“Crèche” for jellies, or How to grow a jellyfish
A new aquarium system has been set up at the Primorsky Aquarium. Specially designed aquaria have regulating valves that can finely adjust the flow rate and thus create much better conditions for jellyfish breeding.
“The new system is almost ideal both for polyps to settle and for juvenile medusae to grow,” says Marat Haidarov, Head of the Department of Exotic Aquatic Species Husbandry. “It is largely because of this equipment that we succeeded in the propagation of the hydrozoan Tima formosa. This species was caught last year in the Russian waters of the Sea of Japan for the first time; it is very uncommon in the area.”
One aquarium is used for polyps, the attached stage of the Tima formosa life cycle. The next stage, ephyrae that detach after strobilation, - tiny creatures of about 1 mm in diameter, - are transferred to a special “crèche” tank, and the juvenile medusae are kept in the third aquarium.
“Adult Tima formosa reaches a diameter of 5-6 cm. It has very long tentacles, which look rather fragile, but are very strong in fact,” clarifies Marat Haidarov. “This species belongs to the same taxonomic group as the clinging jellyfish Gonionemus vertens, notorious among Primorsky krai residents, but, unlike this venomous sea jelly, is absolutely harmless to humans.”
The unusual hydromedusa, raised by the Aquarium specialists, is already on exhibit. Reminder: Tima formosa is the fourth cnidarian species that has been successfully bred at the Primorsky Aquarium.