Peppered catshark
Encyclopedia
The peppered catshark is a common but little-known species
of catshark
, family
Scyliorhinidae, occurring at depths of 130–1326 m (426.5–4,350.4 ft) in the northern Gulf of California
. It is found on or near the bottom and conducts seasonal migrations
, spending winter in deeper water. Reaching a length of 37 cm (14.6 in), this species has a slender grayish body with a fine covering of black dots. On the dorsal edge of its caudal fin is a prominent crest of enlarged dermal denticles. It is oviparous, with the reproductive period probably lasting from May to September. The International Union for Conservation of Nature (IUCN) has listed the peppered catshark under Least Concern
, as it faces no significant threats from human activity.
and Mary Wagner in a 1966 issue of Los Angeles County Museum Contributions in Science; the specific epithet piperatus is derived from the Latin
piper, meaning "pepper". The type specimen is an adult female 30 cm (11.8 in) long, collected halfway between Tiburón Island
and Isla Ángel de la Guarda
. The peppered catshark is barely distinguishable from the G. arae species complex
of the western Atlantic; its anomalous geographical distribution is likely a product of vicariance
stemming from the formation of the Isthmus of Panama
(c. 3 Ma).
, with the southern boundary defined by the city of Guaymas
in Sonora
, and Isla Salsipuedes in Baja California
. This abundant species has been recorded from between 130 and 1326 m (426.5 and 4,350.4 ft) deep, but is most common at a depth of 170–420 m (557.7–1,378 ft). Though main demersal in habits, at night it has been captured as much as 100 m (328.1 ft) above the bottom. At the northern extreme of the Gulf of California, this species virtually disappears during the summer, suggesting that it overwinters in deeper, more southerly waters. This migration
is unusual in that it is opposite pattern observed in most other migratory fishes of the Gulf, and seems to be correlated with reproductive activity with spawning taking place in the summer.
s (protective third eyelids), and lack obvious ridges underneath. Behind each eye is a minute spiracle
. The large mouth is wide and curved, with well-developed furrows at the corners. The teeth have narrow central cusps flanked by up to three pairs of cusplets on either side. There are five pairs of gill slit
s.
The first and second dorsal fin
s originate over the rear of the pelvic fins and the middle of the anal fin respectively. The dorsal fins are similar in shape and size, both having blunt apexes. The pectoral fins are large and broad, with rounded corners. The pelvic and anal fins are rather small and low, with angular corners. The anal fin base measures around 11–13% of the total length, comparable to the distance between the dorsal fins and greatly exceeding the distance between the pelvic and anal fins. The caudal peduncle is compressed from side to side and leads to a low caudal fin, which has a small lower lobe and a ventral notch near the tip of the upper lobe. The dermal denticles are small and overlapping, each with a leaf-shaped crown bearing a median ridge and three marginal teeth. There is a saw-like crest of enlarged denticles along the anterior portion of the upper caudal fin margin. The body and tail are dusky with a covering of fine black dots; young sharks may also have a series of darker brown saddle markings outlined in white. The caudal fin margin is white, and the inside of the mouth is typically blackish.
(Squatina california). The young sharks hatch at a length of 7–8 cm (2.8–3.1 in). Mathews (1984) reported females maturing
at a length of 18 cm (7.1 in), while Compagno (1984) reported males and females maturing at lengths of 28–29 cm (11–11.4 in) and 26–30 cm (10.2–11.8 in) respectively.
in the Gulf of California. As a result, the International Union for Conservation of Nature (IUCN) has assessed it as of Least Concern
.
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, occurring at depths of 130–1326 m (426.5–4,350.4 ft) in the northern Gulf of California
Gulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
. It is found on or near the bottom and conducts seasonal migrations
Fish migration
Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres...
, spending winter in deeper water. Reaching a length of 37 cm (14.6 in), this species has a slender grayish body with a fine covering of black dots. On the dorsal edge of its caudal fin is a prominent crest of enlarged dermal denticles. It is oviparous, with the reproductive period probably lasting from May to September. The International Union for Conservation of Nature (IUCN) has listed the peppered catshark under 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...
, as it faces no significant threats from human activity.
Taxonomy
The peppered catshark was described by Stewart SpringerStewart 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,...
and Mary Wagner in a 1966 issue of Los Angeles County Museum Contributions in Science; the specific epithet piperatus is derived from the Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
piper, meaning "pepper". The type specimen is an adult female 30 cm (11.8 in) long, collected halfway between Tiburón Island
Tiburón Island
Tiburón Island is both the largest island in the Gulf of California and the largest island in Mexico, with an area of . It was made a nature reserve in 1963 by President Adolfo López Mateos. Tiburón is Spanish for shark. The etymology of the Seri name is unknown...
and Isla Ángel de la Guarda
Isla Ángel de la Guarda
Isla Ángel de la Guarda, also called Archangel Island, and called Xazl Iimt east of Bahía de los Ángeles, and separated from the Baja California Peninsula by the Canal de Ballenas . It is the second largest of the eleven Midriff Islands or Islas Grandes. It is part of the state of Baja California,...
. The peppered catshark is barely distinguishable from 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...
of the western Atlantic; its anomalous geographical distribution is likely a product of vicariance
Vicariance
Vicariance is a process by which the geographical range of an individual taxon, or a whole biota, is split into discontinuous parts by the formation of a physical barrier to gene flow or dispersal. Vicariance of whole biotas occurs following large-scale geophysical events such as the uplift of a...
stemming from the formation of the Isthmus of Panama
Isthmus of Panama
The Isthmus of Panama, also historically known as the Isthmus of Darien, is the narrow strip of land that lies between the Caribbean Sea and the Pacific Ocean, linking North and South America. It contains the country of Panama and the Panama Canal...
(c. 3 Ma).
Distribution and habitat
The range of the peppered catshark is limited to the Gulf of CaliforniaGulf of California
The Gulf of California is a body of water that separates the Baja California Peninsula from the Mexican mainland...
, with the southern boundary defined by the city of Guaymas
Guaymas
Guaymas is a city and municipality located in the southwest part of the state of Sonora in northwestern Mexico. The city is located 117 km south of the state capital of Hermosillo, and 242 miles from the U.S. border, and is the principal port for the state. The municipality is located in the...
in Sonora
Sonora
Sonora officially Estado Libre y Soberano de Sonora is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 72 municipalities; the capital city is Hermosillo....
, and Isla Salsipuedes in Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
. This abundant species has been recorded from between 130 and 1326 m (426.5 and 4,350.4 ft) deep, but is most common at a depth of 170–420 m (557.7–1,378 ft). Though main demersal in habits, at night it has been captured as much as 100 m (328.1 ft) above the bottom. At the northern extreme of the Gulf of California, this species virtually disappears during the summer, suggesting that it overwinters in deeper, more southerly waters. This migration
Fish migration
Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres...
is unusual in that it is opposite pattern observed in most other migratory fishes of the Gulf, and seems to be correlated with reproductive activity with spawning taking place in the summer.
Description
The maximum known length attained by the peppered catshark is 37 cm (14.6 in). This species is slender and firm-bodied, with a slightly flattened head and a rather long, pointed snout. The anterior rims of the nostrils are expanded into triangular flaps of skin. The horizontally oval eyes are 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), and lack obvious ridges underneath. Behind each eye is a minute 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...
. The large mouth is wide and curved, with well-developed furrows at the corners. The teeth have narrow central cusps flanked by up to three pairs of cusplets on either side. 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 originate over the rear of the pelvic fins and the middle of the anal fin respectively. The dorsal fins are similar in shape and size, both having blunt apexes. The pectoral fins are large and broad, with rounded corners. The pelvic and anal fins are rather small and low, with angular corners. The anal fin base measures around 11–13% of the total length, comparable to the distance between the dorsal fins and greatly exceeding the distance between the pelvic and anal fins. The caudal peduncle is compressed from side to side and leads to a low caudal fin, which has a small lower lobe and a ventral notch near the tip of the upper lobe. The dermal denticles are small and overlapping, each with a leaf-shaped crown bearing a median ridge and three marginal teeth. There is a saw-like crest of enlarged denticles along the anterior portion of the upper caudal fin margin. The body and tail are dusky with a covering of fine black dots; young sharks may also have a series of darker brown saddle markings outlined in white. The caudal fin margin is white, and the inside of the mouth is typically blackish.
Biology and ecology
Little is known of the natural history of the peppered catshark. Reproduction is oviparous and apparently takes place between May and September. Newly mature females carry only 2–3 eggs, while the largest females may carry 10 or more eggs at a time; each egg is contained within a distinctively olive-green capsule around 3.5 cm (1.4 in) long. The egg cases are consumed by the Pacific angelsharkPacific angelshark
The Pacific angelshark is a species of angel shark, family Squatinidae, found in the eastern Pacific Ocean from Alaska to the Gulf of California, and from Ecuador to Chile, although those in the Gulf of California and southeastern Pacific may in fact be separate species...
(Squatina california). The young sharks hatch at a length of 7–8 cm (2.8–3.1 in). Mathews (1984) reported females maturing
Sexual 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...
at a length of 18 cm (7.1 in), while Compagno (1984) reported males and females maturing at lengths of 28–29 cm (11–11.4 in) and 26–30 cm (10.2–11.8 in) respectively.
Human interactions
The peppered catshark generally lives beyond the depths utilized by commercial fisheriesCommercial 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...
in the Gulf of California. As a result, the International Union for Conservation of Nature (IUCN) has assessed it as of 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...
.