Cladorhiza oxeata, LUNDBECK, 1905

Hestetun, Jon Thomassen, Tompkins-Macdonald, Gabrielle & Rapp, Hans Tore, 2017, A review of carnivorous sponges (Porifera: Cladorhizidae) from the Boreal North Atlantic and Arctic, Zoological Journal of the Linnean Society 181, pp. 1-69 : 33

CLADORHIZA OXEATA LUNDBECK, 1905

( FIGS 26, 27)

Original description: Cladorhiza oxeata Lundbeck, 1905: 97 .

Synonyms and citations: Cladorhiza abyssicola in part ( Hansen, 1885: 16); C. abyssicola ( Fristedt, 1887: 455) ; C. oxeata ( Hentschel, 1929: 935) .

Type material examined: The Danish Ingolf Expedition. Lectotype: ZMUC-DEM-79, st. 15 (4 June 1895, 66°18ʹN, 025°59ʹW, 621 m). Paralectotypes: ZMUC- DEM-295, st. 143 (11 August 1896, 62°58ʹN, 007°09ʹW, 731 m), st. 3 (12 May 1896, 63°35ʹN, 010°24ʹW, 512 m); ‘Wandel’ Expedition, ZMUC-DEM-296 (19 September 1891, 66°57ʹN, 027°00ʹW, 633 m).

Other material examined: ‘Ingegerd’ & ‘Gladan’ Greenland Expedition 1870–1871, M/S ‘Michael Sars’ 1902, HMS ‘Porcupine’ 1869, M/S ‘Michael Sars’, ‘Tjalfe’ Expedition, Godthaab Expedition, Degerbøl Kangerlussuaq 1932, Heimland Expedition, Norw. Fisheries Investigations, BIOICE, R/V ‘Paamiut’ 2010–2014 (see Supporting information).

C o m p a r a t i v e m a t e r i a l e x a m i n e d: C l a d o r h i z a methanophila Vacelet & Boury-Esnault, 2002 , ‘Atlantis’ AT 21-02, J633-5.

Diagnosis: Erect Cladorhiza with arbuscular morphology consisting of a solid, branching main stem with side branches. Stem and branches set with large number of filaments. Megascleres oxeas; microscleres one type of chela c. 23–41 µm, sigmas c. 100–153 µm and sigmancistras, sometimes rare, c. 27–55 µm.

Description: Large, erect, arbuscular Cladorhiza species, commonly over 30 cm tall, with thick branching main stem carrying numerous slightly thinner side branches. Stem typically 5–10 mm wide, thicker towards the base. Side branches 2–5 mm wide. Stem and branches covered in a thick softer, outer layer with 2- to 10-mm-long filaments issuing in all directions, but lower and central part of the stem often bare. The outer layer has a tendency to disassociate from the stem after storage in ethanol. Lower stem is bare and connects to the substrate with a basal plate. Colour white to beige, light brown, pink or reddish brown, with the stem a darker colour than the outer layer ( Figs 26A–C, 27A–D).

Skeleton : The core of the main stem and branches is composed of tightly connected spicule bundles, which creates a rigid, smooth central skeleton. This is surrounded by an outer layer of loose tissue which easily disassociates from the central skeleton.