Poricella Canu, 1904

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 : 2218-2220

Genus Poricella Canu, 1904

Poricella spathulata ( Canu and Bassler, 1929)

( Figure 7E, F )

Hiantopora spathulata Canu and Bassler 1929, p 116 , Plate 11, Figures 13 , 14 . Tremogasterina spathulata: Ryland and Hayward 1992, p 249 , Figure 13e .

Poricella spathulata: Tilbrook et al. 2001, p 65 , Figure 10B ; Tilbrook 2006, p 113, Figure 16B .

Measurements

ZL, 0.45–0.65 (0.538¡0.055). ZW, 0.26–0.48 (0.350¡0.062). OrL, 0.13–0.15 (0.140¡0.006). OrW, 0.12–0.14 (0.129¡0.007). OvL, 0.16–0.24 (0.208¡0.031). OvW, 0.23–0.30 (0.260¡0.033) (ovicell n 55).

Description

Colony unilaminar, encrusting, white, small. Frontal wall convex, with minute marginal pores and with 7–10 large, crescentic pores ( Figure 7E ) in centre, each surrounded by a broad rim, giving the frontal a tessellated appearance. Orifice longer than broad, proximal margin straight, poster about one-third of orifice length and delineated by small lateral condyles; proximal to orifice is a thick crescentic ridge, rising to an umbo or sharp point. Scattered between zooids are large avicularia ( Figure 7E ), budded distolaterally from zooids, with a truncate-spatulate rostrum and mandible of the same shape. Large, vicarious avicularia have been reported in this species ( Cook 1977; Tilbrook et al. 2001) but we did not observe them in the specimens from Hawaii. Ovicell ( Figure 7E ) raised, globose, imperforate, the surface rugose but with irregular smooth areas. Marginal zooids with four distal spines. Ancestrula ( Figure 7F ) tatiform, with 11 spines.

Remarks

This was one of the two dominant bryozoan species at Kealakekua Bay. The other, Hippopodina iririkiensis , grew predominantly on coral rubble, whereas P. spathulata was found exclusively in the surface cavities of porous lava boulders.

Distribution

Widely distributed in Indo-West Pacific, from Red Sea to Philippines; Great Barrier Reef, Australia; Mauritius; Vanuatu (for references, see synonymies). This is the first record for the Hawaiian Islands.

Superfamily LEPRALIELLOIDEA Vigneaux, 1949

Family LEPRALIELLIDAE Vigneaux, 1949

Genus Drepanophora Harmer, 1957

Drepanophora corrugata ( Thornely, 1905)

( Figure 8A, B )

Rhyncopora corrugata Thornely 1905, p 118 , Figure 5 .

Drepanophora corrugata: Harmer 1957, p 1080 , Plate 70, Figures 29–31; Hayward 1988,

p 338, Plate 14c, d.

Measurements ZL, 0.48–0.65 (0.538¡0.066). ZW, 0.28–0.46 (0.369¡0.055). OrL, 0.09–0.14

(0.112¡0.013). OrW, 0.13–0.16 (0.151¡0.008).

Description

Two small colonies adjacent to one another, lacking ovicells, the larger 3.5 mm in diameter, were found on lava rock. Colony encrusting, multiserial, unilaminar at first but becoming multilaminar by frontal budding. Zooids in primary layer irregularly hexagonal, oval, or barrel-shaped, separated by a deep groove; in secondary layer, zooids haphazardly orientated and zooidal boundaries indistinct. Frontal wall ( Figure 8A ) well calcified, markedly convex, inflated; imperforate except for two to four round areolar pores well spaced along each lateral margin; rugose with uniform, low, rounded tubercles. Primary orifice transversely elliptical, the proximal margin typically with a pair of long, prominent, acute lateral condylar processes, with a similarly long and acute denticle between them ( Figure 8B ), often offset to a greater or lesser extent to one side or the other; there is considerable variation in the arrangement of these three orificial processes. In older zooids, primary orifice lies deep in peristome, difficult to observe. Peristome a thick, raised rim, highest proximally; discontinuous, with a deep, more or less circular sinus flanked by the avicularian rostrum near the midline and a sharp, coarse, conical peristomial process lower down arising from the margin of the peristome. Suboral avicularian chamber umbonate; avicularian rostrum offset slightly from midline, oval in outline, angled acutely from the frontal plane, facing laterally, cross bar complete; mandible semicircular, directed obliquely upward from plane of colony surface. Secondary orifice, including the peristomial sinus, longer than broad, irregularly pyriform due to the sinus. Spines lacking. Ovicell not observed in our material, but Harmer (1957) illustrated it has hyperstomial, globose, with a pair of large foramina.

Distribution

Originally described from Ceylon ( Thornely 1905); also reported from Indonesia ( Harmer 1957) and Mauritius ( Hayward 1988). This is the first record for the Hawaiian Islands.

Figures

Figure 5. (A, B) Antropora minor (Hincks): (A) autozooids, bleached; (B) autozooids, bleached; zooid at right is a brooding zooid, with a raised, smooth distal margin that may represent a vestigial ovicell. (C) Beania discodermiae (Ortmann): autozooids, unbleached. (D) Micropora rimulata Canu and Bassler: autozooids and ovicellate zooids, bleached. Scale bars: 200 Mm (A, B); 500 Mm (C, D).

Figure 7. (A, B) Hippothoa flagellum Manzoni: (A) autozooid; (B) autozooid (part) and ovicellate zooid. (C, D) Chorizopora brogniartii (Audouin) sensu lato: (C) autozooids, ovicellate zooids, interzooidal kenozooids, and avicularia; (D) ancestrula (lower left) and early astogeny. (E, F) Poricella spathulata (Canu and Bassler): (E) autozooids, ovicellate zooids, and interzooidal avicularia; (F) ancestrula (bottom centre) and periancestrular zooids. All specimens bleached. Scale bars: 200 Mm (A, B); 500 Mm (C–F).

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).

Figure 10. Junerossia copiosa n. gen., n. sp., intertidal specimens from Sesoko Island, Okinawa, Japan (C, E) and Kapa’a Shore, Island of Hawaii (A–B, D, F–H): (A) holotype (NHM 2006.7.21.8), autozooids and ovicellate zooid; (B) holotype, enlargement of orifice; (C) stages in ovicell formation; (D) paratype 2 (NHM 2006.7.21.10),

Figure 13. (A–C) Cribellopora souleorum n. sp., paratype 1 (NHM 2006.7.21.20): (A) autozooids and ovicellate zooids; note predation hole in ovicell at right and scars on both ovicells; (B) enlargement of orifice; (C) ancestrula (lower right) and three periancestrular zooids; note predation holes in frontal walls of two zooids. (D, E) Nimba

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).

Figure 16. Disporella compta n. sp., holotype (NHM 2006.7.21.22): (A) partial view of colony, showing one elongate and two oval maculae among seven maculae present in colony; (B) enlargement of a macula; (C) columns of fused peristomes of three to four autozooids; (D) enlargement of kenozooidal opening showing palm-tree-shaped pinhead spinules. All specimens bleached. Scale bars: 2 mm (A); 1 mm (B); 400 Mm (C); 50 Mm (D).