Euarche maculosa (Treadwell 1931)

Euarche maculosa (Treadwell, 1931)

Macellicephala maculosa Treadwell, 1931:313, fig. 1 a–g.

Panthalis nigromaculata.—Willey, 1905:255, pl. 1: figs. 28–32. [Not Panthalis nigromaculata Grube, 1878].

Eupanthalis maculosa.—Hartman, 1938b:125.—Strelzov, 1968:141; 1972:307, figs. 3E, 14A–E, 15A–G [part].

Euarche maculosa.—Pettibone, 1976:68.

MATERIAL EXAMINED.—PHILIPPINE ISLANDS. Marinduque Island off Tayabas Light, 13°48′N, 121°43′E, 194 m, black sand, Albatross sta D5379, 24 Feb 1901, holotype (USNM 19543).

TYPE MATERIAL.—The holotype, with the pharynx fully extended and the right palp missing, is incomplete posteriorly, with 63+ segments, 50+ mm long and 5 mm wide with setae. It was examined by Hartman (1938b:125) and referred to Eupanthalis.

DESCRIPTION.—Strelzov (1972:307) reported specimens from Gulf of Tonkin up to 86+ segments, with maximal width 7 mm including parapodia without setae.

Elytra delicate, transparent, rounded to elongate-oval, first few pairs larger, rest leaving middorsum uncovered (Figure 6C–E; Willey, 1905, pl. 1: figs. 28, 31, 32).

Prostomium oval, with 2 pairs of subequal eyes or anterior pair larger than posterior pair; short ceratophore of median antenna, with small lateral papilla, attached to posterior part of prostomium, with short style extending to tip of prostomium; lateral antennae with short ceratophores attached on anterior part of prostomium with styles similar to those of median antenna; palps long, stout, tapered, with longitudinal rows of papillae on distal two-thirds (Figure 6A; Treadwell, 1931, fig. 1a; Willey, 1905, pl. 1: figs. 28, 29; Strelzov, 1972, fig. A).

Tentacular segment distinct dorsally, with median nuchal lobe forming attachment for median antenna. Tentaculophores lateral to prostomium, with single aciculum, row of few papillae on inner dorsal side, and usually without setae; tentacular cirri longer and stouter than antennae, ventral ones slightly longer than dorsal ones (Figure 6A,B).

Segment 2 with first pair of elytrophores, biramous parapodia, and ventral buccal cirri similar to tentacular cirri, longer than following ventral cirri; notopodia conical, with small bundle of finely spinous capillary notosetae extending to about tips of neurosetae; neuropodium with slightly bilobed presetal acicular lobe and rounded postsetal lobe, with slightly developed lower bract; row of neurosetae finely spinous, tapering to fine tips, middle ones somewhat stouter (Figure 6F-J; Strelzov, 1972, figs. 14B, 15G).

Pharynx with 13 (Strelzov, 1972) to 15 (type) pairs of distal papillae, with middorsal one only slightly larger than others, attached to large base, midventral one similar to others (type) or may be 3 or 4 lobed (Strelzov, 1972), also attached to large base: 2 pairs of stout hooked dark jaws with 3–6 lateral teeth (Willey, 1905, pl. 1: figs. 28, 30; Strelzov, 1972, fig. 14A).

Parapodia of cirrigerous segments 3, 6, and 8 with dorsal cirri on short cirrophores on posterior side of notopodia, with styles long, tapered, extending beyond setae (Figure 7A,D); conical notopodia with small bundle of long capillary notosetae on segment 3, fewer and shorter on following parapodia; neuropodia with distinct lower bract; few upper neurosetae lanceolate, spinous (Figure 6H); middle stout, acicular neurosetae with tips rounded, slightly hooked, with distal hairs and arista (Figure 7B); lower neurosetae curved, tapering to fine tips, spinous, with large spines basally and close-set spinous rows distally (Figure 7C).

Beginning with segment 9, notopodia wide, flat, on anterodorsal sides of large neuropodia, with developing spinning glands and only few short notosetae; neuropodia with slightly bilobed presetal acicular lobe and diagonally truncate postsetal lobe, with more or less distinct lower bract (Figure 7E,H,I; Willey, 1905, pl. 1: fig. 32; Strelzov, 1972, fig. 14D). Lower group of neurosetae similar to anterior ones (Figure 7C,L; Treadwell, 1931, fig. 1f; Strelzov, 1972, fig. 15E); middle stout acicular neurosetae with slightly hooked tips and subdistal hairs, with or without aristae (Figure 7G,K; Treadwell, 1931, fig. 1g; Strelzov, 1982, fig. 15B); upper group of neurosetae of 2 types: (a) slender, wider basally, lanceolate, tapering to slender tips, with rather long fine hairs; (b) shorter, pinnate, tapering abruptly to slender tips, with whorls of widely spaced spines (Figure 7F,J; Treadwell, 1931, fig. 1d,e; Strelzov, 1982, fig. 15A,F). Dorsal cirri short, inflated basally, ventral cirri short, subulate (Figure 7H,I). No distinct branchial vesicles.

TUBE.—The tube was described and figured by Strelzov (1972:311, fig. 14E). It resembled the tube described by Ehlers for E. tubifex. The anterior part of the tube is narrower and annulated, formed of parchment-like material, becoming wider posteriorly (maximal width 25 mm), with the compact wall formed of a thick layer of hairs cemented with muddy and sandy particles.

Willey (1905:259) indicated that the body of the worm he examined was quite flaccid and collapsed after segment 31; it was full of glistening silken coils and was firmly attached to the posterior end of the tube. The anterior part of the tube was mostly free from the body of the worm, although slightly connected by loose silken strands. This would explain why anterior fragments removed from their tubes are so common in collections.

DISTRIBUTION.—Indo-Pacific: Philippines, Ceylon, Gulf of Tonkin. In 17 to 194 meters.

Euarche maculosa (Treadwell)

Macellicephala maculosa Treadwell, 1931:313, fig. 1a-g.

Eupanthalis maculosa.—Hartman, 1938:125.

MATERIAL EXAMINED.—Philippine Islands, Marinduque Island, oft Tayabas Light, 13°48′N, 121°43′E, 194 m, Albatross sta. D5369, 24 February 1909, holotype (USNM 19543).