Acanthacaris

Acanthacaris
	Acanthacaris tenuimana
Systematics
Class :	Higher crabs (Malacostraca)
Order :	Decapods (decapoda)
Subordination :	Pleocyemata
Partial order :	Large crayfish (Astacidea)
Family :	Lobster-like (Nephropidae)
Genre :	Acanthacaris
Scientific name
	Acanthacaris
	Bate , 1888

Acanthacaris is a marine genus of the decapods (Decapoda) from the family of the lobster-like (Nephropidae). It comprises two species, Acanthacaris tenuimana and Acanthacaris caeca , which are mainly found in the deep sea . Both species are not fished despite their relatively large size.

description

Acanthacaris reaches body lengths of up to 40 cm, whereby the carapace can be up to 20 cm long .

Most of the Acanthacaris rostrum is indented on the sides and has teeth on the back and abdomen, but not on the sides. The surface of the carapace and pleon is dotted with many small, pointed spines (spinules). The telson also has many spines on its edges. The eyes of Acanthacaris are strongly reduced and not pigmented, the cancers of this genus are probably blind.

The first pair of striding legs is the same, the individual segments shaped into scissors are cylindrical and have many small thorns. The second pair of striding legs is exceptionally long and slender, while the third appears much shorter but more robust. The exopodites of the uropods have a complete diaeresis, a transverse depression.

distribution and habitat

The two species of the genus Acanthacaris have separate distribution areas. Acanthacaris caeca has been found in the Gulf of Mexico, the Caribbean and off Florida, mainly at depths of 550 to 825 m. Acanthacaris tenuimana is native to the coasts of the Indian Ocean and the western Pacific. This species lives mainly at depths between 600 and 1670 m. Both species tend to live on soft mud and in self-dug caves.

Systematics and taxonomy

The genus consists of the following species:

Acanthacaris caeca A. Milne-Edwards , 1881
Acanthacaris tenuimana Bate , 1888

The two types can be determined by the ratio of the lengths of the scissor finger to the scissor hand. In Acanthacaris caeca this ratio is about 1, in Acanthacaris tenuimana it is significantly greater than 1, so the scissor fingers are significantly longer than the scissor hands in the latter species.

The genus seems to be a basal taxon within the lobster-like taxon and is therefore sister taxon to the remaining genera of this family. In some systematics this is taken into account by placing the genus in its own subfamily, the Neophoberinae (Glaessner, 1969). The characteristic autapomorphies include a. the morphology of the rostrum and symmetrical scissors with narrow, cylindrically shaped scissor palms with needle-shaped teeth on the scissor fingers.

The genus was first described in 1881 by Alphonse Milne-Edwards under the name Phoberus with the type species Phoberus caeca . Charles Spence Bate discovered the second species during the Challenger expedition and thus before 1881 and initially named it Acanthacaris tenuimana . The publication of his description could only take place in 1888, which is why he took the generic name from Milne-Edwards. Phoberus , however, is a subgenus of the earth beetles (Trogidae). Martin Glaessner therefore called the genus Neophoberus in 1969 . Acanthacaris is now to be used as the older name . Synonyms of the genus are consequently Phoberus (A. Milne Edwards, 1881) and Neophoberus (Glaessner, 1969), as well as the misspellings Acanthocaris (Bate, 1888) and Phoderus (Ramos, 1950).

There are no known fossil finds. The fossil genus Palaeophoberus (Glaessner, 1932), once considered closely related, is probably one of the Chilenophoberidae .

literature

Individual evidence

^ ^A ^b ^c Lipke B. Holthuis: Marine Lobsters of the World . An Annotated and Illustrated Catalog of Species of Interest to Fisheries Known to Date. Ed .: Food and Agriculture Organization (= FAO Fisheries Synopsis . Volume 125 ). Rome 1991, ISBN 978-92-5103027-1 ( fao.org ).
^ ^A ^b ^c Lipke B. Holthuis: The Lobsters of the Superfamily Nephropidea of the Atlantic Ocean (Crustacea: Decapoda) . In: Bulletin of Marine Science . tape 24 , no. 4 , 1974, p. 723–884 ( nhm.org [PDF; 16.0 MB ; accessed on June 24, 2012]).
↑ ^a ^b Dale Tshudy, Rafael Robles, Tin-Yam Chan, Ka Chai Ho, Ka Hou Chu, Shane T. Ahyong, Darryl L. Felder: Phylogeny of marine clawed lobster families Nephropidae Dana, 1852, and Thaumastochelidae Bate, 1888, based on mitochondrial genes . In: Joel W. Martin, Keith A. Crandall, Darryl L. Felder (Eds.): Decapod Crustacean Phylogenetics . CRC Press, 2009, ISBN 1-4200-9258-8 , pp. 357–368 ( nhm.org [PDF; 1,2 MB ; accessed on June 24, 2012]).

Web links

Genus Acanthacaris. In: Marine Lobsters of the World. Marine Species Identification Portal, accessed June 24, 2012 .

[HolthuisFAO-1] A ^b ^c Lipke B. Holthuis: Marine Lobsters of the World . An Annotated and Illustrated Catalog of Species of Interest to Fisheries Known to Date. Ed .: Food and Agriculture Organization (= FAO Fisheries Synopsis . Volume 125 ). Rome 1991, ISBN 978-92-5103027-1 ( fao.org ).

[Holthuis-2] A ^b ^c Lipke B. Holthuis: The Lobsters of the Superfamily Nephropidea of the Atlantic Ocean (Crustacea: Decapoda) . In: Bulletin of Marine Science . tape 24 , no. 4 , 1974, p. 723–884 ( nhm.org [PDF; 16.0 MB ; accessed on June 24, 2012]).

[Tshudy-3] Dale Tshudy, Rafael Robles, Tin-Yam Chan, Ka Chai Ho, Ka Hou Chu, Shane T. Ahyong, Darryl L. Felder: Phylogeny of marine clawed lobster families Nephropidae Dana, 1852, and Thaumastochelidae Bate, 1888, based on mitochondrial genes . In: Joel W. Martin, Keith A. Crandall, Darryl L. Felder (Eds.): Decapod Crustacean Phylogenetics . CRC Press, 2009, ISBN 1-4200-9258-8 , pp. 357–368 ( nhm.org [PDF; 1,2 MB ; accessed on June 24, 2012]).