Errinopora fisheri Lindner & Cairns 2011

455-458 m

Holotype (Fig. 5A) uniplanar with a secondary flabellum at mid-height, 9 cm in height and 6.5 cm in width, with a basal branch diameter of 10 × 7.5 mm. Branches circular to slightly elliptical in cross section and irregularly dichotomous, small-diameter branches often diverging from larger main branches; branch anastomosis absent. Coenosteum reticulate-granular in texture, the strips being 80-90 µm in width and covered with small granules 5-15 µm in diameter; strips bordered by slits 40-45 µm wide. Coenosteum light orange. Dactylopore spines favor one face of corallum over the other, arranged in abcauline, crescent-shaped terraces flanking one or two gastropores (Fig. 6A-D). Terraces sometimes almost completely surround a gastropore (Fig. 6C-D), resembling a cyclosystem of 1.5 mm diameter with an adcauline diastema, much as in Stylaster, but isolated dactylopore spines also fairly common, especially near base of colony. Dactylopore terraces quite thin (0.35 mm) and up to 1.5 mm in height, and, although laterally fused, the individuality of each dactylopore spine is subsumed into the more continuous terrace structure; compound dactylopore spines absent; exterior surface of spines longitudinally ridged. Terraces often horizontally oriented on branches, and slightly flared around gastropore(s). Dactylotomes not slit-shaped as in most other Errinopora, but instead small elliptical pores about 0.27 mm long and 0.15 mm in width occurring only near tips of spine structure; dactylotomes always directed toward a gastropore. Dactylostyles small, about 50 µm in width, having stubby elements up to 25 µm in length and 10-15 µm in diameter. Secondary dactylopores absent. Gastropores circular, flush with coenosteum, 0.3-0.5 mm in diameter, being fairly consistent in size; gastropores isolated, not arranged in rows; secondary gastropores absent. Gastropore tube cylindrical, but with a slight medial constriction; often a ring palisade is present, the elements 50 µm tall and 15-25 µm in diameter. Gastrostyle squat, an illustrated one being 0.33 mm tall and 0.29 mm in diameter (Fig. 6I). Gastrostyles covered with longitudinal anastomosing ridges as consistent with the genus. Female ampullae (Fig. 6D) hemispherical but often irregular in shape due to protruding dactylopore spines. Female ampullae 1.0–1.2 mm in diameter; efferent pores not observed. Male ampullae unknown.

Known only from Aleutian Islands: off Attu Island; 455-458 m.