Clathria (Clathria) ieoensis, 2018

Kang, Dong Won & Kim, Hyung June, 2018, Two new species of the Genus Clathria (Demospongiae: Poecilosclerida: Microcionidae) from Jeju Island, Korea, Zootaxa 4504 (3), pp. 390-400 : 396-398

Clathria (Clathria) ieoensis sp. nov.

( Figs. 5–6 , Table 3)

Material examined .. Holotype. Korea, Jeju-do Island, Seogwipo-si, Gapa-up , Ieodo , 15 m depth, June 30, 2017, SCUBA, coll. Sang-Hui Lee, MABIK IV001641547

Description. Shape ( Fig. 5 A ): Encrusting, 2 cm in thickness and 7 cm in width, with small oscules flush on surface.

Texture: Soft and compressible.

Oscules: 0.2–0.5 mm in diameter, scattered on the surface.

Colour: Red in life which gradually changes to dark brown in ethanol.

Surface: Smooth and even.

Skeleton ( Fig. 5 B–D): Ectosome membranous, hispid from connected choanosomal spicules tracts. Ectosomal skeleton with tangential layers of auxiliary styles in multispicular tracts. Choanosomal skeleton with regularly developed primary spongin fibres and plumose acanthostyles. Primary spongin fibre diameter about 30–60?. Acanthostyles echinating the primary spongin fibres. Secondary spongin fibres not well developed.

Spicules ( Fig. 5 E–H, Fig. 6 , Table. 3): Megascleres. Two sizes of style( Fig. 5 E–F), large and small styles, long, robust, straight or slightly curved with microspined head. Thin styles( Fig.6 A–B), straight, long, smooth, with microspined base. Two sizes of acanthostyles( Fig. 5 G–H), large acanthostyles, long, robust, sharply pointed, evenly spined. Small acanthostyles, straight, with heavily spined bases. Microscleres. One size of palmate isochelae( Fig. 6 C–D), small, weakly silicified, unmodified. Toxa( Fig. 6 E–G), two size categories of wing shaped toxas, with rounded central curve and slightly reflexed arms. Accolada toxa( Fig. 6 H ), rare, thin, with sharply angular central curvature and straight arms.

Distribution. Only found in Ieodo at a depth of 6– 20 m.

Etymology. Named after the type locality, Ieodo Ocean Research Station, Korea.

Remarks. Clathria (Clathria) ieoensis sp. nov. is allocated in the subgenus by having three sizes of styles and two sizes of echinating acanthostyles megascleres, with palmate isochelae, two categories of wing shape toxas and rare accolada toxas.

Clathria (Clathria) ieoensis sp. nov. differs from all other Clathria species from Korea, Japan based on spicule composition. Compared to Australian Clathria species (see Hooper 1996), the most similar is C. (C.) murphyi Hooper, 1996 in shape, color, microsclere spicule composition (palmate isochelae, accolada toxas), but C. (C.) ieoensis sp. nov. differs in its megasclere spicule type and size ( Table. 3).

Figures

FIGURE 5. Clathria (Clathria) ieoensis sp. nov.: (A) Image of the holotype specimen, (B) Ectosomal skeleton, (C-D) Choanosomal skeleton, (E) a. Large style, b. Small style, (F) Head of style, (G) Large acanthostyle, (H) Small acanthostyle.

FIGURE 6. Clathria (Clathria) ieoensis sp. nov.: (A) Thin style, (B) Head of thin style, (C) Front view of palmate isochela, (D) Side view of palmate isochela, (E) Large toxa, (F) Small toxa, (G) End of toxa, (H) Accolada toxa.