Comprehensive Description

provided by Smithsonian Contributions to Zoology
Malmgreniella murrayensis

Harmothoe lunulata— Monro, 1937:258 [not Delle Chiaje, 1830],

MATERIAL EXAMINED.—INDIAN OCEAN: South Arabian Coast: 18°03′N, 57°02′E, 38 m, Lithothamnion bottom, in cavity of sponge, John Murray Expedition, 29 Jul 1933, holotype (BMNH 1937.9.2.28, as H. lunulata by Monro, 1937).

DESCRIPTION.—Length 8 mm, width 3 mm including setae, 36 segments, last 2 segments very small. Body flattened, tapered slightly anteriorly and posteriorly, ventral side of posterior end with brownish streaks. Elytra 15 pairs, on usual segments, oval to subreniform, with group of microtubercles on anterior side of more anterior elytra, and scattered micropapillae on surface; brownish pigmentation forming almost complete circle, wider in some areas (Figure 14B–D).

Bilobed prostomium with anterior lobes truncate, without peaks; eyes small, anterior pair anterolateral, anterior to greatest width of prostomium, slightly smaller posterior pair posterodorsal; ceratophore of median antenna in anterior notch, style missing; ceratophores of lateral antennae inserted terminoventrally, with styles short, subulate, papillate; palps stout, tapered, appearing wrinkled; tentaculophores lateral to prostomium with single seta on inner side, tentacular cirri missing (Figure 14A). Segment 2 with first pair of large elytrophores, biramous parapodia, and long papillate ventral buccal cirri (Figure 14A). Pharynx not extended and not examined.

Biramous parapodium with notopodium shorter and smaller than neuropodium, rounded with projecting acicular lobe on lower side; neuropodium with subconical presetal acicular lobe with small supraacicular process and shorter, rounded postsetal lobe (Figure 14E,F). Notosetae moderate in number, of several lengths, with faint close-set spinose rows; shorter notosetae with longer tapered bare tips, longer notosetae with wider and shorter blunt bare tips, tips thinner on one side forming sort of flange (Figure 14G). Neurosetae moderate in number, with rather faint spinose rows, all with bifid tips, upper ones with longer spinose regions (Figure 14H). Dorsal cirri with cylindrical cirrophores, with slightly raised glandular areas on posterior sides; styles extending to tips of neurosetae, with filamentous tips and short clavate papillae; dorsal tubercles nodular, ventral cirri short, subulate, with short papillae (Figure 14F). Pygidium with dorsal anus medial to small posterior parapodia; anal cirri missing.

BIOLOGY.—Malmgreniella murrayensis was found living deeply embedded in the cavity of a sponge.

ETYMOLOGY.—The species is named for the John Murray Expedition.

DISTRIBUTION.—Indian Ocean, South Arabian Coast. In 38 meters.
bibliographic citation
Pettibone, Marian H. 1993. "Scaled polychaetes (Polynoidae) associated with ophiuroids and other invertebrates and review of species referred to Malmgrenia McIntosh and replaced by Malmgreniella Hartman, with descriptions of new taxa." Smithsonian Contributions to Zoology. 1-92. https://doi.org/10.5479/si.00810282.538