By Eva Gruber
For the first time in the country, a common Australian shark species, the zebra shark, from an aquarium on the Sunshine Coast has been artificially inseminated with semen from a male on the opposite coast. This was done as part of a trial in perfecting the methods of artificial insemination in shark species, which has been known to vary significantly.
There are over 600 species of sharks, many have yet to be discovered in remote regions of the ocean such as the deep sea. Unlike most bony fish, sharks (which are cartilaginous fish) fertilize their eggs internally. Most sharks then go on to give birth to live young, although some species lay egg cases that hatch later.
Zebra sharks, also known as the leopard shark, are a species of carpet shark that can be found abundantly throughout the tropical Indo-Pacific. Grey nurse sharks, are actually classified as globally vulnerable.
Despite having a wider distribution, in nearly all oceans and in both hemispheres, their populations have been decreasing. The grey nurse shark is also known as the sand tiger shark, and it is likely that you have seen one if you’ve ever visited an aquarium with a shark tank. They are the most popular aquarium shark as they grow rather large, look rather menacing, are relatively docile and do well in captivity.
Australia’s ambition to develop a successful way to artificially inseminate grey nurse sharks is crucial. It is highly important to maintain healthy aquarium populations for the future of the species, by sustaining relative diversity in case the wild population continues its decent. Sand tiger sharks also need a little help reproducing, as their natural reproductive rate is low. The species only produces up to two pups every two or three years.
By “practicing” artificial insemination methods with zebra sharks, master aquarists are ensuring efficiency and effectiveness for future grey nurse shark inseminations. Last year, the Long Beach Aquarium of the Pacific in California was the first to successfully hatch two baby zebra sharks through artificial insemination. The science is out there, and through dedicated study by marine biologists, aquariums and research institutions around the world, it is continuing to progress.
Perfecting artificial insemination in sharks is key to their conservation around the globe – not only in zebra sharks and grey nurse sharks, but across the full colorful spectrum of shark diversity. More than 100 million sharks are killed annually around the world. Sharks face increasing challenges in modern times, from the horrific, wasteful and pointless practice of shark finning, to climate change, habitat loss and pollution. It’s not easy being a shark these days.