Cauloramphus tortilis, 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 : 3704-3708

Cauloramphus tortilis , new species

( Figure 4A–D )

Diagnosis

Zooids closely appressed; mural rim moderately wide, rounded, tumid, completely covered with fine tubercles, cryptocystal; gymnocyst not visible. Spines long, straight or nearly so, 9–15 in total, including four orificial and 5–10 opesial spines, tips of the latter not meeting in the midline. Avicularium long, pedunculate, fusiform; arising in stereotyped position at base of distalmost pair of opesial spines on one or both sides; peduncle twisted around spine; rostrum facing away from zooid.

Type material

Holotype: ETN, unbleached and uncoated ( YPM 35836) . Paratype 1: ETN, unbleached and uncoated (NHM 2005.7.11.2). Paratype 2: KV, specimen KE-17 unbleached and coated for SEM ( YPM 35837) . Paratype 3: KV, specimen KE-10 bleached and coated for SEM (NHM 2005.7.11.3). Paratype 4: KV, specimen KE-37 unbleached and coated for SEM ( ZIRAS 1 /50528) . Paratype 5: KV, specimen KE-54 bleached and coated for SEM ( ZIRAS 2 /50529) .

Etymology

The specific name derives from the Latin tortilis , meaning twisted or twined, referring to the twisting of the avicularium laterally around the spine near which it is attached.

Description

Colony. A unilaminar sheet tightly adhering to hard substrates, orangish brown, forming circular to irregular patches; largest observed 2 cm by 3 cm.

Zooids. Tightly appressed to one another, with a line or slight groove between them; rounded-hexagonal, with proximal margin truncate or extending between proximal pair of zooids; 0.53–0.70 mm long (average 50.625 mm, n 530, 3) by 0.33–0.58 mm wide (average 50.405 mm, n 530, 3). In young, marginal zooids, spine bases bulge from lateral walls, giving zooid a coarsely crenulate outline, intermeshing with spine bases of adjacent zooids ( Figure 4C ); in older zooids, thickening of mural rim with granulate calcification largely obscures crenulate appearance. Mural rim cryptocystal; broad, rounded, tumid, widest proximally, tapering laterally, narrowest distally, completely and evenly covered by fine-tuberculate granulation ( Figure 4B, D ); no smooth gymnocyst visible. Opesia regularly to irregularly oval, 0.30–0.50 mm long (average 50.427 mm, n 530, 3) by 0.20–0.29 mm wide (average 50.242 mm, n 530, 3). Basal wall thinly but completely calcified.

Spines ( Figure 4A ). Total 9–15 (mode511, n 520, 2), including two pairs erect orificial spines (rarely, five spines), and 5–10 (mode57, n 520, 2) long, tapering, stout, straight or slightly curved opesial spines proximal to orifice; spines separated at base by twice or more their width, angled over opesia, meeting at midline in some colonies but not in others; distalmost pair of opesial spines tends to be longer and thicker than any other spines.

Avicularia ( Figure 4A ). Approximately as long as longest spines, 0.30–0.38 mm long (average 50.334 mm, n 512, 2); clavate, with a narrow peduncle one-third to one-half length of avicularium, expanding to a fusiform chamber of greater width than stoutest spines; membranous frontal portion (mandible and post-mandible) occupying about half the length of the expanded chamber; tip of rostrum with a slight, blunt hook; mandible long-triangular. Avicularium attached immediately proximolateral to base of distalmost (largest) opesial spine, on one or both sides; nearly erect, with peduncle twisted around spine near base ( Figure 4A ) so that the chamber lies distal or distolateral to the spine, with the mandible facing away from the zooid. In some colonies, most zooids possess one or two avicularia; in others, most zooids lack them.

Ovicell. Embryos brooded inside the distal part of maternal zooid; ooecium exists as a small kenozooid budded by the maternal zooid and occupying the distal margin of the mural rim ( Figure 4B ), evident as a raised, crescentic lip in brooding zooids.

Ancestrula . Not observed.

Remarks

A character that distinguishes C. tortilis from most other species reported from Alaska ( C. magnus , C. multiavicularia , C. spectabilis , C. spinifer , and C. cymbaeformis ) ( Dick and Ross 1988; Osburn 1950; this study), is that of the closely set zooids, with the cryptocystal exposed frontal surface completely covered with fine tubercles. The only other Alaskan species similar in this regard is C. variegatus (see Dick and Ross 1988). In contrast to C. tortilis , however, C. variegatus has a wider, flatter cryptocyst proximally; the straight, erect orificial spines are markedly thicker than the curved, acuminate opesial spines; the spine bases are often brown; and the avicularium is not long and fusiform.

Distribution

Cauloramphus tortilis is known only from the Ketchikan vicinity.

Genus Tegella Levinsen, 1909 Tegella aquilirostris ( O’Donoghue and O’Donoghue, 1923)

( Figure 4E, F )

Membranipora aquilirostris O’Donoghue and O’Donoghue 1923 p 28 , Plate 2, Figure 16 .

Tegella aquilirostris: O’Donoghue and O’Donoghue 1926 p 37 , Plate 3, Figure 29; Osburn 1950, p 83; McCain and Ross 1974, p 13, Figure 2b; Mawatari and Mawatari 1980, p 92, Figure 32; Dick and Ross 1986, p 89 (in part); Dick and Ross 1988, p 42, Plate 3A.

Membranipora unicornis: Robertson 1900, p 324 .

Membranipora occultata Robertson 1908, p 262 , Plate 14, Figures 6–9 ; not M. occultata

Waters, 1887.

Membranipora occultata: O’Donoghue and O’Donoghue 1923, p 25 .

Tegella robertsoni O’Donoghue and O’Donoghue 1926, p 36 .

Description

Colony. Unilaminar, sheet-like, encrusting hard substrates, the margin sometimes raised in folds and frills; roughly circular, up to several centimetres across; often aggregated, covering considerable areas on benchrock faces and beneath overhangs; tan to rich reddish brown in colour, the growing margin often more heavily pigmented.

Zooids. Barrel-shaped, rounded distally, widest in middle, narrower and truncate proximally, 0.50–0.83 mm long (average 50.648 mm, n 515, 3) by 0.29–0.48 mm wide (average 50.374 mm, n 515, 3); closely appressed, zooidal boundaries indistinct; young zooids with a sharp rim between them. Proximal gymnocyst covered by avicularian chamber; lateral gymnocyst hidden between adjacent zooids; cryptocyst a narrow shelf set below mural rim, smooth or finely tuberculate, extending around entire opesia or absent distally. Opesia occupies roughly two-thirds of zooidal length; round, oval, or roundedrectangular in shape, 0.33–0.58 mm long (average 50.417 mm, n 515, 3) by 0.23–0.38 mm wide (average 50.292 mm, n 515, 3).

Spines. A straight, erect tubular spine on one or both sides of orifice, at or near proximolateral flanges of ovicell; if on both sides, one usually stouter than the other; sometimes two straight spines occur on one side and one on the other; young zooids sometimes have a pair of straight spines on each side. In addition, zooids often have one or two finer, curved, acuminate spines more proximally on one side, arching over opesia.

Avicularia. Each zooid bears a large frontal avicularium with a chamber that is trapezoidal or rectangular in outline, completely covering proximal gymnocyst and connecting through it by several pores, abutting or partly covering ovicell of preceding zooid; rostrum heavy, pointing laterally or distolaterally, sometimes extending around proximolateral margin of opesia, raised at 45 ° to colony surface, the tip hooked. Avicularian mandible long-triangular, strongly hooked at tip.

Ovicell. Broader than long, 0.28–0.38 mm wide (average 50.319 mm, n 515, 3) by 0.15– 0.23 mm long (average 50.188 mm, n 515, 3); endooecium spherical; partly overgrown by ectooecium, the margin of which comprises a thick, sometimes decurved transverse ridge. Proximal margin of endooecium raised as a lip; a large, transverse lumen between endooecial and ectooecial margins is covered by ectocyst.

Ancestrula . Not observed.

Remarks

We found this species only at the East Tongass Narrows site, where it competed for space with Schizoporella japonica on the undersides of rock outcrops. Young colonies can be lighter in colour than astogenetically mature colonies, with the zooids lacking spines and the frontal avicularia smaller, less raised, and not hooked.

Distribution

Boreal North Pacific: California as far south as Santa Barbara ( Osburn 1950); Puget Sound ( McCain and Ross 1974); British Columbia ( O’Donoghue and O’Donoghue 1923, 1926); Kodiak Island, Alaska ( Dick and Ross 1988); Commander Islands ( Grischenko 1997, 2004), Hokkaido to middle Honshu, Japan ( Mawatari and Mawatari 1980); northern Sea of Japan, Sakhalin Island, southern Sea of Okhotsk ( Kubanin 1997).

Figures

Figure 4. (A–D) Cauloramphus tortilis n. sp.: (A) autozooids; unbleached; (B) autozooids, bleached; complete zooid at right is a brooding zooid, with a crescentic kenozooidal ooecium around distal margin; (C) young autozooids near colony margin, showing intermeshing spine bases; bleached; (D) colony margin, showing pore chambers; bleached. (E, F) Tegella aquilirostris (O’Donoghue and O’Donoghue): (E) ovicellate zooids; unbleached; (F) ovicellate zooids; bleached. Scale bars: 500 Mm.

Figure 6. (A, B) Bugula pacifica Robertson: (A) general colony view; (B) autozooids and lateral avicularia. (C, D) Bugula pugeti Robertson: (C) general colony view; (D) autozooids and lateral avicularia; note smaller avicularium near branch point (near top, right of centre). (E, F) Dendrobeania lichenoides Robertson: (E) autozooids and one ovicellate zooid; (F) abfrontal surface of portion of colony, showing attachment radicles. All specimens unbleached. Scale bars: 2 mm (A, C); 400 Mm (B); 1 mm (D, F); 500 Mm (E).

Figure 7. (A, B) Cribrilina annulata (Fabricius): (A) autozooids and frontally budded dwarf ovicellate zooids; bleached; (B) autozooids (lower right), ovicellate zooids in primary layer (lower centre and left), and frontally budded dwarf ovicellate zooids (top); bleached. (C–F) Cribrilina corbicula (O’Donoghue and O’Donoghue): (C) astogenetically young autozooids; unbleached; (D) ovicellate zooids in primary layer and frontally budded dwarf ovicellate zooids; bleached; (E) ovicellate zooids in primary layer and newly forming dwarf ovicellate zooids with membranous front only (upper left of centre) or with incomplete costae (lower right and centre); note compressed, subspatulate suboral costae; unbleached; (F) ancestrula and surrounding zooids; unbleached. Scale bars: 500 Mm (A–E); 1 mm (F).

Figure 8. (A–D) Puellina caesia n. sp.: (A) group of autozooids; bleached; (B) group of ovicellate zooids; bleached; (C) colony margin showing several stages of ovicell formation; bleached; (D) enlargement showing setiform papillae proximolateral to orifice; unbleached. Scale bars: 400 Mm (A); 500 Mm (B, C); 200 Mm (D).

Figure 9. Celleporella hyalina (L.) species complex, showing variation between two colonies encrusting a single mussel (Mytilus edulis) individual collected subtidally; (A, B) are from one colony, (C, D) are from the other; both specimens bleached. (A) Autozooids near colony margin; (B) autozooids in primary layer (large primary orifices), a frontally budded male zooid (small primary orifice, at left), and frontally budded ovicellate zooids; (C) autozooids near colony margin; (D) autozooids in primary layer (large primary orifices), frontally budded male zooids (small primary orifices), and frontally budded ovicellate zooids. Scale bars: 500 Mm.

Figure 16. Schizoporella japonica Ortmann; portion of Ortmann’s (1890) holotype of Schizoporella unicornis var. japonica; bleached: (A) group of ovicellate zooids; (B) enlargement showing typical orifice shape; (C) zooids (top centre and lower left) with a single oral avicularium and a large frontal avicularium; (D) autozooid (left of centre) with perforate closure plate covering orifice. Scale bars: 500 Mm (A, C, D); 200 Mm (B).