Ircinia munsumensis, Sim & Lee & Kim, 2016

Sim, Chung Ja, Lee, Kyung Jin & Kim, Hyung June, 2016, Nine new species of genus Ircinia (Demospongiae: Dictyoceratida: Irciniidae) from Korea, Journal of Species Research 5 (3), pp. 483-497 : 487-488

6. Ircinia munsumensis n. sp. ( Figs. 7 , 8 )

Type specimen. Holotype (NIBRIV0000554225), Korea:

Munseom, Seogwipo­si , Jeju­do, 15 Aug 2015, Kim BI, by SCUBA , Depth 25 m, deposited in the NIBR .

Description. Thick mass, size up to 7 × 7 × 5 cm. Surface with low round conules covered with thick collagenous membrane. Membrane not easy to separate from sponge body. Large holes located on top of sponge. Several oscules, 1­5 mm in diameter, opened on sponge surface. Colour in life pinkish brown. Texture elastic and compressible. Choanosome are very lacunose.

Skeleton: Primary fibres, 200­400 μm in diameter, cored with sands and broken spicules near surface, but uncored in some part of sponge. Choanosomal primary fibres cored with foreign debris irregularly. Two kinds of secondary fibres appeared near surface, irregularly arranged secondary fibres, 700-1000 μm in diameter, and very simply fasciculate branched secondary fibres, 150- 400 μm in diameter. Choanosomal secondary fibres very thick. Filaments, two categories in size, 4 and 8 μm in diameter, terminal knobs, 10­15 μm in diameter.

Etymology. This species is named after the type locality, Munseom, Jejudo.

Remark. This new species is similar to Ircinia lapillus n. sp. in shape, but differs in skeletal structure. Primary fibres in conules of this new species cored with sands and broken spicules, and choanosomal primary fibres are irregularly cored with foreign debris rarely. Secondary fibres are very thick at the choanosome. Filaments of surface membrane are loosely arranged. Trumpet­like branch type of secondary fibres show big different from root­like shape of other genera. Choanosome are very lacunose.

Figures

Fig. 7. Ircinia munsumensis n. sp. A, entire animal; B, closed surface; C, skeletal structure near surface; D, secondary web between cored primary fibres; E, choanosome skeletal structure; F, choanosome thick secondary fibres. Scale bars: A=2 cm, B=10 cm, C=200 μm, D­F=100 μm.

Fig. 8. Ircinia munsumensis n. sp. A, choanosome skeletal structure; B, surface membrane with cored primary fibres; C, branched second­ ary fibres; D, secondary web. Scale bars:A-D=100 μm.