Longfin mako (Isurus paucus)

Description

Longfin mako fact file

• Description
• Biology
• Range
• Habitat
• Status
• Threats
• Conservation
• Find out more
• Glossary
• References
• Print factsheet

Longfin mako description

A little known, elusive shark, the longfin mako is a large, powerful, oceanic predator. With a long, pointed snout, a large dorsal fin and broad pectoral fins, the body of the longfin mako is streamlined for efficient movement through the water ⁽³⁾. Physically similar to the more common and closely related shortfin mako (Isurus oxyrinchus), the longfin mako is distinguished by conspicuous eyes, a conical snout, a more slender body and, as its common name suggests, comparatively longer fins ⁽⁴⁾. The mouth is armed with an array of sharply pointed, serrated teeth that protrude from the jaw, giving the shark a fearsome appearance ⁽³⁾. The longfin mako is a blue to blackish colour on the upperparts, fading to white on the underside, with a dusky colour under the head ⁽⁵⁾.     

Synonyms

Irsus alatus.

French

Petit Taupe, Taupe Longue Aile.

Spanish

Dientuso Prieto, Marrajo Carite.

Size

Maximum length: 4.17 m ⁽²⁾

Longfin mako biology

Despite a widespread range, surprisingly little is know about the biology and behaviour of this enigmatic shark. Slow and sluggish compared to the vigorous shortfin mako, the solitary longfin mako may be observed cruising slowly near the ocean’s surface ^{(3) (6)}. However, when hunting it is capable of short bursts of rapid movement, primarily preying upon schools of small bony fish, but also taking squid and occasionally larger fish, such as swordfish. These high levels of activity are maintained by the possession of a specialised heat exchange circulatory system that enables the body to be warmer than the surrounding water ⁽³⁾.   

An ovoviviparous shark, developing offspring consume unfertilised eggs in the mother’s uterus, resulting in a litter of two to eight well developed live young, measuring between 90 and 95 centimetres at birth ⁽³⁾. It is possible that pregnant females move towards coastal nursing grounds to give birth in shallow waters that offer the developing young protection from predators ⁽¹⁾.

Longfin mako range

Occurring in all tropical and warm waters worldwide, the longfin mako has a widespread range ⁽³⁾. However, due to the secretive nature of this species, it is rarely encountered, and consequently, its exact distribution is unclear ⁽²⁾. 

Longfin mako habitat

Very little is known about the habitat of the longfin mako, but most records of this pelagic shark are from the ocean surface in deep waters ⁽²⁾.

Longfin mako status

Classified as Vulnerable (VU) on the IUCN Red List ⁽¹⁾.

Longfin mako threats

Already uncommon throughout much of its range, there are serious concerns that longfin mako populations are further threatened by bycatch in tropical pelagic longline fisheries for tuna and swordfish. Driven by the demand for shark fins in Southeast Asia, where they are considered a delicacy, the fins of the longfin mako are removed, with the remaining carcass thrown overboard ⁽⁷⁾. Historically, the species was also targeted by shark fisheries in Cuba, where it was the sixth most commonly fished shark between 1971 and 1972, and in the United States, with annual catches between two and 12 tons from 1987 to 1997 ^{(2) (3)}. Although the flesh is considered unpalatable in many countries, the longfin mako may also be captured using hook and line techniques and consumed fresh, frozen or dried and salted ⁽³⁾. As a direct consequence of such severe pressure, the longfin mako is suspected to have undergone a period of dramatic decline. The true extent of this is unclear, as it is often mistaken for the more common, similar looking shortfin mako. The species’ ability to recover from this decline is also severely limited by its comparatively slow reproduction rate ⁽¹⁾.   

Longfin mako conservation

In the absence of international binding treaties for the management of sharks, including the regulation or outlawing of finning, the unsustainable capture of the longfin mako continues ⁽⁸⁾. The conservation of this oceanic species is further complicated by its cosmopolitan distribution, as any future conservation measures require international cooperation. However, careful fisheries management and measures to protect marine habitats, such as the establishment of no-fishing areas, will improve the future prospects for this majestic species ⁽¹⁾.  

View information on this species at the UNEP World Conservation Monitoring Centre.

Find out more

To find out more about the threats to sharks, see:

• The Shark Trust:
  http://www.sharktrust.org/
• The Shark Research Institute: 
  http://www.sharks.org/
• Conservation International: 
  http://www.conservation.org/learn/biodiversity/species/profiles/sharks/Pages/threats.aspx

Authentication

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk

Glossary

Bycatch

In the fishing industry, the part of the catch made up of non-target species.

Dorsal fin

The unpaired fin found on the back of the body of fish, or the raised structure on the back of most cetaceans.

Ovoviviparous

Ovovivipary is a method of reproduction whereby the egg shell is weakly formed and young hatch inside the female; they are nourished by their yolk sac and then ‘born’ live.

Pectoral fins

In fish, the pair of fins that are found one on each side of the body just behind the gills. They are generally used for balancing and braking.

Pelagic

Inhabiting the open oceans.

References

1. IUCN Red List (February, 2010)
   http://www.iucnredlist.org/
2. Compagno, L.J.V. (2001) Sharks of the World. An annotated and illustrated catalogue of shark species known to date. Vol. 2: Bullhead, mackerel and carpet sharks (Heterodontformes, Lamniformes and Orectolobiformes). Food and Agriculture Organization of the United Nations, Rome.
3. Food and Agriculture Organisation of the United Nations Species Factsheet (February, 2010)
   http://www.fao.org/fishery/species/2797/en
4. The Shark Trust (February, 2010)
   http://www.sharktrust.org/
5. The Shark Foundation (February, 2010)
   http://www.shark.ch/
6. Bannister, D.R.K. (1993) The Book of the Shark. New Burlington Books, London.
7. Florida Museum of Natural History (February, 2010)
   http://www.flmnh.ufl.edu/fish/Gallery/Descript/longfinmako/longfinmako.html
8. Spiegel, J. (2001) Even Jaws deserves to keep his fins: outlawing shark finning throughout global waters. Boston College International and Comparative Law Review, 24: 409-438. Available at:
   http://www.bc.edu/bc_org/avp/law/lwsch/journals/bciclr/24_2/07_TXT.htm