Cyclohelia lamellata Cairns, 1991

Cairns, Stephen D. & Lindner, Alberto, 2011, A Revision of the Stylasteridae (Cnidaria, Hydrozoa, Filifera) from Alaska and Adjacent Waters, ZooKeys 158, pp. 1-88 : 7-8

Cyclohelia lamellata Cairns, 1991 Figs 1 D–I3A–C

Cyclohelia lamellata Cairns, 1991: 384-386, figs 1a-g, 2a-g.- Heifetz 2002: 22 (listed).- Wing and Barnard 2004: 10, 27, fig. 25, not Appendix fig. 1 (= Errinopora undulata ).- Stone and Shotwell 2007: 107 (listed).- Brooke and Stone 2007: 529-530, figs 2K, 3E.-Jameison et al. 2007: 224 (listed).- Lindner et al. 2008: 3, and supplemental Table S1: 3 (phylogeny and DNA sequences).

Cyclohelia lamellate .- Heifetz et al. 2005: 133, 137 (listed).

Type material.

The holotype, a dry female colony (USNM 85077, Fig. 1D). Type locality. Off Pribilof Islands, 550 m.

Material examined.

Alaskan Leader 35, 53°01'48"N, 170°06'12"W, 172-178 m, 4 Jun 2002, 1 female, 1 male, USNM 1122491; Alaskan Leader, 54-14, 51°44.4'N, 178°16.7'W, 567-680 m, 11 Jun 2002, 1 female, AB02-0029; Alaska Beauty, 51°42.43'N, 176°56.05'E, 351 m, 3 Feb 2000, 1 female, AB00-15; Delta 5999-8E-5, 52°21.042'N, 179°30.483'W, 115 m, 4 Jul 2003, 3 fragments, AB10-0001; Delta 6000-10D-2, 51°50.8545'N, 179°49.6488'E, 150 m, 5 Jul 2003, 1 indet., AB; Delta 6001-10C-1, 51°52.396'N, 179°46.191'E, 230 m, 5 Jul 2003, 1 female, AB; Delta 6213-12B-1, 2 and 4, 6 males, AB; Delta, 51°50'55"N, 179°48'35"W, 125 m, 17 Jul 2002, 1 female in alcohol (digitate form), USNM 1122494; North Pacific, 52°04.28'N, 176°05.35'E, 366 m, 1 indet., AB00-28; Ocean Olympic, 52°11.89'N, 176°17.3'E, 366 m, 20 Oct 2000, 1 female (digitate form), USNM 1122513; Pacific Knight 941-121, 51°38'00"N, 178°19'00"W, 0-373 m, 5 Jul 1994, 1 female and 1 male, USNM 96235 and 1122900; Pacific Knight 941-179, 52°00'N, 176°44'E, 0-90 m, 23 Jul 1994, 1 female (intermediate form), USNM 96236; Patricia Lee, 51°18'42"N, 179°30'04"E, 329 m, 20 Oct 2000, 1 male, USNM 1122488; Patricia Lee 51°53.44'N, 179°47.7'E, 298 m, 3 male, SEM stub 1488, AB00-41; Sea Storm 107, 52°10'28"N, 175°14'14"E, 214 m, 8 Jul 2002, 1 female in alcohol, USNM 1123297; Sea Storm 108, 52°11'32'N, 175°17'E, 208 m, 8 Jul 2002, 10 female, 6 male, 8 indet. (digitate form) in alcohol and dry, USNM 1122951, -54, -55, -57, -58, -59, 61, 1123290, 91; Sea Storm 111, 52°16'20"N, 175°59'13"E, 137 m, 9 Jul 2002, 1 male in alcohol, USNM 1122949; Sea Storm 112, 52°15'12"N, 176°10'42"E, 137 m, 9 Jul 2002, 1 indet., USNM 1122946; Sea Storm 116, 52°04'10"N, 177°14'25"E, 87-94 m, 11 Jul 2002, 1 male in alcohol (digitate form), USNM 1122942; Sea Storm 122, 52°02'49"N, 179°25'18"E, 143 m, 13 Jul 2002, 8 female, 4 male, 5 indet., USNM 1122899, 1122948, 1123294-96, -98; Sea Storm 123, 52°10'53"N, 179°37'02"E, 124 m, 13 Jul 2002, 2 male, USNM 1122952; Sea Storm 125, 52°12'53"N, 179°56'49"W, 89-96 m, 13 Jul 2002, 1 male, USNM 112305; Vesteraalen 3, 52°38'13"N, 169°47'14"W, 75-83 m, 22 May 2001, 1 male in alcohol, USNM 1076490; Vesteraalen 941-36, 52°56'N, 169°31'W, 0-227 m, 10 Jun 1994, 1 female, USNM 96237; Vesteraalen 941-46, 53°04'N, 170°09'W, 0-174 m, 12 Jun 1994, 1 female, USNM 96238; Vesteraalen 941-153, 52°10'N, 179°43'E, 0-94 m, 11 Jul 1994, 1 male, USNM 96239; "Vessel" 35, 51°45'48"N, 178°09'47"W, 200-400m, 4 Jun 2000, 2 female and 1 male, USNM 1122493; Renfro, coll., 51°56'35"N, 179°17'58"E, 236 m, 1 female, USNM 1122456; coll. Slear, 51°59'52"N, 176°47'05"E, 241 m, 13 Nov 2000, 1 male (digitate form), USNM 1122457; Petrel Bank, 1 male, 1 indet., USNM 1123540; 51°52.11'N, 179°49.51'W, 27 m, 17 Jul 2002, 1 female (digitate form), USNM 1122492.

Remarks.

This species is not redescribed herein as it was adequately described originally ( Cairns 1991) and, being the only species in the genus, conforms to the genus diagnosis above. But, the species was previously known from only two specimens, the type and a specimen sequenced by Lindner et al. (2008), and thus more can be added to its description, including details of the male ampullae, based on the 81 additional specimens reported herein.

Colonies are usually firmly attached to a hard substrate by a robust cylindrical base and stem (Fig. 1H) up to 2.5 cm in diameter, which, at the height of about 2 cm, bifurcates into two lamellae or sheets, each sheet increasing its surface area by folding and undulating its surfaces into a complex three dimensional structure. Large colonies may attain a height of about 8 cm and a width of 10 cm, colonies wider than tall being the norm. However, a subset of colonies from seven stations (see Material Examined), termed the "digitate form", differ from the typical colony morphology in having dissected plates, resulting in numerous flattened lobes and clavate branches (Fig. 1E). Furthermore, one colony (Fig. 1F) is intermediate between these two extremes, suggesting that these shapes are simply variations of the same species.

Male ampullae (Fig. 3A) entirely internal, and elliptical in shape, the greater axis of the ellipse perpendicular to the branch surface, unlike that of the female ampullae. Male ampullae are up to 0.6 mm in greater diameter and 0.45 mm in lesser diameter, occurring in great concentrations and invariably present on almost any broken surface. Each ampulla communicates to the surface by a circular efferent duct, the duct about 0.07-0.09 mm in diameter, which is surrounded by small inward projecting granules, giving the pore a star-shaped appearance (Fig. 3 B–C). Of the 81 specimens examined, 34 are female, 29 male, and 18 indeterminate in gender.

Distribution.

In addition to the type locality off the Pribilof Islands, this species is common throughout the Aleutian Islands from the Rat Islands to the Islands of Four Mountains at 27-567 m, although it was more commonly collected from the western part of this range at depths of 100-300 m. The digitate form is known only from the western Aleutian Islands from 27-366 m.