On Tuesday, January 28, a unique birth of blacknose sharks (Carcharhinus acronotus) took place in the large Shark basin of the Oceanium in Rotterdam Zoo. Early in the morning one of the keepers found four young sharks in a deposited part of the aquarium. Three of them unfortunately died, but the fourth could be transferred to a separate basin.
Blacknose sharks are rarely kept in aquariums. Inquiries with European and American colleagues revealed that this birth might be the first in the world! No other zoo or aquarium seems to have bred with this species. Blacknose sharks are found in the (sub) tropical seas of the western part of the Atlantic Ocean, from North Carolina to the south of Brazil. These slender and fast sharks reach a length of one and a half meters and live on small fish and octopuses.
Since the opening of the Oceanium in 2001, the blacknose sharks in the Shark basin have been swimming together with nurse sharks, sandbank sharks and blacktip sharks. In December, the keepers noticed one of the females looking larger than normal. Because a pregnancy was suspected, she was lured to a separate part of the aquarium as a precaution. Newborn sharks are prey for all other predatory fish in the aquarium.
After three weeks, four sharks of about 45 cm in length and almost half a kilogram in weight were found! Two animals had died. They had bite wounds caused by their mother, a well-known phenomenon. There is no bond between the mother and her youngsters after birth. One of the two living animals clearly also suffered from a bite wound on his tail and unfortunately died 24 hours later. The fourth animal survived unscathed and is now swimming out of sight in a large basin. In the future, she will be on display at the mangrove basin in the Oceanium.
One of the goals of the Oceanium of Rotterdam Zoo is to breed endangered fish species. The blacknose shark is not an endangered species, but the experience that can be gained with this species might later be used to work with other organizations on the breeding of endangered sharks.