Parasmittina Osburn, 1952

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 : 2221-2223

Genus Parasmittina Osburn, 1952

Parasmittina serrula Soule and Soule, 1973 ( Figure 9A–D )

Parasmittina serrula Soule and Soule 1973, p 386 , Figure 3D–F .

Parasmittina serrula: Ryland and Hayward 1992, p 272 , Figures 23e, f, 24a; Tilbrook et al. 2001, p 76, Figure 14E, F ; Tilbrook 2006, p 154, Figures 28C, 31A–C.

Measurements

ZL, 0.28–0.53 (0.378¡0.077). ZW, 0.24–0.36 (0.278¡0.035). SecOrL, 0.09–0.12 (0.098¡0.009). SecOrW, 0.09–0.11 (0.105¡0.010). OvL, 0.15–0.21 (0.185¡0.017). OvW, 0.20–0.25 (0.235¡0.018).

Description

Colony unilaminar, encrusting, tan-white in colour, surrounded by a wide marginal lamina ( Figure 9C ). Frontal wall ( Figure 9A ) convex, tuberculate, surrounded by conspicuous marginal pores. Primary orifice ( Figure 9B ) sunken deep in peristome, broader than long, serrate along distal margin, with a truncate lyrula and conspicuous, proximomedially directed condyles that are denticulate at tip. Peristome a thick, raised collar, often with a groove along inside proximal surface that shows as a sinus in the secondary orifice ( Figure 9A ). An avicularium ( Figure 9A ) lies proximolateral to orifice on one or both sides, sometimes lacking; the smooth-sided chamber is laid over on one side and is both decurved and slightly laterally curved; rostrum long and narrow, typically pointing proximally, serrated on one edge; the avicularia vary considerably in size and orientation, and occasionally one at the base of the peristome is hypertrophied as a giant avicularium with one rostral edge highly and the other moderately serrated, though this type is uncommon in our material. Ovicell ( Figure 9A ) raised, globose; either with two rows of large, irregular pores peripherally and imperforate in centre, or with pores scattered over whole surface, this variation occurring within a single colony; proximal lip of ovicell raised, confluent with peristome. Marginal and non-ovicellate zooids typically with three (two to four) stout distal spines ( Figure 9B ). Ancestrula ( Figure 9D ) modified-tatiform, opesial area small, D-shaped, surrounded by nine spines; ancestrula becomes surrounded by broad marginal lamina interrupted by vertical walls, before periancestrular zooids differentiate.

Distribution

Broadly distributed. Reported from the Hawaiian Islands and Vanuatu; the Great Barrier Reef, Australia; the Philippines; and New Zealand (for references, see synonymies). Also reported from the Caribbean (Winston 1984), although this disjunct population warrants investigation as an anthropogenic introduction or as a cryptic sister species to the Pacific form.

Figures

Figure 3. (A–C) Alderina flaventa n. sp., holotype (NHM 2006.7.21.1): (A) group of autozooids and ovicellate zooids; (B) ovicellate zooid; (C) colony margin showing uniporous septula. (D) Parellisina albida (Hincks): autozooids, ovicellate zooid, and interzooidal avicularia. All specimens bleached. Scale bars: 500 Mm (A, C, D); 400 Mm (B).

Figure 9. (A–D) Parasmittina serrula Soule and Soule: (A) autozooids and ovicellate zooids; (B) enlargement of orifice; (C) young colony showing wide marginal lamina; (D) ancestrula and surrounding marginal lamina. (E, F) Watersipora subovoidea sensu Harmer: (E) autozooids; (F) enlargement of orifice. All specimens bleached. Scale bars: 400 Mm (A); 50 Mm (B); 1 mm (C, E); 200 Mm (D, F).

Figure 14. (A–C) Metacleidochasma verrucosa n. sp., holotype (NHM 2006.7.21.21): (A) autozooids; (B) enlargement of orifice; (C) ancestrula. (D–F) Rhynchozoon ferocula Hayward: (D) view of entire colony; this small colony of 27 zooids has produced eight ovicells; (E) ovicellate zooids; (F) enlargement of primary orifice. All specimens bleached. Scale bars: 400 Mm (A, E); 100 Mm (B, C, F); 1 mm (D).