Crucigera zygophora
Creators: name: Bastida-Zavala, J. Rolando
name: McCANN, Linda D.
name: Keppel, Erica
name: Ruiz, Gregory M.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Sabellida
Serpulidae
Crucigera
Crucigera zygophora

description: Crucigera zygophora (Johnson, 1901)
Figs 2 C–D, 3
Serpula zygophora Johnson, 1901: 433–434, pl. 19, figs 205–208 (type locality: Alki Point, Puget Sound, Washington, United States).
Crucigera formosa Bush, 1905: 233–234, pl. 28, figs 3–4, pl. 33, fig. 4, pl. 39, figs 6–7, 10–11, 14 (type locality: Dutch Harbor, Unalaska Island; also from Wrangell, southern Alaska).
Crucigera hespera Chamberlin, 1919b: 270, pl. 2, fig. 9 (type locality: Mendocino, northern California, United States).
Crucigera zygophora – Bush 1905: 233, pl. 29, fig. 5, pl. 31, fig. 2, pl. 33, fig. 3, pl. 39, figs 8, 12– 13, 15, 17, 20 (Sitka, Orca and Virgin Bay, and Prince William Sound, southern Alaska; attached to shell fragments, in twisted masses). — Treadwell 1914: 227 (Alaska and Santa Barbara, Southern California). — Berkeley 1930: 73 (Nanoose Bay, British Columbia; 36–55 m). — ten Hove & Jansen-Jacobs 1984: 165–170, figs 4a–c, 5d, 8d, 9a–j, 10a, c–d, 11a–h, 12 (revision of the genus; Alaska, British Columbia, Washington and California). — Bastida-Zavala 2008: 17–19, figs 4E–F (Alaska and California; 12–64 m).
Crucigera formosa – ten Hove & Jansen-Jacobs 1984: 166 (synonymy).
Material examined
179 specimens: AK (61) Jul. 2000, AV (1) Aug. 2000, PW (2) Aug. 2003, KD (26) Aug. 2001, ST (58) Aug. 2001, KT (4) Sep. 2003, WA (11) Aug. 2000, OR (3) Aug. 2000, HB (13) Sep. 2003.
Additional material
Approximately 13 specimens: LACMNH N2128, 1 specimen (approx. 55°55' N, 161°27' W, Canoe Bay, north shore, Alaska, King Crab Investigation, sta. 12–40, 17 Sep. 1940; see Hartman 1948); LACMNH N2129, several specimens (approx. 55°19' N, 162°57' W, Cold Bay, Alaska, King Crab Investigation, sta. 70–40, 27– 64 m, 17 Oct. 1940); LACMNH N2789, 1 specimen (approx. 55°55' N, 161°27' W, Canoe Bay, Alaska, from crab trap, 23 Sep. 1940, coll. N.L. Schmitt); LACMNH N412, 1 specimen (approx. 38°15' N, 122°58' W, Dillon Beach, Perch Rock Pt, California, Jun. 1941, coll. S.F. Light).
Diagnosis
Juvenile specimens. Tube white, thin and smooth; without peristomes, transverse ridges, longitudinal ridges or alveoli. Opercular peduncle smooth, white, with a bulbous region below funnel (Fig. 2C). In adult, base of operculum yoke-shaped, with a rounded dorsal process and two latero-ventral ones (Fig. 2D). Operculum a nearly radially symmetric funnel, shallow and smooth, without tubercles, with 13–34 radii with rounded tips (Fig. 2 C–D). Collar with bayonet chaetae, with 1–2 blunt, short teeth and minute accessory teeth, smooth distal blade.
Taxonomic remarks
Juveniles of Crucigera zygophora can be mistaken for Serpula columbiana Johnson, 1901 (Fig. 9A), since the operculum funnel is symmetrical and the basal processes appear as a bulbous region (Fig. 2C), less prominent than in the adult specimens (Fig. 2D). However, the number of radii of the juveniles of C. zygophora is mostly less than 25 radii (Fig. 2C), and in adult between 28 to 34 radii, while S. columbiana have more than 100 radii (Fig. 9B). Also, juveniles of C. zygophora could be confused with C. websteri (see previous remarks on this species).
Ecology
Sublittoral, 12–250 m (ten Hove & Jansen-Jacobs 1984; Bastida-Zavala 2008).
Distribution
Pacific: Northern Japan, U.S. west coast from Alaska to southern California (Treadwell 1914; ten Hove & Jansen-Jacobs 1984; Bastida-Zavala 2008). In this work, Crucigera zygophora juveniles were abundant on fouling plates from Kachemak Bay, Kodiak and Sitka, Alaska; and occasionally found in Valdez, Prince William Sound and Ketchikan, Alaska; Puget Sound, Washington; Coos Bay, Oregon; and Humboldt Bay, northern California (Fig. 3).
description: Published as part of Bastida-Zavala, J. Rolando, McCANN, Linda D., Keppel, Erica & Ruiz, Gregory M., 2017, The fouling serpulids (Polychaeta: Serpulidae) from United States coastal waters: an overview, pp. 1-76 in European Journal of Taxonomy 344 on pages 15-17, DOI: 10.5852/ejt.2017.344, http://zenodo.org/record/3834679