Kaasichiton incubatus (Sirenko, 2017) n. comb.

(Figures 6–8)

Leptochiton sp. 1; Sirenko 2013: 148.

Leptochiton sp.; Sirenko 2015: 29.

Leptochiton incubatus n. sp.; Sirenko 2017: 111, figs 1–3.

Type material. Holotype (ZIN 2255), and paratype (ZIN 2256),

Type locality. Type locality. North-western Pacific, near East Kamchatka Peninsula, 53°27.9′– 53°25.4′N, 160°20.0– 160°21.5′E, 1763–1815 m, pelite, mud and large pebbles.

Distribution. North-western Pacific, eastern Kamchatka, near Kronotskiy Bay, 684–1763 m

Material examined. Three specimens in total. R/ V Vityaz 20 th cruise, st. 3303, Kamchatka Peninsula, Kronotskiy Bay, 53°54.2′N, 160°42.7′E, 684 m, 1 spm, BL 6.0 mm, 24.05.1955; R/ V Akademik Keldysh, 22 nd cruise, st. 2328, North-western Pacific, near Kamchatka Peninsula, 53°27.9′– 53°25.4′N, 160°20.0′– 160°21.5′E, 1763–1815 m, pelite, mud and large pebbles, dredge, holotype (ZIN 2255), BL 6.5 mm and paratype (ZIN 2256), BL 6.6 mm, 14.08.1990.

Remarks. As mentioned in the description of this species (Sirenko 2017), it appeared to bear eggs and juveniles in the pallial groove. The paratype (ZIN 2456) is a female (BL 6.6 mm) brooding 7 young chitons in the pallial grooves, five on the right side and two on the left side. The juveniles have 8 valves and are ready to leave leave pallial groove of the female individual. The young chitons have a body length of 1.1 mm, which is the largest size known among all brooding chiton species (Sirenko 2015).