Watersipora cucullata (Busk, 1854)

(Figs 6–9, 25–34, 65; Table 2)

? Cellepora subovoidea d’Orbigny, 1852: 402 [Red Sea; nomen dubium].

Lepralia cucullata Busk, 1854: 81, pl. 96, figs 4–5 [Aegean Sea].

Schizoporella atrofusca: Hincks 1886: 269 (part), pl. 10, fig. 4 (non fig. 5) [Adriatic]. Non Schizoporella atrofusca Busk, 1856: 178 [Mexico].

Dakaria subovoidea: Harmer 1957: 1022 (part) [Aegean Sea].

Watersipora cucullata: Soule & Soule,1975: 302, pl. 2, fig. 2; pl. 3, fig. 1; pl. 4, fig. 3 [Aegean Sea; Naples].

Watersipora subovoidea: Hayward & McKinney 2002: 63, fig. 29A–B [Adriatic]. Non Watersipora subovoidea: Ryland et al. 2009: 54, fig. 4C, D, G, H [= Watersipora subtorquata].

Material examined. Lectotype (chosen by Soule & Soule 1975): NHMUK 1854.11.15.189 (specimen mounted on one dry slide and two balsam slides), Lepralia cucullata, 1854, G. Busk det., Aegean Sea, E. Forbes. Paralectotypes: NHMUK 1899.7.1.1398, dry, same data as for lectotype; NHMUK 2012.6.30.1, dry slide, same data as for lectotype. Other material: NHMUK 1899.5.1.456, Schizoporella atrofusca, dry slide, T. Hincks det., Adriatic, Pieper coll. NHMUK 1899.5.1.975, dry slide, Schizoporella atrofusca, T. Hincks det., Adriatic. NHMUK 1965.8.14.10, dry slide, Watersipora cucullata, Balearic Islands, Mediterranean, Cox coll.

Description. Colony encrusting, multiserial, unilamellar; blackish in colour. Zooids subrectangular to hexagonal, separated by slightly raised grooves. Frontal shield slightly more convex distally than proximally, with small tubercles and uniformly perforated by round pseudopores about 20 µm diameter; two latero-oral intrazooidal septula, small, near the lateral zooidal margin proximolateral to the orifice; each with 2–4 small pores; frontal shield obscured by thick, black epitheca. Orifice large, slightly wider than long, with a well-defined, broad, shallow, U-shaped sinus demarcated by triangular projections; orificial rim robust and thickened around whole orifice, sometimes better developed proximally than distally; condyles upturned, large and conspicuous. Operculum with broad, parallel-sided dark central band and slightly thinner lateral area. Avicularia absent. Ooecia absent.

Remarks. Watersipora subovoidea has been reported in subtropical and tropical waters, i.e. Brazil, Florida and Australia (Mackie et al. 2006; Geller et al. 2008; Ryland et al. 2009), but the great majority of these records belong to W. subtorquata (see above). D’Orbigny (1852) did not give any description or figures for Cellepora subovoidea, and according to the ICZN Article 75.3.6 “evidence that the neotype came as nearly as practicable from the same original type locality” should be provided, which is not apparent in the Ryland et al. (2009) paper. Thus, we suggest setting aside the neotype selection of Cellepora subovoidea (NHMUK 1854.11.15.189) made by Ryland et al. (2009).

Watersipora cucullata is characterized by a suborbicular orifice with a shallow, wide sinus demarcated by triangular projections (Figs 8, 27, 29, 31, 32, 34), large, conspicuous condyles (Figs 8, 27, 29, 31), and a small latero-oral intrazooidal septula on each side of the zooid (Fig 8, 29, 34). Latero-oral intrazooidal septula are also present in Watersipora aterrima and W. subatra, but these species are distinguished by the shape of the orifice and condyles (see below). Watersipora cucullata differs from W. nigra in having smaller zooids and orificial area (see Canu & Bassler, 1930, p. 26; Fig. 11; Table 2) and paired intrazooidal septula, near the lateral zooidal margin, proximolateral to the orifice.

Watersipora atrofusca (Busk, 1856) (Fig. 10; Table 2), known from Mazatlan (Mexico), resembles W. cucullata in colony shape but differs in having a smaller, almost circular orifice and in lacking intrazooidal septula.

Distribution. Mediterranean (including the Adriatic and Aegean seas).