Arachnids of the Ngerukewid Islands Wildlife Preserve, Palau

Micronesica

n dsrbto o ay pce sucran n sm aes ae ee been never have areas some and uncertain is species many of distribution and

pelago. Arachnids were collected there from therewere collected pelago. Arachnids td wih ouetd h ntrl eore o tee sad (Birkeland islands these of resources natural the documented which study Manner aiis nldn mmes fte res rna, crinsad Amblypygi, and Scorpiones Araneae, orders the of members including families, Nishida & (Samuelson sampled h tils wisopos Sm ueie hv nt en dniid o species. to identified been not have juveniles Some whipscorpions. tailless the archi Palauan the in Islands Kmekumer nearby and Preserve Wildlife Islands

Island

te seies a eudsrbd sc steuuul iard olce on collected pisaurid unusual the as such undescribed, be may specimens Other

oe o h Plun sad a about at Islands Palauan the of comer

sad ubrn i Figure in numbering Island paper only sampled islands have been labeled. The islands are formed of uplifted formed are islands The labeled. been have islands sampled only paper oaln lmsoe n ae ml ad te;acs o hs wtot ece is beaches without those to access steep; and small are and limestone coralline difficult because of undercutting. Palauan limestone forest, described in Cole et Cole in described forest, limestone Palauan undercutting. of difficultbecause al.

lps hr srn seis oiae A opee ecito o te studied the of description complete A dominate. species strand where slopes sad' eeain s on i Manner in found is vegetation islands' emnn hmn naiat, huh t svstd cainly yrsdns of residents by occasionally visited is it though inhabitants, human permanent nearby islands. nearby

(1987)

Abstract-A

three specimens of Araneae were collected by the author from the fam the from author the by collected were Araneaeof specimens three le tnzde Uooia, hlia, ctdde Aaede Lycos Araneidae, Scytodidae, Pholcidae, Uloboridae, Ctenizidae, ilies

australasiae (Gervais) were also recorded. also were (Gervais) conducted was Palau of Republic Islands,

de Psuia, lboia ad atcde Te scorpion The Salticidae. and Clubionidae Pisauridae, idae, ite ok a be dn o te rcnd o irnsa te taxonomy the Micronesia; of arachnids the on done been has work Little

h Neuei ad mkmr sad ae oae i te southwestern the in located are Islands Kmekumer and Ngerukewid The

Arachnids of the Ngerukewid Islands Wildlife Preserve, Palau

16.

1989).

24(2)

covers most of the islands exceptalong cliffs, of islands the leewardsome most covers andbeaches

211-

The Marine Laboratory, University of Guam, Mangilao GU 96923 GU Mangilao Guam, of University Laboratory, Marine The

wnyfv seies eetkn cmrsn eee different eleven comprising taken, were specimens Twenty-five

uvy f rcnd i te grkwd n Kmekumer and Ngerukewid the in arachnids of survey

Fbiis ad h tils whipscorpion tailless the and (Fabricius)

1991

ALEXANDER

follows Wiles follows

1987).

Introduction

Study Site Study

mn tee lcsaete Ngerukewid the are places these Among

7° 11

5-15

Raulerson

N aiue and latitude 'N

KERR

5-15

or ( Conry

January

(1989).

1990),

1988

134 ° 16'E

1988.

hrn grayi Charon

spr f larger ofa part as

h ae hs no has area The

oee, n this in however,

Hormurus

Twenty

longitude.

& I

Palau

Ngerukewid Islands

Methods

Micronesica 24(2), Micronesica 1991

Annotated Species List

0.5km

Islands

(Roewer)

(Opell)

The Ngerukewid and Kmekumer Islands

Km:kumer

Figure

Specimens were collected by hiking across the islands during the day and

Two females found in leaf litter in limestone forest behind strand on Island The arachnids collected in the survey are listed below in taxonomic order.

Three females on horizontal webs 30 cm above the ground and suspended

Tangaroa beattyi

Conothele gressitti

under stones and in leaflitter and rock crevices. Later the specimens were placed Department, University of Southern Illinois at Carbondale. mounted in a clear plastic with case cotton and p-dichlorobenzene a few crystals.

24. 212 Information on each specimen's sex, maturity, habitat and the number taken is included and by followed the number the of island where it Unless collected. was brushing the arachnids into a wide-mouth jar or plastic bag. Cave, limestone otherwise indicated, the specimens are mature individuals and collected were by forest and strand habitats were investigated. Cryptic species were found by looking strandand byfound forest habitats were investigated. Crypticspecies were the author. Voucher specimens were deposited in the University of Guam ar achnid collection, except the pisaurid, which is being curated at the Zoology in ethanol, sexed and labeled. The whipscorpion was eviscertated, dried and

two are from Island 16

between tree seedlings in limestone forest. One is from Island the remaining 13;

Hormurus australasiae australasiae Hormurus

Mollica microphthalma microphthalma Mollica

Island 46. 46. Island

24; 24;

behind strand on Island 50. 50. Island on strand behind

Menemerus bivittatus bivittatus Menemerus

Arctosa Arctosa

shortly after immersion in 70% 70% ethanol. in immersion after shortly

unidentified Pisauridae Pisauridae unidentified

female and male are from the strand on Island 50. 50. Island on strand the from are male and female

among dried seaweed seaweed dried among

Chiricanthium diversum diversum Chiricanthium unidentified Araneidae Araneidae unidentified

Neoscona Neoscona

on Island 16. 16. Island on

Nephi/a maculata maculata Nephi/a

Islands (island number not recorded). recorded). not number (island Islands

vertical in limestone forest. Both are from Island Island from are Both forest. limestone in vertical

beach on Island Island on beach

Leucauge Leucauge

Smeringopus pallidus pallidus Smeringopus

Scytodes striapes striapes Scytodes

the juvenile is from Island 3. 3. Island from is juvenile the

Two of undetermined sex found under rotting rotting under found sex undetermined of Two

One male and one juvenile found in beach litter. The male is from Island Island from is male The litter. beach in found juvenile one and male One

One male from leaflitter under under leaflitter from male One

One juvenile female on on female One juvenile

Three females on vertical orb webs in shaded limestone forest on Island 16. 16. Island on forest limestone shaded webs in orb vertical on females Three

One female on shaded beach in strand litter on Island 16. The tarsi curled curled tarsi 16. The Island on litter strand in beach shaded on female One

Two females and one male. The largest female was collected in full sunlight sunlight full in was collected female largest The male. one and females Two

Two juveniles from vertical webs in limestone forest forest limestone in webs vertical from Two juveniles

One juvenile on orb web in shaded limestone forest from the Ngerukewid Ngerukewid the from forest limestone shaded in web orb on juvenile One

One female and one juvenile in delicate orb webs angled away from the the from away angled webs orb delicate in juvenile one and female One

One of undetermined sex in a web in a cave overlooking the east-facing east-facing the overlooking cave a in web a in sex undetermined of One

One female in foliage foliage of in female One

sp. sp.

24. 24.

(L. (L.

(Fabricius) (Fabricius)

Koch) Koch)

(Dufour) (Dufour)

(Padina) (Padina)

(Blackwall) (Blackwall)

(Fabricius) (Fabricius)

(L. (L.

L. L.

Koch) Koch)

Koch Koch

Cordia subcordata subcordata Cordia

Eugenia cuminii cuminii Eugenia

deposited by high tide on Island 46. The smaller smaller The 46. Island on tide high by deposited

Kerr. Palauan Spiders Spiders Palauan Kerr.

Scaevola sericea sericea Scaevola

in limestone forest of Island 13. 13. Island of forest limestone in

foliage on Island 46. 46. Island foliage on

3. 3.

Hernandia sonora sonora Hernandia

and and

Causurina equisetifolia equisetifolia Causurina

1 1

m above the ground ground the above m

bark on on bark 213 213 Con

Cyrtophora

(Fabricius).

Opell and

Hormurus australasiae

Nephi/a maculata

Tangaroa beattyi

1991

Because of its limited distribution in

comm.). The specimen reported here,

grayi.

sp. and adult

Discussion

Micronesica 24(2)

Acknowledgements

Beatty, pers

Argiope

(Fabricius) extends to Yap

Roewer juvenilesspiders. are Pacific Several could not be identified

Gervais is found in Micronesia only in Palau (Takashima 1950);

(Gervais)

Gervais found in a cave on Island Caves and 16. crevices examined

(Doleschall),

Wiles.

One male on wall of cave in deep twilight zone on Island Three 16. other Most of the spiders found in this survey have been collected from other

The survey was conducted during a severe dry spell which may account for

The second unusual arachnid found was an undescribed pisaurid also col I thank Dr. Harley I. Manner and Dr. Charles E. Birkeland, both of the

Time constraints prevented more than a preliminary survey, but small leaf

1987). A majority of the collected species are widespread, being distributed in

Charon grayi

2l4

individuals were seen but not collected in the dark zone of the same cave. Col Charon grayi lected by G. areas of Micronesia (Roewer 1963, Sabath et al. 1974, Samuelson & Nishida othele gressitti othele molluccensis the Papuan-Malayan region and Pacific. The scorpion

Charon grayi Charon

In spite of the weather and the short time spent collecting, at least two unusual (Fabricius) is found throughout Micronesia (Chapin 1963). The whipscorpion finds were made. The first was a small population of tailless whipscorpions the low number of Araneidae seen (Robinson & Robinson Conspicuously 1973). Nephi/a maculata Micronesia and cavemecolous nature (Millot 1968), this organism is an inter most spiders and the studied islands' proximity to the rest of the archipelago, esting addition to the preserve's arachnid fauna. below genus. lected from Island Members 16. of the family Pisauridae are scarcein Micronesia litter inhabiting arachnids, such as members of Linyphiidae and Oonopidae, are not been found outside the preserve; further sampling is needed to find its true absent in the preserve, but present on the larger Palauan islands, were on other islands did not contain undoubtedly also present. Because of the efficient method of dispersal used by however, is unique in having curled tarsi, a trait previously seen only in New World genera. the species composition of the Ngerukewid and Kmekumer Islands is similar to that reported from the more sampled Palauan islands. The pisaurid, though, has

and are seldom collected (J distribution.

University of Guam, for inviting me to participate in the survey. I am indebted to Dr. Joseph A. Beatty, University of Southern Illinois at Carbondale, for iden- iyn te rcnd ad nwrn m mn qetos Ias tak JoNita thank also I questions. many my answering and arachnids the tifying

er o eiwn te manuscript. the reviewing for Kerr

ikln, C. Birkeland,

hpn E. Chapin,

Cole, T. G., M. C. Falanruw, C. D. MacLean, C. D. Whitesell D. C. MacLean, D. C. Falanruw, C. M. G., T. Cole,

Millot, J. 1968. Ordres des amblypyges. des 1968. Ordres J. Millot, H. Manner,

Sabath, M. D., M. Sabath, Robinson,

Roewer, C. F. 1963. Araneina: Orthognatha, Labidognatha. Insects of Micronesia. of Insects Labidognatha. Orthognatha, 1963. Araneina: F. C. Roewer,

Takashima, H. 1950. Notes on Amblypygi found in territories adjacent to Japan. to adjacent territories in found Amblypygi on 1950. Notes H. Takashima, aulo, .A & .M Nsia 18. net ad lis Atrpd) of (Arthropoda) allies and Insects 1987. Nishida. M. G. & A. G. Samuelson,

Wiles, G. J. G. Wiles,

eevd 3Nv 19,rvsd ue 1991. June 6 1990, revised 13 Nov. Received

and Range Exp. Station Res. Bull. PSW-22. U.S. For. Serv. 13 p. 13 Serv. For. U.S. PSW-22. Bull. Res. Station Exp. Range and South Review. Topic SPREP Palau. of Republic Preserve, Wildlife Islands Pacific Commission, Noumea New Caledonia. 193 p. 193 Caledonia. New Noumea Commission, Pacific

sad Wllf Preserve. Wildlife Islands uvy fte grkwd sad Wllf Peev, eulc fPlu pp. Palau, of Republic Preserve, Wildlife Islands Ngerukewid the of Survey -6 SRP oi Rve. ot PcfcCmiso, oma e Ca New Noumea Commission, Pacific South Review. Topic SPREP 9-56. ledonia. Zool. 149: 1-76. 149: Zool. ntme Sseaiu, ilge Tm 4 p. 6-8. irie d l'A de Libraires 563-588. pp. 4, Tome Biologie. Systematique, Anatomie, aei de cademie

spider

esl o h smsca spider semisocial the of mensals dae) in Guam, Mariana Islands. Micronesica 10: 51-55. 10: Micronesica Islands. Mariana Guam, in dae)

97 eeain uvy fte eulc fPlu PcfcSuhet Forest Southwest Pacific Palau. of Republic the of survey Vegetation 1987. ytmtc, p 1717 US Dp. fEeg, ahntn D.C. Washington, Energy, of Dept. U.S. 147-177. pp. Systematics,

nwtk Atoll. Enewetak 105-132. 3: es, h Ntrl itr o Eeea Aol Vl 2 Boegah and Biogeography 2, Vol. Atoll, Enewetak of History Natural The (eds),

Pacific Sci. 4: 336-338. 4: Sci. Pacific

Wildlife Preserve. Micronesica 23: 41-66. 23: Micronesica Preserve. Wildlife

.&M . oisn 17.Eooyad eair fte in wood giant the of behavior and Ecology 1973. Robinson. H. M. & B.

eh/ macu/ata Nephi/a

& R. & .J or. 90 ersra vrerts fteNeuei Islands Ngerukewid of the vertebrates 1990. Terrestrial Conry. J. P.

93 crind. net o irnsa :6-70. 65- 3: Micronesia of Insects Scorpionida. 1963.

Medecine,

.Sbt & Sabath E.

anr es. 99 eore uvy f h Ngerukewid the of Survey Resource 1989. (eds). Manner

alro. 99 lr ad eeain fte Ngerukewid the of vegetation and Flora 1989. Raulerson.

.M Dvny E .Ree B. Reese, S. E. Devaney, M. D.

Paris.

Fbiis i Nw una Sihoin Contrib. Smithsonian Guinea. New in (Fabricius)

A. M. A.

Kerr: Palauan Spiders PalauanKerr:

ikln, C. Birkeland,

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