Mako shark
Genus of sharks
From Wikipedia, the free encyclopedia
Mako sharks are predatory mackerel sharks of the genus Isurus (meaning "equal tail")[2]. They are largely pelagic,[3] and are fast, predatory fish capable of swimming at speeds of up to 50 km/h (31 mph).[4][5] Both mako sharks are sexually dimorphic, with females being larger than males, and are large sharks. Both species of mako shark are classified as "Endangered" by the IUCN.
| Mako shark Temporal range: | |
|---|---|
| |
| Shortfin mako shark (I. oxyrinchus) | |
 | |
| Longfin mako shark (I. paucus) | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Chondrichthyes |
| Subclass: | Elasmobranchii |
| Division: | Selachii |
| Order: | Lamniformes |
| Family: | Lamnidae |
| Genus: | Isurus Rafinesque, 1810 |
| Type species | |
| Isurus oxyrinchus Rafinesque, 1810 | |
| Synonyms[1] | |
| |
Two species of mako shark currently exist: The shortfin mako shark, and the longfin mako shark. The shortfin mako shark is the fastest shark in the world, capable of speeds of 74 km/h (46 mph) in bursts, and, while the longfin mako shark is larger and slower of the two mako, reaching upwards of 2.5 m (8.2 ft) in length and weighing over 70 kg (150 lb), and is the second largest shark in it's family Lamnidae, after the great white shark.[6]
Fossil history and evolution
Although fossil teeth of Isurus have been reported from as early as the Late Cretaceous,[7][8] they are likely to be of a shark with a similar dentition, Cretoxyrhina; since at one point they were considered to be the same (now defunct) genus Oxyrhina,[9] and modern referrals to Isurus in the Cretaceous are scant. The earliest appearance of Isurus proper seems to be during the Oligocene with Isurus desori.[10][11]
There has been much debate and speculation about the evolutionary origin and relationships between Isurus and its closest relatives, including the extant great white shark (Carcharodon carcharias). Molecular clock analyses place the last common ancestor of Isurus and Carcharodon between 43–60 million years ago during the Late Paleocene-Early Eocene.[12] This insight should guide efforts to better resolve the fossil ancestry of both lineages, by providing a window of time in which to search for ancestor candidates.
Many fossil species of Lamnids have historically been placed under Isurus, which are now largely considered separate genera. These include species of Carcharodon (Cosmopolitodus) like C. hastalis, C. planus,[13] species of Macrorhizodus,[14][15] Isurolamna,[16][17] and others.
Description
The two living species are the shortfin mako shark (I. oxyrinchus) and the longfin mako shark (I. paucus). They range in length from 2.5 to 4.5 m (8.2 to 14.8 ft),[18] and have an approximate maximum weight of 680 kg (1,500 lb).[citation needed] They both have a distinctive blue-gray color scheme common among mackerel sharks.
Species
The genus contains these species:[19]
- Isurus oxyrinchus (Rafinesque, 1810) (shortfin mako shark)[20]
- Isurus paucus (Guitart-Manday, 1966) (longfin mako shark)[21]
- †Isurus desori (Agassiz, 1843)
- †Isurus retroflexus (Agassiz, 1843)
- †Isurus planus? (Agassiz, 1843)(questionable)