Euprognatha limatula, Santana & Tavares, 2008

Santana, William & Tavares, Marcos, 2008, A new species of EUPROGNATHA Stimpson, 1871 (Crustacea, Brachyura, Inachoididae) from off coast of northeastern Brazil, Papéis Avulsos de Zoologia 48 (27), pp. 317-328 : 318-326

Euprognatha limatula n. sp.

( Figures 1 A-E; 2 A, E; 3 D; 6 B)

Type material: Brazil, Ceará, Canopus Bank, 02°15.3’00”S - 38°16.0’00”W, Fishing Vessel “ Piauí VIII”, J. Coltro coll., viii.2005, rocky bottom, 252-260 m: male holotype cl 8.5, cw 7.0 mm ( MZUSP 16940 ) .

Comparative material

Euprognatha bifida – United States, Baja California, Gulf of California, San Jose Island , “Albatross”, station 3001, gray sand and broken shells, 24°55’15”N - 110°39’00”W, 16.iii.1889, M. J. Rathbun det., 60 m: male holotype cl 8.7, cw 7.2 mm ( USNM 17335 ) .

Euprognatha gracilipes – United States, Virgin Islands, St. Croix , Frederikstadt, “Blake”, station 132, 17°37’55”N - 64°54’20”W, A. Agassiz coll., 5.i. 1879, 214 m: 1 male and 2 females ( MCZ 8165 ) . Virgin Islands, St. Croix , Frederikstadt, “Blake”, station 132, 17°37’55”N - 64°54’20”W, A. Agassiz coll., 5.i.1879, A. Milne-Edwards det., 214 m: 1 male ( MCZ 2647 ) . Virgin Islands, St. Croix , Frederikstadt, “Blake”, station 132, 17°37’55”N - 64°54’20”W, A. Agassiz coll., 5.i.1879, M. J. Rathbun det., 214 m: 2 ovigerous females ( MCZ 2651 ) . Dominica, “ Blake ”, station 177, 15°32’18”N - 61°30’10”W, A. Agassiz coll., 24.i.1879, A. Milne-Edwards det., 216 m: 1 ovigerous female ( MCZ 9165 ) . Barbados, “ Blake ”, station 290, 13°11’54”N - 59°38’45”W, A. Agassiz coll., 9.iii.1879, M. J. Rathbun det., 134 m: 3 ovigerous females ( MCZ 2584 ) . “ Blake ”, station 278, 13°04’50”N - 59°37’40”W, A. Agassiz coll., 6.iii.1879, A. Milne-Edwards det., 126 m: 1 ovigerous female ( MCZ 2699 ) . “ Blake ”, station 272, 13°04’12”N - 59°36’45”W, A. Agassiz coll., 05.iii.1879, A. Milne-Edwards det., 139 m: 1 male ( MCZ 2725 ) . “ Blake ”, station 272, 13°04’12”N - 59°36’45”W, A. Agassiz coll., 5.iii.1879, M. J. Rathbun det., 139 m: 1 male ( MCZ 2753 ) . According to the records of the MCZ the type material of E. gracilipes is lost.

Euprognatha granulata – Costa Rica, Cocos Island , “Albatross”, station 3369, 05°32’45”N - 86°55’20”W, 28.ii.1891, Faxon det., 95 m: ovigerous female lectotype cl 7.7, cw 6.0 mm and 1 ovigerous female paralectotype ( MCZ 4477 ) .

Euprognatha rastellifera – United States, Marthas Vineyard , “Fish Hawk”, station 874, soft mud, 40°00’00”N - 70°57’00”W, 13.ix.1880, M. J. Rathbun det., 155 m: male holotype cl 19.3, cw 11.7 mm of Euprognatha rastellifera marthae Rathbun, 1925 ( USNM 18749 ) . Cuba, Havana, “ Albatross ”, station 2342, coral, 23°10’39”N - 82°20’21”W, 19.i.1885, M. J. Rathbun det., 37 m: male holotype cl 9.9, cw 7.4 mm, 3 males paratypes, and 1 ovigerous female paratype of Euprognatha rastellifera spinosa Rathbun, 1894 ( USNM 18108 ) . Saint Kitts, “ Blake ”, station 148, 17°17’12”N - 62°46’43”W, A. Agassiz coll., 14.i. 1879, 381 m: 1 male paralectotype of Euprognatha acuta A. Milne-Edwards, 1880 ( MCZ 2728 ) . Martinica, IFREMER-IGMAR 3, station 431, sample 290, 14°23.01’N - 60°53.47’W, 18.ix.1994, dredge: 1 male ( MZUSP 17346 ) . Saint Vincent, “ Blake ”, station 269, 13°07’55”N - 61°05’36”W, A. Agassiz coll., 3.iii. 1879, 227 m: male lectotype cl 6.6, cw 5.3 mm and 1 male paralectotype of Euprognatha acuta A. Milne-Edwards, 1880 ( MCZ 2580 ) . Barbados, “ Blake ”, station 296, 13°05’24”N - 59°38’45”W, A. Agassiz coll., 10.iii.1879, 154- 156 m: 1 female paralectotype of Euprognatha acuta A. Milne-Edwards, 1880 ( MCZ 2600 ) . Brazil, Rio de Janeiro, Bacia de Campos , Petrobras station 50, G.A.S. Melo det.: 1 male ( MZUSP 11934 ) . Rio de Janeiro, Ilha Grande , station C, 30.vii.1966, G.A.S. Melo det.: 2 males ( MZUSP 3399 ) . Rio de Janeiro, Ilha Grande , station D, 07.ii.1969, G.A.S. Melo det., 200 m: 6 males ( MZUSP 3403 ) . Rio de Janeiro, Ilha Grande , station 135, 04.vii.1966, G.A.S. Melo det., 13 m: 1 male ( MZUSP 2778 ) . Rio de Janeiro, Ilha Grande , station 136, 04.vii.1966, G.A.S. Melo det.: 1 male ( MZUSP 2779 ) . Rio de Janeiro, Projeto Ilha Grande , station 172, 08.vii.1966, G.A.S. Melo det., 15.5 m: 2 males ( MZUSP 2780 ) . Rio de Janeiro, Projeto Ilha Grande , station 290, 30.vii.1966, G.A.S. Melo det., 31 m: 1 female ( MZUSP 9375 ) . São Paulo , 23°33’S - 42°17’W, G.A.S. Melo det.: 1 male ( MZUSP 3478 ) . São Paulo , Projeto Integrado, station 4853, 24°01’S - 44°33’W, 16.xii.1985, fine sand, 104 m: 3 males and 1 female ( MZUSP 10822 ) . Revizee – Score Sul , station 6361, 09.i.1997, F. Mantelatto det.: 2 males and 3 females ( MZUSP 13758 ) . Revizee – Score Sul , station 6661, 24°17.678’S - 43°52.198’W, 09.i.1998, F. Mantelatto det., dredge, 150 m: 30 males and 27 females ( MZUSP 13792 ) . Revizee – Score Sul , station 6661, 24°17.678’S - 43°52.198’W, 09.i.1998, G.A.S. Melo, P.A. Coelho, O. Campos det., dredge, 150 m: 13 males and 5 females ( MZUSP 13402 ) . Revizee – Score Sul , station 6661, 24°17.678’S - 43°52.198’W, 09.i.1998, G.A.S. Melo, P.A. Coelho, O. Campos det., dredge, 150 m: 1 male ( MZUSP 13400 ) . Revizee – Score Sul , station 6661, 24°17.678’S - 43°52.198’W, 04.i.1998, G.A.S. Melo, P.A. Coelho, O. Campos det., dredge, 150 m: 1 male and 1 female ( MZUSP 13409 ) . Revizee – Score Sul , station 6664, 10.i.1998, G.A.S. Melo, P.A. Coelho, O. Campos det.: 1 male ( MZUSP 13406 ) . Revizee – Score Sul , station 6666, 24°17.129’S - 44°12.149’W, 10.i.1998, F. Mantelatto det., 163 m: 1 male and 1 female ( MZUSP 13779 ) . Revizee – Score Sul , station 6673, 24°17.939’S - 44°35.983’W, 11.i.1998, dredge, 133 m: 2 males ( MZUSP 13746 ) . Revizee – Score Sul , station 6673, 24°17.939’S - 44°35.983’W, 11.i.1998, F. Mantelatto det., dredge, 133 m: 1 male ( MZUSP 13781 ) . Revizee – Score Sul , station 6665, sample box C, 24°20.844’S - 44°09.913’W, 10.i.1998, Campos Jr. det., 258 m: 1 male ( MZUSP 17575 ) . Revizee – Score Sul , station 6665, 24°20.844’S - 44°09.913’W, 10.i.1998, G.A.S. Melo, P.A. Coelho, O. Campos det., 258 m: 9 males and 14 females ( MZUSP 13403 ) . Revizee Score Sul , station 6665 bt6, 24°20.844’S - 44°09.913’W, 10.i.1998, F. Mantelatto det., 258 m: 58 males, 85 females and 4 juveniles ( MZUSP 13782 ) . Revizee – Score Sul , station 6672 btp, 24°27.751’S - 44°30.351’W, 11.i.1998, F. Mantelatto det., 166 m: 1 male ( MZUSP 13789 ) . Revizee – Score Sul , station 6674, 24°31.080’S - 44°54.000’W, 11.i.1998, G.A.S. Melo, P.A. Coelho, O. Campos det., 122 m: 2 males ( MZUSP 13397 ) . Revizee – Score Sul , station 6681, 25°11.000’S - 44°56.650’W, 12.i.1998, F. Mantelatto det., dredge, 167 m: 2 juveniles ( MZUSP 13773 ) . Revizee – Score Sul , station 6681, 25°11.000’S - 44°56.650’W, 12.i.1998, F. Mantelatto det., dredge, 167 m: 2 males and 2 juveniles ( MZUSP 13749 ) . Revizee – Score Sul , station 6681, sample box C, 25°11.000’S - 44°56.650’W, Campos Jr. det., 12.i.1998, dredge, 167 m: 1 male ( MZUSP 17576 ) . Revizee Score – Sul , station 6681 bt6, 25°11.000’S - 44°56.650’W, 12.i.1998, F. Mantelatto det., dredge, 167 m: 1 juvenile ( MZUSP 13775 ) . Revizee – Score Sul , station 6686, 25°37.021’S - 45°13.586’W, 13.i.1998, G.A.S. Melo, P.A. Coelho, O. Campos det., dredge, 153 m: 1 female ( MZUSP 13389 ) . Revizee – Score Sul , station 6686, 25°37.021’S - 45°13.586’W, 13.i.1998, dredge: 1 male ( MZUSP 13404 ) . Revizee – Score Sul , station 6686, 25°37.021’S - 45°13.586’W, 13.i.1998, F. Mantelatto det., dredge, 153 m: 4 males and 2 females ( MZUSP 13752 ) . Revizee – Score Sul , station 6686, 25°37.021’S - 45°13.586’W, 13.i.1998, G.A.S. Melo, P.A. Coelho, O. Campos det., dredge, 153 m: 2 males and 2 females ( MZUSP 13395 ) . Revizee – Score Sul , station 6686, 25°37.021’S - 45°13.586’W, 09.i.1998, G.A.S. Melo, P.A. Coelho, O. Campos det., dredge, 153 m: 1 male ( MZUSP 13414 ) . Revizee – Score Sul , station 6686, 25°37.021’S - 45°13.586’W, 13.i.1998, F. Mantelatto det., dredge, 153 m: 4 males ( MZUSP 13753 ) . Rio Grande do Sul , GEDIP, station 1856, 30°42’S - 49°03’W, 06.viii.1972, G.A.S. Melo det., 192 m: 1 male ( MZUSP 6120 ) . Rio Grande do Sul , GEDIP, station 1646, 34°25’S - 51°49’W, 17.i.1972, G.A.S. Melo det., 166 m: 1 male ( MZUSP 6159 ) . Rio Grande do Sul , GEDIP, station 465, 34°38’S - 51°36’W, 11.xii.1968, G.A.S. Melo det.: 1 male ( MZUSP 3439 ) . Rio Grande do Sul , “ Prof. W. Besnard ”, GEDIP, station 1066, 22.i.1972, G.A.S. Melo det.: 1 male ( MZUSP 6075 ) . Rio Grande do Sul , GEDIP, station 1883, G.A.S. Melo det.: 1 female ( MZUSP 9205 ) . Costa Sul 02, DG 10, 27.iii.1972, P.A. Coelho det.: 1 male and 1 female ( MZUSP 6581 ) .

Description: Carapace pyriform, little longer than wide; regions well demarcated, strongly inflated. Carapace covered with minute granules, sub-equals in size, mostly concentrated on flanks; hooked setae sparsely distributed, more dense near base of rostrum, between orbits and in hepatic, gastric, and branchial regions. Carapace with 8 strong spines arranged as follows: 1 metagastric; 1 cardiac; 2 protobranquial, one of each side; 4 mesobranquial, two of each side. Antero-lateral margin of mesobranquial region with small spines and tubercles. Thoracic pleurites 5-8 gimnopleura, consisting of narrow plates densely ornamented with minute, uniformly distributed granules; coxal margin of pleurites spinulous.

Rostrum short, bifurcated, ending in two strong, smooth, acute, directed upward, spines. Supraorbital spines long; orbital margin granulated dorsally. Postorbital spine smooth, markedly long, curved forward, slightly longer than ocular peduncle. Ocular peduncle constricted medially, armed with blunt tubercle distally.

Antennular fossae longitudinally ovate; anterior margins crenulated. Interantennular septum elongated, strongly compressed laterally, forming distinct lobe ventrally directed.

Antennal flagella long; third and fourth antennal articles long, slender, exceeding rostrum. First and second antennal articles fused to epistome; second article with long spine in anterolateral angle, slightly directed upward; ventro-lateral margin of second article with row of sub-equal tubercles.

Epistome slightly wider than long. Epistomial spine and interantennular septa separated by small gap. Mouthfield trapezoidal, strongly produced anteriorly. Pterygostomian region subtriangular, with small tubercles, separated from subhepatic region by shallow groove. Subhepatic region with strong tubercle.

Third maxillipeds completely covering buccal frame. Exopod long, nearly reaching distal margin of merus; dorsal face with small, uniformly distributed tubercles. Ischia longer than broad; mesial margins slightly curved, leaving distinct gap; crista dentata with row of short setae and small teeth; dorsal face of ischium concave longitudinally, with small, well-spaced tubercles. Merus faintly longer than half of ischium, ornamented with small, well-spaced tubercles; anterolateral margin strongly expanded. Palp cylindrical, longer than merus; propodus and dactyl unarmed; carpus ornamented with spinules dorsally.

Sternite IV strongly sloping down in ventral view, densely covered with rounded granules. Sternite III broadly triangular, with sparse granules. Sternites V-VIII densely paved with rounded granules.

Chelipeds equals, subcylindrical, distinctly long. Dactyl and fixed finger distinctly shorter than palm, cutting edges consisting of sub-equal calcareous teeth; when closed fingers leaving gap in proximal half; dactyl with small, blunt, distinct basal tooth. Movable and fixed fingers smooth on mesial and lateral faces, inconspicuous carina on lateral face of dactyl. Propodus slender, weakly inflated, with minute, almost imperceptible granules. Carpus with minute granules on mesial and lateral surfaces, almost smooth dorsally. Merus with minute granules. Ischium coarsely granulated. Pereiopods slender, cylindrical. First ambulatory leg longer, remaining legs decreasing in length posteriorly. Dactyl slightly curved, densely setose, small tubercles on lower edge. Carpus with sparse, minute granules on upper and lower surfaces. Merus with dorsal, strong, backward curved spines; smaller spines on lateral and ventral faces; mesial face of pereopods smooth. Ischium with spinules on lateral surface.

First abdominal segment densely covered with granules, bearing strong spine densely granulated proximally, otherwise smooth; segments 2 and 3 densely tuberculated, remaining segments paved with small, rounded granules medially concentrated. Abdominal segments 1-5 free, slightly raised medially forming low longitudinal ridge. Segment 6 fused to telson. Pleotelson subtriangular, terminating in rounded apex.

Type locality: Brazil, Ceará, Canopus Bank , 02°15.3’00”S - 38°16.0’00”W, between 252 and 260 meters depth .

Distribution: Known so far only from the type locality.

Etymology: From the Latin limatula (diminutive feminine), polish, scrape, in allusion to the aspect of the chelipeds.

Remarks: Euprognatha limatula n. sp. differs from all its congeners by the (i) presence of distinct, subequal protobranchial and anterior mesobranchial spines (versus protobranchial and anterior mesobranchial spines absent, figs. 3-6); (ii) dactyl, propodus, and merus of the cheliped minutely granulated, granules almost imperceptible (versus coarsely granulated, fig. 1A); (iii) dactyl of P4 only slightly longer than half of the maximal length of propodus (versus much longer than half of the propodus, almost reaching proximal end of carpus, figs. 2B-E); (iv) gastric and cardiac regions of the carapace almost smooth, carapace finely granulated on the flanks (versus carapace coarsely granulated or strongly tuberculated all over, figs. 3-6). Additionally, Euprognatha limatula n. sp. is promptly distinguished from E. gracilipes by its second antennal spine much longer than rostrum in dorsal view (versus shorter than rostrum in dorsal view, figs. 3B, D); from E. ricei and E. bifida by the absence of intestinal spine (versus one or two strong intestinal spines, respectively, figs. 3A, D); and from E. granulata by the meri of P2-P4 armed with sparse, strong, backward curved spines (versus densely distributed, short, straight spines, figs. 1B and 2A). Euprognatha limatula n. sp. is further differentiated from E. bifida , E. ricei , and E. gracilipes by its strong interantenular spine (versus interantenular spine absent, fig. 1E).

Figures

FIGURE 1: Euprognatha limatula n. sp. male holotype 8.5 x 7.0 mm (MZUSP 16940). A, lateral view of the left cheliped. B, habitus, dorsal view. C, dorsal view of carapace, cephalotorax and abdomen. D, ventral view of carapace, cephalotorax and abdomen. E, lateral view of carapace, cephalotorax and abdomen. Scales A-E, 4 mm.