Haploblepharus
   HOME

TheInfoList



OR:

''Haploblepharus'' is a
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of deepwater catsharks, belonging to the
family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Pentanchidae Pentanchidae, the deepwater catsharks, is a family of sharks belonging to the order Carcharhiniformes Carcharhiniformes ( from Classical Greek ' (karcharos) 'sharp/jagged' and ' (rhinos) 'nose', plus Latin ''forme'' 'shape'), commonly known a ...
, containing four
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of shysharks. Their
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 con ...
comes from a distinctive defensive behavior in which the shark curls into a circle and covers its eyes with its tail. The genus is
endemic Endemism is the state of a species being found only 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 foun ...
to
southern Africa Southern Africa is the southernmost region of Africa. No definition is agreed upon, but some groupings include the United Nations geoscheme for Africa, United Nations geoscheme, the intergovernmental Southern African Development Community, and ...
, inhabiting shallow coastal waters. All four species are small, stout-bodied sharks with broad, flattened heads and rounded snouts. They are characterized by very large
nostril A nostril (or naris , : nares ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbinates ...
s with enlarged, triangular flaps of skin that reach the mouth, and deep grooves between the nostrils and the mouth. Shysharks are
bottom-dwelling The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...
predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...
s of
bony fish Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...
es and
invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...
s. They are
oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...
, with the females laying egg capsules. These harmless sharks are of no
commercial Commercial may refer to: * (adjective for) commerce, a system of voluntary exchange of products and services ** (adjective for) trade, the trading of something of economic value such as goods, services, information or money * a dose of advertising ...
or
recreational Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or plea ...
interest, though their highly limited distributions in heavily fished South African waters are of potential conservation concern.


Taxonomy and phylogeny

The genus ''Haploblepharus'' was created by American zoologist
Samuel Garman Samuel Walton Garman (June 5, 1843 – September 30, 1927), or "Garmann" as he sometimes styled himself, was an American naturalist and zoologist. He became noted as an ichthyologist and herpetologist. Biography Garman was born in Indiana Co ...
in 1913, in the 36th volume of ''Memoirs of the Museum of Comparative Zoology, at Harvard College'', to contain the
puffadder shyshark The puffadder shyshark (''Haploblepharus edwardsii''), also known as the Happy Eddie, is a species of shark belonging to the Family (biology), family Pentanchidae, the deepwater catsharks. This species is endemism, endemic to the temperate waters ...
, then known as ''Squalus edwardsii''. The name is derived from the Greek ''haplóos'' meaning "single", and ''blepharos'' meaning "eyelid".Bester, C
Biological Profiles: Puffadder Shyshark
Florida Museum of Natural History Ichthyology Department. Retrieved on August 31, 2009.
In 1988,
Leonard Compagno Leonard Joseph Victor Compagno (1943-2024) was an international authority on shark taxonomy and the author of many scientific papers and books on the subject, best known of which is his 1984 catalogue of shark species produced for the Food and Agri ...
placed ''Haploblepharus'' with ''
Halaelurus ''Halaelurus'' is a genus of catsharks in the family Pentanchidae. Species * '' Halaelurus boesemani'' S. Springer & D'Aubrey, 1972 (speckled catshark) * '' Halaelurus buergeri'' ( J. P. Müller & Henle, 1838) (blackspotted catshark) * '' Hal ...
'' and '' Holohalaelurus'' in the tribe Halaelurini of the family Scyliorhinidae, based on morphological characters. This interpretation was corroborated by a 2006
phylogenetic analysis In biology, phylogenetics () is the study of the evolutionary history of life using observable characteristics of organisms (or genes), which is known as phylogenetic inference. It infers the relationship among organisms based on empirical data ...
based on three
mitochondrial DNA Mitochondrial DNA (mtDNA and mDNA) is the DNA located in the mitochondrion, mitochondria organelles in a eukaryotic cell that converts chemical energy from food into adenosine triphosphate (ATP). Mitochondrial DNA is a small portion of the D ...
gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
s. However, that study also found that within this group ''Haploblepharus'' is most closely related to the genus ''Halaelurus'', which is inconsistent with the presence of three autapomorphic traits in ''Haploblepharus'' that are not shared by either ''Halaelurus'' or ''Holohalaelurus''. Within the genus, the puffadder shyshark is the most basal species.


Species

* '' Haploblepharus edwardsii'' ( Schinz, 1822) (puffadder shyshark) * ''
Haploblepharus fuscus ''Haploblepharus'' is a genus of deepwater catsharks, belonging to the Family (biology), family Pentanchidae, containing four species of shysharks. Their common name comes from a distinctive defensive behavior in which the shark curls into a circ ...
''
J. L. B. Smith James Leonard Brierley Smith (26 September 1897 – 8 January 1968) was a South African ichthyology, ichthyologist, organic chemist, and university professor. He was the first to identify a taxidermied fish as a coelacanth, at the time thought t ...
, 1950
(brown shyshark) * '' Haploblepharus kistnasamyi''
Human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...
& Compagno, 2006
(Natal shyshark) * '' Haploblepharus pictus'' ( J. P. Müller & Henle, 1838) (dark shyshark)


Distribution and habitat

All four shyshark species are
endemic Endemism is the state of a species being found only 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 foun ...
to the southern tip of Africa; three of them are found only off
South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
, while the range of the dark shyshark extends to southern
Namibia Namibia, officially the Republic of Namibia, is a country on the west coast of Southern Africa. Its borders include the Atlantic Ocean to the west, Angola and Zambia to the north, Botswana to the east and South Africa to the south; in the no ...
. They are
bottom-dwelling The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...
in nature and usually found in shallow, coastal waters over sandy or rocky bottoms.


Description

Different shyshark species are very similar to one another in appearance but can be reliably differentiated using morphological measurements. However, in the field the only way to readily tell them apart is by their different color patterns, and even this may be problematic as individuals of the same species can vary considerably in coloration. All four species are small, seldom exceeding in length. A shyshark has a stout, spindle-shaped body and a short head comprising less than one-fifth of the total length. The head is broad and dorsally flattened, with a rounded snout. The large, oval eyes have cat-like slit
pupil The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina.Cassin, B. and Solomon, S. (1990) ''Dictionary of Eye Terminology''. Gainesville, Florida: Triad Publishing Company. It appears black becau ...
s, a 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. Most ...
(protective third
eyelid An eyelid ( ) is a thin fold of skin that covers and protects an eye. The levator palpebrae superioris muscle retracts the eyelid, exposing the cornea to the outside, giving vision. This can be either voluntarily or involuntarily. "Palpebral ...
), and a prominent ridge running underneath. A distinguishing trait of this genus are the large
nostril A nostril (or naris , : nares ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called turbinates ...
s partially covered by greatly expanded, triangular flaps of skin that overlap the mouth and cover a pair of deep grooves between the nasal excurrent (outflow) openings and the mouth. The mouth is short and curved, with furrows at the corners extending onto both jaws. The teeth have a central cusp and smaller lateral cusplets. The five pairs of
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 and rays, as well as deep-branching vertebrates such as lampreys. In c ...
s are located on the upper side of the body. The two
dorsal fin A dorsal fin is a fin on the back of most marine and freshwater vertebrates. Dorsal fins have evolved independently several times through convergent evolution adapting to marine environments, so the fins are not all homologous. They are found ...
s are set far back on the body, the first originating behind the
pelvic fin Pelvic fins or ventral fins are paired fins located on the ventral (belly) surface of fish, and are the lower of the only two sets of paired fins (the other being the laterally positioned pectoral fins). The pelvic fins are homologous to the hi ...
midbases and the second originating behind the
anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...
midbase. The
pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...
s are moderately large; the dorsal, pelvic, and anal fins are of similar size. The broad
caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ...
comprises a fifth of the total length; the upper lobe has a deep ventral notch near the tip and the lower lobe is virtually absent. The skin is thick and covered by well-
calcified Calcification is the accumulation of calcium salts in a body tissue. It normally occurs in the formation of bone, but calcium can be deposited abnormally in soft tissue,Miller, J. D. Cardiovascular calcification: Orbicular origins. ''Nature Mat ...
, leaf-shaped
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 scale (zoology), scales, which can also provide effective Underwater camouflage, camouflage through the us ...
s. The coloration is brown above and white below; the brown shyshark is usually plain while the other species have varying patterns of darker "saddles" and white spots.


Biology and ecology

Shysharks feed on a variety of small benthic
bony fish Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondricht ...
es and
invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...
s. In turn, they are preyed upon by larger fishes and
marine mammal Marine mammals are mammals that rely on marine ecosystems for their existence. They include animals such as cetaceans, pinnipeds, sirenians, sea otters and polar bears. They are an informal group, unified only by their reliance on marine enviro ...
s. When threatened, these sharks adopt a curious posture in which they curl their bodies into a ring and cover their eyes with their tails, which is the origin of the name "shyshark". This behavior likely serves to make the shark more difficult for a
predator Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common List of feeding behaviours, feeding behaviours that includes parasitism and micropredation ...
to swallow. Shysharks are
oviparous Oviparous animals are animals that reproduce by depositing fertilized zygotes outside the body (i.e., by laying or spawning) in metabolically independent incubation organs known as eggs, which nurture the embryo into moving offsprings kno ...
with females producing egg capsules (known as "
mermaid's purse An egg case or egg capsule, often colloquially called a mermaid's purse, is the casing that surrounds the eggs of oviparous chondrichthyans. Living chondricthyans that produce egg cases include some sharks, skates and chimaeras. Egg cases t ...
s") two at a time. Reproduction has been investigated in the puffadder and dark shysharks; neither species appears to have a distinct
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 ch ...
, and their eggs take around three and a half weeks to hatch.Dainty, A.M. (2002). Biology and ecology of four catshark species in the southwestern Cape, South Africa. M.Sc. thesis, University of Cape Town.


Human interactions

Due to their small size, shysharks pose no danger to humans and are not sought by either
commercial Commercial may refer to: * (adjective for) commerce, a system of voluntary exchange of products and services ** (adjective for) trade, the trading of something of economic value such as goods, services, information or money * a dose of advertising ...
or recreational fishers. They are taken as
bycatch Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juve ...
and hooked by shore anglers, who regard them (and other catsharks) as minor pests. Although shysharks are not uncommon, their extremely limited distribution within heavily fished waters raises concerns that a local increase in fishing pressure or
habitat degradation Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
could affect entire species populations. As a result, the
International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the stat ...
(IUCN) has assessed two shyshark species as
Near Threatened A near-threatened species is a species which has been Conservation status, categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature (IUCN) as that may be vulnerable to Endangered species, endangerment in the ne ...
.


References

{{Taxonbar, from=Q2093983 Pentanchidae Shark genera * Taxa named by Samuel Garman