Small-spotted catshark

Appearance

The ''S. canicula'' are small, shallow-water sharks with a slender shaped body with 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.McNeill, Ian. "Habitas :: National Museums Northern Ireland." Habitas :: National Museums Northern Ireland. N.p., n.d. Web. 16 Dec. 2010. The nostrils are located on the underside of the snout and are connected to the mouth by a curved groove. The underside is a lighter greyish-white colour and the upper side is greyish-brown with darker spots. Dorsal colour is sandy and tightly tan, with numerous small spots and dark brown or nearly black in colour. The teeth of ''S. canicula'' in males are larger than in females. In male ''S. canicula'' from West African waters, their jaws are stronger, larger and more calcinated. The reasons for the changes in their mouth dimensions during maturation could explain their feeding habits and adaptations for reproductive behavior.

Reproduction

Reproduction is oviparous. They deposit egg-cases that are protected by a horny capsule with long tendrils. The deposited egg-cases are mostly on macroalgae in shallow coastal waters. When the egg-cases are deposited farther from shore, they are placed on sessile erect invertebrates. These eggs 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. Spawning can take place almost all year round. However, there are can be seasonal patterns in spawning activity as well. For example, ''S. canicula'' females that are 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. In 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.

Food

''S. canicula'' is considered an opportunistic species which preys on a wide range of food, such as, molluscs, echinoderms, polychaetes, crustaceans, sipunculids and tunicates. However, decapod crustaceans and fishes are their main food. The dietary preferences change with age; younger animals prefer small crustaceans, older animals prefer hermit crabs and molluscs. It was also observed that the feeding intensity was highest during the summer due to the higher availability of prey life. Diet composition varies with body size. There are no significant differences in the feeding habits of the male and female ''S. canicula''.
Behavioral analysis showed that the ''S. canicula'' uses a consistent behaviour pattern termed 'scale rasping', as a feeding mechanism. The sharks uses this mechanism by anchoring food items near their tail so that their rapid head and jaw movements can tear away bite-sized pieces from their prey. They are able to anchor food items near their body due to the tooth-like structures that are embedded in their skin. These structures normally assist with protection from predators, parasites and abrasions to the skin. This type of feeding in ''S. canicula'' can also be done due to their elongated body morphology.