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).