''Metanephrops'' is a genus of

lobster Lobsters are Malacostraca, malacostracans Decapoda, decapod crustaceans of the family (biology), family Nephropidae or its Synonym (taxonomy), synonym Homaridae. They have long bodies with muscular tails and live in crevices or burrows on th ...

s, commonly known as scampi. Important species for

fishery 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 far ...

include '' Metanephrops australiensis'' (Australian scampi) and '' Metanephrops challengeri'' (New Zealand scampi). It differs from other lobsters such as '' Homarus'' and '' Nephrops norvegicus'' in that its two main

claw A claw is a curved, pointed appendage found at the end of a toe or finger in most amniotes (mammals, reptiles, birds). Some invertebrates such as beetles and spiders have somewhat similar fine, hooked structures at the end of the leg or Arthro ...

s are of equal size, rather than being differentiated into a ''crusher'' and a ''pincher''. There are 18 extant species recognised in the genus:

Species

*'' Metanephrops andamanicus'' (Wood-Mason, 1891) *'' Metanephrops arafurensis'' (De Man, 1905) *'' Metanephrops armatus'' Chan & Yu, 1991 *'' Metanephrops australiensis'' (Bruce, 1966) *'' Metanephrops binghami'' (Boone, 1927) *''

Metanephrops boschmai ''Metanephrops boschmai'', known as the Bight lobster, Bight scampi or Boschma's scampi, is a species of lobster endemic to Western Australia. Distribution and habitat ''M. boschmai'' is found around the west coasts of Australia, from Port Hedl ...

'' (Holthuis, 1964) *'' Metanephrops challengeri'' (Balss, 1914) *'' Metanephrops formosanus'' Chan & Yu, 1987 *''

Metanephrops japonicus ''Metanephrops japonicus'' is a species of lobster found in Japanese waters, and a delicacy, gourmet food in Japanese cuisine. It occurs from Chōshi, Chiba, Chōshi, Chiba Prefecture (Honshu) to the east coast of Kyushu, where it lives at depths ...

'' (Tapparone-Canefri, 1873) *'' Metanephrops mozambicus'' Macpherson, 1990 *'' Metanephrops neptunus'' (Bruce, 1965)

*'' Metanephrops rubellus'' (Moreira, 1903)

*'' Metanephrops sagamiensis'' (Parisi, 1917) *'' Metanephrops sibogae'' (De Man, 1916) *'' Metanephrops sinensis'' (Bruce, 1966) *'' Metanephrops taiwanicus'' (Hu, 1983) *''

Metanephrops thomsoni ''Metanephrops'' is a genus of lobsters, commonly known as scampi. Important species for fishery include '' Metanephrops australiensis'' (Australian scampi) and '' Metanephrops challengeri'' (New Zealand scampi). It differs from other lobsters ...

'' (Bate, 1888) Metanephrops thomsoni

*''

Metanephrops velutinus ''Metanephrops'' is a genus of lobsters, commonly known as scampi. Important species for fishery include '' Metanephrops australiensis'' (Australian scampi) and '' Metanephrops challengeri'' (New Zealand scampi). It differs from other lobsters ...

'' Chan & Yu, 1991 A further three species are known from fossils: *''

Metanephrops jenkinsi ''Metanephrops'' is a genus of lobsters, commonly known as scampi. Important species for fishery include ''Australian scampi, Metanephrops australiensis'' (Australian scampi) and ''Metanephrops challengeri'' (New Zealand scampi). It differs from ...

'' Feldmann, 1989 –

Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...

*'' Metanephrops motunauensis'' Jenkins, 1972 –

Pliocene The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Metanephrops rossensis'' Feldmann ''et al.'', 1993 – Late Cretaceous

Habitat

''Metanephrops'' inhabit burrows located in sticky soft substrate that they build themselves. They typically live at depths ranging between 50 and 994m below the surface of the ocean, but are found in greater abundances at 150m or deeper. This classifies them as a "deep sea lobster" since they inhabit a region below 50m under the surface of the ocean. Occurrences of ''Metanephrops'' are prevalent on the west side of ocean basins, especially the Indo-West-Pacific, ranging from latitudes of 35^∘N to 50^∘S. Only two of the extant species of ''Metanephrops'' inhabit the western basin of the Atlantic Ocean. ''M. binghami'' resides in the Gulf of Mexico and around the Caribbean and Cuba; while ''M. rubellus'' resides off of the southern coast of Brazil and off the coast of Uruguay.

Diet

''Metanephrops'' are scavengers like most lobsters. They consume a diet largely consisting of the corpses of pelagic and benthic species that have fallen to the sea floor. Specific examples of their typical diet include small marine organisms such as plankton and parasites, ghost shark (''Hydrolagus novaezealandiae''), silver warehou (''Seriolella punctata''), tall sea pen (''Funiculina quadrangularis'') and the salp (''Ihlea racovitzai'').

Reproduction

The unique reproductive habits of ''Metanephrops'' are poorly understood due to the difficulty of getting individuals of ''Metanephrops'' to mate in captivity. However, their mating habits appear to follow that of most genera of lobster, with copulation occurring after a female moults. Successful instances of copulation were observed to occur when the male was larger and stronger than the female and was able to turn the female over and pin her down in order for copulation to occur. In one study, viable eggs were produced 3 days following an instance where sperm uptake was successful after copulation. However, the eggs did not hatch for another 222 days, meaning that the total time from spawning to hatch was 225 days.

Development and morphology

''Metanephrops'' begin their lives in a platonic larval stage that must undergo several cycles of multing to reach maturity. During these molting phases, some postlarval aspects of a mature ''Metanephrops'' become apparent with each subsequent molt. The ''Metanephrops'' larva is a zoea larva shared by many other crustaceans, and the time spent in this state is approximately 4–8 days. Before entering the zoea stage of larval development, newly hatched instances of ''Metanephrops'' are surrounded by a cuticle that encompass all appendages, though this stage lacks armed process on the first and second antenna and telson. This stage, like the zoea larval stage, is also typical in decopods. This pre-zoea stage is extremely short lived in individuals that will proceed to enter the zoea larval stage, lasting for only a few minutes to a few hours. Upon entering the zoea larval stage individuals of ''Metanephrops'' are typically 10-15mm long and bear notably well developed eyes that are stalked with small cornea. The zoea larva of ''Metanephrops'' are semi-opaque, but a system of red/orange chromatophores create a visible spot on the abdomen. After the zoea larval stage, ''Metanephrops'' enter a juvenile post larval stage characterized by the presence of all adult characteristics. This is especially apparent in the transferring of locomotion to the abdominal by use of pleopods to walk like other genera of lobsters, as opposed to primary locomotion being swimming as in the larval stage. However, it is likely that they retain some ability to swim through their pleopods and uropods.

Origin

''Metanephrops'' first appeared in the fossils record in the late Cretaceous. Specimens were found on the eastern side of the Antarctic peninsula. Stratigraphic, geographic and cladistic evidence suggest that ''Metanephrops'' developed in high southern latitudes.

Fishing

Certain species of ''Metanephrops,'' such as ''Metanephrops challengeri,'' support commercial fisheries on and off the continental shelf and slope of New Zealand. Scampi make burrows in muddy substrates, and fisheries use a number of methods such as photographic and burrow analysis methods to determine scampi emergence patterns in order to assess catchability. This data suggests that roughly half of all scampi burrows are occupied at any given time. Scampi have been targeted by trawl fisheries since the late 1980s. At that time landings were between 800 and 1000 tons per year for the species ''Metanephrops challengeri.'' Since then landings for ''M. challengeri'' have fallen to between 600 and 800 tons per year in recent years.

References

True lobsters Extant Late Cretaceous first appearances {{decapod-stub