A preliminary phylogeny of Pelagiidae (Cnidaria, Scyphozoa), with new observations of Chrysaora colorata comb. nov.
Author
Gershwin, Lisa-Ann
Author
Collins, Allen G.
text
Journal of Natural History
2002
2002-01-31
36
2
127
148
http://www.tandfonline.com/doi/abs/10.1080/00222930010003819
journal article
10.1080/00222930010003819
1464-5262
5299314
Chrysaora
PeÂron and Lesueur, 1809
Comments.
Chrysaora
can be distinguished from other pelagiids as follows: in the medusa, the sense organs are located at the intersection of one subumbrellar pocket and two deep depressions, one depression funnelling from exumbrella, the other depression formed by overlap of adjacent lappets. The exumbrellar sensory pits are deep rather than shallow, as in
Pelagia noctiluca
(compare
Russell, 1970
: ®gures 42b, 50b), or absent as in
Sanderia
sp.
Information on the sensory apparatus of
P.
X
aveola
and
S. malayensis
is lacking. In the medusa, septa terminate near tentacles rather than near rhopalia, as in species of
Sanderia
, or midway between tentacles and rhopalia, as in species of
Pelagia
. With the exception of
Chrysaora
sp.
#1, the exumbrella has pigment marks that form a star pattern; this pattern is absent in species of
Pelagia
and
Sanderia
. The exumbrella of the medusa is not endowed with conspicuous warts, being either entirely smooth or minutely granulated. In contrast, the exumbrellar warts in species of
Pelagia
and
Sanderia
are conspicuous raised mesogleal bumps. In the medusa, gonadal tissues are contained largely within the gonadal pouches, where gonadal tissues of species of
Pelagia
and
Sanderia
are external. In the ephyra, the nematocyst batteries are arranged in a striking pattern of oblong patches ¯anking each rhopalium, with a corresponding ring of round patches on the exumbrellar surface of the body. This characteristic is shared by all species of
Chrysaora
for which the ephyra is described (Cones, 1969: ®gure 5; Kakinuma, 1967: pl. 3, ®gure 2;
Russell, 1970
: ®gure 53; plus Gershwin, unpublished notes, for
C. achylos
,
C. fuscescens
and
P. colorata
). In contrast, no such pattern is present in the ephyrae of
P. noctiluca
(
Russell, 1970
: ®gure 45) or
S. malayensis
(
Uchida and Sugiura, 1975
)
.