''Emmelichthys nitidus'', the Cape bonnetmouth, bonnetmouth, redbait, pearl fish, picarel, red baitfish, red herring or Southern rover, 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 marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of sk ...

belonging to the family

Emmelichthyidae Emmelichthyidae is a small Family (biology), family of small to medium-sized Marine (ocean), marine ray-finned fishes known commonly as redbaits, rovers, bonnetmouths or rubyfishes. The Emmelichthyidae are poorly known even among researchers who ...

, the rovers and bonnetmouths. This species is found in the

Indian Indian or Indians may refer to: Associated with India * of or related to India ** Indian people ** Indian diaspora ** Languages of India ** Indian English, a dialect of the English language ** Indian cuisine Associated with indigenous peoples o ...

and

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

oceans. This species is of minor importance to

commercial fisheries 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 p ...

Taxonomy

''Emmelichthys nitidus'' was first formally described in 1845 by the Scottish

naval surgeon A naval surgeon, or less commonly ship's doctor, is the person responsible for the health of the ship's company aboard a warship. The term appears often in reference to Royal Navy's medical personnel during the Age of Sail. Ancient uses Specialis ...

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 ...

and

Arctic explorer Arctic exploration is the physical exploration of the Arctic region of the Earth. It refers to the historical period during which mankind has explored the region north of the Arctic Circle. Historical records suggest that humankind have explored ...

Sir John Richardson with its type locality given as

Western Australia Western Australia (WA) is the westernmost state of Australia. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Aust ...

. Richardson classified the new species in a new

monospecific genus In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispe ...

, ''

Emmelichthys ''Emmelichthys'' is a genus of marine ray-finned fishes belonging to the family Emmelichthyidae, the rovers and bonnetmouths. The species in this genus are found in the Atlantic, Indian and Pacific Oceans. Taxonomy ''Emmelichthys'' was first pro ...

'', so this species is that genus’s

type species In International_Code_of_Zoological_Nomenclature, zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the spe ...

. The Cape bonnetmouth was formerly split into two

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

but what was the southeastern Pacific subspecies ''E. n. cyanescens'' has been treated as a separate valid species '' Emmelichthys cyanescens'' since 2014. The specific name nitidus means “neat”, Richardson described the fish as having a “neat aspect”.

Description

''Emmelichthys nitidus'' has a slender, slightly compressed body which is around a fifth as deep as its

standard length Fish measurement is the measuring of individual fish and various parts of fish anatomy, their anatomies, for data used in many areas of ichthyology, including Taxonomy (biology), taxonomy and fishery biology. Overall length Standard length (SL) is ...

and with a

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 ...

which is very thin 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 ...

. It has a moderately small head with large eyes and a moderately-sized, oblique and highly protrusible mouth with just a small number of small conical teeth on the front of the lower jaw with the upper jaw usually being toothless and no teeth on the

vomer The vomer (; ) is one of the unpaired facial bones of the skull. It is located in the midsagittal line, and articulates with the sphenoid, the ethmoid, the left and right palatine bones, and the left and right maxillary bones. The vomer forms ...

palatine A palatine or palatinus (Latin; : ''palatini''; cf. derivative spellings below) is a high-level official attached to imperial or royal courts in Europe since Roman Empire, Roman times.

or tongue, The head and body are covered in small

ctenoid scale 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 scales, which can also provide effective camouflage through the use of reflection and colouration, as w ...

s except for over the preorbital area and the tip of the snout. The

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 ...

contains 13 or 15 spines, with the first 9 or 10 spines contained in the fin membrane with 2 or 3 short isolated spines with the final spine being connected to the membrane of the soft rayed part of the fin which is supported by between 9 and 11 soft rays. 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 supported by 3 spines and 9 or 10 soft rays. The caudal fin is forked, 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 of moderate size and have rounded tips while 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 ...

s are small. This species reached a maximum

total length Fish measurement is the measuring of individual fish and various parts of their anatomies, for data used in many areas of ichthyology, including taxonomy and fishery biology. Overall length Standard length (SL) is the length of a fish measured f ...

of . The colour of the body is a metallic blue-grey on the upper body, with silver flanks and ventral surface, with the flanks having a pink flush and pinkish fins.

Distribution and habitat

''Emmelichthys nitidus'' is found in the south eastern Atlantic around

Tristan da Cunha Tristan da Cunha (), colloquially Tristan, is a remote group of volcano, volcanic islands in the South Atlantic Ocean. It is one of three constituent parts of the British Overseas Territories, British Overseas Territory of Saint Helena, Ascensi ...

and along the southern African coast in Namibia south to the

Western Cape The Western Cape ( ; , ) is a provinces of South Africa, province of South Africa, situated on the south-western coast of the country. It is the List of South African provinces by area, fourth largest of the nine provinces with an area of , an ...

. In the Indian Ocean it has been recorded from Madagascar and occurs around

St. Paul Paul, also named Saul of Tarsus, commonly known as Paul the Apostle and Saint Paul, was a Christian apostle ( AD) who spread the teachings of Jesus in the first-century world. For his contributions towards the New Testament, he is generally ...

and

Amsterdam island Amsterdam ( , ; ; ) is the capital and largest city of the Kingdom of the Netherlands. It has a population of 933,680 in June 2024 within the city proper, 1,457,018 in the urban area and 2,480,394 in the metropolitan area. Located in the Dut ...

s. It occurs along the southern coasts of Australia from southern Western Australia east to

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 ...

and off

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

. It is also found in New Zealand waters. It is a pelagic species found in open water at depths between .

Biology

''Emmelichthys nitidus'' gathers in schools with the juveniles being found near the surface, frequently mixed in with schools of other pelagic fish, especially

clupeid Clupeidae is a family of clupeiform ray-finned fishes, comprising, for instance, the herrings and sprats. Many members of the family have a body protected with shiny cycloid (very smooth and uniform) scales, a single dorsal fin, and a fusiform ...

s while the adults occur close to the bottom in deeper water. They feed on zooplankton, particularly crustaceans such as krill. It is an important prey for a number of marine predators such as tuna, seabirds and marine mammals. Off Tasmania they have a

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

season which lasts for two months and is stimulated by the rising of the water temperature in Spring. The females spawn asynchronously in batchesbut the number of eggs laid is unknown but they spawn a batch of eggs every 3-5 days.

Utilisation

''Emmelichthys nitidus'' is targeted by trawl fisheries and the catch is used for human consumption, for

fishmeal Fish meal (sometimes spelled fishmeal) is a commercial product made from whole wild-caught fish, bycatch, and fish by-products to feed farm animals, such as pigs, poultry, and farmed fish.R. D. Miles and F. A. Chapman.FA122: The Benefits of Fish ...

human consumption, fishmeal, which is used in the

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. Nelu ...

bluefin tuna Bluefin tuna is a common name used to refer to several species of tuna of the genus ''Thunnus''. {{Animal common name Commercial fish Thunnus Fish common names ...

, and as bait. It is a frequent

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 ...

in the pichard fishery off New Zealand and in the demersal trawl fishery for hake off South Africa, where it is then sold as bait.

References

* Tony Ayling & Geoffrey Cox, ''Collins Guide to the Sea Fishes of New Zealand'', (William Collins Publishers Ltd, Auckland, New Zealand 1982) {{Taxonbar, from=Q5230518 nitidus Taxa named by John Richardson (naturalist) Fish described in 1845