Figaro (genus)
Encyclopedia
Figaro is a genus
of catshark
, family
Scyliorhinidae, that until 2008 was generally considered to be a subgenus
of Galeus
(sawtail catsharks). The two known species are found off Australia
, inhabiting deep, offshore waters on or near the bottom. Figaro contains small, slender, firm-bodied sharks that bear distinctive crests of enlarged, spiny dermal denticles along the dorsal and ventral edges of their short caudal fins. The caudal peduncle is relatively long, such as that the anal and caudal fins are some distance apart. In adult males, the inner margins of the pelvic fins are fused together to form a subtle "apron" over the claspers. F. boardmani
is a predator of fishes, crustacean
s, and cephalopod
s, and is oviparous; less is known of F. striatus
. Both are harmless and of no economic importance.
of Pristiurus by Australian ichthyologist Gilbert Percy Whitley
in a 1928 issue of the scientific journal
Records of the Australian Museum, to contain his newly described species P. boardmani. In 1908, Henry Weed Fowler
synonymized
Pristiurus with the genus Galeus
. Though Whitley elevated Figaro to the rank of full genus in 1939, most authors continued to regard Figaro as a subgenus of Galeus. In 1983, Yuan-Ting Chu and colleagues referenced Figaro to contain Galeus boardmani, Dichichthys melanobranchus (=Parmaturus melanobranchus), and F. piceus (=P. melanobranchus). However, it is uncertain whether they intended to resurrect Figaro or were simply unaware of its synonymy with Galeus, and their use of the ventral denticle crest to define the genus posed taxonomic problems. In 2008, Commonwealth Scientific and Industrial Research Organisation
(CSIRO) researchers Daniel Gledhill, Peter Last, and William White resurrected Figaro with additional defining characters, to contain F. boardmani and the new species F. striatus. The genus has since been generally accepted as distinct.
One of the key characteristics of Figaro, the ventral crest of denticles on the caudal fin, is also present in several species of the genus Parmaturus
, as well as the Springer's sawtail catshark (G. springeri) and the mouse catshark
(G. murinus). Figaro also closely resembles the genus Asymbolus
in several morphological
characters, including the fusion of the pelvic fin inner margins in adult males. More research is required to elucidate the relationships between Figaro, Galeus, Asymbolus, and Parmaturus.
n waters, F. boardmani in the south and F. striatus in the northeast. They are deepwater species found on or near the sea floor, inhabiting the outer continental shelf
and upper continental slope.
s (protective third eyelids); a narrow ridge is found beneath each eye and a tiny spiracle
behind. The anterior rims of the nostrils are enlarged into triangular flaps. The mouth is wide, with relatively short furrows at the corners, and contains small multi-cusped teeth. There are five pairs of gill slit
s.
The first and second dorsal fin
s are similar in size and shape, and are placed mostly behind the pelvic and anal fins respectively. The space between the dorsal fins is much longer than the length of either dorsal fin base. The pectoral fins are short and broad, while the pelvic and anal fins are low with rather long bases. The pectoral, pelvic, and anal fins are proportionally smaller than in Galeus. Unlike Galeus species, adult males have a slight "apron" formed by the fusion of the pelvic fin inner margins; the apron partially covers the claspers, which taper towards the tip. The caudal peduncle is long, with the anal and caudal fins well-separated. The caudal fin is short, with a small lower lobe and a ventral notch near the tip of the upper lobe. The body and fins are densely covered by tiny, overlapping dermal denticles. In addition, there are enlarged denticles that form prominent saw-like crests on both the dorsal and the ventral edges of the caudal fin. The dorsal coloration consists of dark saddles along the back and tail, which are wider in F. boardmani and thinner in F. striatus. The two species also differ in various morphometric characters
, such as in the relative size of the eye.
s, and cephalopod
s, and has a oviparous mode of reproduction.
in commercial fisheries
within its range. The International Union for Conservation of Nature (IUCN) has listed F. boardmani as Least Concern
and F. striatus as Data Deficient
. Like other catsharks, Figaro species pose no danger to humans.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of catshark
Catshark
Catsharks are ground sharks of the family Scyliorhinidae, with over 150 known species. While they are generally known as catsharks, many species are commonly called dogfish....
, family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Scyliorhinidae, that until 2008 was generally considered to be a subgenus
Subgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
of Galeus
Galeus
Galeus is a genus of catshark, 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 are found in the Atlantic, the western and central Pacific, and the Gulf of...
(sawtail catsharks). The two known species are found off Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
, inhabiting deep, offshore waters on or near the bottom. Figaro contains small, slender, firm-bodied sharks that bear distinctive crests of enlarged, spiny dermal denticles along the dorsal and ventral edges of their short caudal fins. The caudal peduncle is relatively long, such as that the anal and caudal fins are some distance apart. In adult males, the inner margins of the pelvic fins are fused together to form a subtle "apron" over the claspers. F. boardmani
Australian sawtail catshark
The Australian sawtail catshark is a common species of catshark, family Scyliorhinidae, endemic to southern Australian waters. It is found on or near the bottom over the outer continental shelf and upper continental slope, at depths of...
is a predator of fishes, crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, and cephalopod
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s, and is oviparous; less is known of F. striatus
Northern sawtail catshark
The northern sawtail catshark is a little-known species of catshark, family Scyliorhinidae, endemic to northeastern Australia. It is demersal in nature and inhabits the upper continental slope at a depth of...
. Both are harmless and of no economic importance.
Taxonomy
Figaro was coined as a subgenusSubgenus
In biology, a subgenus is a taxonomic rank directly below genus.In zoology, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the Tiger Cowry of the Indo-Pacific, Cypraea tigris Linnaeus, which...
of Pristiurus by Australian ichthyologist Gilbert Percy Whitley
Gilbert Percy Whitley
Gilbert Percy Whitley was a British-born Australian ichthyologist and malacologist who was Curator of Fishes at the Australian Museum in Sydney for about 40 years. He was born at Swaythling, Southampton, England, and was educated at King Edward VI School, Southampton and Osborne House...
in a 1928 issue of the scientific journal
Scientific journal
In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. There are thousands of scientific journals in publication, and many more have been published at various points in the past...
Records of the Australian Museum, to contain his newly described species P. boardmani. In 1908, Henry Weed Fowler
Henry Weed Fowler
Henry Weed Fowler was an American zoologist born in Holmesburg, Pennsylvania.He studied at Stanford University under David Starr Jordan...
synonymized
Synonym (taxonomy)
In scientific nomenclature, a synonym is a scientific name that is or was used for a taxon of organisms that also goes by a different scientific name. For example, Linnaeus was the first to give a scientific name to the Norway spruce, which he called Pinus abies...
Pristiurus with the genus Galeus
Galeus
Galeus is a genus of catshark, 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 are found in the Atlantic, the western and central Pacific, and the Gulf of...
. Though Whitley elevated Figaro to the rank of full genus in 1939, most authors continued to regard Figaro as a subgenus of Galeus. In 1983, Yuan-Ting Chu and colleagues referenced Figaro to contain Galeus boardmani, Dichichthys melanobranchus (=Parmaturus melanobranchus), and F. piceus (=P. melanobranchus). However, it is uncertain whether they intended to resurrect Figaro or were simply unaware of its synonymy with Galeus, and their use of the ventral denticle crest to define the genus posed taxonomic problems. In 2008, Commonwealth Scientific and Industrial Research Organisation
Commonwealth Scientific and Industrial Research Organisation
The Commonwealth Scientific and Industrial Research Organisation is the national government body for scientific research in Australia...
(CSIRO) researchers Daniel Gledhill, Peter Last, and William White resurrected Figaro with additional defining characters, to contain F. boardmani and the new species F. striatus. The genus has since been generally accepted as distinct.
One of the key characteristics of Figaro, the ventral crest of denticles on the caudal fin, is also present in several species of the genus Parmaturus
Parmaturus
Parmaturus is a genus of catshark in the family Scyliorhinidae.-Species:* Parmaturus albimarginatus Séret & Last, 2007 * Parmaturus albipenis Séret & Last, 2007...
, as well as the Springer's sawtail catshark (G. springeri) and the mouse catshark
Mouse catshark
The mouse catshark is a species of catshark, family Scyliorhinidae, common in the northeastern Atlantic Ocean, from Iceland to Western Sahara. There is much taxonomic confusion regarding this species in Icelandic waters, where it may be confounded with another species of Galeus or Apristurus...
(G. murinus). Figaro also closely resembles the genus Asymbolus
Asymbolus
Asymbolus is a genus of catshark in the family Scyliorhinidae.-Species:* Asymbolus analis * Asymbolus funebris Compagno, Stevens & Last, 1999...
in several morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
characters, including the fusion of the pelvic fin inner margins in adult males. More research is required to elucidate the relationships between Figaro, Galeus, Asymbolus, and Parmaturus.
Species
- Figaro boardmani (WhitleyGilbert Percy WhitleyGilbert Percy Whitley was a British-born Australian ichthyologist and malacologist who was Curator of Fishes at the Australian Museum in Sydney for about 40 years. He was born at Swaythling, Southampton, England, and was educated at King Edward VI School, Southampton and Osborne House...
, 1928) (Australian sawtail catshark) - Figaro striatus Gledhill, Last & W. T. White, 2008 (Northern sawtail catshark)
Distribution and habitat
Both Figaro species are endemic to AustraliaAustralia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
n waters, F. boardmani in the south and F. striatus in the northeast. They are deepwater species found on or near the sea floor, inhabiting the outer continental shelf
Continental shelf
The continental shelf is the extended perimeter of each continent and associated coastal plain. Much of the shelf was exposed during glacial periods, but is now submerged under relatively shallow seas and gulfs, and was similarly submerged during other interglacial periods. The continental margin,...
and upper continental slope.
Description
The larger Figaro species, F. boardmani, reaches 61 cm (24 in) long, while the smaller F. striatus reaches 42 cm (16.5 in) long. Members of this genus closely resemble Galeus, with firm, slender bodies and short heads. The eyes are horizontally oval and equipped with rudimentary nictitating membraneNictitating membrane
The nictitating membrane is a transparent or translucent third eyelid present in some animals that can be drawn across the eye for protection and to moisten it while maintaining visibility. Some reptiles, birds, and sharks have a full nictitating membrane; in many mammals, there is a small...
s (protective third eyelids); a narrow ridge is found beneath each eye and a tiny spiracle
Spiracle
Spiracles are openings on the surface of some animals that usually lead to respiratory systems.-Vertebrates:The spiracle is a small hole behind each eye that opens to the mouth in some fishes. In the primitive jawless fish the first gill opening immediately behind the mouth is essentially similar...
behind. The anterior rims of the nostrils are enlarged into triangular flaps. The mouth is wide, with relatively short furrows at the corners, and contains small multi-cusped teeth. There are five pairs of gill slit
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, rays, sawfish, and guitarfish. Most of these have five pairs, but a few species have 6 or 7 pairs...
s.
The first and second dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
s are similar in size and shape, and are placed mostly behind the pelvic and anal fins respectively. The space between the dorsal fins is much longer than the length of either dorsal fin base. The pectoral fins are short and broad, while the pelvic and anal fins are low with rather long bases. The pectoral, pelvic, and anal fins are proportionally smaller than in Galeus. Unlike Galeus species, adult males have a slight "apron" formed by the fusion of the pelvic fin inner margins; the apron partially covers the claspers, which taper towards the tip. The caudal peduncle is long, with the anal and caudal fins well-separated. The caudal fin is short, with a small lower lobe and a ventral notch near the tip of the upper lobe. The body and fins are densely covered by tiny, overlapping dermal denticles. In addition, there are enlarged denticles that form prominent saw-like crests on both the dorsal and the ventral edges of the caudal fin. The dorsal coloration consists of dark saddles along the back and tail, which are wider in F. boardmani and thinner in F. striatus. The two species also differ in various morphometric characters
Morphometrics
Morphometrics refers to the quantitative analysis of form, a concept that encompasses size and shape. Morphometric analyses are commonly performed on organisms, and are useful in analyzing their fossil record, the impact of mutations on shape, developmental changes in form, covariances between...
, such as in the relative size of the eye.
Biology and ecology
The natural histories of Figaro species are poorly known. F. boardmani feeds mostly on fishes, crustaceanCrustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, and cephalopod
Cephalopod
A cephalopod is any member of the molluscan class Cephalopoda . These exclusively marine animals are characterized by bilateral body symmetry, a prominent head, and a set of arms or tentacles modified from the primitive molluscan foot...
s, and has a oviparous mode of reproduction.
Human interactions
Neither Figaro species is commercially important or significantly threatened by fishing activity, though F. boardmani forms a regular component of bottom trawl bycatchBycatch
The term “bycatch” is usually used for fish caught unintentionally in a fishery while intending to catch other fish. It may however also indicate untargeted catch in other forms of animal harvesting or collecting...
in commercial fisheries
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 pursue fish far into the ocean under adverse conditions...
within its range. The International Union for Conservation of Nature (IUCN) has listed F. boardmani as Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
and F. striatus as Data Deficient
Data Deficient
Data Deficient is a category applied by the IUCN, other agencies, and individuals to a species when the available information is not sufficient for a proper assessment of conservation status to be made...
. Like other catsharks, Figaro species pose no danger to humans.