Tuesday, November 15, 2016

[Crustacea • 2016] Melothelphusa apiaka • A New Genus of Freshwater Crab of the tribe Kingsleyini Bott, 1970 (Decapoda: Brachyura: Pseudothelphusidae) with Description of A New Species from Mato Grosso, Brazil


Melothelphusa apiaka 
 Pedraza, Magalhães & Tavares, 2016  

Abstract

A new genus and species of freshwater crab, Melothelphusa apiaka n. gen., n. sp., from Mato Grosso, Central Brazil is described and illustrated. Brasiliothelphusa dardanelosensis Magalhães & Türkay, 2010, is assigned to the new genus Melothelphusa. Therefore, the genus Brasiliothelphusa Magalhães & Türkay, 1986, is restricted to its type species B. tapajoense Magalhães & Türkay, 1986. The new taxa can be easily separated from their close relatives by a suite of morphological characters from the first gonopod.

Keywords: Crustacea, Amazon region, biodiversity, Brasiliothelphusa, Neotropical region, taxonomy


FIGURE 1: Melothelphusa apiaka n. sp., male holotype, cl 18.8 mm, cw 27.8 mm (MZUSP 32914).
 A, habitus, dorsal view. B, cephalothorax, ventral view. C, cephalothorax, frontal view. D, E, lateral view of right and left chelipeds, respectively.
Abbreviations: CxP 4, coxa of pereopod 4; G 1, gonopod 1; G 2, gonopod 2; St 4 – 8, thoracic sternites 4 to 8. Scale bars A – E, 10 mm.  DOI: 10.11646/zootaxa.4173.1.9 

Family Pseudothelphusidae Ortmann, 1893
Tribe Kingsleyini Bott, 1970

Melothelphusa n. gen.

Included species. Melothelphusa dardanelosensis n. comb. (Magalhães & Türkay, 2010) [Formerly in Brasiliothelphusa]; Melothelphusa apiaka n. gen., n. sp.

Type species. Melothelphusa apiaka n. sp. by present designation.

Distribution. Brazil, northern of Mato Grosso State, Aripuanã River, Apiacás and Juruena.

Diagnosis. Marginal process of G1 short, strongly curved toward spermatic channel, apex truncated; apical plate provided with strong, keel-like process, arranged transversally in abdominal view. Apical field of spines of G1 open, almost as wide as long. Opening of spermatic channel delimited by both the crest of abdominal lobe and the marginal process.


Etymology. The generic name is a masculine patronym in honor or our colleague and friend Gustavo A. S. de Melo (the prefix ‘Melo’) with the suffix "thelphusa" (for ‘freshwater crab’).

Remarks. Melothelphusa n. gen. is established here for M. apiaka n. sp., its type species, and M. dardanelosensis n. comb. (Magalhães & Türkay, 2010), originally described in the Kingsleyini genus Brasiliothelphusa Magalhães & Türkay, 1986. Likewise, Melothelphusa n. gen. is herein assigned to the tribe Kingsleyini, with which it shares two diagnostic characters of the G1, namely the presence of an apical plate located above the opening of the spermatic channel, and base of G1 widened.


Melothelphusa apiaka n. sp.

Distribution. Presently known only from northern Mato Grosso, Brazil, in the interfluvial area between the Juruena and São Manuel Rivers. Diagnosis. Mesial process of G1 large, subquadrate; mesial side of apical plate smooth, devoid of spines; subapical bulge noticeable in sternal view; subapical bulge and crest of sternal lobe both covered by abundant spinules.

Etymology. The species is named after the Indian tribe Apiaká. The specific epithet is used as a noun in apposition.


Manuel Pedraza, Célio Magalhães and Marcos Tavares. 2016. A New Genus of Freshwater Crab of the tribe Kingsleyini Bott, 1970 (Crustacea: Decapoda: Brachyura: Pseudothelphusidae) with Description of A New Species from Mato Grosso, Brazil.
Zootaxa. 4173(1); 94-100. DOI: 10.11646/zootaxa.4173.1.9


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