Ampithoe vacoregue J. L. Barnard 1979

Ampithoe vacoregue

DIAGNOSIS OF FEMALE.—Pleonal epimera 2–3 with weak setule notch at posteroventral corner, no lateral ridges. Article 5 of gnathopod 1 shorter than article 6, posterior edge of article 5 with rounded posterior lobe, palm oblique, gnathopod 2 of female form, article 5 short and lobate, article 2 of both gnathopods with anterodistal lobe laterally. Article 2 of pereopods 1–2 about twice as long as wide. Ventral edges on articles 1–3 of antenna 1 not spiniferous, furnished with elongate setae, especially dense on articles 1–2; antenna 2 much shorter than antenna 1, flagellum of antenna 1 slightly longer than peduncle, flagellum of antenna 2 shorter than article 5 of peduncle, article 4 of peduncle with sharp posterodistal extension medially. Apical lobules of lower lip obsolescent, apices of outer lobes weakly sinuate. Coxa 1 produced forward. Peduncular process of uropod 1 absent; rami of uropod 3 especially small. Article 2 of pereopods 3–5 weakly expanded, with protruding posteroventral corner. Knobs on telson slightly enlarged.

MALE.—Unknown.

HOLOTYPE.—USNM 169017, female “g,” 5.65 mm (illus.).

TYPE-LOCALITY.—DAW 31, Galapagos Islands, Isla Santa Cruz, halfway between Academy Bay and Tortuga Bay, 22 February 1962, 6–9 m, algae and rock wash.

RELATIONSHIP.—The only known species in the eastern Pacific to which this taxon, known only for the female, is related, appear to be A. pollex and A. tahue. The shapes of gnathopod 1 and the lower lip are the clues to this relationship. Ampithoe vacoregue appears on first sight to be identifiable with A. tahue but differs from A. tahue in the duplication on pereopod 3 of the shapes on pereopods 4–5, in the lack of medial cones on antenna 2, the sharpness of the posterodistal and medial extensions on article 4 of the peduncle on antenna 2, the much more setose peduncle of antenna 1 and the more slender gnathopod 2.

MATERIAL.—DAW 31 (4 females only).

DISTRIBUTION.—Galapagos Islands, Isla Santa Cruz, vicinity of Academy Bay, intertidal.