The Life Cycle of the Mako Shark
Posted by Meggs | Fish Life Cycle Posts, Mako fishing ban | Posted on February 19th, 2010
The short fin mako is a powerhouse swimmer
Greetings all!
For those of you that have been following my posts on the Mako shark fishing ban you may want to take a look at the following link. I’d also recommend that you download the fact sheet about the three species listed as migratory species under the Environment Protection and Biodiversity Conservation Act 1999.
Listing of porbeagle and mako sharks as migratory species
Today we’ll take a look at the life cycle of the Mako shark. The marvelous mako has been clocked at around 50 kilometers per hour and is clearly the fastest swimmer of all sharks. As a matter of interest in one of my old posts I discussed the life cycle of the fastest fish in the sea – the sailfish – which has been clocked at speeds of 110 kilometers per hour. In comparison a goldfish in peak physical condition can reach speeds of just over 2 kilometers per hour! But I digress…
The mako is an ovoviviparous shark. What the?
This means that the mako gives birth to live young after their eggs have hatched and developed in the womb. A healthy mako mother’s pregnancy will last between 14 and 18 months after which time they will set off for shallow water to give birth to between 4 to 18 young sharks. A baby mako is around 75cm when born and will already have a full set of razor sharp teeth! It must take a bit out of the poor female mako as she is said to take a break from reproduction for at least 18 months after giving birth. The length of time taken to reproduce and the long break afterwards means that the breeding capacity and potential of the species is quite low. On the upside because the young are quite large they are rarely preyed upon and have good potential to fully develop. In the ocean it pays to be on the top of the food chain!
Makos are internally fertilized by males who inseminate the female with claspers that develop on their pelvic fins.
The maximum age of a mako is said to be just under 30 years. Adult females are larger than their male counterparts and can grow to 4 meters in length and weigh up to 500kg. By the way, the porbeagle shark that is also caught up in the fishing ban is thought to live up to 65 years.
Male makos reach sexual maturity at 2m in length whilst females do so at around 3m.
Although listed as a migratory species over 11500 makos have been tagged in Australian waters and it is said to be a rarity to recapture them beyond our limits. A satellite tagging program that has been going for two years in South Australia suggests that there is little predictability or set pattern in mako migration.
Interestingly this appears to be contrary to makos in northern hemisphere waters who are said to be “highly migratory” and often travel “over entire ocean basins”.
Anyway, so there you have it. In summary with such lengthy gestation periods with few pups born there is a case to be had that overfishing would put pressure on the continued existence of the mako shark. The thing is this – populations within Australian territorial waters are not over-stressed by recreational fishermen. In fact it is the recreational fishermen that continue to tag and release these species. The more data we can capture about the habits of the mako shark will serve to protect the species for years to come.
Sea you later,
Skipper Meggs