Hydroides parva (Treadwell, 1902)

Figs 4I, 6

Eupomatus parvus Treadwell, 1902: 210, figs 79–80 (type locality: Boqueron Bay, Puerto Rico; on encrusting bryozoans).

Hydroides dianthus (non Verrill 1873) – Webster 1884: 327 (Bermuda). — Zibrowius 1971: 699 (synonymy).

Hydroides (Eupomatus) n. sp. – Augener 1925: 16–17 (Saint Croix, Lesser Antilles, Caribbean). — Bastida-Zavala & ten Hove 2002: 127 (synonymy).

Hydroides (Eupomatus) parvus – Augener 1927: 80, textfig. 8 (Spaanse Water and Schottegat, Cura ҫao, Caribbean; on mangrove root). — Augener 1934: 116 –117 (Gairaca, Santa Marta, Colombian Caribbean; intertidal to 15 m).

Hydroides parvus – Bush 1910: 496 –497 (Bermuda). — Treadwell 1939: 305 –306 (Puerto Rico). — Rioja 1958: 251 –254, figs 1–2 (Veracruz, eastern Mexico). — Wells & Gray 1964: 74 (Cape Hatteras, North Carolina; hard substrates). — Zibrowius 1970: 6 –7, pl. 1, figs 5–6 (Recife, Brazil; 30 m; on rocks). — Rullier & Amoreux 1979: 194 (off Ipojuca River and Abrolhos Archipelago, Brazil; intertidal to 27 m; sand, shells and rocks). — Díaz 1994: 618 (Barbados, settlement and succession experiments; 10 m; coral plates, Orbicella annularis). — ten Hove & San Martín 1995: 16 (de la Juventud Island, Cuba; 0.5–4 m; on mollusk shells, algae and mangrove roots). — Carrera-Parra & Vargas-Hernández 1997: 314 (Enmedio Island, Veracruz, eastern Mexico; 1–9 m; on the sponge Ircinia felix (Duchassaing & Michelotti, 1864)) . — Perkins 1998: 95 (checklist of shallow-water polychaetes from Florida). — Dueñas 1999: 14 (Providencia Island, Colombia). — Bastida-Zavala & Salazar-Vallejo 2000b: 851, fig. 2n–p (Puerto Rico and eastern Mexico: Términos Lagoon and Champotón, Campeche; Celestún, Yucatán; Yucatán Canal; Cabo Catoche, Contoy Island, Puerto Morelos, Ascensión Bay and Chinchorro Bank, Quintana Roo; intertidal to 41 m; on mangrove roots, seagrasses and algae, sea urchin spines, gastropods shells, sponges, corals, calcareous rocks and fouling of wood dock pilings). — Bastida-Zavala & ten Hove 2002: 127 –129, figs 12A–K, 15 (Florida; eastern Mexico: Veracruz, Campeche, Yucatán and Quintana Roo; Puerto Rico; Montserrat; Atlantic Panama; Cura ҫao; Atlantic Colombia and Brazil; 0.6–41 m; salinity 31– 37‰; on mangrove roots, seagrasses and algae, sea urchin spines, bivalve and gastropods shells, sponges, calcareous rocks, live corals and fouling of wood dock pilings and canal docks).

Hydroides parva – Day 1973: 132 (Cape Hatteras, North Carolina, United States; intertidal). — Díaz-Díaz & Liñero-Arana 2001: 13 (Cariaco Gulf, Venezuela; PVC dock pilings).

Material examined

One specimen: BB (1) Aug. 2004.

Diagnosis

Tube missing. Opercular peduncle smooth, white. Operculum funnel with 23 radii with pointed tips (Fig. 4I); verticil with seven yellowish spines, curving abruptly inwards, forming an external knob (Fig. 4I); all spines similar in shape and size, with pointed tips; with basal internal spinule and two welldeveloped lateral spinules in middle position, without external spinules, wings or central tooth (Fig. 4I). Special collar chaetae with two pointed, short teeth and smooth distal blade.

Taxonomic remarks

Hydroides parva is frequently confused with H. bispinosa, because both species have vertical spines with a pair of lateral spinules; however, the main difference is the shape of the funnel radii: rounded in H. bispinosa, sharp in H. parva . This species is more often found on natural substrates; however, occasionally it is found on artificial substrates (Bastida-Zavala & Salazar-Vallejo 2000b; Díaz-Díaz & Liñero-Arana 2001; Bastida-Zavala & ten Hove 2002).

Ecology

Intertidal to 41 m. On mangrove roots, bryozoans, seagrasses and algae, sea urchin spines, gastropod shells, sponges, corals ( Orbicella annularis), calcareous rocks and on artificial substrates such as fouling on wood dock pilings (Díaz 1994; Bastida-Zavala & Salazar-Vallejo 2000b; Bastida-Zavala & ten Hove 2002).

Distribution

Caribbean Sea, Bermuda, Gulf of Mexico, eastern United States (Florida and North Carolina) and Brazil (Bastida-Zavala & ten Hove 2002). In this work, only one specimen of Hydroides parva was found on a fouling plate from Biscayne Bay, Florida (Fig. 6).