Narrow-barred Spanish mackerel

Narrow-barred Spanish mackerel
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Scombridae
Genus: Scomberomorus
Species: S. commerson
Binomial name
Scomberomorus commerson
(Lacépède, 1800)

The narrow-barred Spanish mackerel (Scomberomorus commerson) is a mackerel of the Scombridae family found in a wide-ranging area centering in Southeast Asia, but as far west as the east coast of Africa and from the Middle East and along the northern coastal areas of the Indian Ocean, and as far east as the South West Pacific Ocean.[1]

Description

They are vivid blue to dark grey in colour along their backs and flanks and fade to a silvery blue-grey on the belly. Spanish mackerel have scores of narrow, vertical lines down their sides. Spanish mackerel are the largest of all Australian mackerels, growing to about 200 cm and up to 70 kg.

Distribution/habitat

It is found in a wide area centering in Southeast Asia, but as far west as the east coast of Africa and from the Persian Gulf and along the northern coastal areas of the Indian Ocean, and as far east as Fiji in the South West Pacific ocean. They are common down both sides of Australia as far south as Perth on the west coast and Sydney on the east coast. They are also found as far north as China and even Japan..[2][3]

Lifecycle

Spanish mackerel spawn in oceanic conditions on reef edges. Eggs have a large oil droplet that aids in buoyancy and keeps them at the top of the water column which is warmer, well oxygenated, and has an abundant planktonic food supply for the larvae once they are hatched. When in the larval stage, Spanish mackerel are believed to stay in their own species-specific groups and are not normally found with other species of the same genus, such as S. semifasciatus and S. queenslandicus. This is not always the case with adult mackerel, where occasional mixing of different species within the same genus can occur.

Spawning is seasonal, but it is protracted in the warmer waters of the tropics. Many of the fisheries that target this species are based on prespawning feeding aggregations. A significant proportion of the female fish caught in NT waters between July and December have either recently spawned or are close to spawning.[4] In general, spawning times for Spanish mackerel tend to be associated with higher water temperatures that promote optimal food availability for the rapid growth and development of the larvae.[5]

As the young larvae grow, they move from the offshore spawning grounds to inshore and estuarine habitats, where they are frequently found in the juvenile phase of their growth cycle. In the inshore environments, they feed mostly on the larvae and juveniles of small fish and crustaceans until they become large enough to eat small fish and squid.[6] Australian studies of this species suggest females are larger than males.[7][8] [9] Female Spanish mackerel mature at about two years of age or around 80 cm in length.[10]

Feeding habits

Spanish mackerel are voracious, opportunistic carnivores. As with other members of the genus, food consists mainly of small fishes with lesser quantities of shrimp and squid.

Fisheries, Fishing gear and methods

Commercial capture of narrow-barred Spanish mackerel in tonnes from 1950 to 2009

Spanish mackerel are highly valued fish throughout their range in the Indo West Pacific. Recreational anglers catch them from boats while trolling or drifting and from boats, piers, jetties, and beaches by casting spoons and jigs, and live-bait fishing. Commercial methods are primarily run-around gill netting, and rarely, by trolling lures similar to those used by recreational anglers.

Parasites

Cysts of the trypanorhynch Callitetrarhynchus gracilis in the body cavity

As most fish, the narrow-barred Spanish mackerel is infected by a variety of parasites. Spectacular parasites are the cysts of the larvae of the trypanorhynch cestode Callitetrarhynchus gracilis, often found in great numbers in the body cavity.[11] These parasites are not appetizing, but represent no danger to humans.

Young angler with an average-sized Spanish mackerel off Darwin, Northern Territory

Some common names

References

  1. ↑ Fishbase
  2. ↑ Fishbase
  3. ↑ http://www.fishnet.com.au/default.aspx?id=225&fishid=101
  4. ↑ Buckworth and Clark 2001
  5. ↑ Jenkins et al. 1985
  6. ↑ McPherson 1988
  7. ↑ McPherson 1992
  8. ↑ Buckworth 1998
  9. ↑ Mackie et al. 2003
  10. ↑ http://www.nt.gov.au/d/Content/File/p/Fishnote/FN40.pdf
  11. ↑ Beveridge, Ian; Bray, Rodney A.; Cribb, Thomas H.; Justine, Jean-Lou (2014). "Diversity of trypanorhynch metacestodes in teleost fishes from coral reefs off eastern Australia and New Caledonia". Parasite 21: 60. doi:10.1051/parasite/2014060. ISSN 1776-1042. PMC 4234045. PMID 25402635.


External links

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