Malmgrenia darbouxi (Pettibone 1993)

Malmgreniella darbouxi

Harmothoe lunulata.—Katzmann, 1983:93 [not Delle Chiaje, 1830].

MATERIAL EXAMINED.—EASTERN ATLANTIC OCEAN: Mediterranean Sea: Near Zlorin Island, Yugoslavia, middle Adriatic Sea, 20–60 m, sand and mud, 1971, W. Katzmann, collector, holotype (USNM 74370).

DESCRIPTION.—Holotype, male with sperm, 9 mm long, 3.5 mm wide including setae, 34 segments. Ventral surface of posterior segments transversely banded with dark pigmentation (suggesting commensal relationship with unknown host). Elytra 15 pairs, on usual segments, large, oval, delicate, transparent; small group of microtubercles near middle of anterior border; dark pigmentation in form of transverse band over scar of attachment to elytrophore, to medial side, and continuing posteriorly along medial side (Figure 24B).

Bilobed prostomium with anterior lobes truncate, without peaks; anterior pair of eyes just anterior to greatest width, larger than posterodorsal pair; ceratophore of median antenna in anterior notch, with style small, regenerating; ceratophores of lateral antennae inserted terminoventrally, with styles short, subulate, with short papillae; palps long, tapered; tentaculophores lateral to prostomium, with single seta on inner side; dorsal and ventral tentacular cirri longer than prostomium, with short papillae (Figure 24A). Segment 2 with first pair of large elytrophores, biramous parapodia, and long ventral buccal cirri, similar to tentacular cirri (Figure 24A).

Biramous parapodium with smaller notopodium rounded, with projecting acicular lobe on lower side; larger neuropodium with subconical projecting presetal acicular lobe with digitiform supraacicular process and shorter, rounded postsetal lobe (Figure 24C,D). Notosetae moderate in number, slender, of several lengths, with faint spinose rows, longest ones tapering to more slender tips (Figure 24E). Neurosetae numerous, slender, about same width as notosetae; upper ones with longer spinose regions and tapered bifid tips; middle and lower ones with shorter spinose regions and more distinct hooked tips, lower ones with entire tips (Figure 24F). Dorsal cirri with cylindrical cirrophores, inflated basally, with glandular areas on upper side; styles with short papillae, tapered and extending to about tips of neurosetae; dorsal tubercles nodular, ventral cirri short, tapered, with few short papillae (Figure 24D). Pygidium rounded, with pair of long anal cirri.

ETYMOLOGY.—The species is named for J. Gaston Darboux, in recognition of his basic research on the aphroditoid polychaetes (Darboux, 1900).

DISTRIBUTION.—Eastern Atlantic Ocean, Mediterranean Sea (Adriatic Sea), in 20–60 meters.