Errinopora Fisher, 1931

Bernal, M. C., Cairns, S. D., Penchaszadeh, P. E. & Lauretta, D., 2021, Stylasterids (Hydrozoa: Stylasteridae) from Mar del Plata submarine canyon and adjacent area (southwestern Atlantic), with a key to the species off Argentina, Zootaxa 4969 (3), pp. 401-452 : 17

Genus Errinopora Fisher, 1931

Type species. Errina pourtalesii Dall, 1884

Included species. Errinopora cestoporina Cairns ; E. dichotoma Lindner & Cairns ; E. disticha Lindner & Cairns ; E. fisheri Lindner & Cairns ; E. nanneca Fisher ; E. porifera (Naumov) ; E. pourtalesii (Dall) ; E. stylifera (Broch) ; E. undulata Lindner & Cairns ; E. zarhyncha Fisher

Distribution. Central California, 49–183 m; Aleutian Islands, 40–658 m; Okhotsk Sea, 190–250 m; Patagonia, 42° S to 48° S; Tierra del Fuego, 359–384 m (see Cairns & Lindner 2011). New record off Mar del Plata, 819 m.

Diagnosis (from Cairns & Lindner 2011, changes in bold). Colonies uniplanar to slightly bushy; branches round, elliptical, or lamellar in cross section, often robust with blunt tips. Coenosteal texture reticulate-spinose (with wide slits resulting in a spongy texture) or reticulate-granular; exterior surface of dactylopore spines usually inconspicuously longitudinally ridged; coenosteum orange, pink, and white. One species, Errinopora cestoporina , bears numerous perforated mounds on surface. Dactylopores dimorphic, either with a U-shaped spine or without spine, i.e. flush. The most common, termed the primary dactylopore spine,is U-shaped and usually robust (thick-walled),occurring randomly, in pseudocyclosystems, or often laterally fusing to form rows or taller terraces that flank rows of gastropores. When dactylopore spines flank both sides of a gastropore row and their dactylotomes are directed toward the gastropores it is termed bilateral or distichoporine; if only one row of spines flank a row of gastropores, then unilateral. If isolated, dactylotomes usually abcauline in orientation. Much smaller flush dactylopores, termed secondary dactylopores, which in general lack dactylostyles, commonly scattered over coenosteum of many species. Dactylostyles usually well developed, easily seen from external view. Gastropores also dimorphic, the primary gastropores being circular in outline, flush with coenosteum (having no lip), and arranged in irregular vertical rows, short horizontal rows, or randomly. Tabulae and ring palisades absent. Gastrostyles lanceolate, covered with longitudinal or oblique, spiny ridges. Smaller secondary gastropores much smaller, having only a small gastrostyle or none at all. Female ampullae superficial hemispheres, often without an obvious efferent pore. Male ampullae usually smaller hemispheres and spongy.