Natal shyshark
Encyclopedia
The Natal shyshark, eastern shyshark, or happy chappie, (Haploblepharus kistnasamyi) is a species
of catshark
, family
Scyliorhinidae, once regarded as the "Natal" form of the puffadder shyshark
(H. edwardsii). This shark is endemic to a small area off South Africa
from the Western Cape to KwaZulu-Natal
. It is found close to the coast, from the surf zone
to a depth of 30 m (98.4 ft), and has benthic habits. Reaching 50 cm (19.7 in) in length, the Natal shyshark is similar to the puffadder shyshark in appearance but has a stockier body, less flattened head, a compressed caudal peduncle, and a different color pattern. Rare and under threat from habitat degradation and commercial fishing
, it has been assessed as Critically Endangered
by the International Union for Conservation of Nature (IUCN).
, which differed from the main "Cape" form in appearance and habitat preferences. In 2006, Brett A. Human and Leonard J.V. Compagno formally described this shark as a new species, in an article published in the scientific journal
Zootaxa. They named it after South African shark researcher Nat Kistnasamy, the Natal shyshark's original discoverer.
. Its total range is estimated to encompass an area of under 100 square kilometre. A benthic species, it can be found in the surf zone
and on shallow rocky reef
s. As opposed to the puffadder shyshark, which inhabits deeper, cooler waters in the northeastern parts of its range, in those areas the Natal shyshark occurs in warm inshore waters at a depth of 0–30 m (0–98.4 ft).
s and greatly expanded, triangular nasal skin flaps that reach the mouth. There are a pair of deep grooves, covered by the nasal flaps, that run from the excurrent (outflow) openings of the nostrils to the mouth. The mouth has furrows at the corners on both jaws, and contains teeth with 3–5 points. The eyes are large, with a rudimentary nictitating membrane
(protective third eyelid
) and a prominent ridge beneath. The five gill slit
s are positioned somewhat dorsally on the body.
The dorsal
, pelvic, and anal fins are of roughly equal size. The dorsal fins are placed far back on the body, with the first originating behind the pelvic fin origins and the second originating behind the anal fin origins. The pectoral fins are moderately large. The short and broad caudal fin has a ventral notch on the upper lobe and an indistinct lower lobe. The skin is thick, bearing well-calcified
leaf-shaped dermal denticles. The back is brown, with a distinctive pattern of H-shaped, dark brown saddles with well-defined margins, along with numerous small white dots and darker mottling between the saddles. This species attains a length of 50 cm (19.7 in).
where industrial and tourism sectors have undergone rapid expansion. Furthermore, the region is subject to heavy fishing pressure, in particular from the commercial prawn
fishery
. Given its localized occurrence and presumably small population, this species has been assessed as Critically Endangered
by the International Union for Conservation of Nature (IUCN).
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, once regarded as the "Natal" form of the puffadder shyshark
Puffadder shyshark
The puffadder shyshark or happy Eddie is a species of catshark, family Scyliorhinidae, endemic to the temperate waters off South Africa. This common shark is found on or near the bottom in sandy or rocky habitats, from the intertidal zone to a depth of . Typically reaching in length, the...
(H. edwardsii). This shark is endemic to a small area off South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
from the Western Cape to KwaZulu-Natal
KwaZulu-Natal
KwaZulu-Natal is a province of South Africa. Prior to 1994, the territory now known as KwaZulu-Natal was made up of the province of Natal and the homeland of KwaZulu....
. It is found close to the coast, from the surf zone
Surf zone
As ocean surface waves come closer to shore they break, forming the foamy, bubbly surface we call surf. The region of breaking waves defines the surf zone. After breaking in the surf zone, the waves continue to move in, and they run up onto the sloping front of the beach, forming an uprush of...
to a depth of 30 m (98.4 ft), and has benthic habits. Reaching 50 cm (19.7 in) in length, the Natal shyshark is similar to the puffadder shyshark in appearance but has a stockier body, less flattened head, a compressed caudal peduncle, and a different color pattern. Rare and under threat from habitat degradation and commercial fishing
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...
, it has been assessed as Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
by the International Union for Conservation of Nature (IUCN).
Taxonomy
This species was once considered to be the "Natal" form of the puffadder shysharkPuffadder shyshark
The puffadder shyshark or happy Eddie is a species of catshark, family Scyliorhinidae, endemic to the temperate waters off South Africa. This common shark is found on or near the bottom in sandy or rocky habitats, from the intertidal zone to a depth of . Typically reaching in length, the...
, which differed from the main "Cape" form in appearance and habitat preferences. In 2006, Brett A. Human and Leonard J.V. Compagno formally described this shark as a new species, in an article published in 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...
Zootaxa. They named it after South African shark researcher Nat Kistnasamy, the Natal shyshark's original discoverer.
Distribution and habitat
The distribution of the Natal shyshark is restricted to the waters off the KwaZulu-Natal, and possibly also the Western Cape and Eastern Cape Provinces of South AfricaSouth Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
. Its total range is estimated to encompass an area of under 100 square kilometre. A benthic species, it can be found in the surf zone
Surf zone
As ocean surface waves come closer to shore they break, forming the foamy, bubbly surface we call surf. The region of breaking waves defines the surf zone. After breaking in the surf zone, the waves continue to move in, and they run up onto the sloping front of the beach, forming an uprush of...
and on shallow rocky reef
Reef
In nautical terminology, a reef is a rock, sandbar, or other feature lying beneath the surface of the water ....
s. As opposed to the puffadder shyshark, which inhabits deeper, cooler waters in the northeastern parts of its range, in those areas the Natal shyshark occurs in warm inshore waters at a depth of 0–30 m (0–98.4 ft).
Description
The Natal shyshark closely resembles the puffadder shyshark, but has a more robust body, a less flattened head, and a laterally compressed caudal peduncle. The snout is broad and rounded, with very large nostrilNostril
A nostril is one of the two channels of the nose, from the point where they bifurcate to the external opening. In birds and mammals, they contain branched bones or cartilages called turbinates, whose function is to warm air on inhalation and remove moisture on exhalation...
s and greatly expanded, triangular nasal skin flaps that reach the mouth. There are a pair of deep grooves, covered by the nasal flaps, that run from the excurrent (outflow) openings of the nostrils to the mouth. The mouth has furrows at the corners on both jaws, and contains teeth with 3–5 points. The eyes are large, with a rudimentary nictitating membrane
Nictitating 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...
(protective third eyelid
Eyelid
An eyelid is a thin fold of skin that covers and protects an eye. With the exception of the prepuce and the labia minora, it has the thinnest skin of the whole body. The levator palpebrae superioris muscle retracts the eyelid to "open" the eye. This can be either voluntarily or involuntarily...
) and a prominent ridge beneath. The five 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 are positioned somewhat dorsally on the body.
The dorsal
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...
, pelvic, and anal fins are of roughly equal size. The dorsal fins are placed far back on the body, with the first originating behind the pelvic fin origins and the second originating behind the anal fin origins. The pectoral fins are moderately large. The short and broad caudal fin has a ventral notch on the upper lobe and an indistinct lower lobe. The skin is thick, bearing well-calcified
Calcification
Calcification is the process in which calcium salts build up in soft tissue, causing it to harden. Calcifications may be classified on whether there is mineral balance or not, and the location of the calcification.-Causes:...
leaf-shaped dermal denticles. The back is brown, with a distinctive pattern of H-shaped, dark brown saddles with well-defined margins, along with numerous small white dots and darker mottling between the saddles. This species attains a length of 50 cm (19.7 in).
Biology and ecology
The Natal shyshark is rarer than the puffadder shyshark and little is known of its habits. Males are sexually mature at around 50 cm (19.7 in) long, and females at 48 cm (18.9 in) long. The shysharks are so named because they curl into a ring and cover their eyes with their tails when threatened.Human interactions
The highly restricted range of the Natal shyshark is threatened by habitat degradation from coastal development, particularly in the vicinity of DurbanDurban
Durban is the largest city in the South African province of KwaZulu-Natal and the third largest city in South Africa. It forms part of the eThekwini metropolitan municipality. Durban is famous for being the busiest port in South Africa. It is also seen as one of the major centres of tourism...
where industrial and tourism sectors have undergone rapid expansion. Furthermore, the region is subject to heavy fishing pressure, in particular from the commercial prawn
Prawn
Prawns are decapod crustaceans of the sub-order Dendrobranchiata. There are 540 extant species, in seven families, and a fossil record extending back to the Devonian...
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,...
. Given its localized occurrence and presumably small population, this species has been assessed as Critically Endangered
Critically Endangered
Critically Endangered is the highest risk category assigned by the IUCN Red List for wild species. Critically Endangered means that a species' numbers have decreased, or will decrease, by 80% within three generations....
by the International Union for Conservation of Nature (IUCN).