Heterodina mccaini, Schotte & Kensley, 2005

Schotte, Marilyn & Kensley, Brian, 2005, New species and records of Flabellifera from the Indian Ocean (Crustacea: Peracarida: Isopoda), Journal of Natural History 39 (16), pp. 1211-1282 : 1259-1261

Heterodina mccaini sp. nov.

( Figure 27 , 28 )

Material examined

Holotype: USNM 280350 , one male (1.3 mm), sta 1G1, seagrass beds near coral reef off Manifa, Persian Gulf, 3 m, coll. J. McCain, 12 November 1981 . Paratypes: USNM 280351 , one male, 12 ovigerous females, 54 juveniles, from eight stations, seagrass beds near Manifa and Ras Tanajib, Persian Gulf, 3–3.5 m .

Description

Male. Body oval in outline; length somewhat less than twice maximum width. Brownish pigment sparse, more visible in mature males, usually as two submedial rows on dorsum and as patch at base of pleotelson or scattered along lateral margins of pereonites. Epistome flat anteriorly with concave lateral margins and wide, tapering extensions posteriorly. Pleotelson triangular, posterolateral margins slightly sinuous, posterior apex tapering to very obtuse point.

Flagella of antennule and antenna with seven articles each. Maxilla 1, maxilla 2 and mandible as pictured. Pereopod 1 with two stout, fringed setae on propodus, one on carpus and two at posterolateral angle of merus; pereopod two with two fringed setae at posterolateral corner of merus; pereopod 7 with four very stout, fringed setae on carpus only. Pleopod 1, endopod reduced, about one-fourth total area of exopod. Appendix masculina of pleopod 2 extending well beyond apex of endopod, broad, about five times as long as wide, broadly rounded at apex; not on a posteriorly directed lobe. Penes separate throughout most of length, four times longer than wide at base, rami diverging abruptly before tapering to broadly rounded apices. Exopod of uropod one-fifth length of endopod, set into margin.

Ovigerous female. As for male except in sexual characters.

Remarks

The new species differs from its Caribbean congener in the shape of the epistome and of the pleotelson, which is narrowly rounded in H. mosaica ( Kensley and Schotte, 1987) . In the latter, the appendix masculina is swollen basally, tapering to a narrow apex, and the long, more slender penes do not diverge distally as in the new species.

Etymology

The species is named for Dr John C. McCain, who collected it while doing fieldwork under the auspices of the University of Petroleum and Minerals in Dhahran, Saudi Arabia.

Genus Oxinasphaera Bruce, 1997

Restricted synonymy. Oxinasphaera Bruce 1997, p 151 .

Diagnosis

Pereonites 2–7 with one or two rows of distinct, usually acute spikes, segments 3–6 usually with two rows. Pleotelson posterior margin medially excavate, with median process set within or above indentation, occasionally entire. Antennule peduncle article 1 anteriorly with row of prominent, ventrally projecting spikes, posteriorly with two spikes or fewer. Epistome anterior margin with one or two ventrally projecting spikes or blades. Mandible incisor multicuspid; molar process medial margin strongly produced. Maxilliped, articles 3–5 with medial margins greatly elongated and finger-like; distolateral margins of articles 2– 5 provided with abundant long setae. Uropodal exopod short, one-half or less length of exopod, apex deeply bifid; endopod projecting beyond apex of pleotelson, round in section, acute at apex and often with additional abundant tubercles. Penes paired, unfused. Ovigerous female brood pouch composed of four short oostegites arising from sternites 1– 4, overlapping slightly at midline; eggs held in internal pouches.

Figures

Figure 27. Heterodina mccaini sp. nov. (A) Male, dorsal view; (B) antennule; (C) antenna; (D) frontal lamina; (E) right mandible; (F) maxilla 2; (G) left mandible; (H) maxilla 1; (I) maxilliped; (J) pleopod 1; (K) male pleopod 2; (L) pleopod 3.

Figure 28. Heterodina mccaini sp. nov. (A) Pereopod 1; (B) pereopod 2; (C) uropod; (D) pereopod 7; (E) penes; (F) pleopod 4; (G) pleopod 5.