First Records of the Invasive “ Upside-down Jellyfish ”, Cassiopea (Cnidaria: Scyphozoa: Rhizostomeae: Cassiopeidae), from Coastal Lakes of New South Wales, Australia
Author
Keable, Stephen J.
Author
Ahyong, Shane T.
text
Records of the Australian Museum
2016
2016-05-10
68
1
23
30
http://dx.doi.org/10.3853/j.2201-4349.68.2016.1656
journal article
10.3853/j.2201-4349.68.2016.1656
2201-4349
4676804
Cassiopea ndrosia
Agassiz & Mayer, 1899
Figs 2
A–D, 3A–B
Cassiopea ndrosia
Agassiz & Mayer, 1899: 175
, pl. 14, figs 45, 46;
Stiasny, 1934: 913–921
;
Kramp, 1965: 265
;
Southcott, 1982: 159
, pls. 15.3, 15.4;
Gershwin
et al
., 2010: 91
.
Material examined
.
AM
G.18074,
1 specimen
, from bottom of canal through “Jetties By The Lake Lifestyle Village” at
Windang Road
,
Lake Illawarra
,
New South Wales
,
Australia
,
Figure 3. Lappets, oral view.
(A)
Cassiopea ndrosia
, Lake Illawarra
, bd 80 mm,AM G.18075.
(B)
Cassiopea ndrosia
, bd 100 mm, Hayman Island, AM G. 13568.
(C)
Cassiopea
cf.
maremetens
, bd 90 mm, Wallis Lake, AM G.18156.
(D)
Cassiopea maremetens
, paratype, bd 110 mm, Moreton Bay, QM G6645. Scale = 5.0 mm.
34°31'36"S
150°51'53"E
,
0–1 m
,
M. Cameron
,
8 May 2013
;
AM
G.18075,
1 specimen
(
80 mm
), locality data as for G.18074;
AM
G.13568,
3 specimens
(
90–120 mm
),
Hayman Island
,
Whitsunday Passage
,
Queensland
,
20°03'S
148°53'E
, tidal flat, coll. F. A. McNeill,
January 1933
.
Remarks
. The Lake Illawarra specimens, collected in 2013, conform well to
C. ndrosia
according to diagnostic characters indicated by
Mayer (1910)
,
Southcott (1982)
,
Gershwin
et al
. (2010
: tab. 9) and comparative specimens from Queensland (AM P.13568; originally reported by
Stiasny, 1934
). The “pinnate” branching of the oral arms (i.e., with lateral arms opposing each other on the primary arm) is the most significant distinction from
C. maremetens
in which the lateral arms “alternate” in position along the primary arm (see
Fig. 2C
for
C. ndrosia
from Lake Illawarra versus
Fig. 2K
for
C. maremetens
). Additionally, the oral arms are subequally branched just distal of the midpoint of the total arm length in the material from Lake Illawarra, a condition found in
C. maremetens
only on the distal extremity of the oral arms due to the arrangement of alternate branching of the proximal lateral arms. The vesicles are elongate and leafshaped, of varying size, and numerous, especially toward the centre. Numbers of these vesicles are relatively small and no longer than the width of the oral arms, however, initially giving the impression that relatively fewer vesicles are present until examined under magnification. The Lake Illawarra and Queensland (Hayman Island) specimens agree closely and correspond to the current concept of
C. ndrosia
(see
Mayer, 1910
;
Gershwin
et al
., 2010
).
Cassiopea ndrosia
,
first described from
Fiji
, is currently attributed a wide distribution in the central and western Pacific, from
French Polynesia
to
Australia
and
Japan
(
Kramp, 1965
); records, however, require confirmation (
Holland
et al
., 2004
;
Gershwin
et al
., 2010
). In
Australia
,
C. ndrosia
has been reported from
Queensland
(Torres Strait, the
Gold Coast
, Hayman Island;
Stiasny, 1934
;
Kramp, 1965
) and South Australia (Angas Inlet;
Southcott, 1982
).
Gershwin
et al
. (2010)
noted the very close similarity between
C. ndrosia
and
C. maremetens
, with the chief differences recognized in the branching of the oral arms (pinnate versus alternate), and shape and number of lappets per paramere (1–2 indistinctly lobed versus 4 square, deeply incised); we question the latter distinction below under the account of
C.
cf.
maremetens
.
The collector of the Lake Illawarra specimens noted this jellyfish started appearing and multiplying two weeks prior to the samples being obtained. Over 100 individuals were observed at this time at the same location—a small, shallow, artificial canal (
8–10 m
wide, approximately
100 m
long, less than
1 m
deep) within a residential village on the Lake Illawarra foreshore (
Fig. 4A
). Water temperatures measured daily within the canal for over a week while the jellyfish were present ranged from 17 to 22°C but within two months of collection, and the onset of cooler winter weather (water temperature not measured), the population disappeared (M. Cameron, pers. comm.). A check of the area in
May 2014
and discussion with local residents living next to the canal indicates the jellyfish have not reappeared at this location. Other sites along the shoreline within Lake Illawarra were also inspected in
May 2014
without encountering any
Cassiopea
.