Catsharks are
ground shark
Carcharhiniformes , the ground sharks, are the largest order of sharks, with over 270 species. They include a number of common types, such as catsharks, swellsharks, and the sandbar shark.
Members of this order are characterized by the presence ...
s of the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Scyliorhinidae. They are the largest family of sharks with around 160 species placed in 17 genera.
Although they are generally known as catsharks, some species can also be called dogfish due to previous naming.
However, a dogfish may generally be distinguished from a catshark as catsharks lay eggs while dogfish have live young.
Like most bottom feeders, catsharks feed on benthic invertebrates and smaller fish. They are not harmful to humans.
The family is
paraphyletic
In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
, containing several distinct lineages that do not form a
monophyletic
In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...
group.
Genera
The family includes 17 genera and over 150 species,
making it the largest family of sharks.
* ''
Akheilos''
White, Fahmi & Weigmann, 2019
* ''
Apristurus
''Apristurus'' is a genus of catsharks, the family Scyliorhinidae, commonly known as the ghost or demon catsharks.
Species
The 39 currently recognized species in this genus are:
* '' Apristurus albisoma'' Nakaya & Séret, 1999 (white-bodied c ...
''
Garman Garman is a surname or first name. Notable people with the name include:
Sports
* Ann Garman, All-American Girls Professional Baseball League player
* Judi Garman (born 1954), American softball coach
* Mike Garman (born 1949), American baseball pla ...
, 1913
* ''
Asymbolus
''Asymbolus'' is a genus of catsharks in the family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to mai ...
''
Whitley, 1939
* ''
Atelomycterus
''Atelomycterus'' is a genus of catsharks in the family Scyliorhinidae.
Species
There are currently six recognized species in this genus:
* '' Atelomycterus baliensis'' W. T. White, Last & Dharmadi, 2005 (Bali catshark)
* '' Atelomycterus ...
''
Garman, 1913
* ''
Aulohalaelurus
''Aulohalaelurus'' is a genus of catsharks in the family Scyliorhinidae.
Species
* ''Aulohalaelurus kanakorum
The New Caledonia catshark or Kanakorum catshark (''Aulohalaelurus kanakorum'') is a catshark of the family Scyliorhinidae in th ...
''
Fowler, 1934
* ''
Bythaelurus
''Bythaelurus'' is a genus of deep-water catsharks and part of the family Scyliorhinidae. The genus ''Bythaelurus'' Compagno 1988 was first described as a subgenus of ''Halaelurus'' Gill 1862 based on several morphological characteristics includ ...
''
Compagno, 1988
* ''
Cephaloscyllium
''Cephaloscyllium'' is a genus of catsharks, and part of the family Scyliorhinidae, commonly known as swellsharks because of their ability to inflate their bodies with water or air as a defense against predators. These sluggish, bottom-dwelling ...
''
T. N. Gill, 1862
* ''
Cephalurus
The lollipop catshark (''Cephalurus cephalus'') is a little-known species of deep sea catshark, belonging to the family Scyliorhinidae, and the only described member of its genus. A diminutive, bottom-dwelling shark of the outer continental sh ...
''
Bigelow and Schroeder __NOTOC__
Schroeder is a North German (from Schröder) occupational name for a cloth cutter or tailor, from an agent derivative of Middle Low German , "to cut". The same term was occasionally used to denote a gristmiller as well as a shoemaker, w ...
, 1941
* ''
Figaro''
Whitley, 1928
* ''
Galeus
''Galeus'' is a genus of catshark, belonging to the family Scyliorhinidae, commonly known as sawtail catsharks in reference to a distinctive saw-toothed crest of enlarged dermal denticles, found along the upper edges of their caudal fins. They a ...
''
Rafinesque
Constantine Samuel Rafinesque-Schmaltz (; October 22, 1783September 18, 1840) was a French 19th-century polymath born near Constantinople in the Ottoman Empire and self-educated in France. He traveled as a young man in the United States, ultimat ...
, 1810
* ''
Halaelurus
''Halaelurus'' is a genus of catsharks in the family Scyliorhinidae.
Species
* '' Halaelurus boesemani'' S. Springer & D'Aubrey, 1972 (speckled catshark)
* '' Halaelurus buergeri'' ( J. P. Müller & Henle, 1838) (blackspotted catshark)
* '' H ...
''
T. N. Gill, 1862
* ''
Haploblepharus
''Haploblepharus'' is a genus of catshark, and part of the family Scyliorhinidae, containing four species of shysharks. Their common name comes from a distinctive defensive behavior in which the shark curls into a circle and covers its eyes with ...
''
Garman, 1913
* ''
Holohalaelurus
''Holohalaelurus'' is a genus of catshark in the family Scyliorhinidae, commonly known as Izak catsharks or hallelujah sharks.
Member species of this genus are distributed in the western Indian Ocean off the coasts of various Southern African a ...
''
Fowler, 1934
* ''
Parmaturus
''Parmaturus'' is a genus of catsharks in the family Scyliorhinidae. Four species were described in 2007 and another in 2019 with more species likely to be described in the near future.
Species
The following are the currently described species ...
''
Garman, 1906
* ''
Pentanchus''
H. M. Smith and Radcliffe
Radcliffe or Radcliff may refer to:
Places
* Radcliffe Line, a border between India and Pakistan
United Kingdom
* Radcliffe, Greater Manchester
** Radcliffe Tower, the remains of a medieval manor house in the town
** Radcliffe tram stop
* ...
in Smith, 1912
* ''
Poroderma
''Poroderma'' is a genus of catsharks, and part of the family Scyliorhinidae. The color of these sharks are usually grey with dark stripes. They are found in South Africa and are nocturnal. They live preferably in shore areas, close to the bott ...
''
A. Smith, 1838
* ''
Schroederichthys
''Schroederichthys'' is a genus of catsharks in the family Scyliorhinidae.
Species
* '' Schroederichthys bivius'' ( J. P. Müller & Henle, 1838) (narrowmouthed catshark)
* '' Schroederichthys chilensis'' ( Guichenot, 1848) (redspotted catshark) ...
''
A. Smith, 1838
* ''
Scyliorhinus
''Scyliorhinus'' is a genus of catsharks in the family Scyliorhinidae. This genus is known in the fossil records from the Cretaceous period, late Albian age to the Pliocene epoch.Carrier, J. C.; Musick, J. A. & Heithaus, M. R. (2004)''Biology of ...
''
Blainville, 1816
Cladogram
*Scyliorhinidae
**Scyliorhininae
**Galeinae
***Pentanchini
***Galeini
****Galeina
****Halelaelurina
**Atelomycterininae
**Schroedericthyinae
Anatomy and appearance
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
The nursehound (''Scyliorhinus stellaris''), also known as the large-spotted dogfish, greater spotted dogfish or bull huss, is a species of catshark, belonging to the family Scyliorhinidae, found in the northeastern Atlantic Ocean. It is general ...
(''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, and having a long anal fin that ends in front of where the lower caudal fin begins. The snouts of the species of ''Apristurus'' are flat. They also present upper and lower labial furrows.
The
sonic hedgehog
Sonic hedgehog protein (SHH) is encoded for by the ''SHH'' gene. The protein is named after the character ''Sonic the Hedgehog''.
This signaling molecule is key in regulating embryonic morphogenesis in all animals. SHH controls organogenesis and ...
dentition expression is first found as a bilateral symmetrical pattern and is found in certain areas of the embryonic jaw.
Sonic hedgehog
Sonic hedgehog protein (SHH) is encoded for by the ''SHH'' gene. The protein is named after the character ''Sonic the Hedgehog''.
This signaling molecule is key in regulating embryonic morphogenesis in all animals. SHH controls organogenesis and ...
(a secreted protein that, in humans, is encoded by the SHH gene) 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
The chain catshark or chain dogfish (''Scyliorhinus retifer'') is a small, reticulated catshark that is biofluorescent. The species is common in the Northwest Atlantic, Gulf of Mexico and Caribbean. It is harmless and rarely encountered by humans ...
are
biofluorescent
Fluorescence is the emission of light by a substance that has absorbed light or other electromagnetic radiation. It is a form of luminescence. In most cases, the emitted light has a longer wavelength, and therefore a lower photon energy, tha ...
.
Distribution
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 migrates to deeper waters during the winter. 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.
Behaviour
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.
Reproduction
![Katzenhai Ei-Kapseln](https://upload.wikimedia.org/wikipedia/commons/1/1a/Katzenhai_Ei-Kapseln.JPG)
Many species of catsharks, like the
chain dogfish, are oviparous and lay
egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...
s in tough
egg cases with curly tendrils at each end, known as "mermaid's purses", for protection, onto the seabed.
Almost a year is needed for a catshark to hatch from the egg. Instead of laying the eggs and letting them sit for a year, some species of catsharks hold onto the eggs until a few months before the shark hatches. Some catsharks exhibit
ovoviviparity
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...
, aplacental viviparous, by holding onto the embryos until they are completely developed and then give live birth.
Some species of catsharks mate by biting and holding the female’s pectoral fins and wrestle her into a mating position.
Aquaria
The
Australian marbled catshark
The Australian marbled catshark (''Atelomycterus macleayi'') is a catshark of the family Scyliorhinidae, found in the eastern Indian Ocean, endemic to Western Australia between latitude
In geography, latitude is a coordinate that specifies ...
, ''Atelomycterus macleayi'', is a favored type for home
aquaria, because it rarely grows to more than in length. The
coral catshark
The coral catshark (''Atelomycterus marmoratus'') is a species of catshark in the family Scyliorhinidae. It is common on shallow coral reefs across the Indo-West Pacific, from Pakistan to New Guinea. Reaching up to in length, the coral catshark ...
, however, is the most common scyliorhinid in home aquaria.
References
External links
FishBase entry for Scyliorhinidae
{{Authority control
Scyliorhinidae
Extant Late Jurassic first appearances
Taxa named by Theodore Gill