Sesarma sulcatum Smith 1870

Sesarma sulcatum Smith, 1870

Sesarma sulcata Smith, 1870:156.—De Man, 1892a:260.

Sesarma (Sesarma) sulcata.—Rathbun, 1897a:90.

Sesarma (Sesarma s.s.) sulcata.—Tesch, 1917:200.

Sesarma (Sesarma) sulcatum.—Rathbun, 1918:289, pl. 78: figs. 3, 4 [part of material = S. aequatoriale].—Bott, 1955:62.—Von Hagen, 1978:46.

Not Sesarma sulcatum.—Crane, 1947:86 [part only].—Abele, 1976:268 [part of material only].

Sesarma sulcatum.—Crane, 1947:86.—Abele, 1977b:502, figs. 3, 4, 5a, 5b.—Brusca, 1980:302, fig. 20.11.—Abele, 1981:438.

MATERIAL EXAMINED.—Mexico: Gulf of California between Tiburon I. and Sonora mainland, 2, 1, 26 Oct 1969, P. Vreeland, AHF 1970-11; Gulf of California, Kino Bay, 1 ovigerous , 4 Apr 1970, P. Pickens, C. Swift, AHF 1970-11; Nayarit, San Blas, 3, 1, H. Wright, AHF 1966-1; Concepcion Bay, 2, 28 Mar 1940, S.A. Glassell, 19 Jan 1932, USNM 110646; La Paz, 1, L. Beilding, USNM 4631; Puerto Escondido, 1, S.A. Glassell, USNM; San Blas, Tepio, 2, 1 ovigerous , 14 Jun 1897, Nelson and Goldman, USNM 20653.

Nicaragua: Corinto; 1 ovigerous (holotype), J.A. McNiel, MCZ 6243 (transferred from the Peabody Academy of Science, November 1885).

Costa Rica: Golfito, 1, 6–7 Mar 1938, AMNH 13508.

Panama: Diablo Heights swamp, 3, 30 Jul 1967, H.O. Wright, USNM 125912, 125917; swamp near Albrook AFB, 1, 18 Jun 1974, L.G. Abele, USNM; Darien, El Real, 4, 1, 26 Oct 1966, R. Fish, USNM 125916.

Colombia: Port Utria, 1, 25 Jan 1935, AHF.

DESCRIPTION.—Carapace wider than long (c1/cb = 0.81±0.04 for males, 0.82±0.05 for females), covered dorsally with distinct tufts of setae. Carapace widens slightly posteriorly; tooth posterior to anterolateral angle, large acute and set higher and medial to anterolateral angle. Regions of carapace well defined especially in anterior portion where deep grooves mark interobital region. Frontal region about 0.53 of carapace breadth (iw/cb = 0.53±0.02 for both sexes), sinuous with deep median portion.

Eyes well developed, pigmented.

Chelipeds sexually dimorphic, larger with more granules in males. Anterior medial border with about seven strong teeth, posterior border very weakly serrate with distinct lobe proximal to distal margin. Carpus covered with rows of granules, some acute at borders, and with a distinct impression on the anterolateral surface; medial surface with a few acute granules in males. Dorsal surface of palm with distinct row of granules extending slightly beyond distal margin; outer surface smooth to slightly punctate, inner surface with large granules in males, smooth in females. Movable finger with about 11 acute tubercles dorsally; ventrally with tuft of setae at base followed by one large tooth and about nine smaller ones to corneous spooned tip. Immovable finger with about 11 teeth proximal to corneous spooned tip.

Walking legs short, robust, m1/mw of third is 2.2±0.13 in males and 2.04±0.10 in females. Lateral rows of granules on merus with dorsal subdistal tooth. Rows of long dark setae beginning on carpus, extending onto dactylus as three ventral and three dorsal rows of thick setae. Pubescence particularly thick on propodus and dactylus of anterior two legs. About three or four pairs of short, thick black spines on distal margin of propodus.

Male abdomen subtriangular in outline; basal width of telson slightly greater than length at midline. Gonopod robust; amber-colored endpiece directed laterally bending at about a 45° angle.

Female abdomen semicircular in outline; basal width of telson slightly greater than length at midline. Gonopore oblong in outline; operculum longer than wide.

MEASUREMENTS.—Males cb 23.3 to 35.8 mm, large males to 50 mm (Brusca, 1980); females cb 24.7 to 30.7 mm; ovigerous females cb 30.2 to 30.5 mm.

TYPE LOCALITY.—Corinto, Nicaragua.

TYPE.—Ovigerous female (cb 30.5 mm) in the Museum of Comparative Zoology (MCZ 6243). Specimen is in poor condition.

DISTRIBUTION.—Sesarma sulcatum is known from the Pacific Coast of Mexico, Gulf of California, El Salvador, Nicaragua, Costa Rica, Panama, and Colombia.

HABITAT.—Individuals of this species were collected from burrows above the banks of a brackish water river (salinity 22‰) and in mangrove swamps. Although some specimens were collected in very low salinity water (4–6‰), the species appears to be more common in higher salinities. Some of data given on habitat by Crane (1947) refer to S. aequatoriale.