During a scuba dive I encountered this Catshark egg attached to an abandoned anchor rope on the seabed. The Catshark is a predominantly nocturnal fish that hides in the burrows and ravines of submerged cliffs during the day. Typically this small shark fixes its eggs to the various Gorgonians to make the most of the sea currents. In this case, as there were no Gorgonians in the seabed, he used the rope abandoned on the bottom by a boat. The small-spotted catshark (Scyliorhinus canicula), also known as the sandy dogfish, lesser-spotted dogfish, rough-hound or morgay (in Scotland and Cornwall), is a catshark of the family Scyliorhinidae. It is found on the continental shelves and the uppermost continental slopes off the coasts of Norway and the British isles south to Senegal and in the Mediterranean sea. It can grow up to a length of 1 m, and it can weigh more than 2 kg. It is found primarily over sandy, gravelly, or muddy bottoms from depths of a few metres down to 400 m. uovo di gattuccio
Scyliorhinus canicula are small, shallow-water sharks with a slender body and a blunt head. The two dorsal fins are located towards the tail end of the body. The texture of their skin is rough, similar to the coarseness of sandpaper. The nostrils are located on the underside of the snout and are connected to the mouth by a curved groove. The upper side of the body is greyish brown with dark brown spots. The underside is a light greyish white. The teeth of Scyliorhinus canicula are larger in males than in females; in addition, male Scyliorhinus canicula from West African waters have stronger, larger, and more calcinated jaws. The differences in mouth dimensions and tooth length between males and females, and between immature and adult males, could be due to different feeding habits or adaptations for reproductive behaviour.
Scyliorhinus canicula is oviparus. They deposit egg cases protected by a horny capsule with long tendrils. Egg cases are mostly deposited on macroalgae in shallow coastal waters. When the egg cases are deposited farther from shore, they are placed on sessile erect invertebrates. Egg cases usually measure 4 cm by 2 cm, without ever exceeding 6 cm. These egg cases can be found around the coasts of Europe. The embryos develop for 5–11 months depending on the sea temperature, and the young are born with a measurement of 9–10 cm. Spawining can take place almost year round. However, there can be seasonal patterns in spawning activity as well. For example Scyliorhinus canicula females located off the Mediterranean coast of France lay their eggs from March to June and in December. In the waters surrounding Great Britain, egg laying occurs in spring with a gap between August and October. On the Tunisian coast, the sharks lay their eggs starting in spring, peaking in the summer and then slightly decreasing during autumn. Males reach sexual maturity with a length of about 37.1–48.8 cm. Females reach sexual maturity with a length of 36.4–46.7 cm.
Scyliorhinus canicula is an opportunistic species, preying on a wide variety of organisms. Decapod crustaceans, molluscs and fishes are their main prey, but echinoderms, polychaetes, sipunculids and tunicates may also be eaten. Dietary preferences change with age; younger animals prefer small crustaceans, while older animals prefer hermit crabs and molluscs. Feeding intensity is highest during the summer due to the higher availability of prey life. Diet composition varies with body size. There are no significant differences in feeding habits between male and female.
(extract from Wikipedia)