Descriptions of five new species of false spider crabs (Decapoda: Brachyura: Hymenosomatidae) from the Philippines

The Hymenosomatidae is unique among the Brachyura on the basis of spermatozoal ultrastructure and morphological characters of the adults and larvae. The location of the hymenosomatid male gonopore, always a controversial question, is here shown to be sternal, not coxo-sternal. This disposition, analogous to the arrangement of Thoracotremata, contradicts all morphological characters that indicate a heterotreme affiliation, close to the Majoidea and Dorippoidea. Molecular data also support such an assignment. The multiple hymenosomatid plesiomorphies are reviewed. The exceptional male reproductive system, a new scheme for the Eubrachyura, is assumed, at least in part, to be the result of a strong carcinisation in an ancient, deeply rooted group, at present the most ecologically diverse in Brachyura. The presence of the Hymenosomatidae on the former Gondwanan landmasses and its worldwide pattern of distribution are consistent with the hypothesis of a Gondwanan origin of the family.

Section: Location Of Male Gonoporesmentioning

confidence: 99%

The position of the Hymenosomatidae MacLeay, 1838, within the Brachyura (Crustacea, Decapoda)

Guinot

2011

“…Ten species, distributed among five genera, of false spider crab (Crustacea: Hymenosomatidae) are presently known from the Philippines (see Ng & Chuang 1996;Naruse et al 2008;Husana et al 2011): Amarinus wolterecki (Balss, 1934) [Mindanao: Lake Mainit], A. pumilus Ng & Chuang, 1996 [southeastern Luzon: Bicol River, Camarines Norte], A. abatan Naruse, Mendoza & Ng, 2008 [Bohol: Abatan River], Crustaenia palawanensis (Serène, 1971) [Palawan: Quezon]; Elamena castanea Naruse, Mendoza & Ng 2008 [Bohol: Panglao Is. ], E. panglao Naruse, Mendoza & Ng, 2008 [Bohol: Panglao Is.…”

Section: Introductionmentioning

confidence: 99%

“…Ng & Chuang 1996), such as E. mathoei (Desmarest, 1823), E. truncata (Stimpson, 1858), E. abrolhensis Gordon, 1940, andE. panglao Naruse, Mendoza &Ng, 2008, in the general form of the carapace, where the rostrum is truncated rather than tapering, the carapace is subpentagonal, and the anterolateral margin of the carapace is slightly convex, and the junction of the anterolateral and posterolateral margins of the carapace ("posterior lateral angle" of Lucas 1980) is angular (see Gordon 1940;Lucas 1980;Ng & Chuang 1996;Naruse et al 2008). It can be easily distinguished from these congeners, however, by the presence of only one subdistal tooth, rather than two, on the ambulatory dactyli.…”

Section: Introductionmentioning

confidence: 99%

A new species of false spider crab of the genus Elamena H. Milne Edwards, 1837 (Crustacea: Decapoda: Brachyura: Hymenosomatidae), from Davao Gulf, Philippines

Husana

Kase

Mendoza

2013

Self Cite

A new species of hymenosomatid crab of the genus Elamena H. Milne Edwards, 1837, is described from the island of Samal, in the Davao Gulf, Mindanao, southern Philippines. Elamena samalensis sp. nov. belongs to the Elamena truncata species-group and is most similar to E. simplidenta Ng & Chuang, 1996, in the general form of the carapace and in the presence of only one subdistal tooth on the ambulatory dactyli. It can be distinguished from this species, however, by its more projecting rostrum, relatively longer and more slender ambulatory legs, and by the pointed apex of the female pleotelson.

“…The Hymenosomatidae MacLeay, 1838, which includes 118 species in 19 genera (updated from Ng et al 2008: 108), recently removed from the Majoidea Samouelle, 1819, and elevated to a suprafamilial level, Hymenosomatoidea MacLeay, 1838 (Martin & Davis 2001: 74;Chen & Sun 2002: 34;Poore 2004: 390;Števčić 2005: 101), has surprisingly not been credited with any subfamilies despite its many members and heterogeneous organisation. The large morphological variations of the rostrum, epistome, mouthparts, male and female abdomens, gonopods, and vulvae (Melrose 1975;Lucas 1980;Ng 1991;Ng & Chuang 1996;Davie 2002;Poore 2004;Naruse & Ng 2007a, 2007bNaruse, Mendoza & Ng 2008;Naruse, Ng & Guinot 2008) nevertheless provide evidence for the presence of several distinct lineages in the Hymenosomatidae. The family presents actually a unique combination of characters within the Brachyura, some being plesiomorphic and others seemingly derived, the result of a strong carcinisation.…”

Section: Introductionmentioning

confidence: 99%

“…parte;Lucas & Davie 1982;Wear & Fielder 1985;McLay 1988;Chuang & Ng 1994;Towers & McLay 1995;Ng & Chuang 1996;Davie 2002;Johnston & Robson 2005) inhabit inland freshwaters: rivers and streams with rapid currents, swamps, at an altitude of 1600 m in New Guinea for A. angelicus (Holthuis 1968: 112, as Halicarcinus), and may be sometimes confined to lakes in New Zealand (Lucas 1980;McLay 1988). They also inhabit low salinity waters in estuarine environments, having wide tolerance to salinities (e.g., A. abatan, see Naruse, Mendoza & Ng 2008). The presence of odiomarines in marine waters is questionable (see below).…”

Section: Introductionmentioning

confidence: 99%

Odiomarinae nov. subfam., a new subfamily for two primitive genera of Hymenosomatidae MacLeay, 1838, with preliminary remarks on the family (Crustacea, Decapoda, Brachyura)

Guinot

2011

A new subfamily Odiomarinae nov. subfam. is erected to receive two primitive genera of the eubrachyuran family Hymenosomatidae MacLeay, 1838: Odiomaris Ng & Richer de Forges, 1996, and Amarinus Lucas, 1980, mostly from fresh and estuarine waters of the Indo-West Pacific region. The new subfamily is characterised by the presence of "intercalated platelets" on the male abdomen, either articulated and moveable or relatively less well demarcated. The hymenosomatid platelets are actually vestigial uropods that are similar to those, also showing as dorsal plates, of the podotreme Dynomenidae Ortmann, 1892, and Dromiidae De Haan, 1833. The hymenosomatid uropod differs from the podotreme ones by the deep socket that is excavated at its ventral side and thus corresponds to the typical eubrachyuran press-button system. The odiomarine socket is particularly interesting because it provides morphological and phylogenetic criteria for identifying podotreme uropods and eubrachyuran sockets as homologues. In addition to several other plesiomorphic characters, the retention of dorsal uropods in the Hymenosomatidae, a unique known case in the Eubrachyura Saint Laurent, 1980, and evidence of an ancient lineage, allows re-defining and preliminarily interpreting the exclusive combination of characters of the family and to reconsider its status within the Eubrachyura.