---
title: Double-Lined Mackerel (Grammatorcynus bilineatus)
scientific_name: Grammatorcynus bilineatus
common_name: Double-Lined Mackerel
taxon: Scombridae
conservation_status: LC - Least Concern
published: 2024-11-01T18:24:52.252Z
updated: 2026-08-31T06:38:13.688Z
tags: Double-Lined Mackerel, Grammatorcynus bilineatus, Scombridae, Red Sea, Marine Life, Diving
url: https://redseacreatures.com/taxon/fishes/bony-fishes/scombridae/double-lined-mackerel
---

# Double-Lined Mackerel (*Grammatorcynus bilineatus*)

## Quick facts

- **Group:** Scombridae (*Scombridae*)
- **Size:** up to 100 cm
- **Weight:** 3.5 Kg
- **Depth:** 15-50 m
- **Diet:** Piscivore
- **Activity:** Diurnal
- **Rarity:** Uncommon
- **Habitat:** outer reef walls and clear-water drop-offs
- **Reproduction:** Broadcast spawner
- **Conservation status:** LC - Least Concern

## How to recognise it

- Two lateral lines, the lower one looping along the belly
- Dark spot just behind the gill cover
- Small mouth and large eye for a mackerel
- Finlets behind the dorsal and anal fins, keeled tail stalk
- up to 100 cm

Run a finger down this fish and you cross the lateral line twice. Below the first dorsal fin the line forks: one branch keeps to the back and runs straight to the tail, the other drops to the belly, follows it, and climbs back up to the tail stalk. No other mackerel or tuna is built that way, and it is where the name comes from.

Everything else is standard scombrid engineering, which means nothing sticks out. The first dorsal folds flat into a groove along the back, the pelvic fins tuck into a hollow, and behind the second dorsal and anal fins a row of small separate finlets runs down to a tail stalk carrying a hard keel on each side. The tail itself is a stiff crescent. Most fish in this family have also lost the ability to pump water across their gills: they breathe by swimming, and stopping suffocates them.

This is one of the few in the family a Red Sea diver has a real chance of meeting. It keeps to outer reef walls and clear-water drop-offs, mostly between 15 and 50 m, usually in schools, and it will come past a hanging safety stop. Look for the dark spot just behind the gill cover, a mouth that is small for the size of the fish, and a notably large eye.

The small mouth is honest advertising. It hunts sardines, anchovies and other small schooling fish, along with crustaceans, and takes triggerfish and young barracuda when it can. FishBase records 100 cm and 3.5 kg; in this sea 65 cm is a big one.

Until 1983 this fish and the Australian shark mackerel, Grammatorcynus bicarinatus, were treated as a single species. They are the only two in the genus, and the double lateral line belongs to both.

## Also known as

- **English:** Double-lined Mackerel, Doublelined Mackerel, Shark Mackerel
- **Arabic:** سمكة الماكريل ذات الخطين
- **French:** Thazard kusara, Thazard-kusara
- **Spanish:** carite cazón pintado, Carite-cazón Pintado
- **Turkish:** iki cizgili uskumru
- **Portuguese:** Cavala-de-meia-água, Serra-cação-pintada
- **Czech:** makrela dvoupásá
- **Japanese:** ニジョウサバ, Kusarah, Nijosaba
- **Chinese:** 大眼雙線鮁, 大眼雙線鯖, 煙仔魚
- **Russian:** обыкновенная двухлинейная макрель
- **TH:** ปลาอินทรีปากเหม็น, ปลาอินทรีแกลบ

## Scientific synonyms

- *Grammatocrynus bilineatus* (Rüppell, 1836)
- *Grammatorcynos bilineatus* (Rüppell, 1836)
- *Grammatorcyus bilineatus* (Rüppell, 1836)
- *Grammatorycnus bilineatus* (Rüppell, 1836)
- *Nesogrammus piersoni* Evermann & Seale, 1907
- *Thynnus bilineatus* Rüppell, 1836

---

*Source: [Red Sea Creatures](https://redseacreatures.com/taxon/fishes/bony-fishes/scombridae/double-lined-mackerel)*
*Updated: August 31, 2026*