Malmgreniella panamensis Pettibone 1993

Malmgreniella panamensis

MATERIAL EXAMINED.—NORTHWESTERN ATLANTIC OCEAN: Panama: Caribbean Sea, Galeta Reef, 13–14 Sep 1978, 9–12 m, sand, on Ophiopsila cf. polysticta H.L. Clark, G. Hendler, collector, holotype (USNM 133562); 3 Oct 1980, paratype (USNM 133563).

DESCRIPTION.—Holotype, female with eggs, 7 mm long, 3.5 mm wide including setae, with 31 segments; paratype, female with eggs, 8 mm long, 3.2 mm wide, with 35 segments. Posterior two-thirds of body with black pigmentation in form of large oval midventral spots and smaller spots on ventral bases of parapodia, and on basal halves of dorsal cirri (Figure 35B). Elytra 14–15 pairs, oval to subreniform, delicate, transparent, without papillae or microtubercles, with blackish pigmentation in spots over place of attachment to elytrophores, in complete ring on first elytra, semicircular bands on following elytra, and nearly complete circle on posterior elytra (Figure 35C–E).

Bilobed prostomium with subtriangular anterior lobes, with slight indication of peaks; 2 pairs of eyes subequal in size, anterior pair in region of greatest width, posterior pair near posterior border; scattered pigmentation on prostomium and bases of antennae; ceratophore of median antenna in anterior notch, with style about as long as palps; lateral antennae with ceratophores inserted terminoventrally, with short subulate styles; palps stout, tapered; tentaculophores without setae, with dorsal and ventral tentacular cirri about same length as median antenna (Figure 35A). Segment 2 with first pair of elytrophores, biramous parapodia, and long ventral buccal cirri similar to tentacular cirri (Figure 35A).

Biramous parapodium with notopodium shorter than neuropodium, rounded with projecting acicular lobe on lower side; neuropodium with subconical presetal acicular lobe and conical supraacicular process, not sharply set off; postsetal lobe shorter, rounded (Figure 35F,G). Notosetae numerous, forming radiating bundle, short to long, more slender than neurosetae, appearing smooth but finely spinose with short, bare, rounded tips (Figure 35H). Neurosetae moderate in number (about 20) forming fan-shape bundle; supraacicular neurosetae with long spinose regions, prominent spines, with entire, tapered tips (Figure 35I), or few with very small secondary tooth (on paratype); subacicular neurosetae with shorter spinose regions, entire, slightly hooked, bare tips (Figure 35J). Dorsal cirri with long cylindrical cirrophores, with styles long, tapering to filamentous tips, extending far beyond neurosetae; black pigmentation on basal third of styles; dorsal tubercles nodular; ventral cirri short, tapered (Figure 35G). Pygidium with pair of pigmented anal cirri.

BIOLOGY.—Malmgreniella panamensis was collected subtidally in sand on the burrowing ophiuroid Ophionpsila cf. polysticta H.L. Clark by Gordon Hendler.

ETYMOLOGY.—The species is named for Panama, the collection area.

DISTRIBUTION.—Northwestern Atlantic Ocean, Caribbean Sea, Panama. In 9–12 meters.