Scyliorhinus
Scyliorhinus is a genus of catsharks, a group of small sharks belonging to the family Scyliorhinidae. These sharks are commonly known as catsharks, swellsharks, or dogfish sharks, reflecting their cat-like appearance and sometimes their ability to inflate themselves as a defense mechanism. Scyliorhinus species are distributed worldwide in coastal waters, primarily in temperate and tropical regions. They are known for their slender bodies, dorsal fins that are widely spaced, and their generally small size, with most species reaching a maximum length of less than 1 meter.
Characteristics
Catsharks in the genus Scyliorhinus typically possess several distinct characteristics. Their bodies are generally slender and elongated, with a pointed snout and large, prominent eyes. The two dorsal fins are widely spaced, with the first dorsal fin positioned over or slightly behind the pelvic fins. The anal fin is relatively small. They are often characterized by distinctive markings, including spots, stripes, or blotches, which can vary in pattern and coloration depending on the species.
Habitat and Distribution
Scyliorhinus species are found in coastal waters around the world, inhabiting a range of habitats including rocky reefs, sandy bottoms, and seagrass meadows. They are primarily bottom-dwelling and often live in shallow water, though some species have been found at depths of over 500 meters. They are particularly common in temperate and tropical regions of the Atlantic, Pacific, and Indian Oceans.
Diet
Scyliorhinus sharks are primarily nocturnal predators. They feed on a variety of benthic invertebrates, such as crustaceans, mollusks, and worms. They are opportunistic feeders and may also consume small fish and other marine life. Their slender bodies allow them to maneuver through crevices and under rocks, searching for prey.
Reproduction
Scyliorhinus species are oviparous, meaning that they lay eggs. The eggs are encased in a tough, leathery capsule that is often attached to seaweed or other marine plants. The embryos develop inside the egg capsules for a period of several months, feeding on yolk. After hatching, young Scyliorhinus sharks are independent and resemble miniature versions of adults.
Conservation Status
The conservation status of Scyliorhinus species varies depending on the species. Some species, such as the common catshark (Scyliorhinus canicula), are considered to be relatively abundant and are not of conservation concern. However, other species, such as the blackmouth catshark (Scyliorhinus retifer), face threats from overfishing and habitat degradation.
References
The information presented here is based on the following sources:
[1] Froese, R. and Pauly, D. (eds.). (2023). FishBase. https://www.fishbase.se/
[2] Compagno, L.J.V. (1984). FAO Species Catalogue. Vol. 4. Sharks of the World. An Annotated and Illustrated Catalogue of Shark Species Known to Date. Part 1 - Hexanchiformes to Lamniformes. Rome: Food and Agriculture Organization of the United Nations.
[3] Last, P.R.; Stevens, J.D.; Séret, B. (2016). "Scyliorhinus retifer". The IUCN Red List of Threatened Species. 2016: e.T60019A104256274. doi:10.2305/IUCN.UK.2016-3.RLTS.T60019A104256274.en. Retrieved 19 November 2021.