Stylantheca papillosa (Dall, 1884)

Cairns, Stephen D. & Lindner, Alberto, 2011, A Revision of the Stylasteridae (Cnidaria, Hydrozoa, Filifera) from Alaska and Adjacent Waters, ZooKeys 158, pp. 1-88 : 54-58

Stylantheca papillosa (Dall, 1884) Figs 27 D–G29A–L

Allopora papillosa Dall, 1884: 113-114.- Fisher 1938: 527-528, pl. 54, fig. 4, pl. 59, fig. 3.

Stylantheca porphyra Fisher, 1931: 395-397, pl. 15, figs 1, 1a, pl. 16, figs 5, 5a-b, pl. 17, figs 6, 6a-c.- Boschma 1956: F100, text fig. 81-1a-b; 1960: 426-427, text figs 1e-g.- Cairns 1983b: 430, 481-483, figs 18A-I, 24H, 27G, J.- Wing and Barnard 2004: 10, 27.- Heifetz et al. 2005: 133 (listed).- Stone and Shotwell 2007: 108 (listed).- Whitmire and Clarke 2007: 154 (listed).- Jamieson et al. 2007: 224 (listed).

Allopora petrograpta Fisher, 1938: 530-531, pl. 54, figs 5, 5a, pl. 59, fig. 4.- Frichman 1974: 245-258 (larval development).

Allopora porphyra : Fisher 1938: 528-530, pl. 59, figs 1-2, pl. 60, pl. 61,figs 1, 1a, pl. 70, figs 2, 2a.- Thompson and Chow 1955: 30 (mineralogy).

Stylaster (Allopora) porphyrus : Broch 1942: 102.

Stylaster (Stylantheca) porphyra : Boschma 1951: 39, text fig. 5b.

Stylantheca petrograpta : Cairns 1983b: 430.- Wing and Barnard 2004: 10, 27.- Heifetz et al. 2005: 133 (listed).- Stone and Shotwell 2007: 108 (listed).- Whitmire and Clarke 2007: 154 (listed).- Jamieson et al. 2007: 224 (listed).- Lindner et al. 2008: 3, and supplemental Table 1: 2 (phylogeny and DNA sequences).

Stylantheca papillosa : Cairns 1983b: 430.- Wing and Barnard 2004: 10, 27.- Heifetz et al. 2005: 133 (listed).- Stone and Shotwell 2007: 108 (listed).- Jamieson et al. 2007: 224 (listed).

Stylaster porphyra : Jamieson et al. 2007: 224 (listed).

Type material.

Allopora papillosa : holotype, a small (11 mm long) dry encrusting fragment, USNM 6852 (Fig. 27D).

Type locality.

Coal Harbor, Unga Island, Shumagin Islands, Alaska Peninsula, 11 m.

Stylantheca porphyrea : holotype (USNM 43018, Fig. 27G) and 13 paratype colonies (USNM 43019, 43276, 43277 and SEM stub 136), all dry.

Type locality.

Pescadero Point, Carmel Bay, California (36°33'42"N, 121°57'13"W), intertidal.

Allopora petrograpta : two small (15 and 17 mm in length) dry, male encrusting fragments, syntypes, and SEM stub 1506, USNM 43272 (Fig. 27F). Type locality. Kyack Island, mouth of Sitka Harbor, Alaska, intertidal.

Material examined.

Types of the three named species; Middle of Cross Sound, AK, 15-21 m, 27 Jul 1978, 5 female colonies, AB78-120; South of Yasha Island, Chatham Strait, AK, depth unknown, 31 Jul 1976, 8 female colonies in alcohol, and SEM stubs 1532-34, AB76-55; Wooden Island, AK, depth unknown, 2002, 1 indet., AB02-150; Wooden Island, AK, depth unknown, 15 May 2009, 1 male in alcohol, AB09-10; Race Rocks, Victoria, British Columbia, depth unknown, 2002, 8 colonies dry and in alcohol, USNM 1073478; Seontary Island, Victoria, BC, 10 m, Jul 2002, 1 large male colony, USNM 1096626; 48°18'N, 123°31.8'W, 12.1 m, 6 Sep 1973, 1 female colony, USNM 76559; cactus island Channel, BC, 15 m, 1 male, AB02-0006; Lion's Gate Bridge, Burrard Inlet, British Columbia, 18 m, Jan 2002, 2 indet., AB02-0005; Turn Island, Washington, 0-27 m, 6 Jul 1995, 10 colonies, USNM 1084659; Puget Sound, Washington, 27 m, 2, CAS 117458-59; Squaw Island, Oregon, 20 Jul 1962, 1 female colony, USNM 45685; 43°18'15"N, 124°23'56"W (Charleston, Oregon), intertidal, 2 indet in alcohol, USNM 1086321; Pillar Point, Half Moon Bay, California, intertidal, 18 Feb 1996, 16 colonies, USNM 1084663; Pigeon Point, California, intertidal, 12 Jul 1995, 12 colonies (forma porphyra), USNM 1084662.

Description.

The typical form is variable in colony shape, those specimens living in a high energy shallow-water environment usually being encrusting, the layer of coenosteum sometimes less than 1 mm thick (Fig. 27E), the gastrostyle base almost resting on the hard substrate. In deeper water, colonies produce short (up to 17 mm), knobby, clavate, cylindrical branches, which originate from the basal encrustation. Only rarely will these branches bifurcate. Although the types of Stylantheca papillosa and Stylantheca petrograpta are small, beach-worn fragments (Figs 27D, F), the species produces mats up to 30 cm in diameter. Parasitic spionid polychaetes ( Polydora ?alloporis Light, 1970) usually present, forming binary tubes/paired burrows throughout the coenosteum. Coenosteum reticulate-granular in texture, the strips about 50-55 µm in width, separate by slits 12-15 µm wide. Short, porous, conical papillae (nematopores?) common on coenosteum, each about 0.13 mm in diameter and equally tall (Fig. 29B, D, F–G). Coenosteum purple, pink, red, and occasionally white, the tips of the clavate branches usually white.

Cyclosystems uniformly arranged on encrustations and on all sides of branchlets; diameter of cyclosystems 0.9-1.2 mm. Gastropore tube highly constricted, the upper larger portion being infundibuliform to spherical, the lower chamber spherical and almost completely occupied by the gastrostyle(s), the two portions of the chamber constricted near gastrostyle tip. Gastropore tube diameter about 0.3 mm, the tube constriction about half that diameter. Just above the constriction numerous small (up to 45 µm in length) papillae form a wide ring palisade (Fig. 29K) further reducing access to lower chamber. Gastrostyles quite variable and sometimes irregular in shape, including globose (Fig. 29K), lanceolate, or triangular. Regardless, gastrostyles bear quite long (up to 50 µm long and 15 µm in diameter) spines that completely obscure the underlying gastrostyle shaft. Usually there is only one gastrostyle per cyclosystem, but occasionally the upper chambers of two cyclosystems are linked together resulting in two gastrostyles in one cavity, and rarely there appears to be 2 gastrostyles in one normal gastropore chamber.

In well-preserved colonies, dactylopores are slightly raised above surface of coenosteum; dactylotomes 0.10-0.12 mm wide. Number of dactylotomes per cyclosystem variable, depending on size of cyclosystem, but ranges from 2-12, with common modes of 4, 5 and 8 (see Remarks). Dactylostyles robust (Fig. 29A, C, H), the cylindrical elements up to 55 µm long and 13-17 µm in diameter, not unlike the gastrostyle elements.

Female ampullae (Fig. 29L) primarily internal, with little superficial relief, even by an efferent pore; internal diameter 0.7-0.9 mm. Male ampullae also internal, the internal diameter being 0.4-0.5 mm.

Remarks.

Although the holotype of Allopora papillosa is a small, worn colony measuring only 9.4 × 6.6 mm in width and containing only 28 cyclosystems (Fig. 27D), it is not difficult to see the similarity to the two syntypes of Allopora petrograpta Fisher, 1938 (Fig. 27F), also worn specimens (13 and 16 mm in width, constituting over 100 cyclosystems), even though they were collected from shallow water on op posite sides of the Gulf of Alaska. All of the cyclosystems of the type of Stylantheca papillosa have only one gastrostyle, whereas all but four of the cyclosystems of the syntypes of Stylantheca petrograpta have one gastrostyle, the other four having two. The more difficult synonymy is with the more southerly species Stylantheca porphyra Fisher, 1931, described from shallow water in Carmel Bay, California. Stylantheca porphyra is very similar to the encrusting forms of Stylantheca papillosa , differing only in usually having more than one gastrostyle per cyclosystem, sometimes as many as 8. Cairns (1983b) reported an average of 3.3 gastrostyles per cyclosystem (mode = 3) for the holotype. Another typical population of Stylantheca porphyra is reported herein from Monterey Bay (USNM 1084662), also having multiple gastrostyles per cyclosystem, but just 50 km to the north (USNM 1084663) are colonies otherwise identical to Stylantheca porphyra that have only one gastrostyle per cyclosystem. Fisher (1938: 530) was uncertain as to the systematic importance of the number of gastrostyles per cyclosystems, suggesting that this character might have subgeneric or even generic discriminating power. We suggest that it is a matter of intraspecific variation and thus synonymize Stylantheca porphyra with Stylantheca papillosa , resulting in only one valid species in the genus Stylantheca . The number of dactylopores per cyclosystem of Stylantheca porphyra ranges from 6 to16 (n = 34, average = 9.11, σ = 2.08, mode = 10) ( Cairns 1983b), whereas it is lower for the type of Stylantheca petrograpta (n = 30, range =2-7, average = 5.07, σ = 0.94, mode = 5) and slightly lower still for the types of Stylantheca papillosa (n = 14, range = 3-5, average and mode= 4.0, σ = 0.68). Another typical specimen (AB76-55) having only 1 gastrostyle per cyclosystem has a range of 5-12 dactylopores per cyclosystem (n = 30, average = 7.43, σ = 1.61, mode = 8). The higher number of dactylopores per cyclosystem of Stylantheca porphyra is explained by its larger cyclosystems that house multiple gastrostyles, but in general the number of dactylopores per cyclosystem cannot be used as a diagnostic character for this species. Southern populations that have a slightly larger cyclosystems and more than one gastrostyle per cyclosystem can be referred to as the “porphyra” form, a conclusion first suggested by Cairns (1983b: 483). The type of Stylantheca porphyra is illustrated by Cairns (1983b) and as Fig. 27G herein.

Two other eastern Pacific species are similar to Stylantheca papillosa in color and cyclosystem and gastrostyle shape: Stylaster venustus (Verrill, 1870) and Stylaster californicus (Verrill, 1866). Stylantheca venustus (Figs 16A-I, 17 F–G) is known from Monterey Bay, California (USA) to Vancouver Island, BC (Canada) at depths of 10-108 m and, although it may originate with an encrusting base (Fig. 17F, MCZ 5525, holotype), it quickly forms small colonies with delicate branches (Fig. 17G). Sixteen locality records are present at the NMNH, most from off Washington and Oregon (USA), but this species is not treated in this review except to illustrate some of its characters (Table 2). On the other hand, the more southern Stylantheca californicus , known from off southern California (USA) from approximately 21-45 m (see Boschma 1957), forms large colonies with robust branches; this species is not further discussed in this review except for the table of comparisons (Table 2).

Distribution.

Widespread from the Alaska Peninsula (Shumagin Islands) to Monterey Bay, California, although not yet reported from the northern Gulf of Alaska. Common in the inner passages of Alaska and British Columbia; intertidal to 27 m. Forma porphyra known only from Monterey Bay area.