Caulleryaspis fauchaldi, Salazar-Vallejo, Sergio I. & Buzhinskaja, Galina, 2013

Salazar-Vallejo, Sergio I. & Buzhinskaja, Galina, 2013, Six new deep-water sternaspid species (Annelida, Sternaspidae) from the Pacific Ocean, ZooKeys 348, pp. 1-27 : 2-5

Caulleryaspis fauchaldi sp. n. Figures 1, 2

Sternaspis fossor : Hartman 1963: 59; Fauchald and Hancock 1981: 35 (partim, non Stimpson 1853).

Type material.

Northeastern Pacific, Oregon. Holotype (LACM 5360), and paratype (LACM 5361), Cascadia Abyssal Plain, west of Yaquina Bay, R.V. Acona, Sta. AD 33, NAD 21 (44°30.0'N, 125°34.0'W - 44°39.0'N, 125°33.2'W), 2800 m, clayey silt, 25 Jan. 1963 (paratype breaking into two parts, 8.5 mm long, 4 mm wide, introvert not exposed; left shield plate 2.3 mm long, 1.5 mm wide).

Additional material.

Northeastern Pacific. Oregon. Four specimens (CAS 128953f), variably damaged, Sta. BMT 556 (48°7.7'N, 127°4.8'W), 2519 m, 10 Sep. 1971, A. Carey, coll. (9-10 mm long, 4.0-4.5 mm wide; left shield plate 2.2-2.3 mm long, 2.4-2.5 mm wide). One specimen (CAS 129027f), Sta. BMT 557 (48°9.0'N, 127°4.2'W), 2519 m, 10 Sep. 1971, A. Carey, coll. (9.5 mm long, 4 mm wide; left shield plate 2.5 mm long, 2.9 mm wide). Southern California canyons. One specimen (LACM 5362), 8.1 km off Pyramid Head, Lighthouse, San Clemente Island, R.V. Velero IV, Sta. 6839 (32°46'30"N, 118°15'43"W), 1387 m, coarse sand, 30 Jun. 1960 (3.2 mm long, 1.8 mm wide, abdomen 2.5 mm long; left shield plate 0.8 mm long, 0.8 mm wide). BLM (Bureau of Land Management), Baseline Study, Southern California Bight. One specimen (LACM 5333), dried-out, BLM 81304, R.V. Thomas G. Thompson, Sta. 813 (33°0.903'N, 119°2.188'W), 1753 m, olive brown silt, biological box core, rep. 04 BFI/ B4-1, 23 Aug. 1977, K. Fauchald, G. Jones, coll. One specimen (LACM 5335), dried-out, BLM 81308, R.V. Thomas G. Thompson, Sta. 813 (33°0.933'N, 119°1.919'W), 1753 m, olive brown silty mud, biological box core, rep. 08 BFI/ B4-1, 23 Aug. 1977, K. Fauchald, G. Jones, coll. One specimen (LACM 5337), dried-out, BLM 81352,, R.V. Thomas G. Thompson, Sta. 813 (33°1.05'N, 119°1.96'W), 1723 m, olive brown mud, biological box core, rep. 52 BFI/ B4-1, 31 Aug. 1977, K. Fauchald, G. Jones, coll.

Description.

Holotype (LACM 5360) and paratype breaking into two pieces (Fig. 1A, D). Body grayish, with introvert exposed, slightly darker, broken dorsally; abdomen breaking ventrally, ventro-caudal shield grayish. Integument papillae abundant, shorter on introvert, larger on abdomen, incorporating sediment particles forming a thick coat over most of body (including introvert in paratype), arranged in single transverse series in posterior chaetigers. Body 9 mm long, 3 mm wide, about 28 segments.

Prostomium minute globose, ovoid, brownish (Fig. 1B). Peristomium small, oval, bearing abundant papillae resembling those present over introvert, extended as a wide band over prostomium. Mouth oval, small, slightly projected, covered by papillae.

First three chaetigers with about 16 falcate, tapered introvert hooks per bundle, each with subdistal dark areas (tips broken, darker areas look distal; subdistal in complete hooks). Genital papillae not seen (paratype with ventrolateral pores between segments 7 and 8). Pre-shield region with 7 segments (difficult to count because of specimens fragility); capillary chaetae along first pre-shield segment (paratype with capillaries in two segments).

Ventro-caudal shield completely covered by a thick coating of adhered particles (Fig. 1C), perforated, better preserved in paratype (Fig. 1E); suture not visible. Anterior margins clearly rounded; anterior depression deep; anterior keels not exposed. Ribs or concentric lines not visible. Lateral margins rounded, expanded medially, reduced posteriorly. Fan truncate, barely reaching posterior corners. Other features not visible.

Marginal chaetal fascicles include 9 lateral and only 4-5 short, small posterior ones (others probably broken), each with 3-4 chaetae per bundle. Peg chaetae robust, forming thin, short spines, close to posterior margins. Additional chaetal fascicles not visible.

Branchiae lost. Interbranchial filaments lost. Branchial plates slightly divergent, anteriorly expanded, rounded (Fig. 1F).

Juveniles. Juvenile (Fig. 2A) with papillae less abundant and larger than those present in type specimens, homogeneously distributed throughout integument, eroded in introvert and arranged in transverse series as remains of erosion along dorsal surface (Fig. 2D). Body about one-third as large as type specimens, with introvert damaged by compression (Fig. 2B). Ventro-caudal shield with sediment particles and abundant papillae (Fig. 2C); anterior margins poorly defined, lateral margins rounded, medially expanded. About 9 lateral chaetal bundles and 5-6 posterior ones with longer, thinner and fewer chaetae than in larger specimens. Peg chaetae not visible.

Etymology.

This species is named after Dr. Kristian Fauchald, long-time teacher and friend, in recognition of his many contributions to polychaete systematics and especially because of his contribution to the study of deep-sea fauna including the off Oregon species. The epithet is a noun in the genitive case.

Type locality.

W off Yaquina Bay, 2800 m depth.

Remarks.

Caulleryaspis fauchaldi sp. n. is very similar to Caulleryaspis gudmundssoni Sendall & Salazar-Vallejo, 2013 because both have shields with a deep anterior depression and robust peg chaetae. These two species differ, however, in two main features. In Caulleryaspis fauchaldi the anterior shield margins are rounded, the introvert has longer papillae, and the peg chaetae form thin short spines, whereas in Caulleryaspis gudmundssoni the anterior shield margins are more angular, the introvert has shorter papillae, and the peg chaetae form thick, long spines.

Distribution.

From Oregon to Southern California, in 1387-2800 m depth.