Island mackerelRAF

Rastrelliger faughni
13.6 cm FL

Characteristic features:

  • 2 small keels on either side of caudal peduncle
  • Head longer than body depth
  • Adipose eyelids covering front and rear of eye
  • 21–26 gill rakers on lower limb of first gill arch
  • Gill rakers shorter than snout. Not visible from side of head when mouth open
  • 5–6 dorsal and anal finlets
  • Body slender, its depth at posterior margin of opercle 4.9–6 times FL
  • Large interdorsal space

Colour:

Yellowish silver below; 2 rows of spots along sides of back; 2 faint stripes sometimes present at level with lateral line and a black blotch behind pectoral fin base.

Size:

Up to 24 cm TL, maximum weight to at least 0.750 kg.1

Distribution:

Found in tropical waters of the Indo-West Pacific.

No FAO distribution map available.

Habitat:

Inshore epipelagic, neritic. Found in waters above 17°C. Depth range not recorded.

Biology:

Feeds on the largest zooplankton of the 3 Rastrelliger species. Forms schools with similarly sized individuals. Little is known regarding life history, estimated maximum age is 1–3 years.2

Indonesian fisheries:

An important commercial species in the Philippines. Caught in fish corrals, by bag netting, gill netting and in round seines.

Similar species:

Rastrelliger brachysoma
Short mackerel

Rastrelliger brachysoma

Rastrelliger brachysoma differs in having a deep body, its depth at posterior portion of opercle 4.9–6 times in FL (vs. slender 3.7–4.3); head length equal to or less than body depth (vs. greater than body depth); gill rakers not visible from side of head when mouth open (vs. visible) and 30–48 gill rakers on lower limb of first gill arch (vs. 21–26).

 

Rastrelliger kanagurta
Indian mackerel
Rastrelliger kanagurta differs in having gill rakers that are long and visible when mouth is open (vs. shorter than snout, not visible); 30–46 gill rakers on lower limb of first gill arch (vs. 21–26); bristles on longest gill raker moderate in number (100+ for 13 cm specimen) (vs. few (30–55)) and a body moderately deep, its depth at posterior portion of opercle 4.3–5.2 times in FL (vs. slender, 4.9–6).

 

Scomber australasicus
Blue mackerel
Scomber australasicus differs in having teeth present on roof of mouth (palatine teeth) in single or double rows (vs. absent); first anal-fin spine stiff and strong (vs. thin, rudimentary); many oblique wavy dark lines along back and pearl white below with wavy, broken lines giving faintly speckled appearance (vs. 2 rows of spots along back, 2 faint lines level with lateral line and silvery white below) and 25–35 gill rakers on first gill arch (vs. 30–48).

External links:

FishBase
The IUCN Red List of Threatened SpeciesTM

References

1.
Collette BB, Nauen CE. FAO species catalogue. Volume 2. Scombrids of the world. An annotated and illustrated catalogue of tunas, mackerels, bonitos and related species known to date. 1983.
2.
Aripin IE, Showers PAT. Population parameters of small pelagic fishes caught off Tawi-Tawi, Philippines. Naga, the ICLARM Quarterly. 2000;23(4):21–6.