Scyliorhinidae

**Catsharks** are  ground sharks of the family **Scyliorhinidae**. They are one of the largest families of sharks with around 160 species placed in 17 genera. Although they are generally known as catsharks, many species are commonly called **dogfish** or **gato**. Like most bottom feeders, they feed on benthic invertebrates and smaller fish. Catsharks are harmless to humans.

## Appearance and Anatomical Features

Catsharks may be distinguished by their elongated, cat-like eyes and two small dorsal fins set far back. Most species are fairly small, growing no longer than 80 cm (31 in); a few, such as the nursehound (*Scyliorhinus stellaris*) can reach 1.6 m (5.2 ft) in length. Most of the species have a patterned appearance, ranging from stripes to patches to spots.

Characteristics of genus *Apristurus* are mostly dark bodies, having a long anal fin that ends in front of where the lower caudal fin begins. The snouts of the members of *Apristurus* are flat. They also present upper and lower labial furrows.

The sonic hedgehog dentition expression seen in these sharks is first found as a bilateral symmetrical pattern and is found in certain areas of the embryonic jaw. Sonic hedgehog is involved in the growth and patterning of different organs. Every 18–38 days the teeth are replaced as is a common characteristic of the developmental process of sharks.

The "swell sharks" of the genus *Cephaloscyllium* have the curious ability to fill their stomachs with water or air when threatened, increasing their girth by a factor of one to three.

Some catsharks, such as the chain catshark are biofluorescent.

## Behavior

Some catsharks do not undergo long distance migrations because they are poor swimmers. Due to being nocturnal, some species sleep close together in crevices throughout the day and then go hunting at night. Some species such as the small spotted catshark, *Scyliorhinus canicula*, are sexually monomorphic and exhibit habitat segregation, where males and females live in separate areas; males tend to live in open seabeds, while females tend to live in caves. Some species of catsharks may deposit egg cases in structured habitats, which may also act as nurseries for the newly hatched sharks. Most catshark species are buccal respirators or breathe in through spiracles on the head and out through the gills, a trait that allows them to lie motionless on the sea floor.

## Distribution and Habitat

Catsharks are found around seabeds in temperate and tropical seas worldwide, ranging from very shallow intertidal waters to depths of 2,000 m (6,600 ft) or more, such as the members of genus *Apristurus* The Red spotted catshark lives in the shallower rocky waters ranging from Peru to Chile and migrate to deeper waters during the winter months. They are usually restricted to small ranges. Juvenile and adult chain dogfish live on the soft or rocky bottom of the Atlantic from Massachusetts to Nicaragua. Adults tend to live on the soft sandy bottoms possibly due to their need of egg deposition sites.

## Reproduction

Many species of catshark, like the chain dogfish, are oviparous and lay eggs in tough egg cases with curly tendrils at each end, known as "mermaid's purses", for protection, onto the seabed. It takes almost a year for a catshark to hatch from the egg. Instead of laying the eggs and letting them sit for a year, some species of catshark hold onto the egg until a few months before the shark hatches. Some catsharks exhibit ovoviviparity, aplacental viviparous, by holding onto the embryos until they are completely developed and then give live birth. Some, if not most species of catsharks mate by biting and holding the female’s pectoral fins and wrestle her into a mating position.

## In Aquaria

Small species of catshark are often found in public and private aquariums. The Australian marbled catshark, *Atelomycterus macleayi*, is a favored type for home aquaria, because it rarely grows to more than 60 cm (24 in) in length. The coral catshark, however, is the most common scyliorhinid in home aquaria.

## Genera and Species

The family includes 17 genera and over 150 living species, making it the largest family of sharks.

* Genus *Apristurus*
	+ *Apristurus albisoma* (White-bodied catshark)
	+ *Apristurus ampliceps* (Roughskin catshark)
	+ *Apristurus aphyodes* (White ghost catshark)
	+ *Apristurus australis* (Pinocchio catshark)
	+ *Apristurus breviventralis* (Shortbelly catshark)
	+ *Apristurus brunneus* (Brown catshark)
	+ *Apristurus bucephalus* (Bighead catshark)
	+ *Apristurus canutus* (Hoary catshark)
	+ *Apristurus exsanguis* (Flaccid catshark)
	+ *Apristurus fedorovi* (Fedorov's catshark)
	+ *Apristurus garricki* (Garrick's catshark)
	+ *Apristurus gibbosus* (Humpback catshark)
	+ *Apristurus herklotsi* (Longfin catshark)
	+ *Apristurus indicus* (Smallbelly catshark)
	+ *Apristurus internatus* (Shortnose demon catshark)
	+ *Apristurus investigatoris* (Broadnose catshark)
	+ *Apristurus japonicus* (Japanese catshark)
	+ *Apristurus kampae* (Longnose catshark)
	+ *Apristurus laurussonii* (Iceland catshark)
	+ *Apristurus longicephalus* (Longhead catshark)
	+ *Apristurus macrorhynchus* (Flathead catshark)
	+ *Apristurus macrostomus* (Broadmouth catshark)
	+ *Apristurus manis* (Ghost catshark)
	+ *Apristurus melanoasper* (Black roughscale catshark)
	+ *Apristurus microps* (Smalleye catshark)
	+ *Apristurus micropterygeus* (Smalldorsal catshark)
	+ *Apristurus nakayai* (Milk-eye catshark)
	+ *Apristurus nasutus* (Largenose catshark)
	+ *Apristurus parvipinnis* (Smallfin catshark)
	+ *Apristurus pinguis* (Bulldog catshark)
	+ *Apristurus platyrhynchus* (Spatulasnout catshark or Borneo catshark)
	+ *Apristurus profundorum* (Deepwater catshark)
	+ *Apristurus riveri* (Broadgill catshark)
	+ *Apristurus saldanha* (Saldanha catshark)
	+ *Apristurus sibogae* (Pale catshark)
	+ *Apristurus sinensis* (South China catshark)
	+ *Apristurus spongiceps* (Spongehead catshark)
	+ *Apristurus stenseni* (Panama ghost catshark)
	+ *Apristurus sp. X* Not yet described (Galbraith's catshark)
	+ *Apristurus sp. 3* Not yet described (Black wonder catshark)
	+ *Apristurus sp. nov.* Not yet described (White-edged catshark)
	+ *Apristurus sp.* Not yet described (Gray ghost catshark)

* Genus *Asymbolus*
	+ *Asymbolus analis* (Australian spotted catshark)
	+ *Asymbolus funebris* (Blotched catshark)
	+ *Asymbolus galacticus* (Starry catshark)
	+ *Asymbolus occiduus* (Western spotted catshark)
	+ *Asymbolus pallidus* (Pale spotted catshark)
	+ *Asymbolus parvus* (Dwarf catshark)
	+ *Asymbolus rubiginosus* (Orange-spotted catshark)
	+ *Asymbolus submaculatus* (Variegated catshark)
	+ *Asymbolus vincenti* (Gulf catshark)

* Genus *Atelomycterus*
	+ *Atelomycterus baliensis* (Bali catshark)
	+ *Atelomycterus erdmanni* (Spotted-belly catshark)
	+ *Atelomycterus fasciatus* (Banded sand catshark)
	+ *Atelomycterus macleayi* (Australian marbled catshark)
	+ *Atelomycterus marmoratus* (Coral catshark)
	+ *Atelomycterus marnkalha* (Eastern banded catshark)
* Genus *Aulohalaelurus*
	+ *Aulohalaelurus kanakorum* (Kanakorum catshark)
	+ *Aulohalaelurus labiosus* (Australian blackspotted catshark)
* Genus *Bythaelurus*
	+ *Bythaelurus alcockii* (Arabian catshark)
	+ *Bythaelurus canescens* (Dusky catshark)
	+ *Bythaelurus clevai* (Broadhead catshark)
	+ *Bythaelurus dawsoni* (New Zealand catshark)
	+ *Bythaelurus giddingsi* (Galápagos catshark)
	+ *Bythaelurus hispidus* (Bristly catshark)
	+ *Bythaelurus immaculatus* (Spotless catshark)
	+ *Bythaelurus incanus* (Sombre catshark)
	+ *Bythaelurus lutarius* (Mud catshark)
	+ *Bythaelurus naylori* (Dusky snout catshark)
	+ *Bythaelurus tenuicephalus* (Narrowhead catshark)
* Genus *Cephaloscyllium*
	+ *Cephaloscyllium albipinnum* (Whitefin swellshark)
	+ *Cephaloscyllium cooki* (Cook's swellshark)
	+ *Cephaloscyllium fasciatum* (Reticulated swellshark)
	+ *Cephaloscyllium hiscosellum* (Australian reticulate swellshark)
	+ *Cephaloscyllium isabellum* (Draughtsboard shark)
	+ *Cephaloscyllium laticeps* (Australian swellshark)
	+ *Cephaloscyllium pictum* (Painted swellshark)
	+ *Cephaloscyllium sarawakensis* (Sarawak pygmy swellshark)
	+ *Cephaloscyllium signourum* (Flagtail swellshark)
	+ *Cephaloscyllium silasi* (Indian swellshark)
	+ *Cephaloscyllium speccum* (Speckled swellshark)
	+ *Cephaloscyllium stevensi* (Steven's swellshark)
	+ *Cephaloscyllium sufflans* (Balloon shark)
	+ *Cephaloscyllium umbratile* (Blotchy swellshark)
	+ *Cephaloscyllium variegatum* (Saddled swellshark)
	+ *Cephaloscyllium ventriosum* (Swellshark)
	+ *Cephaloscyllium zebrum* (Narrowbar swellshark)
	+ *Cephaloscyllium sp. 1* Not yet described (Philippine swellshark)
	+ *Cephaloscyllium sp.* Not yet described (Tiger swellshark)
	+ *Cephaloscyllium sp.* Not yet described (New Guinea swellshark)
	+ *Cephaloscyllium sp.* Not yet described (Dwarf balloon shark)
	+ *Cephaloscyllium sp.* Not yet described (Dwarf oriental swellshark)
	+ *Cephaloscyllium sp.* Not yet described (New Caledonia swellshark)
	+ *Cephaloscyllium sp.* Not yet described (Red Sea swellshark)
* Genus *Cephalurus*
	+ *Cephalurus cephalus* (Lollipop catshark)
* Genus *Figaro*
	+ *Figaro boardmani* (Australian sawtail catshark)
	+ *Figaro striatus* (Northern sawtail catshark)
* Genus *Galeus*
	+ *Galeus antillensis* (Antilles catshark)
	+ *Galeus arae* (Roughtail catshark)
	+ *Galeus atlanticus* (Atlantic sawtail catshark)
	+ *Galeus cadenati* (Longfin sawtail catshark)
	+ *Galeus eastmani* (Gecko catshark)
	+ *Galeus gracilis* (Slender sawtail catshark)
	+ *Galeus longirostris* (Longnose sawtail catshark)
	+ *Galeus melastomus* (Blackmouth catshark)
	+ *Galeus mincaronei* (Southern sawtail catshark)
	+ *Galeus murinus* (Mouse catshark)
	+ *Galeus nipponensis* (Broadfin sawtail catshark)
	+ *Galeus piperatus* (Peppered catshark)
	+ *Galeus polli* (African sawtail catshark)
	+ *Galeus priapus* (Phallic catshark)
	+ *Galeus sauteri* (Blacktip sawtail catshark)
	+ *Galeus schultzi* (Dwarf sawtail catshark)
	+ *Galeus springeri* (Springer's sawtail catshark)
* Genus *Halaelurus*
	+ *Halaelurus boesemani* (Speckled catshark)
	+ *Halaelurus buergeri* (Blackspotted catshark)
	+ *Halaelurus lineatus* (Lined catshark)
	+ *Halaelurus maculosus* (Indonesian speckled catshark)
	+ *Halaelurus natalensis* (Tiger catshark)
	+ *Halaelurus quagga* (Quagga catshark)
	+ *Halaelurus sellus* (Rusty catshark)
* Genus *Haploblepharus*
	+ *Haploblepharus edwardsii* (Puffadder shyshark)
	+ *Haploblepharus fuscus* (Brown shyshark)
	+ *Haploblepharus kistnasamyi* (Natal shyshark)
	+ *Haploblepharus pictus* (Dark shyshark)
* Genus *Holohalaelurus*
	+ *Holohalaelurus favus* (Honeycomb Izak)
	+ *Holohalaelurus grennian* (Grinning Izak)
	+ *Holohalaelurus melanostigma* (Crying Izak)
	+ *Holohalaelurus punctatus* (White-spotted Izak)
	+ *Holohalaelurus regani* (Izak catshark)
* Genus *Parmaturus*
	+ *Parmaturus albimarginatus* (White-tip catshark)
	+ *Parmaturus albipenis* (White-clasper catshark)
	+ *Parmaturus bigus* (Beige catshark)
	+ *Parmaturus campechiensis* (Campeche catshark)
	+ *Parmaturus lanatus* (Velvet catshark)
	+ *Parmaturus macmillani* (McMillan's cat shark)
	+ *Parmaturus melanobranchus* (Blackgill catshark)
	+ *Parmaturus pilosus* (Salamander shark)
	+ *Parmaturus xaniurus* (Filetail catshark)
	+ *Parmaturus sp.* Not yet described (Roughback catshark)
	+ *Parmaturus sp.* Not yet described (Indonesian filetail catshark)
	+ *Parmaturus sp.* Not yet described (Gulf of Mexico filetail)
* Genus *Pentanchus*
	+ *Pentanchus profundicolus* (Onefin catshark)

* Genus *Schroederichthys*

* *Schroederichthys bivius* (Narrowmouthed catshark)
* *Schroederichthys chilensis* (Redspotted catshark)
* *Schroederichthys maculatus* (Narrowtail catshark)
* *Schroederichthys saurisqualus* (Lizard catshark)
* *Schroederichthys tenuis* (Slender catshark)

* Subfamily Scyliorhininae
	+ Genus *Cephaloscyllium*
		- *Cephaloscyllium albipinnum* (Whitefin swellshark)
		- *Cephaloscyllium cooki* (Cook's swellshark)
		- *Cephaloscyllium fasciatum* (Reticulated swellshark)
		- *Cephaloscyllium hiscosellum* (Australian reticulate swellshark)
		- *Cephaloscyllium isabellum* (Draughtsboard shark)
		- *Cephaloscyllium laticeps* (Australian swellshark)
		- *Cephaloscyllium pictum* (Painted swellshark)
		- *Cephaloscyllium sarawakensis* (Sarawak pygmy swellshark)
		- *Cephaloscyllium signourum* (Flagtail swellshark)
		- *Cephaloscyllium silasi* (Indian swellshark)
		- *Cephaloscyllium speccum* (Speckled swellshark)
		- *Cephaloscyllium stevensi* (Steven's swellshark)
		- *Cephaloscyllium sufflans* (Balloon shark)
		- *Cephaloscyllium umbratile* (Blotchy swellshark)
		- *Cephaloscyllium variegatum* (Saddled swellshark)
		- *Cephaloscyllium ventriosum* (Swellshark)
		- *Cephaloscyllium zebrum* (Narrowbar swellshark)
		- *Cephaloscyllium sp. 1* Not yet described (Philippine swellshark)
		- *Cephaloscyllium sp.* Not yet described (Tiger swellshark)
		- *Cephaloscyllium sp.* Not yet described (New Guinea swellshark)
		- *Cephaloscyllium sp.* Not yet described (Dwarf balloon shark)
		- *Cephaloscyllium sp.* Not yet described (Dwarf oriental swellshark)
		- *Cephaloscyllium sp.* Not yet described (New Caledonia swellshark)
		- *Cephaloscyllium sp.* Not yet described (Red Sea swellshark)
	+ Genus *Poroderma*
		- *Poroderma africanum* (Striped catshark or Pyjama shark)
		- *Poroderma pantherinum* (Leopard catshark)
	+ Genus *Scyliorhinus*
		- *Scyliorhinus boa* (Boa catshark)
		- *Scyliorhinus cabofriensis*
		- *Scyliorhinus canicula* (Small-spotted catshark)
		- *Scyliorhinus capensis* (Yellowspotted catshark)
		- *Scyliorhinus cervigoni* (West African catshark)
		- *Scyliorhinus comoroensis* (Comoro catshark)
		- *Scyliorhinus garmani*  (Brownspotted catshark)
		- *Scyliorhinus haeckelii*  (Freckled catshark)
		- *Scyliorhinus hesperius* (Whitesaddled catshark)
		- *Scyliorhinus meadi* (Blotched catshark)
		- *Scyliorhinus retifer* (Chain catshark)
		- *Scyliorhinus stellaris* (Nursehound)
		- *Scyliorhinus tokubee* (Izu catshark)
		- *Scyliorhinus torazame* (Cloudy catshark)
		- *Scyliorhinus torrei* (Dwarf catshark)
		- *Scyliorhinus ugoi* (Dark freckled catshark)
		- †*Scyliorhinus ambliatlanticus*
		- †*Scyliorhinus angustus*
		- †*Scyliorhinus antiquus*
		- †*Scyliorhinus arambourgi*
		- †*Scyliorhinus arlingtonensis*
		- †*Scyliorhinus biddlei*
		- †*Scyliorhinus biformis*
		- †*Scyliorhinus bloti*
		- †*Scyliorhinus brumarivulensis*
		- †*Scyliorhinus cepaeformis*
		- †*Scyliorhinus coupatezi*
		- †*Scyliorhinus dubius*
		- †*Scyliorhinus elongatus*
		- †*Scyliorhinus entomodon*
		- †*Scyliorhinus fossilis*
		- †*Scyliorhinus ivagrantae*
		- †*Scyliorhinus joleaudi*
		- †*Scyliorhinus kannenbergi*
		- †*Scyliorhinus kasenoi*
		- †*Scyliorhinus luypaertsi*
		- †*Scyliorhinus malembeensis*
		- †*Scyliorhinus monsaugustus*
		- †*Scyliorhinus moosi*
		- †*Scyliorhinus muelleri*
		- †*Scyliorhinus musteliformis*
		- †*Scyliorhinus ptychtus*
		- †*Scyliorhinus reyndersi*
		- †*Scyliorhinus suelstorfensis*
		- †*Scyliorhinus sulcidens*
		- †*Scyliorhinus taylorensis*
		- †*Scyliorhinus tensleepensis*
		- †*Scyliorhinus trifolius*
		- †*Scyliorhinus wardi*
		- †*Scyliorhinus woodwardi*

### Cladogram

* Scyliorhinidae
	+ Scyliorhininae
	+ Galeinae
		- Pentanchini
		- Galeini
			* Galeina
			* Halelaelurina
	+ Atelomycterininae
	+ Schroedericthyinae