Smenospongia arbuscula, Sim & Lee & Kim, 2016

Sim, Chung Ja, Lee, Kyung Jin & Kim, Young A, 2016, Twelve new species of two genera Smenospongia and Cacospongia (Demospongia: Dictyoceratida: Thorectidae) from Korea, Journal of Species Research 5 (1), pp. 31-48 : 34-36

4. Smenospongia arbuscula n. sp. ( Fig. 4 )

Type specimen. Holotype ( NIBRIV0000321368 ), Korea: Gyeongsangbuk-do, Ulleung-gun, Ulleungdo Island (Neunguel), 1 Aug 2001, Lee KJ, by SCUBA diving, Depth 25 m, deposited in the NIBR.

Description. Thick encrusting, size up to 6 × 5 × 2 cm.

Surface with low conules and covered with many other animals and seaweed. Oscules opened on surface. Colour in life golden yellow turns to dark brown in air. Texture firm and compressible.

Skeleton: Primary fibres, 200-300 μm in diameter, branched, dark colour, heavily cored with spicules. Some part of primary fibres, cored with round mass like egg or spore, 20 μm in diameter. Several egg-like mass free appeared in mesohyl. Fibres easily broken like seaweed. Second fibres rare, uncored, 50-100 μm in diameter. In choanosome, many primary fibres, branched without secondary fibres.

Etymology. The specific name, arbuscula , is named after the shape of branched primary fibres.

Remark. This new species is distinguished by its branching primary fibres, which is thick and dark colour. They have no mesh of secondary fibres except a few on the surface. This new species is similar to Smenospongia flavia n. sp. in colour in life, but differs in skeletal structures. Smenospongia flavia has crowded secondary fibres, but this new species has very rare secondary fibres and primary fibres are cored egg-like material.

Figures

Fig. 4. Smenospongia arbuscula n. sp.A, entire animal; B, closed surface; C, surface primary and secondary fibres; D, choanosome primary fibres; E, primary fibres enclosed egg ball; F, free egg ball. Scale bars:A=2 cm, C, D =200 μm, E=50μm, F=10 μm.