Gaudichaudius iphionelloides (Johnson 1901)

Gaudichaudius iphionelloides (Johnson, 1901)

Harmothoe iphionelloides Johnson, 1901:391, pl. 1: figs. 2–7.—Hartman, 1938b:4.

Gattyana iphionelloides.—Berkeley and Berkeley, 1945:321; 1948:12, fig. 12.—Hartman, 1948:14.—Pettibone, 1949:2; 1953:44, pl. 22: figs. 194–200.—Reish, 1965:136.—Uschakov, 1982:155, pl. 54: figs. 7–12.

MATERIAL EXAMINED.—WASHINGTON. Off Foulweather Bluff, Puget Sound, 60–64 m, 2 Aug 1938, M. Pettibone, collector, 1 specimen (USNM 25182). West Sound, Orcas Island, San Juan Archipelago, dredged in mud, 16 Jul 1940, M. Pettibone, collector, 1 specimen (USNM 32249). SE Lawrence Point, Orcas Island, 82 m, shelly, 7 Aug 1940, M. Pettibone, collector, 1 specimen (USNM 21120). Between Dinner Island and Griffin Bay, San Juan Island, dredged in eel grass, Aug 1934, M. Pettibone, collector, 1 specimen (USNM 25181). Off Neah Bay, Strait of Juan de Fuca, 27 m, 7 Jul 1940, M. Pettibone, collector, 2 specimens (USNM 25183).

BRITISH COLUMBIA. Cardale Point, Valdez Island, 19 May 1921, E. Berkeley, collector, 1 specimen (USNM 41653). Reef at False Narrows and near Dodds Narrows, Nanaimo, 17 Jul 1940, E. and C. Berkeley, collectors, 2 specimens (USNM 41651, 41652).

ALASKA. Alitak Bay, 27–55 m, Alaska King Crab Invest. sta. 106–40, 2 Nov 1940, 1 specimen (USNM 21385).

BERING SEA. Little Diomede Island, 65°36.7′N, 168°45′W, 0–30 m, Hugh Smith sta. 54, 30 Jul 1960, J. Tibbs, collector, 1 specimen (USNM 31416).

DESCRIPTION.—The body is oval, tapering anteriorly and posteriorly, flattened dorsoventrally, with lengths up to 35 mm, widths up to 12 mm, and up to segments 36. The 15 pairs of elytra are deeply imbricated and cover the dorsum. The elytra are thick, light amber-colored to dark brown, orbicular (first pair) and irregularly reniform with a deep or shallow anterior notch, and with lateral and posterior fringes of long and short papillae (Figure 18I–L; Johnson, 1901, pl. 1: fig. 3; Pettibone, 1953, pl. 22: fig. 195). The elytra are covered in large part with areoles, variable in size, very small and numerous on the anterior part of the elytra. The surface of the areoles are smooth or roughened, some with raised microtubercles. The elytrophores are prominent, extending posteriorly and with an extra lobe on the base of the posterior side (Figure 18B).

The prostomium is oval, bilobed, without or with only a slight indication of cephalic peaks, and with 2 pairs of rather large eyes (Figure 18A; Johnson, 1901, pl. 1: fig 2; Pettibone, 1953, pl. 22: fig. 194). The ceratophore of the median antenna is long, slender, inserted in the anterior notch of the prostomium, with a long papillate style. The ceratophores of the lateral antennae are inserted terminoventrally, lateral to the ceratophore of the median antenna, with short, tapered papillate styles. The palps are stout, tapered, and minutely papillate. The tentaculophores of the first segment are lateral to the prostomium, each with a few (3–4) setae on the inner side and a pair of dorsal and ventral tentacular cirri similar to the median antenna. The second or buccal segment has a raised nuchal fold covering the posterior part of the prostomium, large bulbous elytrophores of the first pair of elytra, biramous parapodia and long ventral buccal cirri similar to the tentacular cirri and attached basally on the neuropodia lateral to the ventral mouth.

The dorsal cirri have elongate cirrophores, bulbous basally, attached on the dorsoposterior bases of the notopodia; the long papillate styles extend beyond the tips of the setae. The dorsal tubercles on the cirrigerous segments, in line with the elytrophores, are delicate, transparent, forming raised subrectangular areas (Figure 18A,B,D; Johnson, 1901, pl. 1: fig. 4). The dorsum has transverse ciliated bands extending between the elytrophores and dorsal tubercles, 2 per segment (Figure 18A,B).

The biramous parapodia have small rounded notopodia with a projecting acicular process on the lower side, located on the anterodorsal side of the large neuropodia; the neuropodia are diagonally truncate with a projecting acicular process on the anterior side (Figure 18C,D; Johnson, 1901, pl. 1: fig. 4; Pettibone, 1953, pl. 22: figs. 196, 197). The notosetae are very numerous, white, spreading fanlike anteriorly and dorsally, all with spinous rows; they are of 4 lengths: those of the first and second rows are stout, short and longer, curved, with blunt tips (Figure 18E; Johnson, 1901, pl. 1: fig. 6); those of the third row are stout, longer, slightly curved, with more slender blunt tips (Figure 18F); and those of the fourth row are slender, longest, tapering to long slender, almost capillary tips (Figure 18G; Johnson, 1901, pl. 1: fig. 7a,b). The neurosetae are numerous, straw-colored, stout, with spinous rows and rather long, slightly hooked bare tips (Figure 18H; Johnson, 1901, pl. 1: fig. 5; Pettibone, 1953, pl. 22: fig. 200); the upper neurosetae are longer, with longer spinous regions, and the lower ones are shorter, with shorter spinous regions. The ventral cirri are short, tapering, papillate, attached on small cirrophores on the middle of the neuropodia (Figure 18C,D). The pygidium has a pair of rather short papillate anal cirri.

BIOLOGY.—G. iphionelloides is found intertidally under rocks and dredged in eel grass and on muddy, shelly and rocky bottoms in 4–82 meters.

DISTRIBUTION.—Northeastern Pacific from the Arctic (near Bering Strait), Kurile Islands to Washington (Puget Sound), in low water to 82 meters.