Potamocarcinus magnus Rathbun 1896
Creators: name: Magalhães, Célio
name: Wehrtmann, Ingo S.
name: Lara, Luis Rólier
name: Mantelatto, Fernando L.
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Pseudothelphusidae
Potamocarcinus
Potamocarcinus magnus

description: Potamocarcinus magnus (Rathbun, 1896)
(Figs. 71, 72, 86)
Pseudothelphusa magna Rathbun, 1896: 377, fig. 1, 2; pl. 29, 30, figs. 7–10.— Rathbun 1898: 534, 537.— Young 1900: 217.— Rathbun 1904: 242 (in list).— Rathbun 1905: 299.— Coifmann 1939: 108.
Potamocarcinus magnus — Ortmann, 1897: 317.— Rodriguez 1982: 111, figs. 69b, 72a, b.— Guinot 1988: 14, 29.— Rodríguez & Hedström 2000: 420.— Rodríguez 2001: 436.— Ng et al. 2008: 176 (in list).— Lara et al. 2013: 689 (table), 691, fig. 4 (map).
Pseudothelphusa (Megathelphusa) magna — Smalley 1964b: 9.
Potamocarcinus (Potamocarcinus) magnus magnus — Pretzmann, 1965: 2.
Potamocarcinus (Megathelphusa) magnus magnus — Pretzmann 1971: 20.— Pretzmann 1972: 69, figs. 377–380, 400, 411.— Hobbs et al. 1977: 149.— Holthuis 1986: 594.
Potamocarcinus maanus [sic]— Hobbs 1994: 101.
Potamocarcinus magnus fma. Costa Rica—Villalobos Hiriart & Álvarez 2008: 297 (in list).
Material examined. COSTA RICA. 1 female, UCR-MZ 164, San Pedro, 13.ii.1965, J. de Abate leg.; 1 male, syntype (cw 134.9, cl 85.7), USNM 19049, Pozo Azul, 4.iv.1888, J. Zeledon leg.—Alajuela Province, Atlantic drainage: 5 males, 3 females, UCR-MZ 709, San Carlos Canton, creek aprox. 10 km from La Fortuna, road to Volcán Arenal, 18.ii.1972, V. Ramírez, R.A. Cruz & C. Villalobos leg.; 1 subad. male, 3 males immat., 3 females immat., UCR-MZ, San Carlos Canton, La Habana creek, aprox. 2 km antes de La Fortuna, 17.ii.1972, R.A. Cruz & C. Villalobos leg.; 1 male, 1 female, UCR-MZ 708, San Carlos Canton, creek 0.9 km from La Guaria, road to Arenal River, 18.ii.1972, R.A. Cruz, V. Ramírez & C. Villalobos leg.; 1 male immat., 4 males juv., 1 female immat., 1 female juv., UCR-MZ 713, San Carlos Canton, creek 0,9 km from La Guaria, road to Arenal River, 1.vi.1972, R.A. Cruz & C. Villalobos leg.; 1 male, UCR-MZ 3127-01, spring of Santa Rita, 10°16'07.36"N 84°30'43.8"W, 22.i.2013, L.R. Lara leg.—Alajuela Province, Pacific drainage: 1 immat. male, softshell, 2 immat. males, 1 immat. female, TMNH 4437, Grande de Tárcoles River. 3 mi E Atenas, small tributary on east bank of Tárcoles, 0.5 mi from Atenas-Alajuela highway, 7.vi.1962, A.E. Smalley & G. Smalley leg.; 1 male, 2 females, UCR-MZ 2706-01, Machuca, 5.5 km of San Mateo, road to Maderal, 10.vii.1977, C. Villalobos & C.E. Villalobos leg.—Guanacaste Province, Atlantic drainage: 1 juv. male, UCR-MZ, creek on Road 142, approx. 100 m of Arenal, in Toad Hall Vilarejo Lake, 10º29'15.4"N 84º49'59.3"W, 602 m, 02.ii.2013, I.S. Wehrtmann et al. leg; 3 juv. males, 1 juv. female, 17 young, UCR-MZ, road to Cabanara, 2 km on Road 142, neighborhood S. Antonio, 10°33.236"N 84º53.198"W, 02.ii.2013, F. Mantelatto et al. leg.; 2 juv. males, INPA 2080, same data; 1 juv. male, 1 juv, female, CCDB 4555, same data.—Guanacaste Province, Pacific drainage: 2 males, 2 females, 1 juv., UCR-MZ, neighborhood Los Angeles, road on Road 142, 25 km direction Tilarán to Cañas, Tilarán, Costa Rica, 10º28'33.5"N 84º01'37.0"W, 3.ii.2013, I.S. Wehrtmann et al. leg.; 1 immat. male, 1 immat. female, INPA 2082, same data; 1 immat. male, 1 immat. female, CCDB 4551, same data; 1 male, 1 female, 3 juv., CCDB 4552, river on Road 142 from Tilarán to Cañas, close to the exit of the city, 10º29'14.5"N 84º59'12.7"W, 478 m, 3.ii.2013, I.S. Wehrtmann et al. leg.; 1 male immat., 2 males immat., UCR-MZ 710, Corobicí River, La Pacífica Farm, Cañas, 9.iv.1972, C. Villalobos leg.; 2 males juv., UCR-MZ 712, Corobicí River, La Pacífica Farm, Cañas, 8.iv.1972, C. Villalobos leg.; 1 male, INPA 1866, Bagaces, almost at the entrance to Palo Verde National Park, 5–10.xi.2004, D. Norman leg.; 1 juv. male, 2 juv. females, 1 young, CCDB 5016, Bagaces, road to Reserva Biologica Lomas Barbudal, 10°31’26.9”N 85°21’34.5”W, 78 m, 17.vii.2013, F.L. Carvalho, E. Souza-Carvalho & S.V. Esquivel-Montoya leg.; 2 males, 3 females, UCR-MZ 3223-01, neighborhood Los Angeles, on Road 142, 2.5 km direction to Tilarán, 10°28'33"N 84°01'37"W, 390 m, 3.ii.2013, I.S. Wehrtmann et al. leg.; 1 male, 1 female, UCR-MZ 3221-01, river at bridge at entrance to Tilarán on Road 142, 10°28'45.0"N 84°57'45.0"W, 3.ii.2013, I.S. Wehrtmann et al. leg.; 1 male ad., 2 males immat., 1 female ad., UCR-MZ 701, [River] San Juan de Santa Cruz, La Lechuza creek, Eustacio Cabalceta’s farm, B. Cabalceta & C. Villalobos leg.; 1 male, UCR-MZ, Casitas creek, Casitas de Nicoya, 5 km road to Mansion Carrera Vieja, 30.xii.1984, F. Cedeño leg.; 1 female with young, UCR-MZ 751, Morote River, Peninsula de Nicoya, 17.iii.1974, W. Bussing & L. Madriz leg.—Cartago Province, Atlantic drainage: 1 female, UCR-MZ 705, Juan Viñas, 24.v.1972, G. Machado leg.; 1 female, UCR-MZ 163, Cachí, Tunnel, 19.v.1968, D.C. Robinson leg.—Limón Province, Atlantic drainage: 1 female, UCR-MZ 746, Guápiles, 1.xii.1971, R. Barrantes; 1 female immat., UCR-MZ 2351-02 (ex-IVIC 1070), Caño Seco River, afluente Barbilla River, Barbilla National Park, 300 m, 7.i.1999, I. Hedström leg.; 1 female immat., UCR-MZ 2354-01 (ex-IVIC 1072), Barbilla River, Barbilla National Park, 100 m, 28.i.1999, I. Hedström leg.; 1 male, immat., UCR-MZ 2353-01 (ex- IVIC 1071), Casas Negras, Dantas River, Parque Nacional Barbilla, 200 m, 8.i.1999, I. Hedström leg.; 1 male, UCR-MZ 3226-01, Limón municipality, Veragua Rainforest Research and Adventure Park, creek at camp, 27.vii.2013, D. Hernández & L. Vargas leg.; 1 male, UCR-MZ, Limón municipality, Veragua Rainforest Research and Adventure Park, 2013, J. Salazar leg.; 1 immat. male, UCR-MZ, Limón municipality, Veragua Rainforest Research and Adventure Park, Ciccaba creek, 19.i.2013, A. Rodriguez & D. Hernández leg.; 1 juv. male, CCDB 4554, Limón municipality, Veragua Rainforest Research and Adventure Park, Ciccaba creek, 30.i.2013, 9.92970°N 83.19102”W, 409 m, I.S. Wehrtmann et al.; 1 male, CCDB 4889, stream on road between Cahuita and Puerto Viejo, 9°38’07.77”N 82°47’02.69”W, 62 m, 19.vii.2013, F.L. Carvalho, E. Souza-Carvalho & S.V. Esquivel- Montoya leg.— Puntarenas Province, Pacific drainage: 1 male, INPA 1871, Miramar, 24.iv.1977, C. Villalobos leg.; 1 male, UCR-MZ 1975, Reserva de Cabo Blanco, Bolzitar creek, Península de Nicoya, 8.ix.1994, L. Mena leg.; 1 male, 2 females, UCR-MZ 2656-01, Cacao creek (Flor de Maíz), 09°02'5.54"N 83°25'54.11"W, Zona Sur, 23.v.2007, L. R. Lara leg.; 1 male immat., INPA 1566, Cacao creek, tributario del Fresco River, drainage of Grande de Térraba River, 09°02’06.02”N 83°25’53.98”W, 23.v.2007, L.R. Lara leg.; 1 male, UCR-MZ 703, Osa Canton, Rincón, 22.viii.1970, C. Sennell leg.—San José Province, Pacific drainage: 1 male, UCR-MZ 166, Montes de Oca Canton, Lourdes, San Pedro, 23.ix.1966, M.T. Chincillaleg.; 2 females, UCR-MZ 748, Montes de Oca Canton, San Pedro, 27.vii.1972, F. Marín leg.; 1 female, UCR-MZ 747, Montes de Oca Canton, San Pedro, Ciudad Universitaria, creek behind building of Economic Sciences, 12.i.1971, M. Marín & R. Carvajal leg.; 1 male, UCR- MZ 700, San José, Ciudad Universitaria Rodrigo Facio, creek at Economic Sciences, 27.v.1971, leg. unknown; 1 male subad., UCR-MZ 698, San José, Montes de Oca Canton, Ciudad Universitaria, creek in front of Economic Sciences, 2.vi.1971, leg. unknown; 1 male, UCR-MZ 165, San José, Ciudad Universitaria, vi.1965, leg. unknown; 1 male, UCR-MZ 702, San José, Guadalupe, Pilar neighborhood, 23.vii.1972, A. Camacho & M. Jiménez leg.; 1 female, UCR-MZ 167, San José, Montes de Oca Canton, San Rafael, 19.x.1967, C.E. Valerio leg.; 1 male (right G1 missing), UCR-MZ, San José, La Presa, 100 m of bridge over Tiribí River, road to Alajuelita, 19.ix.1970, J. Rojas; 1 male, INPA 1867, Tiribí River, San José, v.1972, leg. unknown; 1 male, UCR-MZ, Tiribí River, San José, date and leg. unknown; 3 males, 3 females, UCR-MZ 704, San Felipe, Alajuelita, 30.viii.1971, R. Barrantes; 2 males juv., TMNH 4452, 1 mi NW Tabarcia, tributary of Candelaria River, 17.vii.1962, A.E. Smalley & G. Smalley leg.; 1 male juv., TMNH 4709, Tabarcia, 16.ii.1960, R.D. Suttkus & S. Jiménez-Canossa leg.; 1 male, UCR-MZ 699, Pérez Zeledón Canton, Los Calderón creek, 3,5 km of the hanging bridge of General River, road to Rivas, 27.ii.1971, V. Juárez, C. Villalobos & R.A. Cruz leg.; 6 males, 3 females, UCR-MZ 706, Pérez Zeledon Canton, Los Solís creek, 0,5 km of the cross-way to La Linda, 27.ii.1971, V. Juárez, C. Villalobos & R.A. Cruz leg.; 1 male, UCR-MZ 752, Pérez Zeledón Canton, Los Chiles, 14.vii.1972, C. Villalobos leg.
Description of gonopod. Thick, straight in both caudal, mesial views, moderately compressed mesio-laterally; lateral border concave on its distal third in mesial-caudal view, with tuft of minute to short setae medially; mesiocaudal surface with elongated patch of caudal setae along proximal half; mesio-cephalic surface with subdistal, elongated patch of setae increasing in size distally. Spermatic channel opening on apex cavity, situated towards lateral end at base of caudal process. Marginal suture on mesial side, straight along most of stem, slightly curved to lateral side distally in mesial view, with row of marginal setae proximally. Marginal process (caudal process, sensu Smalley 1964a) broadly rounded, slightly shorter than mesial lobe (as long as mesial lobe in mesial view), partially surrounding lobe. Lateral suture incomplete, marked by rather deep sulcus on the first three-fourths of the caudal surface. Mesial process (cephalic process, sensu Rodríguez & Hobbs 1989) as strong, subtriangular tooth directed cephalad on distal portion of mesial border. Apex distorted in cephalic direction; mesial lobe (marginal lobe, sensu Rodríguez & Hobbs 1989) enlarged, subquatrate in mesio-caudal view, folded over the apex cavity, partially covering the field of apical spines. Apex cavity oblong; field of apical spines moderately developed, with short, small spines. Cephalic process (lateral process, sensu Rodríguez & Hobbs 1989) bifid, with 2 distinct spiniform teeth apically, both pointing cephalad.
Syntypes and type locality. Two males, USNM 19048 and 19049. Costa Rica, Pozo Azul. Rathbun (1896) offered no further information about this locality.
Distribution. Western and central Costa Rica, in both Atlantic and Pacific drainages (Fig. 86). The species also occurs in Mexico, Guatemala, El Salvador (Rodriguez 1982), Honduras (Pretzmann 1980, as Potamocarcinus (Megathelphusa) magnus hondurensis), and Nicaragua (C. Magalhães, unpublished).
Remarks. In all specimens examined and syntypes the marginal process is nearly as long as the caudal process in caudal view (Fig. 71).
description: Published as part of 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), pp. 301-344 in Zootaxa 3905 (3) on pages 329-333, DOI: 10.5281/zenodo.235127