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Records of the Australian Museum (2017) Vol. 69 
Distribution. Recluzia lutea occurs uncommonly throughout 
the world tropical and temperate ocean, but its limits are 
very poorly known. Large rafts of specimens are cast ashore 
in some locations, but much less frequently than for all 
Janthina species. In New Zealand, R. lutea is recorded only 
from the northeastern North Island warm-water region, in 
eastern Northland and the Bay of Plenty, as far southeast as 
Waihau Bay, easternmost Bay of Plenty. Much the largest lots 
have been seen from Great Exhibition Bay and Ninety Mile 
Beach in the northernmost North Island, where specimens 
are sometimes cast ashore in large numbers after unusually 
persistent onshore winds. Thompson (1991) gave a popular 
account of wash-ups of “about three hundred” specimens 
during Easter 1991 at Cape Maria van Diemen and Great 
Exhibition Bay, northernmost North Island. Large numbers 
of specimens also are cast shore from time to time all around 
eastern, northern and Western Australia. Specimens are also 
recorded from throughout the Indo-West Pacific province as 
far north as central Japan, in the Red Sea, and rarely in the 
eastern Pacific and the Atlantic Ocean. 
Dimensions. See Table 13. 
Diagnosis. Moderate-sized (H to 36, D to 22 mm), larger 
than Janthina exigua and J. umbilicata but smaller than 
all other Janthina species and Recluzia johnii ; taller and 
narrower than all Janthina species, but shorter and wider than 
R. johnir, mean height: diameter 1.44, mean diameter: spire 
height 1.51. Teleoconch of 4.5-5.5 whorls; whorls strongly 
and evenly inflated, of almost circular cross-section, wider 
than in R. johnii', suture deeply impressed; without obvious 
sculpture. Aperture slightly flared anteriorly in many large 
specimens. Lays smooth, narrow, cylindrical to weakly club- 
shaped, yellow egg capsules on underside of float. 
Remarks. Recluzia lutea is superficially smooth and 
lightly polished when the periostracum is removed, but 
most specimens are found with the thin, pale brown, matt 
periostracum still at least partly adhering. Recluzia lutea has 
strongly and evenly inflated whorls and a much more deeply 
impressed suture than in any Janthina species. Weak axial 
and spiral grooves and ridges occur on many specimens, 
varying individually. The outer lip is vertical and straight, 
i.e., with no sinus in the lip, and the inner lip is narrowly 
but variably reflected over the narrow umbilicus. 
Bennett’s (1840) description of Janthina lutea is quite 
adequate to make this name available, although which 
species he had is not determinable from the description. 
Bennett (1840: 298) stated “In the course of the narrative 
I have had occasion to mention a yellow and very rare 
species of this genus [Janthina]'. and for which I would 
propose the name Janthina lutea”. This is a reference to 
his earlier description (Bennett, 1840: 63): “One species 
of this family, which I obtained here, was new to me: and 
is certainly very rare: its shell was yellow: rather smaller 
and more elongated than J. communis [i.e., J. janthina ]; and 
the whirl more prominent and spiral. The contained animal 
was also of a yellow colour: but in the form of the float 
and other respects, it closely resembled the ordinary blue 
shelled species”. The neotype designated here establishes 
that this name applies to the shorter Recluzia species 
identified here as Recluzia lutea. Bennett (1834) earlier 
described a specimen of Janthina captured at sea at 0°14'S 
20°07'W, NW of Ascension Island, central Atlantic Ocean, 
but did not mention the “yellow species”. 
Petit de la Saussaye (1853: 118-119, pi. 5, figs 2-3) 
named two short-spired species of Recluzia, distinguishing 
the two by R. rollandiana having more inflated whorls, a 
more deeply impressed suture, and more pronounced spiral 
striae than R. jehennei. However, his illustrated shells are 
both well within the range of variation of R. lutea. A. Adams 
(1861) provided no dimensions or illustration of Recluzia 
bensoni, but the holotype was illustrated by Yen (1942: pi. 
19, fig. 122). The illustration and examination of the holotype 
(NHMUK1878.1.28.394) demonstrate that this is a very 
small, narrow specimen of R. lutea. Souverbie’s (1872: pi. 
1, fig. 8) illustration of a syntype and examination of the 
syntypes of R. montrouzieri demonstrate that this also is 
indistinguishable from the holotype of R. rollandiana, and 
falls within the variation of R. lutea. Wattebled’s (1886: pi. 
3, fig. 4) illustration of a syntype and examination of the 
syntypes of Recluzia rollandiana var. annamitica show 
that this also is closely similar to the type material of R. 
rollandiana and R. jehennei, and again is part of the variation 
of R. lutea. Four specimens (Figs 36M-P) from the same 
sample from Great Exhibition Bay, Northland, New Zealand, 
are illustrated to show the range of variation of R. lutea, 
although they do not include the most extreme specimens 
observed. The specimen in Fig. 2S-T is from the same sample. 
A collection of specimens of Recluzia lutea cast ashore 
on the beach at Taupiri Bay, Northland, New Zealand 
(NMNZ M081518, collected by A. Alio, 24 Mar 1982; 
12 moderate-sized to large shells plus 14 small juveniles) 
consists of specimens ranging in height from 29.4 mm to 
larval shells. Some of these were studied by SEM (Figs 
37A-G). All specimens less than c. 13 mm high are short 
and wide and closely resemble Alexania natalensis and the 
holotype of R. globosa in all characters. Several have dried 
floats attached, each now forming a thin, dark brown, rigid, 
irregular mass. Several larval shells were incorporated in 
the float material of some of the moderate-sized specimens 
(some now separated). One small shell has 10 larval shells 
attached to the exterior of its teleoconch by dried float 
material (Figs 37C-D, G). These confirm statements by 
Colman (1986) and Churchill et al. (2011a) that juveniles 
of R. lutea, including recently metamorphosed larval shells, 
live attached to the floats of adults. Also, a photograph 
of a living specimen of R. lutea published on a web page 
(Churchill et al., 2011b: figs 1A-B; Riek, 2017; Fig. 6C) 
clearly shows a relatively large juvenile specimen of R. 
lutea on the float of an adult female, lying between the 
float and the foot. The protoconch in the specimens studied 
by SEM, although very similar to that of Janthina species, 
with very similar sculpture and an identical protoconch 1, 
is shorter and has a protoconch 2 of only 2.2 whorls, rather 
than 3.2 whorls in the Janthina species available for study. 
However, the significance of this apparent distinction is 
uncertain, in view of the lack of knowledge of the number 
of protoconch whorls in J. pallida. 
