CoP17 Prop. 48

Inclusion of all species of Chambered Nautiluses in the Family Nautilidae inAppendix II
Proponents: Fiji, India, Palau and United States of America
Summary: The Family Nautilidae, or Chambered Nautiluses, is a highly distinctive group of marine molluscs
occurring in tropical, reef, and deep-water habitats in the Indo-Pacific. Two genera are recognised
Allonautilus and Nautilus. The genus Allonautilus is generally considered to have two species: A. perforatus(known from Indonesia and possibly Papua New Guinea1) and A. scrobiculatus (known from Papua New
Guinea and possibly the Solomon Islands1). The number of species in the genus Nautilus ranges from two to12 according to different authors; the most recent taxonomic work considers that there are two species,Nautilus pompilius and N. macromphalus1. N. pompilius has a wide range, being known from 11 range
States and possibly occurring in five others, from India in the west to American Samoa in the east. The
Supporting Statement lists four other species: N. macromphalus endemic to New Caledonia and also
N. belauensis, N. repertus and N. stenomphalus which are from Palau and Australia and are now considered
to be part of N. pompilius. It is thought there may also be other as yet unrecognized but separate species
existing as genetically distinct, geographically-and reproductively-isolated populations.
Chambered Nautiluses are extreme habitat specialists living in close association with steep-sloped fore reefs
and associated silty, muddy or sandy-bottomed substrates, in preferred depths of 150 to 300m and rarely
down to 700m. Distribution is patchy and erratic and they may be absent from apparently suitable habitats.
They have a relatively narrow temperature range tolerance. Geographic barriers to movement include
shallow areas where water temperatures exceed 25°C and open water areas which Chambered Nautiluses
avoid, presumably because they are vulnerable to predation there.
They are slow-growing, late-maturing (10 to 15 years) and long-lived (at least 20 years), producing one large
egg at a time1 that requires a lengthy incubation period (about one year) and lacking a mobile larval stage. It
is not known how many eggs a single wild female might lay over an entire year. Trapping data indicate thatjuvenile Chambered Nautiluses represent less than 10 to 20% of populations, indicative of a low-productivity
species. The majority of animals captured in traps are male suggesting a male-biased sex ratio and a
population structure based on multiple paternity; there is no evidence to suggest that adult males might bemore likely to enter baited traps1.
There are no global population estimates but there is good evidence that populations are naturally sparse,small, and isolated. Surveys have found abundance of most unexploited populations of N. pompilius to be
low and in some cases less than one individual per km2 (Australia, Fiji, American Samoa), but on one reef inAustralia, abundance was found to be 10 to 15 individuals per km2. Their attraction to baited traps and easeof recapture1 may give a false impression of their abundance.
Chambered Nautiluses are the object of targeted fisheries and may also be caught incidentally in otherfisheries. Commercial harvesters use fish traps baited with meat dropped to depths of 130 to 250m. The
largest commercial fisheries are in the Philippines and Indonesia. The shells and the meat are both used,although the latter is thought to be essentially a by-product, with the shell the primary product in trade. Shells
are sold whole as decorative objects or collectors’ items and also in pieces, for example in inlay. There isboth domestic use and international trade. Much of the domestic sale of shells is to tourists; a proportion ofthis is likely to be destined for export as personal effects. Some, though probably only a small proportion, ofthe supply of Chambered Nautilus shells is provided by beach-drift specimens. There is a small amount ofuse of live specimens for display in aquaria and research.
The Philippines and Indonesia have the largest commercial fisheries. In the Philippines harvest and trade of
Chambered Nautiluses has occurred at least since the 1970s. A catch survey in 2001/2002 in Panay
estimated an annual harvest of some 12,200 N. pompilius; in Palawan, about 9000 animals were reported
harvested in 2013 and 37,000 in 2014. More than 18,500 whole shells were found in a recent survey of 162
shops across the Philippines. Commercial harvested reportedly occurs widely in Indonesia with products soldlocally and exported. Export in recent years has been notable. According to USA trade data, between 2004and 2013, some 3700 shells, were exported from Indonesia to the USA, the majority (2630) in 20072. In
addition between 2007 and 2010 up to 25,000 specimens were reportedly exported for their meat fromIndonesia to China. Overall, however, there is little information on the relative importance of harvest forexport compared with that for domestic use in Indonesia.

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CoP17 Prop. 48
Targeted fisheries are reported to have taken place in the past in New Caledonia (France), Palau andVanuatu. Harvests are also thought to take place in China (notably Hainan) and Papua New Guinea, but theextent and impact of these and the proportion, if any, of the harvest that enters international trade isunknown.
There are numerous importing countries but data are available for the USA only. In the period 2005 to 2014,
an annual average of around 12,000 whole individuals and over 85,000 parts was imported into the USA,
almost all from the Philippines (85%) and Indonesia (12%)2. Virtually all imports were reported asN. pompilius, but all other species except A. scrobiculatus and N. stenomphalus were reported in trade albeit
in very small numbers (some in under 10 specimens). Total annual imports to the USA declined over thisperiod. Imports from the Philippines to the USA declined markedly after 2009, and a shift to imports fromIndonesia suggests there may have been a switch from Philippine suppliers to Indonesian suppliers.
Most information on population changes comes from the Philippines. Abundance estimates on a reef inBohol that is subject to commercial harvest were one to three orders of magnitude lower than those ofunfished populations. Trap yields from Tañon Strait reportedly declined by 97% between the 1970s when afishery started and the 1980s when the fishery ceased as the species was considered commercially extinct;
Chambered Nautiluses now appear to be completely absent here1. Anecdotal reports and results of surveysof harvesters and traders indicate declines, some severe, elsewhere (Palawan, the Visayan Regions andTawi-Tawi Province). It has been suggested that N. pompilius populations in the Philippines are being
serially depleted and that trade may be shifting to Indonesia and elsewhere.
There are reports of declines associated with harvest in India (where N. pompilius occurs), Indonesia (whereA. perforatus and N. pompilius occur) and New Caledonia (where N. macromphalus and N. pompilius occur),although very little quantitative information is available.
The habitat on which Chambered Nautiluses are dependent is affected by pressures that have an impact on
deep reefs (150m and deeper) such as pollution, sedimentation, deep water mining and fishing3, and climatechange (sea water warming and acidification).
Chambered Nautiluses are not known to be included in any fisheries management plans. Chambered
Nautiluses have been protected in Indonesia since 1990. Enforcement is reportedly poor, as evidenced by
the quantities exported to the USA, although seizures of shells have been made. Harvest of N. pompilius in
China requires a permit. Captive-breeding has never been successful; eggs have been hatched but none
has been raised to maturity.
The shells of different Chambered Nautilus species resemble each other. Experts are generally able todistinguish between different species but non-experts have difficulty doing so, and species are usually notdifferentiated in international trade.
Analysis: Chambered Nautiluses are believed generally to occur in small, scattered populations. They arehighly vulnerable to overexploitation and are known to be targeted in fisheries, with the products, chiefly
shells, known to enter international trade. The main species in trade, Nautilus pompilius has an extensive
range in the Indo-Pacific. In one range State – the Philippines – harvest has been associated with severe
local population declines; the country has exported large quantities of Chambered Nautiluses and it seems
that international trade is a significant driver of the harvest. There are indications that harvest for trade has
now shifted elsewhere. There are reports of historic and ongoing declines associated with harvest in otherparts of the range. It is unclear how extensive such declines are or how important international trade is as adriver of harvest relative to domestic consumption. However, given the extreme vulnerability of Chambered
Nautiluses to overharvest, any additional fishing pressure as a result of harvest for export is likely to lead todepletion or local extirpation of populations. Given this and the absence of management plans for thespecies, it is likely that N. pompilius at least meets the criteria for inclusion in Appendix II in Annex 2a of Res.
Conf. 9.24 (Rev. CoP16).
Chambered Nautilus species resemble each other in the major form in which they appear in trade (shells) sogiven that N. pompilius appears to meet the criteria, all other species in the Family Nautilidae would therefore
appear to meet the criteria in Annex 2b (lookalike criteria).
Reviewers: P. Ward and E. Woods.
References:Information not referenced in the Summary section is from the Supporting Statement.

2CoP17 Prop. 48

1Ward, P. (2016) In litt. to the IUCN/TRAFFIC Analyses Team. Cambridge, UK.

2 Analysis of US Fish & Wildlife Service Law Enforcement Management Information System (LEMIS) data, May 2016.
3 Woods, E. (2016) In litt. to the IUCN/TRAFFIC Analyses Team. Cambridge, UK.

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