Hydroides gairacensis Augener, 1934

(Figures 4, 11 H)

Hydroides (Eupomatus) gairacensis Augener, 1934: 117, Figs 20a–c. Type locality: Gairaca, Santa Marta, Colombian Caribbean, intertidal to 15 m.

Hydroides uncinata (not Philippi, 1844).— Monro 1933b: 1082, Text-figure 25 (Taboga Island, Panamá, 2–3 m, on dead broken coral).

Hydroides gairacensis .— Zibrowius 1969: 366–374, Figs 1–2 (redescription based on Mexican Caribbean and Brazilian specimens); Zibrowius 1970: 4–5, pl. 1, Fig. 2 (Santa Catarina Bay, Brazil, hard bottom; 33 m) ; de León-González et al. 1993: 879 (Puerto Escondido Bay, Baja California Sur, epifauna on the oyster “ Spondylus princeps unicolor ”; 30 m) ; Bastida-Zavala & Salazar-Vallejo 2000b: 848, Fig. 2 G (Cuba and Cozumel, Mexican Caribbean); Bastida-Zavala & ten Hove 2002: 129–132, Figs 13 A–P (Florida, Quintana Roo, Cuba, Barbuda, Atlantic coast of Colombia, Brazil; 0.3– 50 m) ; Bastida-Zavala & ten Hove 2003: 87–89, Figs 22R (Ecuador; 2–9 m); Salazar-Vallejo & Londoño-Mesa 2004: 54 ( Tropical Eastern Pacific, checklist); Cohen 2006: 167 (possible introduction from the Atlantic to the Pacific by means of Panamá Canal); Bastida-Zavala 2008: 26, fig. 6I (mentioned only); Bastida-Zavala 2009: 535, Fig. 2 G (identification key for Tropical America); ten Hove & Kupriyanova 2009: 53 (worldwide serpulid checklist).

Material examined. One specimen.

Oaxaca: UMAR-Poly 768 (Panteón Beach, Puerto Ángel, 10 m, November 23, 2005, coll. GRC).

Habitat. Intertidal to subtidal (50 m, Bastida-Zavala & ten Hove 2002). On fire coral Millepora (Mörch 1863), oyster “ Spondylus princeps unicolor ” (de León-González et al. 1993), and dead coral (Bastida-Zavala & ten Hove 2003).

Distribution. Native to the Caribbean Sea (Zibrowius 1969), it was recorded early in the Pacific of Panamá (Monro 1933b); later in Ecuador from specimens collected in 1966 (Bastida-Zavala & ten Hove 2003); and from the Gulf of California (de León-González et al. 1993). This new record extends its known geographical range to the north, with approximately 2,000 km along the littoral, from Panamá to Puerto Ángel, Oaxaca.

Remarks. Hydroides gairacensis is recorded only from four sites in the Tropical Eastern Pacific: Taboga Island , Panamá (Monro 1933b); Guayaquil, Ecuador (Bastida-Zavala & ten Hove 2003); Puerto Escondido Bay, Baja California Sur (de León-González et al. 1993); and Puerto Ángel, Oaxaca; each record is represented by one specimen, maybe these are incidental introductions to the Pacific via the Panamá Canal. Here it is considered to be a cryptogenic species.