![]() Sharks are keystone species and have a strong effect on multiple ecosystems due to their predatory role and wide dispersal range (Feretti, Worm, Britten, Heithaus, & Lotze, 2010). One example of anthropogenically influenced mortality is seen in 1966 when a longfin mako ( Isurus paucus) died from a fishing hook retained in its flesh (Adams, Borucinska, Maillett, Whitburn, & Sander, 2015). There is evidence of parasitic activity in shortfin makos, although it could not be determined if there was a negative effect on the shark (Borucinska & Hege, 1999). oxyrinchus to be apex predators at the top of their food chain they have no natural predators which results in low natural mortality. Sharks have evolved for 400 million years (Donley et al., 2004), leading species such as I. As shark body length increased, so did the average volume of food, indicating that as makos grow larger, they may switch to larger prey items (Kohler et al., 2002). Stillwell and Kohler (1982) analysed the stomach contents of shortfin mako sharks and found evidence of bony fish, swordfish, and cephalopods. Late maturity, moderately long longevity, the estimated low natural mortality rate, and low annual fecundity causes low productivity in the species (Bishop et al., 2006 Mollet et al., 2000). ![]() The same study found the sharks grow quickly within their first year after birth this growth rate rapidly reduces in the subsequent years to steadier growth. (2006) found evidence of New Zealand shortfin makos living to 29 years, although this number is probably higher because there is a lower chance of catching older sharks which make up a small percentage of the overall population. Francis and Duffy’s (2005) study on sexual maturity of New Zealand shortfin makos concluded that maturity occurs between 7-9 years for males and 19-21 years for females (Bishop et al., 2006). Bishop, Francis, Duffy, and Montgomery (2006) concluded that New Zealand shortfin mako births are concentrated in spring and gave a theoretical birth date of 1 October, with the average length of the shark at birth to be 61cm. They have a 3-year reproductive cycle (Mollet & Cailliet, 2002). (2000) predicts a gestation period of 15-18 months, although a study by Duffy and Francis (2001) puts makos in New Zealand waters at a 21-month gestation period. Shortfin mako sharks are oophagous and ovoviviparous (Kohler et al., 2002), and a study by Mollet et al. oxyrinchus,with females often occurring larger than males, with males reaching a maximum size of 2.6m and females reaching a maximum size of 3.4m (Barreto et al., 2016 Cema & Lincandeo, 2009 Chan, 2001 Doño, Montealegre-Quijano, Domingo, & Kinas, 2014 Hsu, 2001 Natanson et al., 2006 Semba, Nakana, & Aoki, 2009). Shortfin mako habitat extends globally in tropical and temperate oceans and they can be found inshore in coastal areas or at least 500m down in oceanic zones (Kohler et al., 2002). oxyrinchus is 2-3 times larger than other pelagic shark species, which could aid in the mako’s speed, agility, and ability to swim long distances. ![]() Emery and Szczepanski (1986) concluded that the gill area of I. They have streamlined bodies, and aerobic muscles centred closer to their rear, which aids in thunniform swimming and increases power (Donley, Sepulveda, Konstantinidis, Gemballa, & Shadwick, 2004 Wegner, Sepulveda, Olson, Hyndman, & Graham, 2010). Shortfin mako circulatory systems utilise a heat-exchanging technique that raises their internal temperature above that of the surrounding environment (Carey, Teal, & Kanwisher, 1981 Kohler et al., 2002). There is an estimated decline in biomass and abundance of 99.9% since the early 1800s, the main reason being overfishing (Ferretti et al., 2008). (n.d.) concluded that shortfin mako’s population trend is decreasing there is an estimated decline everywhere except in the South Pacific and an overall estimated average reduction of 46.6% over 72-75 years. oxyrinchus is classified as “Endangered” on the International Union for the Conservation of Nature’s (IUCN) Red List (Rigby et al., n.d.). There is high demand for mako shark meat, and it is a prize game species in recreational fishing worldwide (Barreto et al., 2016).Īs of 2019, I. The shortfin mako shark ( Isurus oxyrinchus) is a pelagic, cartilaginous fish with a wide distribution range that covers most oceans and undergoes migrations that can be as large as 5,300km in just under 1.5 years (Barreto, de Farias, Andrade, Santana, & Lessa, 2016 Kohler, Turner, Hoey, Natanson, & Briggs, 2002).
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