Protula balboensis Monro, 1933 Figs 7 B–E, 8 Protula tubularia var. balboensis Monro, 1933: 1088–1090, figs 30A–D (type locality: Balboa and Taboga Island, Pacific Panama; Gorgona Island, Colombia; on rocks, rock-pools, pier pilings and intertidal at low tides). Protula tubularia (non Montagu 1803) – Steinbeck & Ricketts 1941: 367 (Gulf of California: Puerto Refugio, Angel de la Guarda Island, Baja California). — Rioja 1942: 133–134 (from Acapulco, Guerrero, southern Mexican Pacific, according to Rioja 1963: 222). — Rioja 1963: 220–222 (Gulf of California: Carmen Island, Baja California Sur; 111 m). All indeterminable records are presumably P. balboensis (see taxonomic remarks). Portula balboensis – Zibrowius 1970: 17–18, pl. 4, figs 7–8 (Recife de Liza, Bahia, Brazil; 5 m). Protula tubularia balboensis – Kudenov 1975: 228 (Gulf of California: Cholla Bay, Puerto Peñasco, Sonora; intertidal; on rock). Protula balbaoensis – Perkins 1998: 95 (checklist of shallow-water polychaetes from Florida). Protula balboensis – Bastida-Zavala 2008: 37, fig. 8H (Mexican Pacific: Baja California, Baja California Sur, Sonora and Guerrero; incorrectly located in Puerto San Carlos, Baja California Sur; shore; in rocky reef and shingle). — Bastida-Zavala et al. 2016: 429–430, figs 7, 13A–B (Baja California and Michoacán, Mexican Pacific, and Atlantic Panama; intertidal to 1 m; in marinas and harbors, fouling). Protula diomedea (non Benedict 1887) – Bastida-Zavala & Salazar-Vallejo 2000a: 817, fig. 7h–o (Jururú Bay, northeastern Cuba). Material examined 16 specimens: JX (13) Aug. 2001, BB (2) Aug. 2004, CC (1) Sep. 2002. Additional material One specimen collected on the pier of the Smithsonian Institution station in Bocas del Toro, Caribbean side of Panama (photographed in vivo by Betel Martínez-Guerrero, 14 Aug. 2008, coll. Leslie Harris). Diagnosis Tube white; with shallow transverse ridges; without longitudinal ridges, peristomes or alveoli (Fig. 7B). Branchial crown with 24 radioles per lobe; radioles with rounded process at end of interradiolar membrane (Fig. 7D, detail); two small specimens with 9–12 radioles per lobe. Thoracic membrane wide, reaches seventh chaetiger. Operculum and opercular peduncle absent (Fig. 7 C–D). Collar chaetae limbate. Living adult specimens have a reddish thoracic membrane and radioles with numerous red spots (Fig. 7E). Taxonomic remarks Large specimens of Protula balboensis were found in small assemblages attached to other serpulids (Hydroides dianthus). Protula balboensis differs from P. longiseta, in that the latter species lacks the characteristic rounded processes on the radioles at the end of the interradiolar membrane (Fig. 7D, detail); however, the differences between these species are very small and need a more detailed morphological review (ten Hove & Kupriyanova 2009). Some records from the Gulf of California and Acapulco, Guerrero, in the southern Mexican Pacific (Steinbeck & Ricketts 1941; Rioja 1942, 1963) are indeterminable because there are no voucher specimens; however, later Bastida-Zavala (2008) confirmed the presence of P. balboensis along the Gulf of California (Baja California, Baja California Sur, Sonora) and from Acapulco, southern Mexican Pacific. Recently, Bastida-Zavala et al. (2016: 430) confirmed more specimens of P. balboensis from the Mexican Pacific and Atlantic Panama. Ecology Intertidal to 111 m (Rioja 1963). In rock-pools, on rocks, shingle, and as fouling on pier piling at marinas (Monro 1933; Bastida-Zavala 2008; Bastida-Zavala et al. 2016). Distribution Tropical eastern Pacific, from Gulf of California to Colombia; possibly as NIS in the western Atlantic from Cuba, Florida (Perkins 1998; Bastida-Zavala & Salazar-Vallejo 2000a) and questionably from Brazil (Zibrowius 1970). However, it is also possible that the origin of this species is the western Atlantic and that it has been introduced in the eastern Pacific. In this study, Protula balboensis was found occasionally on fouling plates from Jacksonville, Florida, and it was rare from Biscayne Bay, Florida, and Corpus Christi, Texas (Fig. 8). This species provisionally extends its westward range from western Florida (Perkins 1998) to Corpus Christi, Texas (1400 km).

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 42-43, DOI: 10.5852/ejt.2017.344, http://zenodo.org/record/3834679