Common name(s)
Shortfin Mako, Mako Shark, blue pointer, bonito shark.
Identification
A large, powerful shark with a conical pointed snout. Teeth long and pointed. Lower rows of teeth slightly visible when mouth closed. First dorsal fin has a vertical posterior margin. First dorsal origin slightly posterior to pectoral fin free rear tip. Second dorsal fin very small; same size as anal fin. Pelvic fins small. Prominent lateral keels on caudal peduncle support a large, powerful falcate, caudal fin. Upper and lower caudal lobes about the same length.
Dorsal coloration slate grey, dark blue, or metallic blue, flanks more silver-blue. Ventral surface white. Dorsal coloration usually stops above the mouth. Mouth area generally white but large specimens sometimes have grey spots or blotches.
Size
Maximum length 445cm. Size at birth 60-70cm.
Habitat
Temperate and tropical oceanic waters. Occasionally inshore. Prefers water above 16ºC but will perform short deep dives into water 10ºC. From the surface to at least 888m.
Distribution
Cosmopolitan in temperate and tropical oceanic environments.
Conservation Status
ENDANGERED
The Shortfin Mako is caught globally as target and bycatch in pelagic commercial and small-scale longline, purse seine, and gillnet fisheries. The majority of the catch is taken as bycatch of industrial pelagic fleets in offshore and high-seas waters (Camhi et al. 2008). It is also captured in coastal longlines, gillnets, trammel nets, and sometimes trawls, particularly in areas with narrow continental shelves (Camhi et al. 2008, Martínez-Ortiz et al. 2015).
The species is generally retained for the meat and fins (Clarke et al. 2006a, Clarke et al. 2006b, Dent and Clarke 2015, Fields et al. 2017), unless regulations prohibit retention. Under-reporting of catches is likely in pelagic and domestic fisheries (Dent and Clarke 2015, Campana et al. 2016a). The species is highly valued by big-game recreational fishers, and although many practice catch and release, recreational fishing could be a threat due to post-release mortality, although such mortality is reported at 10% for recreational fishing (Camhi et al. 2008, French et al. 2015). Commercial post-release mortality has been reported as 30–33% for the Shortfin Mako on longlines (Campana et al. 2016b). The species is taken in beach protection programs that target large sharks (Dudley and Simpfendorfer 2006, Simpfendorfer et al. 2010, Reid et al. 2011).
Citations and References
Rigby, C.L., Barreto, R., Carlson, J., Fernando, D., Fordham, S., Francis, M.P., Jabado, R.W., Liu, K.M., Marshall, A., Pacoureau, N., Romanov, E., Sherley, R.B. & Winker, H. 2019. Isurus oxyrinchus. The IUCN Red List of Threatened Species 2019: e.T39341A2903170. https://dx.doi.org/10.2305/IUCN.UK.2019-1.RLTS.T39341A2903170.en. Downloaded on 15 December 2020.
Reproduction
An aplacental viviparous species with oophagous (egg eating) embryos. Few full term gravid females have been examined because it appears that gravid females probably abort during capture. 4-25 embryos per litter.
Diet
Shortfin mako sharks generally feed on bony fishes, other sharks, and squid. Large adults may also consume cetaceans. They are one of the few shark species that is fast enough to hunt tuna.
Behavior
Shortfin Makos are extremely fast swimmers that are capable of attaining speeds of at 75km/h and possibly faster in short bursts. They are able to maintain a body temperature 7-10ºC above ambient water temperatures. This gives them an advantage when chasing cold-blooded prey through thermoclines.
Makos undergo extremely long migrations. Specimens tagged in New Zealand have been recaptured near the equator in the Marquesas. They have also been recorded crossing the Atlantic.
Reaction to divers
May make fast, exploratory passes of divers in the open ocean but usually shy unless baited. In baited situations, makos are fearless, making extremely close passes. When they first approach a boat they tend to be very inquisitive and will bite anything metallic that gives off an electric signal in their search for the source of the attractant. Generally, their inquisitiveness quickly fades and they circle at distance or quickly move on.
Diving logistics
There are numerous locations around the world that offer baited, open-ocean diving and/or snorkeling with shortfin mako sharks.
Probably the most consistent encounters are off of Cabo San Lucas in southern Baja, Mexico. Encounters may occur year round but the best season seems to be from December until April. The encounters take place on snorkel. Big Fish Expeditions offers multi day mako snorkeling trips in March each year. During this period, blue sharks and smooth hammerheads are also commonly seen.
In North America, there are operators running trips in San Diego, California, and off of Rhode Island in the Northeast Atlantic.
In South Africa, operators run scuba diving trips to see shortfin makos and blue sharks off of the Western Cape. Boats leave from Simonstown.
In Azores, blue shark snorkeling trips occasionally attract shortfin makos but the latter are hit and miss.
In South Australia, white shark diving trip operators occasionally attract makos too.
Similar species
Longfin Mako Shark Distinguished by larger eyes, much longer pectoral fins with rounded tips, and dark grey snout and mouthparts.
Porbeagle Shark Distinguished by a more anterior first dorsal fin and a small secondary caudal keel positioned below the main one.
The Shark Forum
Let’s talk about sharks