Hydroides sanctaecrucis Kroyer in Morch 1863

Hydroides sanctaecrucis Krøyer in Mörch, 1863

Figs 4J, 6

Hydroides (Eucarphus) sanctae crucis Krøyer in Mörch, 1863: 378–379, pl. 11, fig. 12 (type locality: Saint Croix Island, Lesser Antilles, Caribbean Sea).

Hydroides (Eupomatus) dianthoides Augener, 1922: 49–50 (type locality: Haiti; partial synonymy).

Eupomatus sanctae crucis – Fauvel 1919: 478 –479, fig. 2e–g (Père Island, Mère Island, Montabo Cove, French Guiana). — Rioja 1958: 262 –264, fig. 6A–E (Verde Island and Santiaguillo Island, Veracruz, eastern Mexico; on mollusk shells and corals).

Hydroides sanctaecrucis – Zibrowius 1971: 699 –700 (Caribbean: Saint Croix Island, Puerto Rico, Jamaica, Atlantic Panama, Aruba and French Guiana; extensive revision; intertidal to 2 m; on hull of ship). — Day 1973: 132 (North Carolina). — Long 1974: 28 (Oahu, Hawaii; 15 m; asbestos plates). — Perkins 1998: 95 (checklist of shallow-water polychaetes of Florida). — Dueñas 1999: 14 (Cartagena Bay and Cispatá Bay, Colombia). — Bastida-Zavala & ten Hove 2002: 146 –149, figs 25A–R, 28 (French Guiana, Florida, Caribbean: Haiti, Puerto Rico, U.S. Virgin Islands, Atlantic Colombia, Atlantic and Pacific side of Panama; intertidal to 5 m, salinity 18–31‰; in tidal creek and in marinas, on floats, docks and fouling plates). — Bastida-Zavala & ten Hove 2003: 101 –102, fig. 19P–Q (Oaxaca, southern Mexican Pacific and Pacific Panama; salinity 19–25‰; on rocks and floats). — Lewis et al. 2006: 666 –669, figs 1–2 (North Queensland, Northern Territory and Tasmania, Australia and Singapore; marina and vessel hulls). — Bastida-Zavala 2008: 29, fig. 6R (Huatulco, Oaxaca, southern Mexican Pacific; intertidal to 1 m; on pier pilings). — Sun et al. 2012: 20 –21, figs 10A–G (Hong Kong; intertidal to 10 m; on pier pilings and fouling plates at fish farm). — Tovar-Hernández et al. 2012: 18 –19 (Gulf of California: Topolobampo, Sinaloa; Guaymas, Sonora; La Paz, Baja California Sur); 2014: 386, 388, 390, fig. 2f (Gulf of California: Topolobampo, Sinaloa; Guaymas, Sonora; La Paz, Baja California Sur). — Sun et al. 2015: 76 –79, fig. 25 (Northern Territory and Queensland, Australia; 0.5 m; on hulls of vessels and settlement plates). — Bastida-Zavala et al. 2016: 426, figs 6, 12E (Mexican Pacific: Sonora, Baja California Sur and Oaxaca; in marinas and harbors, fouling; intertidal to 1 m).

Hydroides santaecrusis – Dueñas 1981: 99 –100, fig. 29A–F (Cartagena Bay, Colombia; on mangrove roots; auct. lapsus). — Quirós-Rodríguez et al. 2013: 91, Table 3 (Córdoba, Colombian Caribbean; intertidal; on red algae).

Hydroides (Eupomatus) dianthoides – Bastida-Zavala & ten Hove 2002: 147 (partial synonymy).

37 specimens: BB (28) Aug. 2004, TB (9) Jul. 2002, Jun. 2012 and Jun. 2014.

Tube white, with two longitudinal ridges or none; without peristomes or alveoli. Opercular peduncle smooth, white. Opercular funnel with 19–28 radii with pointed tips (Fig. 4J); verticil with 11–14 spines, all curving ventrally, with or without one basal internal spinule, with an external spinule on all or almost all spines, without lateral spinules, with wings extending more than half of spine length (Fig. 4J). Special collar chaetae with two blunt or pointed teeth and smooth distal blade.

Hydroides sanctaecrucis is an invasive species that has established itself in several localities along the Pacific coast of the Americas (Mexican Pacific: Oaxaca and Gulf of California, and Panama), in Australia and Hong Kong. The species has been found only once in Hawaii (Long 1974), so it is not clear whether it is established there. The main means of dispersal is likely as fouling on vessels; the species was generally limited to polluted harbors in the sites invaded (Bastida-Zavala & ten Hove 2002, 2003; Lewis et al. 2006; Tovar-Hernández et al. 2014; Sun et al. 2012, 2015; Bastida-Zavala et al. 2016).

Intertidal to 15 m, salinity 18–31‰. On mangrove roots, mollusk shells, corals, rocks and on artificial substrates at marinas and piers, on floats, docks and fouling plates (Rioja 1958; Dueñas 1981; Bastida-Zavala & ten Hove 2002; Lewis et al. 2006; Sun et al. 2015).

Caribbean Sea, French Guiana, Gulf of Mexico, east coast of United States, Pacific side of Panama, Oaxaca (southern Mexico), Gulf of California, Hawaii, Australia, Hong Kong (Zibrowius 1971; Bastida-Zavala & ten Hove 2002, 2003; Lewis et al. 2006; Sun et al. 2012, 2015; Tovar-Hernández et al. 2014; Bastida-Zavala et al. 2016). In this work, Hydroides sanctaecrucis was found abundantly on fouling plates from Biscayne Bay, Florida, and occasionally from Tampa Bay, Florida (Fig. 6).