Fenestruloides tongassorum, 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 : 3766-3769

Fenestruloides tongassorum , new species

( Figure 24A–D )

Fenestruloides morrisae Soule, Soule, and Chaney 1995, p 163 , Plate 57 (in part?).

Fenestrulina ? porosa Canu and Bassler 1923, p 117 , Plate 37, Figure 4 .

Diagnosis

Zooids markedly inflated; frontal wall completely covered with stellate pores except for small area proximal to ascopore; conspicuous umbo lacking; ascopore broader than deep, the opening narrow, crescentic, crenulate; orifice subterminal, broader than long, with one or two rows of pores distal to it; two orifice types, that of ovicellate zooids broader than that of non-ovicellate zooids, with two stout, widely separated spines and one or two finer spines in between; non-ovicellate zooids have one to three fine spines close together. Ovicell smooth, imperforate, globose.

Type material

Holotype: ETN, specimen KE-58 bleached and coated for SEM ( YPM 35842).

Etymology

The species name derives from the word Tongass, name of a clan of Tlingit Indians from the Ketchikan vicinity, now also applied to the surrounding Tongass National Forest.

Description

Colony. Unilaminar, encrusting, sheet-like; porcellaneous, whitish in colour.

Zooids. Distinct, separated by a groove and deep incision; regularly to irregularly hexagonal or barrel-shaped; quite variable in size and shape, 0.55–0.71 mm long (average 50.641 mm, n 515, 1) by 0.31–0.58 mm wide (average 50.465 mm, n 515, 1).

Frontal wall. Highly convex, inflated; with a slightly raised, crescentic area around proximal margin of ascopore; frontal wall entirely perforated with somewhat regular columns and rows of stellate pores except for a small area proximal to ascopore; four rows of pores between ascopore and orifice.

Orifice ( Figure 24B ). Subterminal, with one or sometimes two rows of pores distal to it; semicircular, broader than long, of two sizes ( Figure 24D ): wider in ovicellate zooids or those that can produce ovicells, 0.13–0.16 mm long (average5 0.146 mm, n 510, 1) by 0.19–0.24 mm wide (average 50.212 mm, n 510, 1), narrower in non-ovicellate zooids, 0.13–0.15 mm long (average 50.135 mm, n 510, 1) by 0.16– 0.19 mm wide (average 50.174 mm, n 510, 1); proximal margin straight or slightly convex, smooth, corners depressed, with a flattened condyle scarcely evident at each corner.

Ascopore ( Figure 24B ). Located roughly halfway between orifice and proximal zooidal margin, thus closer to proximal than to distal zooidal margin; 0.05–0.6 mm long by 0.08–0.10 mm deep; proximally directed shelf smooth; opening narrow, broadly crescentic, crenulate, with denticles of shelf and proximal margin meshing between one another.

Spines. All spines short; non-ovicellate zooids ( Figure 24A, D ) with one to three spines equal in size close together along distal margin of orifice (frequencies: one514%, two562%, three524%; n 529, 1); ovicellate zooids ( Figure 24C ), or those with potential to form ovicells ( Figure 24A, D ), have two thicker spines widely separated at distolateral corners of orifice, with one or two thinner spines between them; the thicker spines come to lie outside to the proximolateral extensions of the ovicell.

Ovicell ( Figure 24C ). Raised, globose, conspicuous, 030– 0.36 mm long (average5 0.330 mm, n 512, 1) by 0.31–0.35 mm wide (average 50.326 mm, n 512, 1); proximal margin with a narrow horizontal border; imperforate, the surface smooth in texture but slightly irregular; with small pores around sharp, slightly raised margin.

Avicularia. Lacking in our specimens.

Ancestrula . Not observed.

Remarks

Fenestruloides tongassorum is similar to F. morrisae Soule, Soule, and Chaney, 1995 . However, the original description of F. morrisae seems to include two species, one tropical and the other more northern in distribution. The holotype of F. morrisae (Revillagigedo Islands off western Mexico, 19 ° N) has zooids with an orifice about as long as broad, and with the ascopore situated in the distal half of the zooid; an avicularium is also present. Our specimens resemble those of nominal F. morrisae from the Gulf of California and the Channel Islands off southern California ( Soule et al. 1995, Plate 57B–D) more than they do the holotype from farther south ( Soule et al. 1995, Plate 57A). The Ketchikan specimens have in common with the Gulf and Channel Island specimens orifices clearly broader than long; a larger orifice in ovicellate than in non-ovicellate zooids; large and small spines on ovicellate zooids; and the ascopore closer to the proximal than the distal zooidal margin. The main difference is a more flattened ovicell in the Gulf and Channel specimens. It is unclear whether the Ketchikan specimens are conspecific with nominal F. morrisae from the Gulf of California and the Channel Islands; in any case, we describe our material as new because we consider it distinct from the holotype of F. morrisae .

Fenestruloides tongassorum differs from nominal Fenestruloides porosa (Canu and Bassler) from Kodiak, Alaska ( Dick and Ross 1988) in that the latter has a smaller, more open ascopore that is closer to the distal than the proximal zooidal margin; a smaller orifice; a larger ovicell; sometimes a large umbo; and fewer (two to three) rows of pores between ascopore and orifice. Fenestruloides tongassorum is similar to F. porosa (Canu and Bassler) in having ovicellate zooids with larger orifices than non-ovicellate zooids, three to four rows of pores between ascopore and orifice, and no conspicuous umbo; the latter differs in having a smaller, more open ascopore situated near the middle of the zooid. Soule et al. (1995) noted lack of spines in F. porosa (Canu and Bassler) as a character distinguishing that species from F. morrisae , but this is an error; Canu and Bassler (1923) mentioned two spines, and their illustration shows two to three spines, for F. porosa .

Distribution

Pending resolution of the question of identity with populations from the Gulf of California and the Channel Islands, we consider the Ketchikan vicinity to be the only known locality for F. tongassorum .

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 24. Fenestruloides tongassorum n. sp.; holotype: (A) group of autozooids; (B) enlargement of orifice and ascopore of ovicellate zooid; (C) ovicellate zooids; (D) group of zooids, showing small orifices with closely set distal spines indicative of non-ovicellate zooids, and large orifices with widely set distal spines indicative of zooids that have the potential to form an ovicell. Specimen bleached. Scale bars: 500 Mm (A, C, D); 200 Mm (B).