Cryptolarella abyssicola ( Allman, 1888 )

Watson, Jeanette E., 2019, Bathyal and abyssal hydroids (Hydrozoa, Leptothecata) from southeastern Australia, Memoirs of Museum Victoria 78, pp. 65-72 : 66

Cryptolarella abyssicola ( Allman, 1888)

Figure 1c−e

Cryptolaria abyssicola Allman, 1888: 40 , pl. 18, fig. 2, 2a.

Cryptolarella abyssicola . − Marques et al. 2005: 711 , fig. 1, Table 1 , (synonymy, discussion).

Records. QM G337422 , microslide. Coll: off Freycinet , Tasmania, 41.626 S, 149.5515 E to 41.6892 S 149.5843 E, 4022–4052 m, beam trawl, 18/05/2017 . QM G337426 , microslide. Coll: off Flinders Island Tasmania, 40.386 S, 148.928 E to 40.383 S 148.951 E, 932–1151 m, beam trawl, 20/05/2017 . QM G337427 , microslide. Coll: off Flinders Island Tasmania, 40.464 S, 149.3967 E to 40.464 S, 149.4255 E, 4114– 4139 m, beam trawl, 20/05/2017 . QM G337438 , microslide. Coll: off Jervis Bay , New South Wales, 35.333 S, 151.258 E to 35.332 S, 151.214 E, 2650– 2636 m, beam trawl, 29/05/2017 . QM G337439 , microslide. Coll : off Newcastle, New South Wales, 33.435 S, 152.702 E to 33.435 S, 152.665 E, 4280– 4173 m, beam trawl, 30/05/2017 . QM G337443 , microslide. Coll : off central New South Wales coast, 30.099 S, 153.596 E to 30.128 S, 153.571 E, 1257– 1194 m, beam trawl, 5/06/2017 . QM G337448 , microslide. Coll: off Byron Bay , New South Wales, 28.0544 S, 154.083 E to 28.097 S, 154.081 E, 999–1013 m, beam trawl, 9/06/2017 . QM G337452 , microslide. Coll: Coral Sea , Queensland, 23.587 S, 154.194 E to 23.617 S, 154.1947 E, 1013–1093 m, beam trawl, 13/06/2017 . QM G337421 , Coll: off Freycinet Tasmania, 41.7305 S, 140.1197 E, to 41.7913 S, 149.1558 E, 2751– 2820 m, beam trawl, 18/05/2017 . QM G337431 , Coll: Bass Strait , 39.552 S, 149.553 E, to 39.496 S, 149.598 E, 4197– 4133 m, beam trawl, 23/05/2017 . QM G337435 , Coll: off Bermagui , New South Wales, 36.418 S, 150.8 E, 3980 m, beam trawl, 26/05/2017 . QM G337440 . Coll : off Newcastle, New South Wales, 32.985 S, 152.952 E, to 33.015 S, 152.913 E, 2704–2902 m, beam trawl, 31/05/2017 .

Description. Small lax colonies to several centimetres high; some colonies fertile.

Colonies fasciculated basally, ultimate branches monosiphonic. Hydrothecae numerous, tubular, given off from around branches in fasciculated sections, more or less subalternate on monosiphonic branches. Hydrotheca adherent to branch for more than half of length, abcauline wall variably concave, adcauline wall convex, curving smoothly outwards, free wall shorter than adnate wall. Hydrotheca narrowing basally but without floor. Margin circular, not everted, without replications.

Gonothecae large, sausage-shaped, adnate to outer stem tubes, body narrow proximally, becoming tubular, abcauline wall minutely wrinkled, orifice wide, circular, upturned to varying degrees.

Perisarc soft and thin throughout, colour (preserved material) grey.

Remarks. Without a discernible floor, the length of the hydrothecae is highly variable, making it difficult to provide a precise estimate of length.

Cryptolarella abyssicola was first described from Challenger Station 160 from a depth of 4755 m south of Australia (42°42 S, 134°10 E) ( Allman 1888). In his description Allman commented on the “vast depth” from which the species came, and the height of the colony, about 2 inches (= 4.5 cm). C. abyssicola has since been recorded world-wide from Sierra Leone, the Azores, Tierra del Fuego, Peru and the Antarctic ( Marques et al. 2005) and from abyssal depths under several specific names. The present specimens conform well to the redescription and dimensions of the holotype given by Marques et al. (2005). This survey indicates that C. abyssicola is a dominant abyssal species around southern Australia.

Distribution. Australia (type locality), Sierra Leone, Azores, Tierra del Fuego, Peru, Antarctic.