Celleporella nodasakae, Dick & Grischenko & Mawatari, 2005

Dick, Matthew H., Grischenko, Andrei V. & Mawatari, Shunsuke F., 2005, Intertidal Bryozoa (Cheilostomata) of Ketchikan, Alaska, Journal of Natural History 39 (43), pp. 3687-3784 : 3729-3732

Celleporella nodasakae , new species

( Figure 11A–F )

Diagnosis

Colony strictly unilaminar; growth form uniserial, biserial, oligoserial, aggregated, or coherent, often in same colony; only autozooids and ovicellate female zooids occur; male polymorphs and zooeciules lacking; zooids loosely connected by tubular pore chambers with conspicuous lacunae between them; ovicells with four to five pores, generally around perimeter; autozooidal orifice with a deep, U-shaped sinus and sharp condyles pointing distally, flanked by a notch; proximal margin of female orifice Mshaped, with a U- or rounded V-shaped sinus between triangular, distally directed projections.

Type material

Holotype: SC, specimen KE-26 bleached and coated for SEM ( YPM 35839) . Paratype 1: SC, specimen KE-24 bleached and coated for SEM ( YPM 35840) . Paratype 2: SC, specimen KE-119 bleached and coated for SEM (NHM 2005.7.11.4). Paratype 3: SC, specimen KE-57 on bivalve fragment, lightly bleached and coated for SEM ( YPM 35841) . Paratype 4: SC, specimen KE-32 bleached and coated for SEM ( ZIRAS 1 /50530) . Paratype 5: SC, specimen KE-13 bleached and coated for SEM (NHM 2005.7.11.5).

Etymology

The species is named for Dr Yoshinobu Nodasaka, Hokkaido University School of Dentistry, to whom we are deeply indebted for cheerful assistance with scanning electron microscopy over a period of many years.

Description

Colony. White, vitreous; strictly unilaminar; at Ketchikan found on rocks and dead bivalve shells. Zooids arranged in branching uniserial, biserial, or oligoserial series; an anastomosing, aggregated network; or a coherent crust; sometimes a single colony displays most or all of these forms in different parts ( Figure 11A ). Ovicellate female zooids interspersed with autozooids ( Figure 11B ); male polymorphs and zooeciules lacking.

Zooids. Autozooids oval or spindle-shaped, sometimes with a cauda one-third to two-fifths of zooid length, tapering to one-third to one-half of zooid width; separated by a groove, more-or-less loosely appressed to one another, with three to five conspicuous lacunae along each lateral margin between coarse tubular connections; 0.33–0.73 mm long (average 50.447 mm, n 530, 4) by 0.18–0.28 mm wide (average 50.230 mm, n 530, 4). Ovicellate zooids triangular, smaller than autozooids, 0.29–0.49 mm long including ovicell (average 50.380 mm, n 530, 4) by 0.13–0.25 mm wide at orifice (average 50.192 mm, n 530, 4). Zooids interconnect by two tubular pore chambers distally and four to six along each lateral margin ( Figure 11E ). Basal wall with a narrow, marginal calcified shelf surrounding the uncalcified centre.

Frontal wall. Thin, vitreous, translucent, imperforate, convex, with transverse striae or weak transverse ridges; umbo lacking in our specimens.

Orifice. Autozooidal orifice ( Figure 11C ) slightly longer than broad, 0.06–0.09 mm long (average 50.074 mm, n 530, 4) by 0.05–0.08 mm wide (average 50.065 mm, n 530, 4); proximal margin with a deep, broadly U-shaped sinus flanked by small, sharp, distally or distomedially directed condyles separated by a notch from lateral orificial margin. Female secondary orifice ( Figure 11D ) semicircular; proximal margin M-shaped, with a U- or rounded V-shaped median sinus flanked by coarse, triangular, distally pointing projections.

Ovicell ( Figure 11B, D ). Raised, globose, nearly circular in outline, 0.16–0.23 mm long (average 50.185 mm, n 530, 4) by 0.16–0.24 mm wide (average 50.204 mm, n 530, 4); with four to five pores scattered mostly around the sloping perimeter, generally away from the central area; sculptured with faint concentric growth lines and sometimes a slight umbo.

Spines and avicularia. Lacking.

Ancestrula . One observed ( Figure 11F ); similar in form to subsequent autozooids, though smaller, 0.30 mm long by 0.20 mm wide. This ancestrula produced one daughter zooid distally, which in turn produced two buds, one distally and the other at the proximolateral margin, directed laterally.

Remarks

We have placed this species in Celleporella , rather than Hippothoa , because of its coherent growth form in at least parts of colonies, and its tubular pore chambers. Celleporella nodasakae is similar in growth form to C. reflexa Dick and Ross ; both can range from uniserial to narrowly multiserial to coherent, and both can have female zooids in the primary layer. However, compared to C. reflexa , C. nodasakae has a greater tendency to be uniserial; lacks male zooids and zooeciules; was never observed to become multilaminar; has a distinctly smaller autozooidal orifice; has fewer pore chambers; has fewer, larger interzooidal lacunae; has fewer pores in the ovicell; and has the orifice of ovicellate zooids with a diagnostic, M-shaped proximal margin. The ancestrular budding pattern of C. nodasakae is somewhat similar to that of C. reflexa ; in both species, the ancestrula first buds a distolateral daughter zooid, from which arises another zooid from the proximolateral margin. However, whereas this proximolaterally budded zooid grows back alongside the ancestrula in C. reflexa , it grows laterally or proximolaterally in C. nodasakae , away from the ancestrula. We found both species in the Ketchikan vicinity; however, whereas C. reflexa occurred at all three collecting sites, C. nodasakae occurred only at Settlers Cove, a silty environment with much freshwater influence.

Celleporella nodasakae is similar to Hippothoa minitumulosa Morris, 1980 , which also ranges from uniserial to coherent in form, displays only unilaminar growth, and lacks male polymorphs (the latter two characters were not specifically mentioned in the original description, but Morris (1980) gave no measurements for male polymorphs, and her figure shows only unilaminar growth). However, compared to C. nodasakae , H. minitumulosa has smaller zooids with midline tubercles, ovicells with more pores, and a differently shaped female orifice.

Celleporella nodasakae is also similar to H. santacruzana Pinter, 1973 , in which the ovicell likewise can have a few peripheral pores, and in which the proximal margin of the female orifice has two rounded-triangular projections flanking a median sinus. However, H. santacruzana forms only disc-shaped coherent crusts, and male polymorphs occur.

Distribution

Settlers Cove near Ketchikan is the only known locality.

Figures

Figure 11. Celleporella nodasakae n. sp.: (A) general colony view, showing uniserial branch giving rise to coherent sheet followed by oligoserial rami; (B) autozooids and an ovicellate zooid; (C) enlargement of autozooidal orifice; (D) enlargement of ovicell and female orifice; (E) photomicrograph of several autozooids from basal side, showing interzooidal connections; az, autozooid; o, orifice; tpc, tubular pore chamber; lc, interzooidal lacuna; (F) ancestrula (bottom, right of centre) and first daughter zooid (bottom, left of centre); from proximal margin of latter is budded a zooid directed perpendicularly. All specimens except (F) were bleached. Scale bars: 2 mm (A); 200 Mm (B); 50 Mm (C); 100 Mm (D); 250 Mm (E, F).