Melita oba J. L. Barnard 1972

Melita oba

DESCRIPTION.—The general morphology is like that of Melita awa J. L. Barnard (in press) from New Zealand; illustrations and descriptions of the following, therefore, are not replicated: urosome, uropods 1–3, lower lip, body of mandible, maxillae 1–2, maxilliped, articles 2–3 of gnathopod 1, and pereopods 1–2. Following is the new description: anteroventral cephalic notch almost evenly quadrate; eyes black, ovatocircular; accessory flagellum 4–5 articulate; length ratio of articles 2–3 of mandibular palp 9:10 in female, 7:10 in male; article 3 with 2 distal setae and 2–4 other setae, article 2 with 2–3 setae; maxillipedal palp article 3 with small distal process; gnathopod 1 similar in both sexes but male palm more oblique and dactyl longer; female dactyl with extra small setae besides main setal-tooth, gnathopod 1 slender, hand evenly wide at both ends, palm oblique or subtransverse but deeply convex, defined by 1 (male) or 3 (female) submarginal spines on inner face, male hand with small posterior cusp far proximal from tapering end of dactyl, fitting palm, not grossly swollen basally, bearing deep hemilunar slit near mark 65; female gnathopod 2 like that of M. awa but article 4 without sharp process; male gnathopod 2 with sharp process on article 4, hand not strongly broadened in middle, palm oblique, bearing low subquadrate process distally and several spines on medial face of hand near base of dactyl, medial face otherwise without sculpture except for weak hemilunar line distally, strongly setose, lacking channel, dactyl subclavate, slightly overriding palm onto face of hand; coxae 1 and 4 distally expanded, male coxa 6 with rounded anterior lobe, female with broadly truncate anterior lobe, coxae poorly setose; article 2 of pereopods 3–5 ovate and subovate, article 2 of pereopod 5 broader than on pereopod 4, all with well-rounded posteroventral lobes; pereopodal dactyls with accessory cusp on outer side of apex, pereopod 5 with 2 accessory cusps (male), with chopped off setule near slit constriction and thick unchopped setule proximal to slit; pleonal epimera 1–3 with lateral ridge, 1–2 with obsolescent posteroventral cusp, 3 with medium tooth, posterior margins very weakly notched, epimera 2–3 with line of small ventral spines, 3 with several posteroventral serrations; pleonite 5 with pair of small, sharp posterolateral cusps on each side, each pair of cusps embracing 1 spine; uropods 1–3 like M. awa but ridge on peduncle of uropod 3 weak or absent; telson elongate, apices blunt but coniform, each bearing pair of short spines.

HOLOTYPE.—WAM, male, 7.2 mm.

TYPE-LOCALITY.—JLB Australia 5, west of Bunker Bay, Cape Naturaliste, Western Australia, intertidal, wash of algae and rocks, 2 September 1968.

RELATIONSHIP—This species, like M. matilda, resembles M. awa, and more so than M. matilda, in characters of head, pleonite 4, epimera, pereopods 3–5, and gnathopod 2, but far less so in telson, gnathopod 1, and maxillipedal palp.

Melita oba differs from M. awa and M. matilda in the expanded coxa 4 and coxa 1, in the process of maxillipedal palp article 3, in the rounded lobes and regularly ovate article 2 of pereopods 3–5, and in the elongate, narrow telsonic lobes bearing only 2 spines each.

Melita oba differs additionally from M. matilda in the presence of 2 cusps on each side of pleonite 4 (instead of 1), in the weak cusps of the pereopodal dactyls, in the small tooth of pleonal epimeron 3, in the simplified male hand of gnathopod 2, in the absence of a sharp tooth on article 4 of female gnathopod 2, and in the more oblique palm of gnathopod 1.

In the adult male one of the locking spines of pereopods 3–5 is apically bifid.

MATERIAL.—Slack-Smith 1 (14); JLB Australia 2 (2), 4(1), 5 (17), 6 (5), 11 (2).

DISTRIBUTION.—Southwestern Australia, littoral and sublittoral.