Le profondità
Species present in the tank
Basket star
Size: when arms are extended its diameter can reach 80 cm.
Habitat: usually on caralligenous rock, but also on sandy and muddy bottoms between 50 and 800 m.
Distribution: Mediterranean, Eastern Atlantic, English Channel and Northern Sea.
Basket stars are a type of brittle stars, echinoderms related to sea stars and sea urchins. They have a circular central disc from which ten repeatedly branched arms originate. Despite lacking eyes, they are light-sensitive and curl up their arms whenever lighted. It is a filter-feeder animal: they orientate themselves perpendicular to the water current extending their arms and catching organic particles and small plankton with the prehensile arm tips that curl up around the prey when they are hit. In the wild they may live up to 35 years.
Mermaid's purses
Dogfish and skates are oviparous and reproduce by laying eggs. Eggs, which are typically produced in pairs, are protected by an horny capsule made of collagene, which i commonly known as Mermaid's purse. The female attaches these egg cases to objects such as seaweeds growing on the sea bed. Empty egg cases are often found washed up along the beaches. Dogfish Mermaid's purses are distinctive, with curly tendrils coming from each corner that help anchorage them until hatching, which takes place after 5-11 months, depending on water temperature. The egg cases of skates are larger, generally black or dark brown, more rectangular and instead of tendrils they have pointed extensions ('horns') arising from their four corners. They can be covered with a layer of fibrous material for a better adhesion to the substrate. Egg cases have distinguishable characteristic traits that are unique to each species, thus making it a great tool for identifying a skate.
Big belly seahorse
Size: from 18 a 35 cm
Habitat: from the surface to 100 mt of depth in coastal areas in the South East Pacific Ocean (Australia and New Zealand) and also reported in Thailand and the Philippines.
A rather nocturnal and sedentary species that lives substantially anchored to gorgonians or marine plants thanks to its prehensile tail. The male has a bag (marsupium) where he protects the young before abandoning them to independent life.
Cavalluccio panciuto - Big belly sea horse