Nassarius harpularia (Marrat, 1877), a sibling species of Nassarius jacksonius (Quoy & Gaimardm 1833) (Gastropoda: Nassariidae)

Miscellanea Malacologica 4(4't: 6346,3 1 .X-20I0

Nassarins harpularia (Marrat, 1877), a sibling species ofNassarias joeksonianas (Quoy & Gaimard, 1833) (Gastropoda: Nassariidae) Hugo H. KOOL Honorary associate of the Department of Malacologr, Zoölogisch Museum Amsterdanr, University of .A,msterdam. Magnolialaan 21, 6951 NY Dieren, The Nethorlands, hh.kool@hetneLnl

ABSTRACT

rVassan'as harpuiwia (Marrat, 187?), found in Singapore's ilratrgrove forests, has been considercd a qnonym of If. jacksoniams {Quoy & Gaimar{ 1833) by authors for the last 70 years. Morphologically both spocies arc Yery similar, but fhey live in different microhabitaf r*'ithin the mangroye eoosysterrL The two species are herein taken out of syaonymy. Key words: Nassariidae, dassarins, taxonomy, Pacific, Singaporg sibling species.

INTRODUCTION

SY§TEMATICS

Chan Sow-Yan, rnalacologist from Singapore,

Family: Nassariidae

sent me some photogmphs and several specimens of aNsssartus species, living in the mangrove forests of §ingapore. He identified these specimes as 'Nassarius hryaloria (Marrat, 1877)', which usually has been regarded Bs a junior synonym of Àf. jacksonianas (Quoy & Gaimard, 1833). After

(§pe species arculafia Linnaeus, 1 758)

Cenus: Nassarius Duméril, 1806 B uecinum

Nassarins

h*palada (Marrat 1 877) (Fiss 1-6)

Nassa harpularÍa Marrat, 1877:6. Nassa harpularua; Tomlirl 1940: 16.

detailed examination of the shell morpholory

Nassarius harpularia; Cemohorsky, 1982:. 17 -217. Nassarius (Niotha) lwrrylaria; Cernohors§, 1984: 96,

and ecological daf4 followed by some discussions with Chan Sow-Yan, the conclusion is that N. haryularia is indeed a

pl.

13 fig- 2. Nassarius harpuÍaria: Tan

valid species. The main reason, contributing to the u4iustified slmonymisation, was that the apparent similarity in shell morpholory of both species had obscured the fact that these species do not occur sympatrically but live in different microhabitats. In this article, the diferences in shell morphology between the two species will be discussed, as well as their ecological

& \[roo,2010:43.

Description.Shell elongate-ovate. Protoconch of all ts available specimens damaged, certainly due to the acidic mangrove environment, Teleoconch: approximately 5 convex, axially ribbed w-horls, ribs round and strong 10 on penultimate and on body whorl, last 2-4 weakening down to base. Spiral sculpture consists of a subsutural cord and fiumerous fine inceased lines all over

I

differences.

surfrce of the shell, not more prominent or stronger at base.

ACKNOWLEDGEMENTS

Aperture oval, varix very strong and flattened at outer lip. Inside lip with 5 prominent denticles. Columella also with 3-5 denticles and prominent parietal tooth. Columellar callus ttrin, anteriorly somewhat elevated. Anal canal deep. Colour usually dark brown, rarely

This article could not have been written without the cooperation of my &iend Chan Sow-Yan from Singapore. He drew my attention to the species and was kind eoough to

a number of specinens, shell descriptions and some photographs of the habitat. I thank Robert G. Moolenbeek and Bram van der Bijl (both Zoölogisch Museum Amsterdam) and Mike Filmer (Chobham, UK) for their assistance. Leon Hoffinan, Zoetenneero The Netherlands was so kind to make and to sompose the photographs of the shells. This pap€r was reviewed by two give me

light-beige. Outer

lip, anterior part of

columella and parietal tooth yellow; inside of

aperture brown, showing outside

band.

Consistent yellow-beige spiral line at the upper half ofthe bodpvhorl in all samples examined.

Operculum serrated.

anon)rmous referees.

63

oval, olive-yellowish,

finely

'rliij{ll 'l:,'ifi !,,'iïft l.::':iA tt;i1

'

Kool, 2010: Nsssarius harpulria Type locality.Unknown by Marrat (1877). Singapore, Pasir Ris Parlq is designated here as the type locality ofthe Nassarius harpularia (Marra! lS77).

and threadlike spread over the entire outside surface cfthe shell, as shown in Figs. 4-6. Besides morphological differences betrveen ttre two species they can also be separated by their habitats. Nassdrius

Distribution.Restricted to Singapore, as far as known.

harpularïa lives

Habitat.-

Mangrove areas,

in

by the in

quiet and sheltered mÍurgrolre forests, usually in small puddles of water around rotting leaves and muddy debris (Figs 10-1I), and cae be se* in groups when

shaded muddy pool

the tide is low. N jacksanianas., on the other hand, prefers a more *'he-less"' aad open habitat, parficularly the more sandy flats extending seaward from the mangroye forest and, occasionally, is frund in n*oasoon canal mouths. lile have evidence that the two species do not live sympatrically.

ditches.

DISCUS§ION Marrat (1877:8) wrote about his new species as: 'I fancy that I have seen this shell named, but as there is no account of it in any work to which I have access, it appears to me it wiÍl be better to name and describe if- Probably he thought af N. harpaÍorta as different from tr[. jaclesonianns (Quoy & Gaimard, 1833) but was not very confident and/or convinced. He also mentioned that ttre habitat was unknown to him. Tomlin (1940: 36) and Cernohors§ (1982: 17-217; 1984: 96) regarded lYcssarins harpularia (Manat, 1877) a junior synonym of N. jacksonianar (Quoy & Gaimard, 1833). A description of the very common À[ jocksonianns (Quoy & Gaimard, 1833) (Figs 7-9) is found in Cernohors§ (1984: 96). He figured this species on plate 13, figs l, 34, whereas his fig. 2 is the lectospe of .Nassa harpulariaM Íat,1877.

REFERENCES

Cernohors§, W. O. (in: Wagner & Abbott, 1982. Catalogue of the family Nassariidae lredale, 19L6. Standard catalog of shelÍs (3) sapplem.ent 2: ?AL243.

dr.),

Cernohors§, \try'. 0., 1984. §ystematics of the family Nassariidae (Mollusca: Gastropoda). Bulleíin of the Aucklsnd fnsfiÍute and lWaseam 14: l-356.

Marra! F. P, 1877. On forty proposed new forms in the genus Nassa. Liverpool: MeeL Thomas & Co.. t5 pp., one plate-

Tan, S. K. & H. P. M. Woo, 2010. A prellminary checklist of the malluscs of Singapore. Singapore: Raffles Museum of

Both species can be

separated as on the basis of their

morphologically as well habitats. Nasssrfrr§ *aryutaria has numerous

Biodiversity Resereh National University of

fin.ly

inceased, equally sized spirals, tr jackso"nianlrs has less spirals and strong basal cords. The former has a dark brown colour with a single yellow-beige band whereas the colour and the bands of N jacksonianrxs are rather variable. Adrdt specimens of lv. harpularia have a very thick lip with skong denticles, somewhat like the lips of specimens belonging to the genus Cassidulo. The best character to identify À[ harputaria is the periostracum on &esh shells, which is axially

Singapore. 78 pp.

Tomlin, J. R. le 8., 1940. Marrat's species of Nossa- Proceedings of the Malacologicat Society of London 24:344A.

64

.:11

$'l--41

-

i, t' ;lri:lil ?ri.:,rll

! ..

i;:,

{i. ;!;

1r :Ii:

i ,'.:

t:

i:!

l

::l:l i.*

;

Figs 1-9. Nassariidae, Nassarius. 14. N. harplarr, (Marrat, 187?), Singapore, Pasir Ris Park. 1-3. Height 12.7 mm; 1. ve;kd; 2. left lateral; 3. dorsal; 4-6. height 133 mm, showing peíiostracum. (ZMÀ Moll. 185145); ; 4. venkal; 5. left lateral; 6.dorsal;7-9.N-jackso4amrs(Quoy&Gaimard, 1833), Singapore,KatoogBeach, hoightl3.7mm.(ZMAMoll.0978Í); 7. vental; 8. left lateral; 9. dorsal. (plrotographs by Leon Hoffman).

_{

i

ï

;.

r

lr iil

,

i :,

i !i a

65

Kool, 2010: Nassarius harpularia

i 10 ;.""....

11

-.,-""-".-"...._...

i

Figs 1&11. Impression of the habitat of.lí4§§@,t-nr harpularia,Singapone, Pasir Ris Park (photographs by Chaa §ow-Yan).

66