Acoetes grubei (Kinberg 1856)

Acoetes grubei (Kinberg, 1856)

Eupompe Grubei Kinberg, 1855 [1856]:387; 1858:24, pl. 7: fig. 35, pl. 10: fig. 59.

Panthalis grubei.—Hartman, 1939b:87; 1948 [1949]:30, pl. 4: figs. 1–4.

Panthalis marginata Hartman, 1939b:88, pl. 26: figs. 313–318. [New synonym.]

MATERIAL EXAMINED.—ECUADOR. Guajaquil, about 46 m, Eugenie Expedition, 4 syntypes of Eupompe grubei (NRS 2613).

MEXICO. El Golfo, Sonora, M. Crezee, collector, Apr 1968, 1 specimen (USNM 50731).

GUATEMALA. off San Jose Light, 13–20 m, sand, shell, mud, sta 770–38, 11 Jan 1938, holotype of P. marginata (AHF 51).

PANAMA (Pacific). Venado Beach, sieving in sand spit, sta 132–2, 4 Apr 1973, M.L. Jones, collector, 1 small specimen (USNM 71501).

TYPE MATERIAL.—Syntypes of Eupompe grubei consisting of 4 anterior fragments, 3 with pharynx fully extended (jaws of one had been cut out), with 56–85+ segments, 50–100+ mm long, 11–12 mm wide with setae; also some middle and posterior fragments; according to Kinberg, complete worm of about 185 segments, 220 mm long, 12.5 mm wide. Holotype of Panthalis marginata, along with portion of tube, consisting of anterior fragment of 48+ segments, 20+ mm long, 5 mm wide.

DESCRIPTION.—Elytra oval, delicate, leaving middorsum uncovered, without lateral pouch, brownish on medial part with light border, with net-like areolate areas (Figure 66C–E; Kinberg, 1858, pl. 7: fig. 33A,H). Prostomium bilobed, with globular ommatophores and long neck; median antenna with ceratophore in middle of prostomium, with lateral papillae, continuing posteriorly as more or less distinct posterior crest, with style extending almost to tips of ommatophores; lateral antennae inserted ventrally on ommatophores, similar to median antenna; posterior pair of small eyespots lateral to ceratophore of median antenna; palps stout, tapered, smooth, about twice as long as prostomium, irregularly banded with brown pigment (Figure 66A,B; Kinberg, 1858, pl. 7: fig. 35B). Tentacular segment visible dorsally with slightly raised nuchal ridge; tentaculophores lateral to prostomium, each with 2 bundles of setae, pair of dorsal and ventral tentacular cirri, similar to median antenna, all with subdistal brown bands (Figure 66B).

Second segment with first pair of elytrophores, ventral buccal cirri longer than following ventral cirri and biramous parapodia; notopodium with upper projecting acicular lobe and truncate lower part, with numerous finely spinous capillary notosetae; neuropodium wide, subconical, with subacicular anterior and supraacicular posterior parts somewhat digitate, and lower bract, with numerous finely spinous capillary neurosetae (Figure 66A,F–I; Hartman, 1939b, pl. 26: fig. 314). Distal border of extended pharynx with 15 pairs of border papillae, middorsal and midventral ones larger than others, upper one longer than lower one; 2 pairs of hooked jaws each with 4–6 lateral teeth (Kinberg, 1858, pl. 7: fig. 35A,E, pl. 10: fig. 59).

Third segment with first pair of dorsal cirri, with short cirrophores and styles extending beyond parapodia; ventral cirri short, subulate; notopodium and notosetae similar to those of segment 2; neuropodium somewhat smaller, with middle neurosetae stout, acicular with tapering spinous tips (Figure 66J–M; Hartman, 1939b, pl. 26: fig. 315). Parapodia of segments 4–8 with fewer and shorter notosetae (Figure 67 A,B).

Beginning with segment 9, notopodium rounded, flattened, on anterodorsal side of larger neoropodium, with notoaciculum, spinning glands, and few short notosetae; neuropodium with truncate presetal acicular and postsetal lobes and anteroventral bract; lower neurosetae numerous, within anteroventral bract, slender, slightly curved, with larger spines on enlarged basal part and close-set short spines on tapering capillary part; middle row of stout acicular aristate neurosetae; upper group of neurosetae, emerging from low anterodorsal bract, hidden by notopodium, of 2 types: (a) slender, tapering abruptly to slender tip, with long hairs subdistally and shorter spines more basally; (b) short, slender, bipinnate, hidden by notopodium (Figure 67C–F; Kinberg, 1858, pl. 7: fig. 35G; Hartman, 1939b, pl. 26: figs. 316–318; Hartman, 1948 [1949], pl. 4: figs. 2–4). Posterior parapodia larger, with some acicular neurosetae with subdistal spines on one side; cirrophores of dorsal cirri wide, inflated, with style short, conical; ventral cirri short, tapered (Figure 67G–M). Branchiae beginning about segment 10 as several small digitiform pustules on anterior and posterior bases of elytrophores and dorsal cirri; more posteriorly, single large one (Figure 67K; Kinberg, 1858, pl. 7: fig. 35F).

TUBE.—Fragment with holotype of Panthalis marginata a soft felty mucous tube.

DISTRIBUTION.—Eastern Pacific from Mexico to Ecuador. Low water to 46 meters.