Escharoides longirostris Dumont, 1981

Dick, Matthew H., Tilbrook, Kevin J. & Mawatari, Shunsuke F., 2006, Diversity and taxonomy of rocky-intertidal Bryozoa on the Island of Hawaii, USA, Journal of Natural History 40 (38 - 40), pp. 2197-2257 : 2220-2221

Escharoides longirostris Dumont, 1981

( Figure 8C, D )

Escharoides longirostris Dumont 1981, p 630 , Figure 1A . Escharoides longirostris: Hayward 1988, p 293 ; Hayward and Ryland 1995, p 548, Figure 8A ; Tilbrook et al. 2001, p 70.

Measurements

ZL, 0.38–0.54 (0.479¡0.050). ZW, 0.40–0.48 (0.448¡0.030). OrL, 0.12–0.14, (0.131¡0.007). OrW, 0.11–0.15 (0.130¡0.011). OvL, 0.21–0.26 (0.245¡0.015). OvW, 0.24–0.34 (0.289¡0.030).

Description

Colony small, the largest observed 4.5 mm ×3.0 mm; unilaminar, encrusting, sheet-like. Zooids irregularly hexagonal or barrel-shaped, distinct, delineated by a fine incision. Frontal wall moderately convex, imperforate centrally, with numerous circular areolar pores closely spaced along margins, sometimes with an additional row at lateral corners of zooid; texture smooth in young zooids, with buttresses of secondary calcification ( Figure 8C ) growing centripetally between areolae; with age, frontal uniformly tuberculate or with scattered nodules. Primary orifice ( Figure 8D ) reminiscent of a fleur-de-lis in shape, with a large, coarse median denticle and swollen lateral projections; the proximal margin is raised and thickened to form a low peristome, and the denticle and lateral projections extend along the length of the inner surface. Three pairs of spines ( Figure 8D ) flank the orifice laterally and distally. Lateral to proximal margin of orifice is a large adventitious avicularium on one or both sides ( Figure 8C, D ), sometimes lacking; the laterally directed rostrum up to 0.25 mm long but generally shorter, laterally compressed, often hooked at the end, with the rostral margin finely serrate; mandible long-triangular, acute. Avicularian chamber with a row of areolae at the base. Ovicell ( Figure 8C ) hemispherical, somewhat flattened, slightly broader than long, ringed by conspicuous circular pores around margin, with scattered minute pores inside that, the perforate area rugose with age; smooth and imperforate centrally and proximally; proximolateral corners of ovicell abut the middle pair of spines.

Distribution

Originally described from the Sudanese Red Sea ( Dumont 1981), this species has also been reported from Mauritius ( Hayward 1988) and Vanuatu ( Tilbrook et al. 2001). This is the first record of the genus and the species from the Hawaiian Islands.

Figures

Figure 1. Outline map of the Island of Hawaii, showing the location of the main town, Hilo, and the four localities examined for bryozoans (smaller circles).

Figure 8. (A, B) Drepanophora corrugata (Thornely): (A) autozooids; (B) enlargement of orifice from distal view showing lyrula and condyles. (C, D) Escharoides longirostris (Dumont): (C) autozooids and one ovicellate zooid; (D) enlargement of orifice and lateral oral avicularium. All specimens bleached. Scale bars: 500 Mm (A, C); 100 Mm (B, D).