Conservation status:** LC - Least Concern

## How to recognise it

- small pale cardinalfish, translucent with a silvery belly
- large eye
- below about fifteen meters and mostly far deeper
- up to 5.2 cm

Almost everything on this site lives in the top forty meters, because that is where people go. This one mostly does not.

Its range runs from about fourteen meters down past a hundred and fifty, which puts the bulk of the population in what is called the mesophotic zone: the dim band below recreational diving and above the deep sea, roughly thirty to a hundred and fifty meters, where there is still light but not much. It is the least explored habitat on any coral coast. Reaching it takes technical diving or a submersible, so most of what is known about it comes from a small number of expeditions, and the reliable result of those expeditions is that they keep finding species nobody had recorded.

The mesophotic reef also matters for the shallow one. It is cooler, it bleaches less, and there is an open argument about whether it can act as a refuge that reseeds the reefs above it after a bad summer.

The fish is a small pale cardinalfish with a large eye, which is the standard equipment for living where the light has mostly gone.

## Also known as

- **English:** Offshore Cardinalfish, Bryx Cardinalfish
- **Portuguese:** Cardeal-do-Mar-Vermelho
- **Czech:** parmovec příbřežní

## Scientific synonyms

- *Apogon bryx* Fraser, 1998

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/cardinals/offshore-cardinalfish)*
*Updated: August 18, 2026*