Sesarma rhizophorae Rathbun 1906

Sesarma rhizophorae Rathbun, 1906

Sesarma (Sesarma) rhizophorae Rathbun, 1906:99; 1918:294, pl. 79.—Von Hagen, 1978:46.

Sesarma rhizophorae.—Crane, 1947:86.—Abele, 1976:268.

MATERIAL EXAMINED.—Costa Rica: Boca del Jesus, 1 (holotype), Apr 1905, J.F. Tristan, USNM 32491.

Panama: Panama Province, swamp near Albrook AFB, 9, 2, 2 ovigerous , 18 Jun 1974, L. Abele; same locality, 1, 4, 1 ovigerous , 13 Mar 1977, L. Abele; adjacent to Miraflores locks, 2, 3, 13 Mar 1977, L. Abele; Diablo Heights mangrove swamp, 5, 3, 13 Mar 1977, L. Abele.

DESCRIPTION.—Carapace broader than long (c1/cb = 0.793±0.03 for males, 0.780±0.05 for females), convex anterior to posterior; regions weakly defined with about four rows of low granules on lateral surface. Anterolateral angle acute, followed posteriorly by a deep sinus and large tooth set laterally and on a higher level than anterolateral angle. Small indentation posterior to lateral tooth. Front slightly expanded distally about 0.534±0.01 of carapace breadth; frontal margin arcuate, weakly concave medially.

Eyes well developed and pigmented.

Chelipeds sexually dimorphic, larger and with more granules in males. Merus weakly serrate on anterior and posterior medial margins, a few tubercles on anterior margin. Carpus covered with short rows of granules. Palm distinctly punctate with row of granules on dorsal surface and larger scattered tubercles on medial surface of males. Movable finger with about eight acute tubercles on dorsal surface extending about half length of finger; ventral surface usually with two large teeth, one basal and one distal in location. Immovable finger similarly armed. Teeth very much reduced on females.

Walking legs relatively slender, m1/mw of third about 2.65±0.20. Merus armed on distal dorsal surface with thin acute tooth. Fine brown-colored pubescence present on walking legs, especially on the propodus, carpus, and dactylus; dactylus length about 0.75 of propodus length.

Male abdomen subtriangular in shape; telson width at base greater than length. Gonopod slender, almost straight, narrowing distinctly in distal portion (about 0.15 of length). Amber-colored endpiece continuous with main shaft, not set off at an angle.

Female abdomen subcircular in outline; telson width at base greater than length. Gonopore recessed in sternum, oblong in lateral axis; operculum longer than wide.

MEASUREMENTS.—Males cb 9.3 to 13.7 mm; females cb 9.6 to 13.4 mm; ovigerous females cb 11.7 to 13.4 mm.

TYPE LOCALITY.—Boca de Jesus Maria, Costa Rica.

TYPE.—Male cb 13.7 mm, USNM 32491.

DISTRIBUTION.—Costa Rica, Boca del Jesus Maria, Puntarenase, Ballenas (Crane, 1947; Rathbun, 1918); Panama, common along Pacific Coast (Abele, 1976); Peru, Puerto Pizarro (von Hagen, 1978). See “Remarks.”

HABITAT.—Sesarma rhizophorae is common in burrows in mangrove swamps. It was collected in salinities of 20 to 27‰.