The Australian sawtail catshark (''Figaro boardmani'') is a common

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 ...

catshark Catsharks are ground sharks of the family 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 n ...

, and part 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,

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to southern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

n waters. It is found on or near the bottom of the outer

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 ...

and upper

continental slope A continental margin is the outer edge of continental crust abutting oceanic crust under coastal waters. It is one of the three major zones of the ocean floor, the other two being deep-ocean basins and mid-ocean ridges. The continental margin ...

, at depths of . This slim-bodied species is characterized by crests of enlarged

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 along both the dorsal and ventral edges of its

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 ...

and

caudal peduncle 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 ...

, along with a color pattern of broad, dark saddles outlined in white. It can grow to in length. The Australian sawtail catshark feeds mainly on fishes,

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s, and

cephalopod A cephalopod is any member of the molluscan class Cephalopoda (Greek plural , ; "head-feet") such as a squid, octopus, cuttlefish, or nautilus. These exclusively marine animals are characterized by bilateral body symmetry, a prominent head ...

s. Females are

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 ...

and lay eggs enclosed by capsules. This species is often caught incidentally by commercial bottom trawl

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 ...

, but is not significantly threatened by fishing activity. Thus, it has been assessed as of Least Concern by the International Union for Conservation of Nature (IUCN).

Taxonomy

Australian

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish ( Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of Octobe ...

Gilbert Percy Whitley originally described the Australian sawtail catshark as ''Pristiurus boardmani'', in a 1928 issue of the

scientific journal In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. Content Articles in scientific journals are mostly written by active scientists such as s ...

''Records of the Australian Museum'', and placed it within his newly created subgenus ''Figaro''. Whitley named the species after his friend and colleague William Boardman, who collected the first known specimens, including the holotype: a long adult male trawled by the ''Bar-ea-mul'' on 18 July 1925, northeast of Montague Island off New South Wales. Another

common name In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrast ...

for this species is banded shark. Both ''Pristiurus'' and ''Figaro'' have generally been considered

junior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linna ...

s of the genus '' Galeus''; in 2008, Commonwealth Scientific and Industrial Research Organisation (CSIRO) researchers Daniel Gledhill, Peter Last, and William White resurrected ''Figaro'', with ''F. boardmani'' as the type species. Whitley regarded sharks from the Great Australian Bight as representing a distinct subspecies, ''F. b. socinus'', which has not been recognized by subsequent authors. However, individuals from different portions of its range do exhibit minor differences in morphology and coloration, which merit further study.

Description

The maximum known length of the Australian sawtail catshark is . Its slender body is firm and nearly cylindrical in cross-section. The snout is rather short and narrow, with a somewhat angular profile from above. The eyes are horizontally oval and equipped with 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 (protective third eyelids). Beneath the eye is a thin ridge, and behind is a 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 ...

. The nostrils have triangular flaps of skin in front. The mouth is wide and arched, with furrows of medium length at each corner. The teeth are small, each with a long central cusp and multiple smaller cusplets on each side. There are five pairs of gill slits. The two dorsal fins have rounded apexes, with the first slightly larger than the second. The first and second dorsal fins originate over the rear of 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 ...

and

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 ...

s respectively. The pectoral fins are broad and moderate in size. The pelvic fins are small and low with an angular shape; in adult males their inner margins are fused to form a subtle "apron" over the claspers. The

is roughly triangular; its base measures 11% of the total length, exceeding the distance between the pelvic and anal fins but not the distance between the dorsal fins. The

is short and low, with a small but obvious lower lobe and a ventral notch near the tip of the upper lobe. Small, overlapping

s cover the body and fins; each denticle has three marginal teeth. In addition, there are enlarged spiny denticles forming prominent crests along the front half of the upper caudal fin edge, and beneath the

to the ventral caudal fin edge. This species is grayish above and light below. Dorsally, there are 12–13 variegated dark saddles or bands along the body and tail, including three saddles before the dorsal fins that are separated by narrow bands. The saddles are highlighted by a lighter edge, and may contain white flecks. The dorsal and pectoral fins are dark at the bases and light at the margins.

Distribution and habitat

Widely distributed off southern

, the Australian sawtail catshark has been found from Carnarvon in Western Australia to Noosa in Queensland, including all of Tasmania. This abundant,

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 ...

species inhabits the outer

and upper

at a depth of .

Biology and ecology

The Australian sawtail catshark has been known to assemble in groups of a single sex. It feeds primarily on fishes,

s, and

s. Reproduction is

, possibly without a well-defined

breeding season Seasonal breeders are animal species that successfully mate only during certain times of the year. These times of year allow for the optimization of survival of young due to factors such as ambient temperature, food and water availability, and cha ...

as is the case in other catsharks. Adult females have a single functional

ovary The ovary is an organ in the female reproductive system that produces an ovum. When released, this travels down the fallopian tube into the uterus, where it may become fertilized by a sperm. There is an ovary () found on each side of the body. ...

and two functional oviducts; apparently a single egg matures in each oviduct at a time. The eggs are enclosed in capsules measuring long, across, and thick. Males and females attain sexual maturity at roughly and long respectively.

Human interactions

The Australian sawtail catshark is a frequent incidental catch of bottom trawl commercial fisheries operating throughout its range, including the Western Australian Deep Water Trawl Fishery, the South East Trawl Fishery, and the Queensland East Coast Trawl Fishery. It may be retained and utilized, but is more commonly discarded; the survival rate of discarded sharks is unknown. This species remains widespread and common, and fishing activities do not appear to pose a substantial threat to its population at present. As a result, the International Union for Conservation of Nature (IUCN) has listed it under Least Concern.

References

{{Taxonbar, from=Q1947188

Australian sawtail catshark The Australian sawtail catshark (''Figaro boardmani'') is a common species of catshark, and part of the family Scyliorhinidae, endemic to southern Australian waters. It is found on or near the bottom of the outer continental shelf and upper con ...

Marine fish of Southern Australia Taxa named by Gilbert Percy Whitley