Specific aspects of taming sea predators

Specific aspects of taming sea predators

Biologists of the Primorsky Aquarium have tamed tawny nurse sharks; the process took them just a few weeks. The predators – two females from Indonesia – arrived in Vladivostok on the last day of 2019. Acclimation of animals to a new environment is a demanding process, and it has required efforts of ichthyologists, water chemists and fish pathologists. Then the fish were placed under the care of scuba diving biologists whose goal was to adapt them to another mode of feeding, that is, to make the sharks go from hunting for prey to taking food from human hands without biting them.

«At the first stage of quarantine the sharks were kept in small individual tanks where we quite quickly trained them to receive food from hands,” said scuba diving biologist Alexander Zyabkin. “But there the sharks did not see us standing in full length, and after they were transferred to a large pool, our charges had to accustom themselves to a periodic human presence in it.” 

A while back the scuba diving biologists of the Primorsky Aquarium tamed grey reef sharks, whitetip reef sharks, blacktip and zebra sharks. Every time the specialists started working with a newly arrived species of marine predators, they took into account its specific traits. Since the grey reef shark is an agile, swift predator, scuba divers are constantly in motion while interacting with it. Tawny nurse sharks behave very differently: though able to rush forth at lightning speed, they spend most of their time staying inactive.

“Plunging into their pool, I “turn” into a third tawny nurse shark,” said Alexander Zyabkin. “I slowly move, go down to the bottom and wait for them to approach me. The tawny nurse shark is one of those shark species that allow people to interact with them but each individual, as well as each species, has its own peculiarities. Ours have proved docile and even affectionate – in their own way. Coming into contact with the sharks, we try to stroke them, and if at first they simply did not mind us touching them, now the fish fawn on the scuba divers”.

The Primorsky Aquarium’s tawny nurse sharks are about three years old: by shark standards they are juveniles. Each female is some 1.5 m long from the nose to the tip of the tail, and it is only half of their adult size. To keep the sharks actively growing and maturing, the Aquarium staff provides them with a special diet, which the predators obviously enjoy.

“Right now each shark consumes about one kilo of food – 300 gram of salmon, 300 gram of whitefish, 300 gram of squid and 100 gram of smelt, and we add multi-vitamins to their food,” said Alexander Volkov, a scuba diving biologist at the Aquarium. “As our charges continue to grow, the amount of food increases linearly. Our tawny nurse sharks prefer salmon but we always start feedings with whitefish so that the sharks do not become satiated too quickly – in this case training sessions are more productive.”

After the sharks got acclimatized to their new surroundings, the scuba diving biologists developed a training program for them. When the predators are moved to the main building of the Aquarium, they will join the Dancing with Rays program and surely bring some unique tricks to it.

General information

—        The tawny nurse shark is the only member of the genus Nebrius in the family Ginglymostomatidae.

—        The average length of the predator is between 2.2 and 3.7 meters, the largest reported specimen was 4 meters long.

—        To breathe, the tawny nurse shark uses its spiracles and buccal pump, which enable the fish to ventilate its gill apparatus and to lie still on the sea-floor for a long time. The pump also allows the predator to suck out the prey hiding in cracks and crevices.