A new genus and two new species of brooding chitons (Mollusca: Polyplacophora) from the North-Western Pacific
Author
Sirenko, Boris I.
text
Zootaxa
2024
2024-08-07
5492
4
505
529
http://dx.doi.org/10.11646/zootaxa.5492.4.2
journal article
10.11646/zootaxa.5492.4.2
1175-5326
13268886
9EAFBF80-9862-480A-8CAA-9DB544AE614E
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
.
FIGURE 8.
Kaasichiton incubatus
, Eastern Kamchatka, near Kronotskiy Bay, 1763–1815 m, holotype (ZIN 2255), 6.5 mm:
A.
Sutural needle;
B.
Dorsal scales;
C.
Dorsal needle;
D.
Marginal needle;
E.
Ventral scale;
F.
Central and first lateral tooth of radula;
G-J.
heads of major lateral teeth, frontal view (G-I), lateral view (J);
K.
Granule with aesthete pore, diameter of granule about 50 µm. Scale bar: 100 μm (A-J). The drawing was taken from an article by
Sirenko 2017
, where it was poorly depicted.
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
).