The epaulette shark ('', Hemiscyllium ocellatum'') is a

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 longtailed carpet shark of 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 ...

Hemiscylliidae The Hemiscylliidae are a family of sharks in the order Orectolobiformes, commonly known as longtail carpet sharks and sometimes as bamboo sharks. They are found in shallow waters of the tropical Indo-Pacific. They are relatively small sharks, ...

, found in shallow, tropical waters off

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

and

New Guinea New Guinea (; Hiri Motu: ''Niu Gini''; , fossilized , also known as Papua or historically ) is the List of islands by area, world's second-largest island, with an area of . Located in Melanesia in the southwestern Pacific Ocean, the island is ...

(and possibly elsewhere). The

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 ...

of this shark comes from the very large, white-margined black spot behind each

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 ...

, which are reminiscent of military epaulettes. A small species (usually under long), the epaulette shark has a slender body with a short head and broad, paddle-shaped paired fins. The

caudal peduncle 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 ...

(to which the tail fin is attached) comprises over half the shark's length. Adults are light brown above, with scattered darker spots and indistinct saddles. Epaulette sharks have

nocturnal Nocturnality is a ethology, behavior in some non-human animals characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnality, diurnal meaning the opposite. Nocturnal creatur ...

habits and frequent shallow water on

coral reef A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in group ...

s or in

tidal pool A tide pool or rock pool is a shallow pool of seawater that forms on the rocky intertidal shore. These pools typically range from a few inches to a few feet deep and a few feet across. Many of these pools exist as separate bodies of water only ...

s. This shark has evolved to cope with the severe night time

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

depletion ( hypoxia) in isolated tidal pools by increasing the blood supply to its brain and selectively shutting down non-essential neural functions. It is capable of surviving complete anoxia for two hours without ill effects, and at a much higher temperature than most other hypoxia-tolerant animals. Rather than swim, epaulette sharks often "walk" by wriggling their bodies and pushing with their paired fins. This species feeds on a wide range of small

benthic 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". ...

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 and

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. Epaulette sharks 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 depositing pairs of egg capsules around every 14 days from August to December. Due to their hardiness and small size, epaulette sharks are popular with both

public In public relations and communication science, publics are groups of individual people, and the public (a.k.a. the general public) is the totality of such groupings. This is a different concept to the sociology, sociological concept of the ''Öf ...

and home aquaria. 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 this species as of

Least Concern A least-concern species is a species that has been evaluated and categorized by the International Union for Conservation of Nature (IUCN) as not being a focus of wildlife conservation because the specific species is still plentiful in the wil ...

, as outside of the small aquarium trade it is of little interest to

fisheries Fishery can mean either the enterprise of raising or harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place ( a.k.a., fishing grounds). Commercial fisheries include wild fisheries and fish farm ...

Taxonomy and phylogeny

The epaulette shark was originally described as ''Squalus ocellatus'' by the French

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

Pierre Joseph Bonnaterre Abbé Pierre Joseph Bonnaterre (1752, Aveyron – 20 September 1804, Saint-Geniez-d'Olt) was a French zoology, zoologist who contributed sections on cetaceans, mammals, birds, reptiles, amphibians, fish, and insects to the ''Tableau encyclopéd ...

in the 1788 '' Tableau encyclopédique et méthodique des trois règnes de la nature''. The name was later changed to the currently valid ''Hemiscyllium ocellatum''. The

type specimen In biology, a type is a particular wikt:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to ancho ...

was a long immature male caught near

Cooktown Cooktown is a coastal town and locality in the Shire of Cook, Queensland, Australia. Cooktown is at the mouth of the Endeavour River, on Cape York Peninsula in Far North Queensland where James Cook beached his ship, the '' Endeavour'', for ...

Queensland Queensland ( , commonly abbreviated as Qld) is a States and territories of Australia, state in northeastern Australia, and is the second-largest and third-most populous state in Australia. It is bordered by the Northern Territory, South Austr ...

. Other common names for this species are the itar shark and the blind shark (also used for ''

Brachaelurus waddi The blind shark (''Brachaelurus waddi'') is one of two species of carpet sharks in the family Brachaeluridae, along with the bluegrey carpetshark (''Brachaelurus colcloughi''). Found along the coast of eastern Australia, this nocturnal, bottom ...

''). Goto's 2002 morphological analysis of the

carpet shark Carpet sharks are sharks classified in the order (biology), order Orectolobiformes . Sometimes the common name "carpet shark" (given because many species resemble ornately patterned carpets) is used interchangeably with "wobbegong", which is the ...

s showed the genus ''Hemiscyllium'' as a

polytomy An internal node of a phylogenetic tree is described as a polytomy or multifurcation if (i) it is in a rooted tree and is linked to three or more child subtrees or (ii) it is in an unrooted tree and is attached to four or more branches. A tree ...

, meaning that the

phylogenetic 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 dat ...

relationships between the epaulette shark and its sister species could not be resolved.

Distribution and habitat

The range of the epaulette shark extends from the southern coast of

to the northern coast of

, as far south as

Sydney Sydney is the capital city of the States and territories of Australia, state of New South Wales and the List of cities in Australia by population, most populous city in Australia. Located on Australia's east coast, the metropolis surrounds Syd ...

.Bester, C
Biological Profiles: Epaulette Shark
. Florida Museum of Natural History Ichthyology Department. Retrieved on May 14, 2009. The Capricorn-Bunker Group of the

Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system, composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...

contains a particularly large population, with thousands estimated to inhabit the reefs around Heron Island alone. Additionally, there are unsubstantiated reports of this species from

Malaysia Malaysia is a country in Southeast Asia. Featuring the Tanjung Piai, southernmost point of continental Eurasia, it is a federation, federal constitutional monarchy consisting of States and federal territories of Malaysia, 13 states and thre ...

Sumatra Sumatra () is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the list of islands by area, sixth-largest island in the world at 482,286.55 km2 (182,812 mi. ...

, and the

Solomon Islands Solomon Islands, also known simply as the Solomons,John Prados, ''Islands of Destiny'', Dutton Caliber, 2012, p,20 and passim is an island country consisting of six major islands and over 1000 smaller islands in Melanesia, part of Oceania, t ...

. Epaulette sharks are found in shallow water to a maximum depth of , and are often seen in water barely deep enough to cover their bodies. They prefer

s, coral flats, and stands of

staghorn coral The staghorn coral (''Acropora cervicornis'') is a branching, stony coral, within the Order Scleractinia. It is characterized by thick, upright branches which can grow in excess of 2 meters (6.5 ft) in height and resemble the antlers of a ...

Description

The epaulette shark has an elongated body, over half of which is comprised by the slender caudal peduncle. The snout is short and rounded, with the nares placed almost at the tip along with a pair of tiny

barbels In fish anatomy and turtle anatomy, a barbel is a slender, whisker like sensory organ near the mouth (sometimes called whiskers or tendrils). Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the z ...

; there are grooves running from the nares to the mouth. There are 26–35 tooth rows in the upper jaw and 21–32 tooth rows in the lower jaw. The teeth are small, with broad bases and triangular cusps. The eyes are oval in shape and elevated, with a large spiracle below each. 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 small, with the fourth and fifth very close together. The pectoral and

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 ...

s are broad and rounded and are thickly muscled. The two similarly sized

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 placed well back on the body. 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 ...

is low and positioned just in front of the

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 ...

. The caudal fin has only an upper lobe, which contains a prominent ventral notch near the tip and is angled almost horizontally relative to the body. Adult epaulette sharks are beige to brownish above with many widely spaced brown spots and subtle darker bands. There is a very large black spot ringed in white located behind each pectoral fin; this pair of spots are the origin of this shark's common name. Juveniles have alternating light and dark bands over their body and fins, which break up as they mature. Epaulette sharks are typically long; the maximum reported length is .

Biology and ecology

As an

adaptation In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the p ...

for navigating its complex reef environment, the epaulette shark moves by seemingly walking, bending its body from side-to-side and pushing off of the substrate with its paddle-shaped pectoral and pelvic fins. Its gait is similar to that of

salamander Salamanders are a group of amphibians typically characterized by their lizard-like appearance, with slender bodies, blunt snouts, short limbs projecting at right angles to the body, and the presence of a tail in both larvae and adults. All t ...

s, an example of

convergent evolution Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last comm ...

. The shark is capable of swimming, but often prefers to walk along the sandy or coral bottom even when the water is deep enough to allow it to swim freely. The

cartilaginous Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...

supports of the epaulette shark's paired fins are reduced and separated when compared to other sharks, allowing them to be rotated for use as limbs. This mode of locomotion even enables the shark to crawl out of the water to access isolated tidal pools. The gait of the epaulette shark is convergently similar to those of

tetrapod A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetr ...

s such as

s, suggesting that the movements needed for walking on land may predate, and perhaps contributed to the evolution of, the first terrestrial

vertebrate Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain. The vertebrates make up the subphylum Vertebra ...

s. Epaulette sharks are largely

and are most active in low water. They often hide inside or below coral heads, though it is enough for the head to be covered even if the rest of the body is exposed. Sometimes they perch in the open on sandy flats or atop reefs facing into the current, a form of orientation known as rheotaxis that may improve

respiration Respiration may refer to: Biology * Cellular respiration, the process in which nutrients are converted into useful energy in a cell ** Anaerobic respiration, cellular respiration without oxygen ** Maintenance respiration, the amount of cellul ...

or predator awareness. Epaulette sharks are preyed upon by larger fishes such as other sharks. Its coloration provides protective

camouflage Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the b ...

, while its epaulette is speculated to be an eyespot for distracting or deterring predators. Epaulette sharks are almost all parasitized by the praniza (parasitic)

larva A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect development such as insects, some arachnids, amphibians, or cnidarians typically have a larval phase ...

l stage of gnathiid

isopod Isopoda is an Order (biology), order of crustaceans. Members of this group are called isopods and include both Aquatic animal, aquatic species and Terrestrial animal, terrestrial species such as woodlice. All have rigid, segmented exoskeletons ...

s. The larvae feed on

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is com ...

and mostly attach to the skin around the

cloaca A cloaca ( ), : cloacae ( or ), or vent, is the rear orifice that serves as the only opening for the digestive (rectum), reproductive, and urinary tracts (if present) of many vertebrate animals. All amphibians, reptiles, birds, cartilagin ...

and the

claspers In biology, a clasper is a male anatomical structure found in some groups of animals, used in mating. Male cartilaginous fish have claspers formed from the posterior portion of their pelvic fin which serve to channel semen into the female's c ...

, though they are also found inside the mouth and on the

gills A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...

. These parasites cause little damage and are not believed to adversely affect the health of the shark. Other parasites of this species include a species of

myxosporea Myxosporea is a class of microscopic animals, all of whom are parasites. They belong to the Myxozoa clade within Cnidaria. They have a complex life cycle that comprises vegetative forms in two hosts—one an aquatic invertebrate (generally an ann ...

n in the genus ''Kudoa'', which infests the

skeletal muscle Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous system, voluntary muscular system and typically are a ...

s, the hemogregarine

protozoan Protozoa (: protozoan or protozoon; alternative plural: protozoans) are a polyphyletic group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic debris. Historically ...

'' Haemogregarina hemiscyllii'', which infects the blood, the

ostracod Ostracods, or ostracodes, are a Class (biology), class of the crustacean, Crustacea (class Ostracoda), sometimes known as seed shrimp. Some 33,000 species (only 13,000 of which are extant taxon, extant) have been identified,Brandão, S.N.; Antoni ...

''Sheina orri'', which attaches to the gills, and the

nematode The nematodes ( or ; ; ), roundworms or eelworms constitute the phylum Nematoda. Species in the phylum inhabit a broad range of environments. Most species are free-living, feeding on microorganisms, but many are parasitic. Parasitic worms (h ...

''Proleptus australis'', which infests the stomach.

Hypoxia tolerance

At night, the shallow reef platforms inhabited by the epaulette shark often become isolated from the ocean by the receding tide. The amount of

dissolved oxygen Oxygen saturation (symbol SO2) is a relative measure of the concentration of oxygen that is dissolved or carried in a given medium as a proportion of the maximal concentration that can be dissolved in that medium at the given temperature. It can ...

in the pool can drop 80% or more overnight from the combined respiration of all the organisms within the pool. The epaulette shark has evolved to cope with these hypoxic conditions, being able to survive for over three hours in 5% of the atmospheric O₂ level without losing behavioral responsiveness. In the laboratory, epaulette sharks have survived for an hour without any oxygen at , which is also unusual in that most animals capable of tolerating oxygen deprivation do so at low temperatures. The physiological responses of the epaulette shark to low oxygen are mediated by the

nucleoside Nucleosides are glycosylamines that can be thought of as nucleotides without a phosphate group. A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotid ...

adenosine Adenosine (symbol A) is an organic compound that occurs widely in nature in the form of diverse derivatives. The molecule consists of an adenine attached to a ribose via a β-N9- glycosidic bond. Adenosine is one of the four nucleoside build ...

. In hypoxic conditions, the heart and ventilation rates drop sharply. The shark's

blood pressure Blood pressure (BP) is the pressure of Circulatory system, circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term ...

falls by half as the

blood vessel Blood vessels are the tubular structures of a circulatory system that transport blood throughout many Animal, animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the Tissue (biology), tissues of a Body (bi ...

s dilate to deliver more blood to the brain and heart. Unlike in bony fishes and tetrapods, the blood flow rate remains constant and there is no elevation of blood

glucose Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae d ...

levels. The brains of sharks only consume a third as much ATP as those of

teleost Teleostei (; Ancient Greek, Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts (), is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all neontology, extant species of f ...

s. The epaulette shark is able to lower this energy demand further by reducing the

metabolism Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the co ...

of certain areas of its brain, e.g. keeping the sensory nuclei functional while deactivating the motor nuclei. This allows the shark to supply enough ATP to prevent

neuron A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...

death, while still remaining alert to its environment.

Temperature susceptibility

Epaulette shark development rate and fitness are strongly affected by temperature during development. Temperature rises due to

climate change Present-day climate change includes both global warming—the ongoing increase in Global surface temperature, global average temperature—and its wider effects on Earth's climate system. Climate variability and change, Climate change in ...

are sufficient to weaken the sharks, which risks damage to ecosystems.

Feeding

The epaulette shark is an opportunistic predator of

crustaceans Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of Arthropod, arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquat ...

, worms, and small

. Off Heron Island, over 90% of the epaulette shark's diet consists of

polychaete worm Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are ma ...

s and

crab Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek language, Greek), which typically have a very short projecting tail-like abdomen#Arthropoda, abdomen, usually hidden entirely under the Thorax (arthropo ...

s, with juveniles taking mostly the former and adults mostly the latter. It hunts most actively at dawn and dusk, though feeding can occur at any time during the day.Martin, R.A
Intertidal Zone: Epaulette Shark
. ReefQuest Centre for Shark Research. Retrieved on May 14, 2009. This shark relies mainly on its

olfactory The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, it ...

and

electroreceptive Electroreception and electrogenesis are the closely related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes, such ...

senses to locate hidden prey. It is capable of sucking prey into its mouth by expanding its muscular

buccal cavity The buccal space (also termed the buccinator space) is a fascial space of the head and neck (sometimes also termed fascial tissue spaces or tissue spaces). It is a potential space in the cheek, and is paired on each side. The buccal space is super ...

. While searching for food, the epaulette shark sometimes turns over debris with its snout or thrusts its head into the sand, swallowing food items while expelling the sand grains through its gill slits. Unlike most sharks, the epaulette shark may

chew Chewing or mastication is the process by which food is crushed and ground by the teeth. It is the first step in the process of digestion, allowing a greater surface area for digestive enzymes to break down the foods. During the mastication proc ...

its food for up to 5–10 minutes. Its teeth can be depressed to form a flat surface for crushing hard-shelled prey.

Life history

Mating In biology, mating is the pairing of either opposite-sex or hermaphroditic organisms for the purposes of sexual reproduction. ''Fertilization'' is the fusion of two gametes. '' Copulation'' is the union of the sex organs of two sexually repr ...

in the epaulette shark takes place from July to December, though in captivity reproduction occurs continuously. Courtship may be initiated by the female following and biting the male. The male then holds onto the pectoral fin of the female with his mouth and lies alongside her, while inserting one of his

into her

Copulation Sexual intercourse (also coitus or copulation) is a sexual activity typically involving the insertion of the erect male penis inside the female vagina and followed by thrusting motions for sexual pleasure, reproduction, or both.Sexual inte ...

lasts about one and a half minutes. Epaulette sharks readily breed in aquariums, even in tanks as small as 135 gallons, but larger tanks are recommended to allow room for the hatched offspring. This species is

, with females depositing eggs from August to December. The female drops the egg capsules two (rarely four) at a time every 14 days, producing a total of 20–50 eggs per year. Each egg case measures long and wide. The young emerge after 120–130 days, at a length of . The growth rate of the young is slow at first but increases to about per year after three months. Both males and females

mature sexually Sexual maturity is the capability of an organism to reproduce. In humans, it is related to both puberty and adulthood. ''Puberty'' is the biological process of sexual maturation, while ''adulthood'', the condition of being socially recognized as ...

at a length of , corresponding to an age of at least seven years.

Human interactions

Epaulette sharks are harmless to humans, though if handled they may nip their captors. They are easily observed and handled by beachgoers as they move slowly whilst out of water, and show little fear of humans; the shark is often injured by these encounters. This species adapts readily to captivity and is displayed by many public aquariums in the United States, Canada, and Australia. In an article for ''Aquarium Fish Magazine'', Scott W. Michael referred to the epaulette shark as "the best shark for the home aquarium." They will breed in captivity, even in tanks as small as 510 L (135 gal), though full-grown sharks are best housed in tanks of 680 L (180 gal) or more. They are not compatible with community tanks as they will eat other fish. The

(IUCN) has assessed the epaulette shark as of

. This species is common in Australian waters, where it is not captured 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 fisheries, and is minimally affected by collection for the aquarium trade and fishery

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 ...

. Much of its Australian habitat is encompassed by protected marine parks. Off New Guinea, the epaulette shark has been assessed 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 ...

, as there it faces

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 ...

destructive fishing practices Destructive fishing practices are fishing practices which easily result in irreversible damage to habitats and the sustainability of the fishery ecosystems. Such damages can be caused by direct physical destruction of the underwater landform and ve ...

, and

over-exploitation Overexploitation, also called overharvesting or ecological overshoot, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable t ...

artisan fishers An artisan (from , ) is a skilled craft worker who makes or creates material objects partly or entirely by hand. These objects may be functional or strictly decorative, for example furniture, decorative art, sculpture, clothing, food ite ...

. In 2015, the behaviour of an epaulette shark was filmed in detail by the

BBC The British Broadcasting Corporation (BBC) is a British public service broadcaster headquartered at Broadcasting House in London, England. Originally established in 1922 as the British Broadcasting Company, it evolved into its current sta ...

for the first episode of a new documentary series named ''Shark'', released around the 40th anniversary of '' Jaws''. The documentary shows an epaulette shark's ability to walk over land, and its hunting behaviours in the ebbing tide.

References

External links

Fishes of Australia: ''Hemiscyllium ocellatum''

Video about Research on Epaulette Sharks
at

Raja Ampat Raja (; from , IAST ') is a noble or royal Sanskrit title historically used by some Indian rulers and monarchs and highest-ranking nobles. The title was historically used in the Indian subcontinent and Southeast Asia. The title has a long ...

, Indonesia {{Taxonbar, from=Q29243

epaulette shark The epaulette shark ('', Hemiscyllium ocellatum'') is a species of longtailed carpet shark of the family (biology), family Hemiscylliidae, found in shallow, tropical waters off Australia and New Guinea (and possibly elsewhere). The common name o ...

Taxa named by Pierre Joseph Bonnaterre Fish of New Guinea

Walking fish