New phase in the Primorsky Aquarium’s shark breeding program
A young female zebra bullhead shark has laid her first eggs.
“It is the second individual of this species that has begun releasing eggs at the Aquarium,” said biologist Artyom Novikov. “This time it is the youngest of our three females who reproduces. Prior to this, eggs were laid by the largest and oldest female – she was relocated from the exhibit to the Science and Acclimation Building where we had created an environment similar to the natural one for egg laying and incubation. Now we have a chance to compare the development of eggs in the exhibit tank with that of eggs kept in the quarantine area.”
In zebra bullhead sharks, spawning is prolonged and lasts for 2 months, with eggs released at intervals of a few days. For example, the oldest female has laid eggs nine times during the current spawning period, her twelve eggs are being incubated, and the process is not over yet. The young shark has just started producing offspring: by now biologists have transferred only two eggs to the special net cage. Before a baby shark hatches, the egg develops in the external environment for seven to twelve months.
General Information:
The zebra bullhead shark is a member of the genus Heterodontus whose representatives appeared about 242 million years ago and have scarcely changed since the dinosaurs’ era.
The zebra bullhead shark inhabits shallow waters of the Indo-Pacific region. It is a benthic predator feeding mainly on sea urchins, shrimps, crabs, molluscs and sometimes fish.
Shark egg cases washed ashore are called “mermaid’s purses”, and in times past, they were believed to have mystical properties.