Fenestruloides Soule, Soule, and Chaney, 1995

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 : 3764-3766

Genus Fenestruloides Soule, Soule, and Chaney, 1995 Fenestruloides blaggae Soule, Soule, and Chaney, 1995

( Figure 23A–F )

Fenestruloides blaggae Soule, Soule, and Chaney 1995, p 169 , Plate 60.

Description

Colony. Vitreous when young, chalky white with age; unilaminar, encrusting, sheet-like, circular to irregular; largest observed 5 cm across.

Zooids. Regularly or irregularly hexagonal, distinct, separated by a groove and a sharp incision, 0.43–0.66 mm long (average 50.573 mm, n 515, 3) by 0.30–0.46 mm wide (average 50.379 mm, n 515, 3).

Frontal wall. Inflated, convex, with a slight to pronounced umbo proximal to, but independent of, ascopore; one or two (occasionally three) rows of stellate pores between ascopore and orifice, usually two to three (range one to four) rows along lateral margins, and a single row along proximal margin and distal to orifice; median area between umbo and proximal margin of zooid is imperforate.

Orifice ( Figure 23B ). Semicircular; 0.08–0.13 mm long (average 50.099 mm, n 515, 3) by 0.11–0.14 mm wide (average 50.131 mm, n 515, 3); proximal margin straight, slightly depressed at corners, condyles scarcely evident; orifices of ovicellate zooids tend to be broader than those of non-ovicellate zooids.

Ascopore ( Figure 23B, C ). Ascopore 0.04–0.06 mm across, depressed slightly from frontal surface, with a few sharp incisions around margin of depression; with a broad, proximally directed shelf; opening crescentic, narrow, with denticulate proximal and distal margins.

Spines ( Figure 23A, B, D ). Non-ovicellate zooids with two (occasionally one) short, conical spinous projections along distal orificial rim; long spines not observed; ovicellate zooids with a pair of stubby spines visible lateral to orifice, outside proximolateral extensions of ovicell; zooids forming ovicells also show the extended base of a median spine (see below).

Avicularia. Lacking.

Ovicell ( Figure 23D ). Raised, globose, imperforate, 0.31–0.40 mm long (average5 0.353 mm, n 515, 3) by 0.30–0.39 mm wide (average 50.335 mm, n 515, 3; surface texture smooth; ovicell smooth, slightly rugose, or with pronounced, rounded lumps on top; surrounded by a raised border, with numerous pores around base; proximal margin concave, with a narrow horizontal border. In incompletely formed ovicells, a conical structure is evident distal to the zooidal orifice; this appears to be the extended base of a median distal spine (removed by bleaching) that is enveloped by the fully formed ovicell.

Ancestrula ( Figure 23F ). A small version of subsequent zooids, first budding a zooid similar to it in size distally, then a pair of zooids distolaterally, and finally three to four larger zooids proximally and proximolaterally. Ancestrula with five distal spines; firstgeneration periancestrular zooids with two to four distal spines; subsequent generations with normal complement of one or two. Zooids for several generations from ancestrula have only a single row of pores between ascopore and orifice, and a single row of marginal pores.

Remarks

Soule et al. (1995) described three similar new species of Fenestruloides ( F. eopacifica , F. blaggae , and F. miramara ) from California, but indicated that the differences among them are slight and that they might be synonymous. If this proves to be the case, the name F. eopacifica will take page priority. Ketchikan specimens have the following characters in common with F. blaggae : the ascopore separate from the umbo; ovicells often rugose or lumpy; spine number usually two; predominantly two rows of pores between ascopore and orifice; and the ascopore slightly depressed, with unusual incisions around the margin (compare Soule et al. 1995, Plate 60D with Figure 23C herein). The extended, conical base of a median distal spine on zooids forming ovicells, not mentioned in the original description but evident in our material, might also be a diagnostic character; F. tongassorum (following species), for example, does not show this character.

Distribution

The only previous record of F. blaggae is the holotype from Carmel , California . Our specimens extend the known range from north-central California to south-eastern Alaska.

Figures

Figure 23. Fenestruloides blaggae Soule, Soule, and Chaney: (A) group of autozooids; (B) enlargement of orifice and ascopore; (C) enlargement of stellate pores and ascopore; note that ascopore has narrower opening than in (B); also note incisions around margin of ascopore depression; (D) two ovicellate zooids; knobs on ovicells are variable, and some ovicells are smooth; (E) marginal zooids, showing pore chambers and stages of ovicell formation; (F) ancestrula (lower centre) and surrounding zooids. All specimens bleached. Scale bars: 500 Mm (A, D–F); 100 Mm (B); 50 Mm (C).