The quagga catshark (''Halaelurus quagga'') is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of catshark, belonging to 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. A small, slim-bodied shark reaching in length, it has a distinctive color pattern of narrow, dark brown vertical bars, which resemble those of the

quagga The quagga ( or ) (''Equus quagga quagga'') is a subspecies of the plains zebra that was endemic to South Africa until it was hunted to extinction in the late 19th century. It was long thought to be a distinct species, but early genetic ...

. Its head is short and flattened, with a pointed snout tip that is not upturned. Little is known of the quagga catshark's natural history, as it is known only from nine specimens caught off southwestern India and eastern Somalia. Inhabiting the offshore waters of

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

at depths of or more, it is a bottom-dwelling

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

s. It exhibits an

oviparous Oviparous animals are animals that lay their eggs, with little or no other embryonic development within the mother. This is the reproductive method of most fish, amphibians, most reptiles, and all pterosaurs, dinosaurs (including birds), and ...

mode of reproduction, with a record of a female containing eight eggs that were enclosed in brown capsules bearing long tendrils at the corners. The

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(IUCN) presently lacks sufficient data to assess the conservation status of this species. It is not economically valued but is taken as

bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...

Taxonomy

The first specimen of the quagga catshark was a long adult male collected by the

paddle steamer A paddle steamer is a steamship or steamboat powered by a steam engine that drives paddle wheels to propel the craft through the water. In antiquity, paddle wheelers followed the development of poles, oars and sails, where the first uses wer ...

RIMS ''Investigator'' from a depth of off the

Malabar Coast The Malabar Coast is the southwestern coast of the Indian subcontinent. Geographically, it comprises the wettest regions of southern India, as the Western Ghats intercept the moisture-laden monsoon rains, especially on their westward-facing m ...

of India. It was described by British naturalist Alfred William Alcock in ''A Descriptive Catalogue of the Indian Deep-sea Fishes in the Indian Museum'', published in 1899. He assigned the new species to the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Scyllium'' (a

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

of ''

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 ...

'') and named it after the

(''Equus quagga quagga'') because of their similar color patterns. Later authors moved this species to the genus ''

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 ...

''. Only nine quagga catshark specimens have been recorded. In addition to Alcock's

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

, four males were

trawl Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different speci ...

ed from off the eastern Somali coast by the research ship RV ''Anton Bruun'' in 1964. Four more individuals, two male and two female, were found amongst the contents of

commercial fishing Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often ...

trawls conducted off

Quilon Kollam (), also known by its former name Quilon , is an ancient seaport and city on the Malabar Coast of India bordering the Laccadive Sea, which is a part of the Arabian Sea. It is north of the state capital Thiruvananthapuram. The city i ...

, India in 2010. A male specimen reported from the

Gulf of Aden The Gulf of Aden ( ar, خليج عدن, so, Gacanka Cadmeed 𐒅𐒖𐒐𐒕𐒌 𐒋𐒖𐒆𐒗𐒒) is a deepwater gulf of the Indian Ocean between Yemen to the north, the Arabian Sea to the east, Djibouti to the west, and the Guardafui Channe ...

in 1939 was later re-identified as a speckled catshark (''H. boesemani'').

Description

Slender and firm-bodied, the quagga catshark has a short and flattened head with a pointed snout. The slightly protruding tip of the snout is not upturned like in some other ''Halaelurus'' species. The anterior rims of the nostrils bear triangular flaps of skin. The small, horizontally oval eyes are placed high on the head and have rudimentary

nictitating membrane The nictitating membrane (from Latin '' nictare'', to blink) is a transparent or translucent third eyelid present in some animals that can be drawn across the eye from the medial canthus to protect and moisten it while maintaining vision. All ...

s; below the eyes are thick ridges, and behind them are tiny

spiracle Spiracle or spiraculum may refer to: * Spiracle (arthropods), opening in the exoskeletons of some arthropods * Spiracle (vertebrates), openings on the surface of some vertebrates * Spiraculum, a genus of land snails in family Cyclophoridae Cycl ...

s. The rather large mouth is curved, with the upper teeth exposed when closed. There are short furrows at the corners of the mouth. The jaws contain 26–28 upper and 27 lower

tooth row Sharks continually shed their teeth; some Carcharhiniformes shed approximately 35,000 teeth in a lifetime, replacing those that fall out. There are four basic types of shark teeth: dense flattened, needle-like, pointed lower with triangular up ...

s on each side; in addition, there are three tooth rows at the upper symphysis (jaw midpoint) and one row at the lower. The teeth have three cusps. The five pairs of

gill slit Gill slits are individual openings to gills, i.e., multiple gill arches, which lack a single outer cover. Such gills are characteristic of cartilaginous fish such as sharks and rays, as well as deep-branching vertebrates such as lampreys. In con ...

s are placed higher than the level of the mouth; the fifth pair are smaller than the rest. The moderately large and rounded

pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...

s are positioned fairly close to the

pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two en ...

s. Adult males have thin, tapering

claspers In biology, a clasper is a male anatomical structure found in some groups of animals, used in mating. Male cartilaginous fish have claspers formed from the posterior portion of their pelvic fin which serve to channel semen into the female's ...

with a denticle-covered knob on the outer side near the tip. The first dorsal fin is placed just behind the pelvic fin bases, while the larger second dorsal fin is placed just behind the

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

. The anal fin is larger than the second dorsal fin and comparable in size to the pelvic fins. The

caudal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

has a small but discernible lower lobe and a large upper lobe with a notch in its trailing margin. The thick skin is covered by

dermal denticle A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as we ...

s, which have arrowhead-shaped crowns with a central ridge and three posterior teeth. This shark has a striking dorsal color pattern consisting of over 20 narrow, dark brown vertical bars on a light brown background; the bars run from the head to the tail and extend onto the dorsal fins. The underside is off-white, and the pectoral, pelvic, and anal fins have pale trailing margins. The largest known specimen is long.

Distribution and habitat

The known specimens of the quagga catshark have been collected from the

Laccadive Sea The Laccadive Sea or Lakshadweep Sea is a body of water bordering India (including its Lakshadweep islands), the Maldives, and Sri Lanka. It is located to the southwest of Karnataka, to the west of Kerala and to the south of Tamil Nadu. This war ...

off southwestern India and from the Indian Ocean off Somalia. The Indian sharks were caught between the depths of or possibly , while the Somalian sharks were caught at depths of . This is a bottom-dwelling species found far from shore over the

Biology and ecology

The diet of the quagga catshark consists of deep-living

s. Its reproduction is

like the other members of its genus. One of the female Indian specimens was

gravid In biology and human medicine, gravidity and parity are the number of times a woman is or has been pregnant (gravidity) and carried the pregnancies to a viable gestational age (parity). These terms are usually coupled, sometimes with additional te ...

with eight eggs, divided evenly between the two

oviduct The oviduct in mammals, is the passageway from an ovary. In human females this is more usually known as the Fallopian tube or uterine tube. The eggs travel along the oviduct. These eggs will either be fertilized by spermatozoa to become a zygote, o ...

s. The eggs are enclosed in brown purse-shaped capsules measuring in length, with long coiled tendrils at their four corners. The smallest known specimen is long, which is probably close to the size at hatching. Males reach

sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans it might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definitio ...

at between long; female maturation size is unknown.

Human interactions

The quagga catshark is harmless and is not utilized by humans. It is caught incidentally by

demersal The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life; or more commonly, the site where such enterprise takes place ( a.k.a. fishing ground). Commercial fisheries include wild fisheries and fish farms, both ...

in bottom trawls and potentially other gear; such fishing activity is very intense in Indian and Somalian waters, though specific data on this species is lacking. Therefore, the

(IUCN) has listed it as

Data Deficient A data deficient (DD) species is one which has been categorized by the International Union for Conservation of Nature (IUCN) as offering insufficient information for a proper assessment of conservation status to be made. This does not necessaril ...

References

{{Taxonbar, from=Q577761 quagga catshark Fish of Somalia Fish of the Indian Ocean quagga catshark