Stylaster parageus parageus (Fisher, 1938) Fisher, 1938

Cairns, Stephen D. & Lindner, Alberto, 2011, A Revision of the Stylasteridae (Cnidaria, Hydrozoa, Filifera) from Alaska and Adjacent Waters, ZooKeys 158, pp. 1-88 : 43-45

Stylaster parageus parageus (Fisher, 1938) new rank Figs 21A22 A–J

Allopora campyleca paragea Fisher, 1938: 507-509, pl. 41, figs 1-1d, pl. 43.- Thompson and Chow 1955: 30 (mineralogy).

Stylaster (Allopora) boreopacificus forma typica.- Broch 1936: 56-60, in part: specimens from Alaska, pl. 8, fig. 22, pl. 9, figs 23, pl. 10, figs 24-25, text figs 17c-d.

Stylaster campylecus .- Lowenstam 1964: 382 (mineralogy).

Stylaster campylecus parageus .- Cairns 1983b: 430.- Cairns and Macintrye 1992: 100-101 (mineralogy).- Wing and Barnard 2004: 27 (listed), not fig. 32.- Heifetz et al. 2005: 134 (listed).- Stone and Shotwell 2007: 108 (listed).-Jameison et al. 2007: 224 (listed).

Type material.

Holotype: 1 dry male colony 13 cm in height, plus many tiny branch fragments, and SEM stub 1514, USNM 42871 (Fig. 21A). Paratypes: Alb-4245, 1 female colony, and SEM stub 1515, USNM 76812; near Sitka, Alaska, coll. E. R. Ricketts, 1 female, deposition unknown (not seen); Alaska, deposition unknown (not seen); Yakutat Bay, Alaska, 152 m, specimens reported by Broch (1936), Zoological Museum Copenhagen (not seen). Type locality. Tenakee Springs, near Juneau, Alaska, depth unknown.

Material examined.

Types; Alaskan Leader 21-91A, 59°31'18"N, 144°42'42"W, 401-600 m, 31 Jul 2002, 1 male, USNM 1122485; Lambert, coll., 55°18'N, 129°57'18"W, 23 m, 28 Mar 1976, 1 male in alcohol, USNM 76976; Freege and Worth, coll., 57°48'N, 134°02'W, 30 m, 17 Apr 2000, 4 branches in alcohol, USNM 1122523; "an Indian", coll., Sitka Bay, depth unknown, about 1884, 2 male branches, USNM 4192.

Description.

Corallum consisting of overlapping flabella, also with short branchlets oriented perpendicular to flabella, producing what Fisher (1938: 507) calls “subflabellate’ or a "flattened bush." Branches do not anastomose, are circular to slightly flattened in cross section, and distally are quite delicate. Largest colony (the holotype, Fig. 21A) 13 cm tall and wide, with a basal branch diameter of 3.2 cm. Commensal spionid worm tubes common. Coenosteum reticulate-granular in texture (Fig. 22 E–F), the coenosteal strips 60-65 µm in width, the slits only 6-8 µm wide, the strips covered with low rounded granules, altogether presenting a smooth dense aspect. Coenosteum white.

Cyclosystems occur on branch edges and anterior face, but rarely on posterior face. Cyclosystems circular in shape, small (0.9-1.0 mm in diameter, not 0.6 mm as stated by Fisher 1938), and only slightly elevated above coenosteum; gastropores circular and quite narrow (0.25-0.30 mm in diameter, Fig. 22B). Gastropore tubes cylindrical, slightly curved, such that gastrostyle tip rarely seen in view from above; well-developed ring palisade present (Fig. 22C), consisting of elongate elements oriented longitudinally, each about 45 µm in length and 30 µm in width. Gastrostyles lanceolate, up to 0.5 mm in height, and occupying the lower half of third of the gastropore tube; H:D about 2.7.

Dactylotomes 0.09-0.10 mm wide, the inner slit very shallow, resulting in a ring of essentially apical dactylopores surrounding a thick-walled gastropore tube (Fig. 22B). Dactylostyles well developed, the elements up to 35 µm in height and 10-11 µm in diameter (Fig. 22H). Range of dactylopores per cyclosystem 5-11 (n = 50, average = 8.54 (σ = 1.20), mode = 8). Supernumerary dactylopores present but not common. Pseudosepta 0.12-0.13 mm in width; diastemas rare.

Female ampullae (Fig. 22I) superficial hemispheres 0.8-1.0 mm in diameter, the lateral efferent pores being 0.15-0.20 mm in diameter. Male ampullae (Fig. 22A, J) partially submerged in coenosteum (internal) on distal branches, entirely internal on larger-diameter branches, the outer diameter being about 0.5 mm, the internal diameter of internal ampullae about 0.42 mm; male ampullae often clustered on branch faces.

Remarks.

Although Fisher (1938: 508) included this taxon as a subspecies of Stylaster campylecus , considering it to be "the southern shallow-water race of campyleca," there are sufficient differences to warrant raising this subspecies to species rank (Table 2). Distinctive features include its bushy delicate colony, extremely small gastropores surrounded by a thick wall, and relatively low number of dactylopores per cyclosystem. Geographically it occurs only off southeastern Alaska in relatively shallow water, not in the Aleutian Islands. Comparisons to the other subspecies are made in the following account.

Distribution.

Bays and inland passages of southeastern Alaska from off Kayak Island to just north of Dixon Entrance (i.e., Prince of Wales Islands and Portland Canal); 23-401 m.