Elasmopus bampo J. L. Barnard 1979

Elasmopus bampo

Elasmopus rapax of Alamitos Bay.—J. L. Barnard, 1962b, fig. 17; 1969b:119. [In part.]

?Elasmopus rapax of Hawaii.—J. L. Barnard, 1970:131–135, figs. 79, 80.

DIAGNOSIS.—Eyes ordinary. Mandibular palp article 3 deeply falcate. Palm of male gnathopod 2 with ordinary spinose hump near dactylar hinge, then supernumerary (4th) sharp enlarged tooth on same plane, naked apically, rounded mediofacial tooth, palm defined by tapering medial tooth, palm and posterior margin of hand evenly and sparsely setose. Article 2 of pereopods 3–5 with long posterior setae in male only; locking spines of pereopods 1–5 ordinary, inner margin of dactyl smooth but with minute shagreen proximally, main subapical setule thick but apically flexible. Epimera 2–3 with long ventral setae, epimera 1–3 with short ventral spines; epimeron 3 with nearly straight posterior margin bearing 5 or more sharp denticles becoming blunter dorsally, each sinus armed with setule except ventralmost, posteroventral tooth not larger than other denticles and its guarding sinus not enlarged greater than other sinuses. Rami of uropod 3 equally long in male, inner ramus shortened in females and juveniles; inner ramus with several stout basomedial spines. Telson with naked protrusive apices placed mediad, laterally defined by sinus and sharp tooth, spines submarginal from sinuosity and forming row of about 3 laterally; some spines very long in female, all spines short in male.

DESCRIPTION.—Female lacking long setae of article 2 on pereopods 3–5, small females and large juveniles lacking serrations of epimeron 3 except for ventralmost sinus and tooth; juvenile males with fourth tooth of palm on gnathopod 2 much smaller than in adults, small juvenile males apparently with gnathopod 2 as in E. rapax and therefore indistinguishable from that species.

Following parts as shown for E. rapax (Figures 35–37) head, antennae, accessory flagellum, eye, mouthparts (except for parts of mandibles illustrated), pereopods 1–5 (except 1 slightly anomalous pereopod 5 illustrated), dactyls, gnathopod 1 except article 4 as illustrated, urosome, uropods 1–2, female gnathopod 2 except proportions as outlined in figures, female uropod 3, coxae, cuticle, medial view of article 1 on antenna 1 except for several additional ventral setae.

VARIANT.—Subadult males from PAZ 9 with long spines on telson.

HOLOTYPE.—USNM 149390, male “a,” 6.88 mm (illus.).

TYPE-LOCALITY.—TOP 3, Topolobampo, Mexico, 25 November 1971, 1.6 km seaward of town, 1 m, rock wash.

VOUCHER MATERIAL.—Type-locality, female “u,” 6.56 mm (illus.); PAZ 9, male “p,” 6.2 mm (illus.), female “w,” 6.3 mm (illus.).

RELATIONSHIP.—This species differs from Mexican E. rapax in the presence of a fourth tooth on the hand of male gnathopod 2 and in the even serrations of epimeron 3 in terminal adults.

The Elasmopus rapax described from Alamitos Bay, California, by Barnard (1962b:94, 1969b:119) appears to belong with E. bampo. However, the telsonic spines of the juveniles are not as long as those of typical E. bampo and adults were said to have the spines reduced to the size one sees in the E. rapax of Hawaii described by J. L. Barnard (1970:131). One must place the Hawaiian taxon provisionally in E. bampo until the nature of telsonic spines can be elucidated; they would form an excellent subspecific or specific distinction between the two widely separated regions were it not for the variability encountered in Alamitos Bay, California.

MATERIAL.—SCO 16; KNO 1; TOP 2, 3; PAZ 5, 9.

DISTRIBUTION.—Gulf of California: Puerto Peñasco, Bahía Kino, Isla Espiritu Santo and Isla Partida, intertidal; California, bay form in Alamitos Bay; ?Hawaii, as a subspecies.