Descriptions of skate egg cases (Chondrichthyes: Rajiformes: Rajoidei) from the eastern North Pacific
Author
Ebert, David A.
Author
Davis, Chante D.
text
Zootaxa
2007
1393
1
18
journal article
10.5281/zenodo.175296
e2a01bd5-e044-4bd8-bfbe-e95cb0480f75
11755326
175296
Raja rhina
Jordan
& Gilbert, 1880
Description
: The egg cases of
Raja rhina
(
Figure 10
) are large,
93 to 102 mm
in length, with MAW about 62– 70% of ECL. Egg case dorsal surface covered with dense wovenlike fibers, ventral surface with either a thin fibrous layer or without. Surface of egg case beneath fibrous layer is finely striated and smooth to the touch. LKW broad, about 13–19% of MAW, and extending length of case including outer edge of horns; an inner keel is present along edge of both anterior and posterior horns. Attachment fibers present along lateral keels, originating about midway along egg case. Anterior apron border broad and concave, anterior horns also about onehalf ECL, and flattening towards tips, becoming threadlike. Posterior apron nearly straight, broad, transverse, and about
1–7 mm
wider than anterior apron width. Posterior horns relatively short, about onehalf ECL, curved, flattening towards tips, and becoming threadlike. Color from fresh specimens a uniform golden brown.
Remarks
:
DeLacy and Chapman (1935)
, who first described these egg cases, found that they may range up to
130 mm
in length, making it one of the larger skate egg cases found in the ENP. Although
Cox (1963)
stated that these egg cases were very similar to that of
R. inornata
we found them to be quite distinct. The egg case of
R. inornata
is much smaller, lacks a fibrous covering, and has a broader lateral keel, without attachment fibers, relative to the maximum egg case width.
Material examined
:
CAS
224343,
74.8 cm
TL, off central California (
36.4701 N
,
121.5312 W
),
488 m
,
10 December 2002
;
MLML
RR
121602
311,
85.6 cm
TL, off central California (
36.4574 N
,
121.5469 W
),
186 m
,
16 December 2002
;
MLML
RR
121602
104,
73.1 cm
TL, off central California (
36.4536 N
,
121.5382 W
),
91 m
,
16 December 2002
.