Metanephrops
Metanephrops challangeri
Metanephrops is a meeresbewohnende genus of decapods ( Decapoda ) from the family of lobster -like ( Nephropidae ). Today it includes 18 species that are distributed in the Atlantic, Pacific and Indian Ocean. Some species are caught and are therefore of commercial interest.
Description
The types of Metanephrops have a typical for decapods physique, divided into the tagmata cephalothorax and abdomen. Your body sizes are different depending on the type, but are relatively large compared to other genera of the family of the lobster -like.
For reliable distinction between Metanephrops and the genera of the lobster -like can not serve a feature, but rather the combination of:
- Two distinct, tipped burrs that run on the dorsal side of the carapace of the eyes ( supraorbital ) to the transverse groove of the carapace ( postcervical groove );
- A clear, fine line on the front sides of the carapace ( antennal carina );
- Usually three pairs of ridges on the chest area of the carapace ( thoracic carinae );
- Approximately symmetric, oblong- slim scissors that can be strong in some species provided with ridges.
The Exopoditen the second maxillipeds are reduced and do not have a flagellum. The third Maxilliped some mandrels in the rear edge of the Merus. Are at all peraeopods pairs both sporadically, than standing in rows of hair. In males, the first pair of swimming legs is rigid and consists of two fixed, fused segments. Of the exo-and endopodite the uropod has the same shape as that of the Nephrops species.
Distribution and habitat
The types of Metanephrops are in the shelf on the west coast of the Pacific, the Indian Ocean and spread on the west coast of the Atlantic. In the eastern and central Pacific Ocean and in the eastern Atlantic Metanephrops does not occur. The distribution extends north to about 35 ° N in Japan and south to about 50 ° S in New Zealand.
Cancers of this genus are found at depths from 50 to 1,000 meters, where the vast majority of observations from depths greater than 150 meters comes. There they live rather than on soft mud to sand.
System
Richard Jenkins told in 1972 to the genus Nephrops and put up on the lobster all species in the genus Metanephrops, since many details differ. So has Metanephrops on Rostrum only one instead of three lateral spines, dorsolateral ridges extend from the rostrum to the carapace and the ante signals mandrel ( antennal spine ) is greater. Nephrops other hand, has the carapace only five runs in the longitudinal direction burrs, the Exopod the antennae ( antennal scale) is narrow - lanceolate and the first pair of walking legs is noticeably uneven. Although all types of Metanephrops were initially attributed to the genus Nephrops and there are many morphological similarities, the genera Metanephrops and Nephrops are probably not be sister. There is thus a convergence.
M. challengeri
M. rossensis †
M. jenkinsi †
M. binghami
M. rubellus
M. thomsoni
M. formosanus
M. mozambicus
M. velutinus
M. sagamiensis
M. andamanicus
M. japonicus
M. armatus
M. sinensis
M. boschmai
M. sibogae
M. australiensis
M. arafuensis
M. motunauensis †
M. neptunus
The genus comprises a total of 18 Metanephrops tart and 3 fossil species known. Due to the geographical and morphological variety within the genus was divided by Jenkins in four groups as follows:
- Arafuensis group; not widespread in the Atlantic, among others, characterized by a carapace provided with many thorns, the terga of Pleons possess at least a deep, transverse depression, the uropods have spines, the scissor -bearing walking legs are finely granulated to prickly. Metanephrops arafurensis ( De Man, 1905)
- Metanephrops australiensis ( Bruce, 1966)
- † Metanephrops motunauensis Jenkins, 1972 ( Pliocene )
- Metanephrops neptunus ( Bruce, 1965)
- Binghami group; in Westatalantik native, inter alia, characterized by a rather smooth (not flashless ) carapace, the terga of Pleons are without sculpture, uropods have no spines dorsal side, scissor- bearing walking legs are provided with six longitudinal, sharp burrs. Metanephrops binghami ( Boone, 1927)
- Metanephrops rubellus ( Moreira, 1903)
- Japonicus group; not widespread in the Atlantic, among others, characterized by a rather smooth (not flashless ) carapace, the terga of Pleons which are structurally complex, uropods have no spines dorsal side, scissor- bearing walking legs have an elongated recess and are usually spiny. Metanephrops andamanicus (Wood - Mason, 1892)
- Metanephrops armatus Chan & Yu, 1991
- Metanephrops formosanus Chan & Yu, 1987
- Japanese Lobster ( Metanephrops japonicus ( Tapparone - Canefri, 1873) )
- Metanephrops mozambicus Macpherson, 1990
- Metanephrops sagamiensis ( Parisi, 1917)
- Metanephrops velutinus Chan & Yu, 1991
- Thomsoni group; not widespread in the Atlantic, among others, characterized by a rather smooth (not flashless ) carapace, the terga may be completely unstructured or have slanted wells, uropods have no spines dorsal side and / or are provided with a weak ridge, scissor- bearing walking legs are finely granulated. Metanephrops boschmai ( Holthuis, 1964)
- Metanephrops challengeri ( Balss, 1914)
- Metanephrops sibogae ( De Man, 1916)
- Metanephrops sinensis ( Bruce, 1966)
- Metanephrops taiwanicus ( Hu, 1983)
- Metanephrops thomsoni ( Bate, 1888)
- Without assignment † Metanephrops jenkinsi Feldmann, 1989 ( Cretaceous, Maastrichtian )
- † Metanephrops rossensis Feldmann and others, 1993 ( Cretaceous, Campanian )
The groups are probably not safe enough to be distinguished from each other in order to define it as a subgenus. Nevertheless, the Arafuensis, Binghami and japonicus - group after a based on morphology, phylogenetic analysis monophyletic (see cladogram ).