Ptychophallus exilipes ( Rathbun, 1898 )

Magalhães, Célio, Wehrtmann, Ingo S., Lara, Luis Rólier & Mantelatto, Fernando L., 2015, Taxonomy of the freshwater crabs of Costa Rica, with a revision of the genus Ptychophallus Smalley, 1964 (Crustacea: Decapoda: Pseudothelphusidae), Zootaxa 3905 (3), pp. 301-344 : 310-311

Ptychophallus exilipes ( Rathbun, 1898) , species inquirenda

( Figs. 22–30 , 80 )

Pseudothelphusa exilipes Rathbun, 1898: 514 , 534, fig. 1.— Young 1900: 211.— Rathbun 1904: 242 (in list).— Rathbun 1905: 279.— Coifmann 1939: 107 (in list).

Pseudothelphusa (Ptychophallus) exilipes — Smalley 1964b: 11, figs. 13, 14.

Ptychophallus (Ptychophallus) exilipes — Pretzmann, 1965: 5.— Pretzmann 1971: 21.— Pretzmann 1972: 87, figs. 508–510, 522–524.

Ptychophallus exilipes — Rodriguez 1982: 85.— Campos & Lemaitre 1999: 560 (map).— Rodríguez & Hedström 2000: 423.— Ng et al. 2008: 176 (in list).— Villalobos Hiriart & Álvarez 2008: 297 (in list).

Material examined. COSTA RICA. San José Province, Atlantic drainage: 1 female, holotype, USNM 19488, El Coronel, 700 m, undated, P. Biolley & E. Fernández leg.—San José Province, Pacific drainage: 1 male, USNM 39096, Cangrejal de Aserrí, Pacific drainage, 800 m, iv.1906, J.F. Tristan leg.; 1 male, USNM 39089, Dota Canton, San José, Santa María de Dota, 1600 m, i.1907, P. Biolley leg.; 1 male, 4 females, USNM 39089 (sic), same data; 1 male, UCR-MZ 742-02, Los Tubos Creek, 1 km W Boquete, Adan Bonilla’s farm (San Isidro del El General), V. Juárez leg.; 1 male, INPA 1857, same data; 3 males, UCR-MZ 737, Pérez Zeledón Canton, Painer, creek 14 km N San Isidro, 26.ii.1972, V. Suarez leg.; 1 male, 1 female, UCR-MZ 739, Talari River, Los Ángeles de Canaan, road to Chirripó, 11.iv.1972, V. Juárez leg.; 3 males, UCR-MZ 741, Perez Zeledón Canton, creek 4 km N (La Ese), 7.iv.1972, V. Juárez leg.; 1 right G1, 1 female, UCR-MZ 2784, grassland between Peje River and road, El Joroz, approximately 6 km S San Isidro del General, 14.v.1972, J.E. Baldrige leg.; 1 male, 1 female, INPA 1846, forest in Frank Weber’s farm, approximately 11 mi S San Isidro del General, vi.1972, J.E. Baldrige leg.—Alajuela Province, Atlantic drainage: 1 male, 1 female, CCDB 4538, Paradero 1, unnamed creek, Balsa River tributary, CTRM 480153/ 251228, 7.x.2010, L.R. Lara leg.— Puntarenas Province, Pacific drainage: 1 male, SMF 36264, La Cusinga, near Uvita, 9°08'09.3"N 83°43.2'W, 18.i.2008, G. Köhler leg.; 1 male, SMF 36265, Coto Brus Canton, Estación Biológica Las Cruces, 08°47'09"N 82°57'37"W, 1220 m, 15.ii.2007, G. Köhler leg.

Description of gonopod. Straight in mesiocaudal view, apex bent approximately 90° in laterocephalic direction. Marginal suture on mesial side, straight; marginal process subtriangular, not produced beyond caudal border of apex. Mesial process small, subtriangular, usually strongly downturned. Lateral process well developed, slightly bilobed, approximately 50–60% of stem length (from proximal opening to caudal border of apex), with shallow depression around middle, usually distinctly wider than lateral end of apex; lateral border nearly straight or slightly bilobed, with proximal lobe rounded, usually larger, wider, distal lobe thicker distally. Distocaudal ridge short, narrow, separated from distal border of lateral process by distinct depression. Apex oblong, slightly oblique, narrow; caudal border slightly convex, with small notch near lateral end. Field of apical spines well developed, facing towards cephalolateral side.

Holotype and type locality. Female, cw 24.0, cl 14.3, USNM 19488. Costa Rica, El Coronel (Atlantic drainage). According to Smalley (1964b), this locality is probably the one situated on the Sucio River, 10°07’N 83°55’W, at the border of San José and Cartago Provinces.

Distribution. Except for two records (including the type locality), all the available records point to a distribution on the Pacific drainage of central and southern Costa Rica, San José and Puntarenas Provinces ( Fig. 80 ).

Remarks. The USNM has two jars with the same catalogue number (39089) from Santa María de Dota, one with a single male (cw 23.8, cl 14.3) and the other with one male and four females. Smalley (1964b) assigned a male from this lot to the taxon, which was identified with the types by M.-J. Rathbun. Smalley (1964b) nevertheless remarked that collections made only six miles from the type locality consisted only of specimens of P. tumimanus and P. montatus and, therefore, males from the type locality would be very valuable. We were unfortunately not able to obtain new collections from the type locality. Specimens collected at nearby locations from El Coronel examined in the present study belong to P. tristani and P. montanus . A male (cw 23.5, cl 14.3; USNM 39096) from Cangrejal de Aserrí (possibly Acosta Canton instead of Aserrí Canton), a locality about 50 km SW from the type locality, also shows a G1 similar to that of the male from Santa María de Dota ( Fig. 27 ).

The Sucio River, the presumptive type locality of P. exilipes , is on the Atlantic drainage. Almost all other specimens examined in this study, however, came from rivers that drain into the Pacific. We consider this taxon a species inquirenda rather than a nomen dubium status until further investigation helps establish its correct identity.

The shape of the lateral process of the G1 can vary to some extent. It is usually broadly subtriangular, with the proximal lobe larger and wider, which gives the lateral border a gentle asymmetric concave outline (e.g. SMF 36264, Fig. 30 ) or even this border be more or less convex: e.g. USNM 39096 ( Fig. 27 ), SMF 36265 ( Fig. 29 ). In a few specimens this concavity can be a little more pronounced, e.g. INPA 1857, Fig. 28 ). All of these variations can be found in the males of lot UCR-MZ 741 ( Figs. 24–26 ).

In spite of the great similarities between the gonopods of P. exilipes and P. l av a l l en s i s we prefer to treat them as separate species based on their distribution (central-southern Costa Rica and central Panama, respectively) and because of some of the gonopod characters, as already mentioned by Rodríguez (1994). Although the presence of long setae in the G1 of P. lavallensis varies (the holotype bears a few, see Fig. 31 ), in P. exilipes the apical peduncle is a little longer and the apex is not so strongly bent towards the cephalic side; in addition, the caudal ridge is more clearly distinct and longer than in P. lavallensis ( Figs. 22, 30, 31 ). Whether these differences are consistent or due to variability must be further investigated when new collections become available, in particular from western and central Panama.

Figures

FIGURE 80. Distribution map of Ptychophallus costaricensis Villalobos, 1974, and P. exilipes (Rathbun, 1898).

FIGURES 22 – 32. Ptychophallus exilipes (Rathbun, 1898): 22, left first gonopod, USNM 39089, caudo-mesial view; 23, same data, latero-cephalic view of distal part; 24 – 26, outline of right first gonopod from three males of UCR-MZ 741, caudo-mesial view; 27, outline of right first gonopod, USNM 39096, caudo-mesial view; 28, same data, INPA 1857, caudo-mesial view; 29, outline of left first gonopod, SMF 36265, caudo-mesial view; 30, same data, SMF 36264, caudo-mesial view. Ptychophallus lavallensis Pretzmann, 1978: 31, left first gonopod, holotype, NHMW 4002, caudo-mesial view; 32, latero-cephalic view. Scale bars = 1 mm.