The Sea Aquarium in the beach village has existed since 1954 and is a first with the twin egg. “No one here has ever experienced that there are two living embryos in one egg,” says Bart proudly. “This is very special and rare in general.”
Dogfish lay transparent eggs that normally produce one shark. “The mothers lay the eggs and then attach them to something. She then leaves them to their fate. Depending on the water temperature, the sharks hatch after five to eleven months.”
Fraternal twin dogfish
Shark eggs are also called mermaid bags named because of their shape. “These twins are fraternal: they are in an egg capsule with two egg yolks,” Bart explains. The duo would not survive in the wild. “But here we can give them a helping hand if necessary.”
The dogfish eggs are now hanging separately in a kind of nursery. “That is for safety against other, larger fish. And we can keep a close eye on them here and also show them to the public at all stages.”
The expectation is that the twins – if all goes well – will swim out in about seven months.
