Crucigera zygophora ( Johnson, 1901 )

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, European Journal of Taxonomy 344, pp. 1-76 : 15-17

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 ).

Figures

Fig. 2. Serpulids from United States fouling plates. Crucigera websteri. A. Operculum, juvenile from Humboldt Bay, California. B. Operculum, adult from San Pedro, California (LACMNH-N8819). – C. zygophora. C. Operculum, juvenile from Alaska (SERC). D. Operculum, adult from Canoe Bay, Alaska (LACMNH-N2128). – Ficopomatus enigmaticus. E. Tubes from Lake Merritt, California (LACMNH-N5141). F. Body, from Chesapeake Bay, Virginia (SERC-59327). G. Operculum, from Chesapeake Bay, Virginia (SERC-60530R). H. Colonies in Long Beach, California (photo by Bruno Pernet).– F. miamiensis. I. Tubes, from Chetumal Bay, Mexican Caribbean (ECOSUR). J–K. Operculum, from Galveston Bay, Texas (SERC-88344RF). – F. uschakovi. L. Tube, from Corpus Christi, Texas (SERC-88883). M. Thorax and operculum, from Galveston Bay, Texas (SERC-86995). N. Operculum, from La Encrucijada, Chiapas (UMAR-Poly 113). O. Thorax and operculum, from Corpus Christi, Texas (SERC-88883).

Fig. 9. Serpulids from United States fouling plates. Serpula columbiana. A. Operculum, from Ketchikan Bay, Alaska (SERC-81981). B. Operculum, adult from San Diego, California (LACMNH-Poly4928);. – Spirobranchus kraussii. C-D. Operculum and tube fragment, from Oahu, Hawaii (SERC-114603). E. Colony, from Natal, South Africa (LACMNH-N5217). – S. minutus. F. Tube, from Santa Catarina, Brazil (USNM-43239). G. Operculum, From Tampa Bay, Florida (SERC-93759). Types of collar chaetae. H–J. Bayonet. K. Bayonet with proximal rasp. L. Capillaries. M. Limbate. N. Fin-andblade chaetae. O. Coarsely serrated. – Hydroides sanctaecrucis (H, L). – H. cf. brachyacantha (I). – Spiraserpula ypsilon (J). – H. elegans (K). – H. ochotereana (M).– Pseudochitinopoma occidentalis (N).– Ficopomatus uschakovi (O, modified from Arteaga-Flórez et al. 2014).

Fig. 3. Distribution of serpulids (Crucigera and Ficopomatus spp.) from United States fouling plates (closed symbols) and literature records (open symbols).