Crypthelia trophostega 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 : 58-60

Crypthelia trophostega Fisher, 1938 Figs 27 H–I30A–L

Crypthelia trophostega Fisher, 1938: 533-535, pl. 62, figs 1-8, pl. 63.- Cairns 1986: 24 (ampulla code); 1991: 386 (off Pribilof Island).- Cairns and Macintrye 1992: 102-103 (mineralogy).- Heifetz 2002: 22 (listed).- Wing and Barnard 2004: 10, 27, fig. 29.- Heifetz et al. 2005: 133, 136 (listed).- Stone and Shotwell 2007: 107 (listed).- Brooke and Stone 2007: 530, figs 2L, 3F.-Jameison et al. 2007: 224 (listed).- Lindner et al. 2008: 3, and supplemental Table S1: 1 (phylogeny and DNA sequences).

Cryptohelia trophostega : Thompson and Chow 1955: 30 (mineralogy).

Type material.

Holotype: Alb-3480, 1 large dry male colony, 15 cm in width, SEM stubs 1482-1484, USNM 42876 (Fig. 27H). Paratypes: Alb-3480, 2 dry colonies, male and female, USNM 52264; Alb-3480, 1 female colony in alcohol, USNM 43769; Alb-3480, 1 dry colony, CAS 69609.

Type locality.

Alb-3480: 52°06'N, 171°45'W (Amukta Pass), 517 m.

Material examined.Alaskan Leader 40, 52°09'18"N, 175°40'42"W, 174 m, 8 Jun 2002, 1 indet., USNM 1137354; Alaskan Leader 54-14, 51°44.4'N, 178°16.7'W, 567 -680 m, 11 Jun 2002, 1 indet., AB02-29; Alb-4771, 54°30'N, 179°17'E, 779 m, 4 Jun 1906, 2 males, USNM 76780; Alb-4780, 52°01'N, 174°39'E, 1913 m, 7 Jun 1906, 2 female, USNM 62371; Alb-4781, 52°14'30"N, 174°13'E, 882 m, 7 Jun 1906, 3 male, USNM 43770; Delta 6230 –20– 19, 52°28.142'N, 173°35.882'W, 190 m, 8 Jul 2004, 1 female, AB; Dominator 971-142, 51°43'10"N, 178°35'E, 215 m, 17 Jul 1997, 1 male, USNM 1123356; Dominator 971-181, 51°27'43"N, 178°35'E, 384 m, 27 Jul 1997, 1 indet., USNM 1123354; Dominator 971-201, 51°54'28"N, 378 m, 1 Aug 1997, 1 male, USNM 1123355; Dominator 971-126, 51°34'16"N, 177°47'36"W, 237 m, 12 Jul 1997, 1 indet. in alcohol, USNM 1123353; Jason II-2095 –2-9– 5, 51°48.682'N, 173°50.070'W, 843 m, 26 Jul 2004, 1 male, AB08-0035; Jason II-2099 –17– 1, 51°30.101'N, 177°02.354'W, 1453 m, 30 Jul 2004, 1 indet. in alcohol, AB09-0029; Ocean Olympic, 52°22.5'N, 176°03.5'E, 237 m, 1 female, AB 00-0024; Patricia Lee, 51°59'N, 179°30.08'E, 457 m, 1 male, AB00-0042; Sea Storm 93, 51°50'59"N, 178°26'02"E, 390 m, 5 Jul 2002, 1 male in alcohol, USNM 1122897; Sea Storm 108, 52°11'32"N, 175°28'18"E, 208 m, 8 Jul 2002, 1 male, USNM 1122893; Sea Storm 109, 52°17'16"N, 175°20'56"E, 238 m, 8 Jul 2002, 1 female in alcohol, USNM 1122894; Sea Storm 133, 52°13'40"N, 176°02'19"E, 148 m, 15 Jul 2002, 1 female and 1 male in alcohol, USNM 1122889-90; Sea Storm 138, 52°13'50"N, 175.242'E, 146 m, 16 Jul 2002, 1 female and 1 male, USNM 1122891-92; Sea Storm 148, 52°28'16"N, 173°19'10"W, 194 m, 2 female, SEM stub 1485, USNM 1122887-88; Sea Storm 150, 52°30'47"N, 173.2935°W, 220 m, 21 Jul 2002, 1 female, USNM 1075952; Sea Storm 151, 52°33'40"N, 173.3195°W, 203 m, 21 Jul 2002, 1 male, USNM 1122895; Sea Storm 155, 52°38'43"N, 172°16.38'W, 393-401 m, 22 Jul 2002, 1 indet., USNM 1122896; Shishaldin, 54°12'37"N, 179°30'05"E, 179 m, 1 female and 1 male, USNM 1122435and 1122446; Shishaldin, 54°07'N, 179°45'E, 366 m, 20 Feb 2000, 1 female, SEM stubs 1486-87, USNM 1122487; Vesteraalen 941-138, 51°28'N, 178°38'W, 0-311 m, 7 Jul 1994, 1 male, USNM 96248; Vesteraalen 941-167, 51°54'N, 178°20'E, 0-150 m, 19 Jul 1994, 1 female, USNM 96240; 51°50'32"N, 176°00'08"E, 272 m, 5 Dec 2000, 1 male, USNM 1122441; "Gulf of Alaska", 219-274 m, 1 female, USNM 77415; "Bering Sea", 1 male in alcohol, USNM 76570; University of Washington, 51°32'N, 179°15'W, 278-289 m, 1 Sep 1968, 1 female, USNM 62372.

Description.

Colonies variable in shape, usually uniplanar (Fig. 27H) but sometimes forming three dimensional bushes (Fig. 27I) or multiplanar colonies. Largest colony known (USNM 1122446) is multiplanar, 20 cm tall and 12 cm wide, with a basal diameter of 11.5 mm, this colony only slightly larger than the holotype. Branching irregularly dichotomous and often anastomotic, which reinforces strength of a uniplanar colony. Coenosteum linear-imbricate in surface texture, the parallel strips 50-70 µm wide. Strips covered with irregularly shaped platelets, which are rarely continuous across a strip but dissected into 2-5 smaller sections, each of which has an irregular leading edge and only a slight imbricating overlap with more distal platelet, altogether producing a rough microtexture. Shallow, circular (0.06-0.13 mm in diameter) nematopores very common, occurring on branch coenosteum, cyclosystem lids, and even on pseudosepta (Fig. 30 A–C, F–G, J), most concentrated around cyclosystem edge. Nematopores flush with coenenchyme or encircled with a very low rim. Coenosteum white.

Cyclosystems unilinearly arranged either bifacially or on one face, both conditions sometimes occurring on same colony. Unifacially arranged cyclosystems seem to be more common on uniplanar colonies, whereas the bifacial arrangement favors bushy coralla. Cyclosytems circular to slightly elliptical in outline (2.2-2.6 mm in diameter), the greater axis of ellipse being perpendicular to branch axis. Cyclosystems slightly flared, each covered with a horizontal lid that covers most of cyclosystem, sometimes even fusing to opposite side of cyclosystem. Lids usually greatly inflated, containing the male or female ampullae. Cyclosystems have a range of 13-23 dactylopores (n = 50, average = 18.66 (σ=1.96), and mode = 19). Upper gastropore chamber spherical, about 0.9-1.0 mm in diameter, which is separated from lower, flattened chamber by a circular gastropore ring constriction 0.4-0.6 mm in diameter, the lower chamber being about 0.8-0.9 mm in diameter (Fig. 30H). Dactylotomes uniform in width, 0.14-0.16 mm; pseudosepta quite slender, having a thin (20-60 µm) blade-like inner edge (Fig. 30F). Upper edges of pseudosepta not exsert, but gradually attenuate in size near cyclosystem edge.

Female ampullae (Fig. 30 H–J) smooth, massive, hemispherical swellings in cyclosystem lid, often two ampullae contained in same lid (Fig. 30I). Efferent pores quite large (up to 0.5 mm in diameter), opening beneath lid (type A ampulla formula of Cairns 1986, Fig. 30 H–I). Male ampullae (Fig. 30 K–L) irregularly shaped swellings in cyclosystem lid, up to 11 occurring in one lid. Efferent pores smaller (10-12 um in diameter), also opening beneath the lid (type A2 ampulla formula of Cairns 1986)(Fig. 30C, K).

Remarks.

Among the 31 Recent species of Crypthelia ( Cairns et al. 1999; www.marinespecies.org), Crypthelia trophostega is unique in having a tendency to have a bifacial cyclosystem arrangement and for having more than one female ampullae per cyclosystem lid. Furthermore, only one other species is known to have the A–A 2 ampulla formula (see Cairns 1986), that being Crypthelia pudica Milne Edwards and Haime 1849. Crypthelia trophostega differs from Crypthelia pudica in having bifacial cyclosystems, a rougher coenosteal texture, more nematopores, larger cyclosystems, and lower lids. The corallum was found to be 100% aragonitic according to Cairns and Macintrye (1992). Of the 42 specimens examined: 18 are female, 18 male, and 6 indeterminate in gender.

Distribution.

Aleutian Islands from Near Islands to Amuka Pass, Petrel and Bowers Banks, off Pribilof Bank; 146-1913 m, although most records between 200 and 400 m.