Sarcotragus chagwiensis, Sim & Lee & Kim, 2016

Sim, Chung Ja, Lee, Kyung Jin & Kim, Hyung June, 2016, Ten new species of genus Sarcotragus (Demospongiae: Dictyoceratida: Irciniidae) from Korea, Journal of Species Research 5 (3), pp. 443-458 : 445

4. Sarcotragus chagwiensis n. sp. ( Fig. 4 )

Type specimen. Holotype (NIBRIV0000325792), Korea: Chagwido, Gosan­ri, Hankyung­myeon , Jeju­si , Jeju­do, 6 Nov 2000, Lee KJ, by SCUBA, Depth 20 m, deposited in the NIBR.

Description. Thick irregular mass, size up to 12 × 10 × 3.5 cm. Surface very low conules covered with loose filamentous membrane, and mixed with rare spicules. Subdermal branched skeletal fibres, very complex. Oscules, 1.5­4 mm in diameter, open on sponge surface. Colour dark beige in life. Texture soft and compressible.

Skeleton: Primary fibres porous cylindrical fascicles, 700­1000 μm in diameter, filled with wads of filaments. Secondary fibres, branch with loose fascicles 180­300 μm in diameter. Secondary web like thin plate broaden between adjacent primary fibres. Filaments, 4 μm in diameter, terminal knobs, 10 μm in diameter. Fibres difficult to separate from wads of filaments.

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

Remark. This new species is similar to Sarcotragus gapaensis Sim and Lee, 2000 in skeletal structure, but differs in sponge shape and surface conules. Subdermal branched skeletal fibres of this new species are very complex and primary fibres fascicles filled with wads of filaments ( Fig. 4G ). Surface conules of S. gapaensis are very sharp and easily distinct, but conules of this new species are very low and difficult to distinct.

Figures

Fig. 4. Sarcotragus chagwiensis n. sp. A, entire animal; B, closed surface; C, primary and secondary fibres; D, secondary web; E, skeletal structure; F, surface thin secondary fibres; G, primary fibres; H, secondary web. Scale bars:A=2 cm, B=7 cm, C­H=100 μm.