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| Richerius marqueti
Guinot & Mazancourt, 2020
DOI: 10.5852/ejt.2020.671
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Abstract
A new genus and species, Richerius marqueti gen. et sp. nov., of a crab of the family Hymenosomatidae MacLeay, 1838 are described from the inland waters of New Caledonia based on several specimens collected in two streams at altitudes of 180 m and 500 m, respectively. Richerius marqueti gen. et sp. nov. was compared to the other freshwater species known in New Caledonia, Odiomaris pilosus (A. Milne-Edwards, 1873), and to species of Amarinus Lucas, 1980, a genus comprising many freshwater species in New Zealand, Australia, Indonesia, the Philippines, and Papua New Guinea, but never recorded in New Caledonia. The barcode fragment of the COI mitochondrial gene was sequenced for seven specimens of R. marqueti gen. et sp. nov., and all sequences were deposited in GenBank. A brief and updated review of the New Caledonian marine and freshwater hymenosmatid fauna is provided.
Keywords: Richerius marqueti; new genus; new species; New Caledonia; COI
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| Fig. 5. Richerius marqueti gen. et sp. nov., holotype, ♂, New Caledonia, South Province, Pouéo River, tributary of the Néra, Bouïrou village, Bourail township, 180 m a.s.l., Valentin de Mazancourt and Gérard Marquet leg., 28 Sep. 2016, 4.9 × 5.0 mm (MNHN-IU-2014-21500). A. Type locality, stream where several specimens of the species were collected. B–D. Views of the holotype in vivo: dorsal (B), ventral (C) and frontal (D). |
Infraorder Brachyura Latreille, 1802
Subsection Heterotremata Guinot, 1977
Superfamily Hymenosomatoidea MacLeay, 1838
Family Hymenosomatidae MacLeay, 1838
Subfamily Odiomarinae Guinot, 2011
Genus Richerius gen. nov.
Diagnosis: Carapace circular to oval, width only slightly exceeding length; dorsal carapace surface not strongly
outlined by grooves; only gastrocardiac and thoracic grooves well defi ned, not reaching antero- and
posterolateral margins; carapace rim continuous across behind rostrum. Rostrum broadly rounded,
spade-shaped, slightly defl exed but not ending in narrow triangular tip extending between antennules.
Proepistome represented by ventral expansion of rostrum (and not rostrum itself). Antennules obliquely
folded along hollowed ventral parts of rostrum, entirely hidden dorsally. Antennae well separated from
antennules, at least at their bases; urinary article at level of moderately developed epistome. Proepistome
represented by ventral expansion of rostrum (and not rostrum itself). Lower orbital margin with one conspicuous knob, not visible dorsally. Mxp3 gaping at level of ischion/merus junction; merus and
ischium broad, short, about subequal.
....
Etymology:
The genus name is in honour of Bertrand Richer de Forges for his lifetime commitment to carcinology,
especially of New Caledonia, for having always been an excellent and untiring researcher, and for his
friendship.
Richerius marqueti gen. et sp. nov.
Etymology:
The species name is in honour of Gérard Marquet, who made extensive collections of freshwater
crustaceans for more than 30 years in the Indo-Pacific islands and in particular in New Caledonia where
he collected the new species here described, for his friendship and his constant enthusiasm in the field
as well as in the laboratory.
Danièle Guinot and Valentin de Mazancourt. 2020. A New Freshwater Crab of the Family Hymenosomatidae MacLeay, 1838 (Crustacea, Decapoda, Brachyura) and An Updated Review of the Hymenosomatid Fauna of New Caledonia. European Journal of Taxonomy. 671; 1-29. DOI: 10.5852/ejt.2020.671
