Sesarma cookei Hartnoll 1971

Sesarma cookei Hartnoll, 1971

Sesarma cookei Hartnoll, 1971:257, pl. 1.—Abele and Means, 1977:91.—Guinot, 1988:11.

MATERIAL EXAMINED.—Jamaica: Portland Parish, John Crow Mountains “2.5 miles [4 km] SW of Ecclesdown on Project Road, 6, 5, 4 May 1976, L. Abele, B. Means.

DESCRIPTION.—Carapace broader than long (cl/cb = 0.891±0.04 in males, 0.918±0.04 in females), widening posterirly. Outer orbital angle acute, lateral margin slightly convex to strong anterolateral tooth. Striae on lateral carapace surface weak. Interorbital region subdivided into four lobes; median sinuses strong, lateral sinuses weak. Frontal region with margins subparallel; concave medially, convex to anterolateral angles; iw/cb = 0.423±0.04 in males, 0.442±0.02 in females. Dorsal surface of carapace smooth, regions weakly defined with few scattered pubescent tufts.

Eyes relatively small, not filling orbital region.

Chelipeds of both sexes relatively long and narrow; merus with posteromedial margin granulate and subdistal lobe, anteromedial margin with teeth slightly expanded distally; two rows of comb setae on lateral surface, anterior row strong. Carpus granulate becoming acute on medial margin; anteromedial margin raised in males and expanding into a lobe distally in both sexes. Chelae granulate, no well-defined dorsal ridge on palm, granules large, acute on medial surface; male palm swollen compared to female. Fingers long, slender, about 1.6 times palm length; movable finger with about 9 to 12 acute granules dorsally, many fewer in females; about four large teeth present, two basal, one about midway, and one subdistal to corneous acute tip. Immovable finger with about three large teeth, about equidistant from corneous asymmetrical bifid tip.

Walking legs long, slender; ml/mw of third 4.19±1.0 in males, 3.93±0.4 in females with ratio increasing with size in both sexes. Propodus of pereopods 2 and 3 with thick pubescence on distal half of ventral surface; scattered tufts on dorsal surface. Dactylus shorter than propodus with three dorsal and three ventral rows of pubescence.

Male abdomen subtriangular in outline; telson length and width subequal; distal margin lined with setae. Gonopod relatively short, simple, unarmed; distal region narrowing at amber-colored endpiece, slightly curved laterally.

Female abdomen subcircular in outline, not extending to coxae of pereopods, margins lined with setae; telson broader than long. Female gonopore almost subcircular with slight expansion toward pore posteromedially; operculum raised well above sternum, tilted toward midline, almost subrectangular in outline. Eggs large (1.25 mm diameter) and few.

HABITAT.—This species appears to terrestrial in habit. Individuals have been collected in dry limestone rubble and in a talus pile. The sites were shaded, but no standing water was in the collecting areas (Abele and Means, 1977).

DISTRIBUTION.—Sesarma cookei is known only from the John Crow Mountains in eastern Jamaica from about 400 to 650 m elevation.