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Records of the Australian Museum (2017) Vol. 69 
purple dye, without distinguishing the types of dye they 
produce. Moseley (1877a: 13-14, pi. 2, figs 15a-c) named 
janthinid dye “ianthinin”, and published three analytical 
spectra. Comfort (1961: 313) stated that “several older 
authors assume that [the dye of Janthina ] is identical with 
Murex purple (6-6'-di-bromoindogotin), to which it bears no 
resemblance, either in spectral absorption or solubilities”. 
Comfort (1961) stated that ianthinin is distinct from all other 
described molluscan pigments, and is also distinct from the 
blue colouring chemical of its prey, Velella. Therefore, if 
the violet colouring of Janthina is extracted from Velella 
and Porpita , as in the nudibranch Fiona (Willan, 1979), it 
evidently is modified by Janthina after ingestion; it seems 
more likely that the purple dye is independent of that of its 
prey. The yellow-brown shell and yellow animal of Recluzia 
species and the lack of reports of a purple dye in this genus 
indicate that Recluzia does not secrete ianthinin. However, 
the secretion of purple dye is well-known in some benthic 
Epitoniidae (Allan, 1934: 151; Robertson, 1983: 10; 2007a: 
9). This is presumably another character of phylogenetic 
significance, requiring investigation in Recluzia and its 
possible parent genus Alexania. 
Feeding and prey. The discussion above of the use of 
ianthinin dye as an anaesthetic leads to more general 
consideration of the prey of Janthina and Recluzia. 
Photographs sent by Dimitris Poursanidis of specimens 
collected at Arina Beach, Heraklion, Crete, and kept together 
in a glass container show specimens of J. janthina feeding 
on the eggs of J. pallida. Risbec (1953: 201) reported 
small entire Janthina shells and numerous fragments in the 
alimentary tract of Janthina specimens he studied. He noted 
that he had verified the “cannibalism” of these species many 
times, but he had never found any cnidarians in the digestive 
tract of the specimens he collected in New Caledonia. 
Laursen (1953) reported copepods, the “water-strider” 
insect Halobates , barnacle plates ( Lepas ), and Janthina 
radulae and small shells in the gut of Janthina , so evidently 
Janthina eats anything it comes in contact with. However, 
all direct observations of feeding by Janthina species have 
reported Velella and/or Porpita as the main prey, and beach 
strandings of Janthina almost invariably are accompanied 
by abundant specimens of Physalia, Velella and/or Porpita, 
and in warmer waters by the other cosmopolitan members 
of the neustonic community. Presumably Risbec (1953) did 
not observe siphonophores because soft-bodied cnidarians 
disintegrate rapidly in the gut. Abbott (1968: 93, text-fig.; 
Abbott, 1974: 114), Cheng (1975: 195; Minyadidae) and 
Robertson (1997: 11, 2007a: 7) stated that Recluzia lutea 
preys on the floating sea anemone Minyas (i.e., Actinecta). 
Specimens of Recluziajohnii photographed in northern New 
South Wales by Denis Riek (Fig. 7 A) also were observed 
feeding on large brown Actinecta anemones. Minyadidae 
comprises two genera and five species of anemones that float 
by means of a chitinous float secreted by their foot disc (Daly 
et al. , 2007: 134). Cairns et al. (2009) recorded two species 
of oceanic Minyadidae from New Zealand waters ( Actinecta 
viridula (Quoy & Gaimard, 1833); Oceanactis rhodactylus 
Moseley, 1877b). The more common “wandering anemone” 
Phlyctenactis tuberculosa (Quoy & Gaimard, 1833) (Powell, 
1951: 7, fig. 13, as P retifera) was also placed in Minyadidae 
by Fautin (2013), although Recluzia evidently does not 
feed on this coastal species, which occurs in New Zealand 
at least as far south as Cook Strait (Powell, 1951: 7; AGB 
pers. obs.). At least these two oceanic species presumably 
occur also in Australia, explaining the occurrence of their 
predator Recluzia in the Australasian region. A specimen of 
R. lutea photographed in northern New South Wales (Fig. 
6C) is located against a specimen of Physalia. Churchill 
et al. (2011a: fig. IB) illustrated the same living specimen 
of R. lutea said to be “feeding on the cnidarian Physalia 
physalis ”, but the photographer, Denis Riek (Brunswick 
Heads, NSW, pers. comm. 12 Nov 2015) stated that he did 
not observe the Recluzia specimen feeding on the Physalia 
specimen; they merely were located together in an aquarium. 
Previous authors have not reported Recluzia preying on 
siphonophores, but Recluzia is so rare that its habits have 
been reported by very few authors. It is possible that, like 
Janthina species, it feeds on any animals it comes in contact 
with, but all direct observations report it feeding only on 
Minyadidae. 
Independent evolution of the neustonic 
habit in Janthina and Recluzia 
In the writer’s opinion, Janthina and Recluzia very likely 
adopted the pelagic habit, feeding on neustonic cnidarians, 
independently from distinct benthic epitoniid ancestors. 
Recluzia has no fossil record. It also has less extreme 
adaptations to a neustonic life than those of Janthina , with 
a taller spire, i.e., a more nearly “normal” narrow epitoniid 
teleoconch shape, and an almost smooth, yellow-brown 
rather than violet shell. It is assumed to be yellow-brown 
mainly because it is constructed of uncoloured calcite, but 
also possibly in part because it preys on the brown floating 
anemone Actinecta (Abbott, 1968: 93, text-fig.; Abbott, 
1974: 114; Minyadidae, Cheng, 1975: 195; Robertson, 1997: 
11,2007a: 7) rather than the blue chondrophores Velella and 
Porpita and the blue siphonophore Physalia that form the 
predominant prey of Janthina. 
The differences listed in Table 1 and ages derived from 
the fossil record (described below) indicate that Janthina 
evolved late in Miocene time, c. 7-5.5 Ma, from a short, 
wide, finely axially sculptured and rather coarsely spirally 
sculptured benthic epitoniid similar to Alora H. Adams, 1861 
(type species Trichotropis gouldii A. Adams, 1857; Recent, 
eastern Pacific; Keen, 1971: 436, fig. 669; Gittenberger & 
Gittenberger, 2012: figs 1, 3-8). Alora gouldii reaches 38 
mm in height (Weil etal, 1999: 144, fig. 439) and is similar 
to Janthina species in its short shape and coarse sculpture. 
The inner lip also curls over the narrow umbilical chink 
enough to close it, and closely resembles that of Janthina 
species. However, Alora gouldii is significantly taller and 
narrower than Janthina species. Other benthic Epitoniidae 
that resemble Janthina shells in shape include: 
1 Globiscala bonaespei (Barnard, 1963: 104, fig. 17b) 
from bathyal depths off Cape Point, South Africa 
(Weil et ail., 1999: 54, fig. 139). Globiscala bonaespei 
resembles Janthina janthina in shell shape because 
of its rather weakly inflated whorl sides and base and, 
consequently, angled periphery and weakly trochiform 
shape. Its sculpture is also a combination of fine axial 
lamellae and low, narrow, closely spaced spiral cords. 
