Laubierpholoe swedmarki (Laubier 1975)

Laubierpholoe swedmarki (Laubier, 1975)

Pholoe swedmarki Laubier, 1975:673–678, figs. 1, 2.

MATERIAL EXAMINED.—None. Figure references are to Laubier (1975).

DESCRIPTION.—Holotype 1.5 mm long, 0.4 mm wide, 27 segments. Body very small, linear, strongly flattened, slightly attenuated posteriorly, smooth dorsally, with scattered small papillae with pointed tips on ventral side of body (figs. 1A,B, 2A). Color white, with 4 black eyes. Elytra on bulbous elytrophores not covering middorsum. Elytra oval, transparent, with 5–8 simple papillae on external border and few on surface; some elytra enclosing developlng embryos and juveniles (fig. 2A,B,G,H).

Prostomium and tentacular segment fused; prostomium rounded, bilobed, with lateral horns; median antenna with small ceratophore and short style in anterior notch of prostomium; 2 pairs of eyes near anterolateral border, anterior pair larger than posterior pair; tentaculophores lateral to prostomium, each with dorsal tentacular cirrus twice as long as median antenna, and very short ventral tentacular cirrus, half as long as median antenna and hidden from view dorsally; palps long and slender, with small papillae on lateral sides, emerging lateral to tentaculophores; 4 small conical expansions on anterior lip of mouth (corresponding to facial tubercle?) (fig. 1A,B). Second segment with first pair of bulbous elytrophores and elytra, biramous parapodia, and ventral buccal cirri lateral to mouth and slightly longer than dorsal tentacular cirri (fig. 1A,B). Dorsal tubercles nodular (fig. 1A). Pharynx with 9 dorsal and 9 ventral border papillae, central 3 papillae in each row smaller, and 2 pairs of brown jaws.

Notopodia small, in form of small, conical acicular lobe on anterodorsal side of larger neuropodia; neuropodia with presetal conical acicular lobe and shorter rounded postsetal lobe (fig. 1A,B). Notosetae few (2–4), forming fan-shaped bundle, slender, tapering to fine tips, with series of small denticles (fig. 2B). Neurosetae stouter than notosetae, moderate in number (6–10), in single row, compound, with shafts diagonally truncate and with numerous distal and subdistal spines; blades short and falcate, with entire tips, upper blades longer, with more numerous spines, lower ones shorter with fewer, minute spines (fig. 2D–F). Ventral cirri short, tapered, with ovoid cirrophores (fig. 1B). Pygidium rounded, without anal cirri (?).

DEVELOPMENT.—Development was characterized by extreme reduction of egg number, internal fertilization, and extension of the reproductive period with gestation inside the elytra (viviparity). A mature animal had a single large ovum in the body of segment 13, and, in the same segment, a developing embryo in the left 7th elytron, and a developing juvenile with 6 setigerous segments, showing neurosetae, head appendages, and jaws, in the right elytron (fig. 2A,G,H).

DISTRIBUTION.—Northeast Atlantic Ocean, Bermuda, in 2–8 meters.