Haliclona (Haliclona) ieoensis sp. nov.

(Fig. 2)

Material examined. Holotype. Korea, Jeju-do, Seogqipo-si, Daejeong-eup, Ieodo, 15 m, June 7, 2016, SCUBA diving, coll. Sang-Hui Lee, MABIK IV00155509 .

Paratype. Ieodo, 6–20 m, November 5, 2015, SCUBA diving, coll. In young Cho, MABIK IV00155510– IV00155513.

Description. Shape (Fig. 2A): Holotype. Encrusting, 1.6 cm in thickness and 5 cm in width, with small oscules flush on surface. Paratype. Irregularly massive, encrusting with low chimney- and volcano- shaped elevations, about 0.3–0.5 cm in height and 4.5 cm in diameter.

Oscula: Holotype. 0.1–0.5 cm in diameter, scattered on surface. Paratype. Irregularly scattered and commonly situated at the top of volcano or chimney shaped elevations.

Colour: Beige in life, gradually changing to ivory in alcohol.

Texture: Soft, fragile, and compressible.

Surface: Smooth and even.

Skeleton (Fig. 2 B–E): Ectosomal skeleton not specialized, reticularly arranged by unispicular oxea. Choanosomal skeleton composed of ladder-like reticulation by uni-paucispicular primary lines regularly connected by unispicular secondary lines.

Spicules (Fig. 2F, Table 1): Two types of oxea, no microscleres. Thick oxea approximately 190 to 230 × 10 to 12.5 µm in size. Thin oxea approximately 160 to 175 × 2.5 to 5 µm in size.

Remarks. Haliclona ieoensis sp. nov. is similar to Haliclona (Haliclona) tonggumiensis Kang & Sim 2013 in shape, but the former differs from the latter in its ectosomal skeleton structure and spicule size. The ectosomal skeleton of Haliclona ieoensis sp. nov. is not specialized. It is reticularly arranged by unispicular oxea. However, skeletal structure on surface of H. (H.) tonggumiensis arranged by unispicular oxea under membrane with pores, and single oxea slightly hispid to outer surface. The size of the oxeas of Haliclona ieoensis sp. nov. is larger than that of H. (H.) tonggumiensis (Table 2).

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

Etymology. Named after the type locality, Ieodo, Jejudo, Korea.

Specimen Shape Thick Oxeas Thin Oxeas Material examined. Holotype. Korea, Jeollanam-do, Sinan-gun, Heuksan-Myeon, Gageodo, October 18, 2015, SCUBA diving, 18 m depth, coll. Kim H.J., MABIK IV00155508 .

Description. Shape (Fig. 3A): Hollow, cylindrical or slightly compressed tube from flexible stalk, 0.5 cm in thickness, 5–6 cm in height, and 1–2 cm in width.

Colour: Ivory while live. Beige in alcohol.

Oscula: 1.5 cm in diameter, open at top of tube.

Texture: Soft, fragile, compressible.

Surface: Smooth, even, minutely hispid.

Skeleton (Fig. 3B–D): Ectosomal skeleton absent, single or triple oxea slightly hispid to outer surface. Choanosomal skeleton composed of ladder-like reticulation by uni—paucispicular primary lines regularly connected by unispicular secondary lines.

Spicules (Fig. 3E–F): Megascleres are two type of oxeas and the microscleres are toxa. Oxea, slender, slightly flexuous. Thick oxea approximately 140 to 160 × 8 to 10 µm in size. Thin oxea approximately 110 to 150 × 2.5 to 4 µm in size. Toxa approximately 25–40 µm in size.

Remarks. The species described here is similar to H. (H.) urceolus (see Weerdt, 1986). Both species are similar in shape and skeletal arrangement. The megascleres consist mainly of oxea. However, H. (H.) urceolus differs from the present species by the spicule size and abundant toxa (microscleres). Haliclona sumenyoensis sp. nov. has two types (oxea and toxa), but that of H. (H.) urceolus only has oxea.

Distribution. Only found in the Gageodo Island at depth of 18 m.

Etymology. Named after the type locality, Sumenyo, Gageodo, Korea.