Springer's sawtail cat shark
Encyclopedia
The Springer's sawtail catshark (Galeus springeri) is a little-known species
of catshark
, family
Scyliorhinidae, found in water 457–699 m (1,499.3–2,293.3 ft) deep off the islands of the Antilles
, from Cuba
to the Leewards
. A small, slim-bodied species reaching a length of 48 cm (18.9 in), the Springer's sawtail catshark can be identified by its color pattern of horizontal dark stripes in front of the first dorsal fin, and dark dorsal saddles behind. It is additionally characterized by the presence of saw-toothed crests, made of enlarged dermal denticles along both the dorsal and the ventral edges of the caudal fin. The Springer's sawtail catshark is oviparous. The International Union for Conservation of Nature (IUCN) presently lacks the information to assess its conservation status.
(G. antillensis, formerly G. arae antillensis). The first known specimen had resided in the National Museum of Natural History
for over 20 years, until an artifact of preservation revealed the distinctive ventral dermal denticle crest on the caudal fin. The species was described in a 1998 issue of the scientific journal
Copeia by Hera Konstantinou and Joseph Cozzi, who named it after leading shark taxonomist Stewart Springer
. The type specimen is a 32 cm (12.6 in) long immature male collected on December 8, 1969 near the Leeward Islands
. This shark belongs to the G. arae species complex
, which also includes G. antillensis, G. arae, G. cadenati, and G. mincaronei.
, Jamaica
, Hispaniola
, Puerto Rico
, the Leeward Islands, and probably the U.S. Virgin Islands. The full extent of its distribution is uncertain due to confusion with related species. Recorded from depths of 457 to 699 m (1,499.3 to 2,293.3 ft), this species is found on or near the bottom over upper continental and insular slopes.
s (protective third eyelids); they are followed by tiny spiracle
s and lack prominent ridges underneath. The nostrils are divided by triangular flaps of skin on their anterior rims. The large mouth forms a wide arch, and bears moderately long furrows at the corners. The teeth are small and have a narrow central cusp flanked by multiple cusplets; they are similar in both jaws, and between sexes. There are five pairs of gill slit
s.
The first dorsal fin
has a blunt apex and is placed over the aft part of the pelvic fins. The second dorsal fin is similar in shape and nearly equal in size to the first, and placed over the aft part of the anal fin. The pectoral fins are fairly large and broad. The small pelvic fins are low relative to their bases, and have angular margins. The anal fin is elongated and placed close to the pelvic and caudal fins; the anal fin base measures 11% of the total length, about comparable to the space between the dorsal fins. The caudal fin has a small lower lobe and a ventral notch near the tip of the upper lobe. The body is covered by small, overlapping dermal denticles, each with a teardrop-shaped crown with a median ridge and three marginal teeth. There are enlarged denticles forming distinctive saw-like crests along the anterior portions of both the dorsal and ventral caudal fin edges. This species has a unique dorsal color pattern, consisting of dark horizontal stripes outlined in white in front of the dorsal fins, and a series of dark saddle-like markings running from the first dorsal fin base to the tail, on a dusky background. The underside is uniformly white.
by a length of 43 cm (16.9 in).
, as there is little information on fishery
activities within its geographic and depth range. Given its restricted range, it may be negatively affected by any expansion of deepwater fisheries in the region. It is occasionally caught in bottom trawls.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
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, found in water 457–699 m (1,499.3–2,293.3 ft) deep off the islands of the Antilles
Antilles
The Antilles islands form the greater part of the West Indies in the Caribbean Sea. The Antilles are divided into two major groups: the "Greater Antilles" to the north and west, including the larger islands of Cuba, Jamaica, Hispaniola , and Puerto Rico; and the smaller "Lesser Antilles" on the...
, from Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
to the Leewards
Leeward Islands
The Leeward Islands are a group of islands in the West Indies. They are the northern islands of the Lesser Antilles chain. As a group they start east of Puerto Rico and reach southward to Dominica. They are situated where the northeastern Caribbean Sea meets the western Atlantic Ocean...
. A small, slim-bodied species reaching a length of 48 cm (18.9 in), the Springer's sawtail catshark can be identified by its color pattern of horizontal dark stripes in front of the first dorsal fin, and dark dorsal saddles behind. It is additionally characterized by the presence of saw-toothed crests, made of enlarged dermal denticles along both the dorsal and the ventral edges of the caudal fin. The Springer's sawtail catshark is oviparous. The International Union for Conservation of Nature (IUCN) presently lacks the information to assess its conservation status.
Taxonomy
The Springer's sawtail catshark was originally regarded as the striped color morph of the Antilles catsharkAntilles catshark
The Antilles catshark is a common but little-known species of catshark, family Scyliorhinidae. It is found on or near the bottom at a depth of off Florida and the West Indies from Jamaica to Martinique. It was once regarded as a subspecies of the similar roughtail catshark , along with the...
(G. antillensis, formerly G. arae antillensis). The first known specimen had resided in the National Museum of Natural History
National Museum of Natural History
The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. Admission is free and the museum is open 364 days a year....
for over 20 years, until an artifact of preservation revealed the distinctive ventral dermal denticle crest on the caudal fin. The species was described in a 1998 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...
Copeia by Hera Konstantinou and Joseph Cozzi, who named it after leading shark taxonomist Stewart Springer
Stewart Springer
Stewart Springer, was a world renowned expert on shark behavior, classification , and distribution of shark populations. There are more than 35 species of sharks, skates, rays, and other animals either classified originally by him or named after him.-Education:Springer was a field naturalist,...
. The type specimen is a 32 cm (12.6 in) long immature male collected on December 8, 1969 near the Leeward Islands
Leeward Islands
The Leeward Islands are a group of islands in the West Indies. They are the northern islands of the Lesser Antilles chain. As a group they start east of Puerto Rico and reach southward to Dominica. They are situated where the northeastern Caribbean Sea meets the western Atlantic Ocean...
. This shark belongs to the G. arae species complex
Species complex
A species complex is a group of closely related species, where the exact demarcation between species is often unclear or cryptic owing to their recent and usually still incomplete reproductive isolation. Ring species, superspecies and cryptic species complex are example of species complex...
, which also includes G. antillensis, G. arae, G. cadenati, and G. mincaronei.
Distribution and habitat
The range of the Springer's sawtail catshark is limited and overlaps that of the similar Antilles catshark; it occurs off CubaCuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...
, Jamaica
Jamaica
Jamaica is an island nation of the Greater Antilles, in length, up to in width and 10,990 square kilometres in area. It is situated in the Caribbean Sea, about south of Cuba, and west of Hispaniola, the island harbouring the nation-states Haiti and the Dominican Republic...
, Hispaniola
Hispaniola
Hispaniola is a major island in the Caribbean, containing the two sovereign states of the Dominican Republic and Haiti. The island is located between the islands of Cuba to the west and Puerto Rico to the east, within the hurricane belt...
, Puerto Rico
Puerto Rico
Puerto Rico , officially the Commonwealth of Puerto Rico , is an unincorporated territory of the United States, located in the northeastern Caribbean, east of the Dominican Republic and west of both the United States Virgin Islands and the British Virgin Islands.Puerto Rico comprises an...
, the Leeward Islands, and probably the U.S. Virgin Islands. The full extent of its distribution is uncertain due to confusion with related species. Recorded from depths of 457 to 699 m (1,499.3 to 2,293.3 ft), this species is found on or near the bottom over upper continental and insular slopes.
Description
The largest known specimen of the Springer's sawtail catshark measured 48 cm (18.9 in) long. It has a slender body and a somewhat flattened head with a long, pointed snout. 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); they are followed by 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...
s and lack prominent ridges underneath. The nostrils are divided by triangular flaps of skin on their anterior rims. The large mouth forms a wide arch, and bears moderately long furrows at the corners. The teeth are small and have a narrow central cusp flanked by multiple cusplets; they are similar in both jaws, and between sexes. 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 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...
has a blunt apex and is placed over the aft part of the pelvic fins. The second dorsal fin is similar in shape and nearly equal in size to the first, and placed over the aft part of the anal fin. The pectoral fins are fairly large and broad. The small pelvic fins are low relative to their bases, and have angular margins. The anal fin is elongated and placed close to the pelvic and caudal fins; the anal fin base measures 11% of the total length, about comparable to the space between the dorsal fins. The caudal fin has a small lower lobe and a ventral notch near the tip of the upper lobe. The body is covered by small, overlapping dermal denticles, each with a teardrop-shaped crown with a median ridge and three marginal teeth. There are enlarged denticles forming distinctive saw-like crests along the anterior portions of both the dorsal and ventral caudal fin edges. This species has a unique dorsal color pattern, consisting of dark horizontal stripes outlined in white in front of the dorsal fins, and a series of dark saddle-like markings running from the first dorsal fin base to the tail, on a dusky background. The underside is uniformly white.
Biology and ecology
There is little known of the natural history of the Springer's sawtail catshark. Reproduction is presumably oviparous; other females of the G. arae complex produce flask-shaped egg capsules around 5 cm (2 in) long, with tendrils at the upper two corners. Adult males have yet to be captured; the largest immature male measured 32 cm (12.6 in) long. Females are matureSexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...
by a length of 43 cm (16.9 in).
Human interactions
The International Union for Conservation of Nature has listed the Springer's sawtail catshark under Data DeficientData 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...
, as there is little information on fishery
Fishery
Generally, a fishery is an entity engaged in raising or harvesting fish which is determined by some authority to be a fishery. According to the FAO, a fishery is typically defined in terms of the "people involved, species or type of fish, area of water or seabed, method of fishing, class of boats,...
activities within its geographic and depth range. Given its restricted range, it may be negatively affected by any expansion of deepwater fisheries in the region. It is occasionally caught in bottom trawls.