1999. The Journal of Arachnology 27:229±235

SALTICIDAE (ARACHNIDA, ARANEAE) OF ISLANDS OFF

Barbara Patoleta and Marek ZÇ abka: Zaklad Zoologii WSRP, 08±110 Siedlce, Poland

ABSTRACT. Thirty nine of Salticidae from 33 Australian islands are analyzed with respect to their total distribution, dispersal possibilities and relations with the continental fauna. The possibility of the Torres Strait islands as a dispersal route for salticids is discussed.

The studies of island faunas have been the ocean level ¯uctuations over the last 50,000 subject of zoogeographical and evolutionary years, at least some islands have been sub- research for over 150 years and have resulted merged or formed land bridges with the con- in hundreds of papers, with the syntheses by tinent (e.g., Torres Strait islands). All these Carlquist (1965, 1974) and MacArthur & Wil- circumstances and the human occupation son (1967) being the best known. make it rather unlikely for the majority of Modern zoogeographical analyses, based islands to have developed their own endemic on island faunas, began some 60 years salticid faunas. ago (Berland 1934) and have continued ever When one of us (MZ) began research on since by, e.g., Forster (1975), Lehtinen (1980, the Australian and New Guinean Salticidae 1996), Baert et al. (1989), ZÇ abka (1988, 1990, over ten years ago, close relationships be- 1991, 1993), Baert & Jocque (1993), Gillespie tween the faunas of these two regions were (1993), Gillespie et al. (1994), ProÂszynÂski expected. Consequently, it was hypothesized (1992, 1996) and Berry et al. (1996, 1997), that the Cape York Peninsula and Torres Strait but only a few papers were based on veri®ed islands were the natural passage for dispersal/ and suf®cient taxonomic data. expansion. In fact, the parts of this area cov- The present contribution is mostly based on ered with savannah and Eucalyptus forests do material collected by one of us (MZ) while form such a passage zone within these habi- visiting Museum (Brisbane), Aus- tats, but mostly in one directionÐfrom Aus- tralian Museum (Sydney), Western Australian tralia to South Papua, and no further north be- Museum (Perth) and Australian National In- cause of rainforest barrier. During glacial sect Collection (Canberra). The main purposes cooling, aridization and rainforest regression, of this paper are (1). To analyze the species habitats were further enhanced in favor of the composition in respect to their origin, total Australian fauna. Thus, for northern (Oriental distribution and dispersal abilities; (2). To es- and New Guinean) rainforest dwellers, the timate the expansiveness of Australian conti- Cape York Peninsula and Torres Strait islands nental faunas towards studied islands; (3). To should be treated as ®lters rather than a dis- evaluate the role of Torres Strait islands in persal route. faunistic exchange between Australia and New . THE SALTICIDS Continental faunaÐthe source.ÐAbout THE AREA 340 salticid species have been reported from The islands are of coral, volcanic or con- Australia so far (Davies & ZÇ abka 1989; ZÇ ab- tinental origin and are (with few exceptions) ka 1990, 1991, unpubl. data). Of them 286 located along the NE coast of Australia (Fig. belong to 63 veri®ed genera, others are clas- 1). Their surfaces are rather ¯at, either barren si®ed as incertae sedis. Approximately 60% or vegetated, mostly by Eucalyptus, wattles, of species are endemic and these increase in palms and ferns. Few have developed rain- number towards southern and central-western forest or mangrove communities. Due to Australia. The long-term isolation of the con-

229 230 THE JOURNAL OF ARACHNOLOGY

platys, Ligurinus, Mopsus, Mopsolodes, Si- maetha, Tauala). Four species of this group (Ergane cognata, E. insulana, Simaetha atyp- ica and Tauala minutus) are known exclu- sively from the islands. However, their en- demic island status seems doubtful due to the young age of the inhabited islands. Group 2: At least 11 species are of wide distribution, ranging from west through to western Paci®c islands (in one case even to Hawaii) and belong to genera of alien (outside Australian) originÐusually SE Asian and New Guinean. Cytaea plumbeiv- entris, reported from 12 islands, was the most common here. This species can be found in gardens and parks of NE Queensland and as such has probably been dispersed by man. Figure 1: Map showing the geographical location of the analyzed islands along the coast of Australia Cosmophasis thalassina has a similar biology (for detailed information see Table 1). and distribution, though it is less common (three islands). Group 3: Four island species have cosmo- tinent and uniqueness of the Australian biota politan/pantropical distribution, and all live in made the speciation so successful. Further- human habitations and are spread by man. more, inhabiting various Eucalyptus com- Dispersal.ÐFor the analyzed case two dis- munities, remote desert and semi-desert areas persal methods, aerodispersal and antropod- and/or microhabitats (e.g., under bark, in leaf ispersal, should be considered. Rafting, litter), particular species have biological and though theoretically possible, is not discussed structural limitations to expansion. The sec- because of lack of published or other data re- ond largest group of continental salticids, but garding Salticidae. smaller than expected especially in compar- Aerodispersal: Salticidae occupy various ison with other spider families (Araneidae, habitats, each providing different aerodisper- Theridiidae, see Main 1981), is formed of sal possibilities. Leaf-litter or bark dwellers, tropical immigrants from the Oriental Region for instance, are poorer candidates for bal- and . They spread to north and looning than those living in open areas, tree north-eastern coastal rainforest remnants, and canopies or human habitats. Salticidae con- decrease in number to the south. Finally, the stitute only 1.5±7% of all in aero- third group is made up of cosmopolitan/pan- plankton (Horner 1975; Salmon & Horner tropical species, distributed by human activ- 1977; Greenstone et al. 1987). It is widely ity. known that juveniles are more effective bal- Island fauna.ÐDuring the last ten years looners than adults; and in our research they substantial progress has been made in studies constituted 50.7% of all specimens which of the Paci®c island Salticidae (ZÇ abka 1988; seems to support the aerodispersal hypothe- ProÂszynÂski 1992, 1996; Berry et al. 1996, sis. Some indirect data from the analyzed 1997). In our research, we analyzed 39 spe- area were provided by ZÇ abka (1991) from cies, though no island had more than eight tree canopies of NE Queensland. Amongst 70 species. Being aware of the limitations, we specimens found there, the most common distinguish three groups of species (Tables 2, were representatives of , Simaethula, 3). Opisthoncus, Prostheclina. Except for the Group 1: The largest (24 species) is made latter, those genera have also been recorded up of Australian endemics. Although some of in our study. Tara and Simaethula have not them have also spread to south Papua (savan- been considered as identi®ed to the nah, Eucalyptus forests) they seem to be of (not species) level only. Helpis minitabunda Australian origin and belong to Australian en- (found in tree canopies) is spread from Aus- demic genera (Abracadabrella, Astia, Holo- tralia and New Guinea to adjacent archipel- PATOLETA & ZÇ ABKAÐSALTICIDS OF AUSTRALIAN ISLANDS 231

Table 1.ÐNumber of species recorded on individual islands.

Number Geographical location of species Island SE 8 Fitzroy 16Њ56Ј, 146Њ00Ј Queensland 8 Masthead 23Њ32Ј, 151Њ43Ј Queensland 7 Horn 10Њ37Ј, 142Њ17Ј Torres Strait 5 Heron 23Њ26Ј, 151Њ55Ј Queensland 4 Barrow 20Њ46Ј, 115Њ24Ј 4 Lizard 14Њ40Ј, 145Њ28Ј Queensland 4 Motmot 3 Cairncross West 11Њ15Ј, 142Њ55Ј Torres Strait 3 Hannibal East 11Њ36Ј, 142Њ56Ј Torres Strait 2 Campbell 9Њ34Ј, 143Њ29Ј Torres Strait 2 Darnley 9Њ35Ј, 143Њ46Ј Torres Strait 2 Fraser 25Њ22Ј, 153Њ07Ј Queensland 2 Friday 10Њ36Ј, 142Њ10Ј Torres Strait 2 Murray 9Њ56Ј, 144Њ04Ј Torres Strait 2 North West 23Њ18Ј, 151Њ42Ј Queensland 2 Pellew 15Њ31Ј, 136Њ53Ј 2 Pethebridge 14Њ44Ј, 145Њ05Ј Queensland 2 Stephens 9Њ31Ј, 143Њ32Ј Torres Strait 2 Thursday 10Њ35Ј, 142Њ13Ј Torres Strait 2 Tryon 23Њ15Ј, 151Њ46Ј Queensland 2 Yam 9Њ53Ј, 143Њ45Ј Torres Strait 1 Binstead 13Њ13Ј, 143Њ33Ј Queensland 1 Gannett Cay 21Њ59Ј, 152Њ28Ј Queensland 1 Little Fitzroy 16Њ55Ј, 146Њ01Ј Queensland 1 Low 22Њ03Ј, 150Њ06Ј Queensland 1 Moreton 27Њ11Ј, 153Њ24Ј Queensland 1 Percy 21Њ42Ј, 150Њ20Ј Queensland 1 Rocky 15Њ36Ј, 145Њ21Ј Queensland 1 Saibai 9Њ23Ј, 142Њ40Ј Queensland 1 Tana 1 Wharton Reef 14Њ08Ј, 144Њ00Ј Queensland 1 Wilson 23Њ18Ј, 151Њ55Ј Queensland 1 Yorke 9Њ44Ј, 143Њ25Ј Torres Strait agos and to New Zealand, and has also been inappropriate. Even some large continental found in our research. genera are missing on the islands or are rep- Anthropodispersal: This way of dispersal is resented by single species only (Table 4). This typical for species occupying human habita- supports the idea (quite obvious for resident tions, and their distribution is world-wide. Australian arachnologists) that the enormous- Four such species (Hasarius adansoni, Me- ly diverse Australian spider/salticid fauna is nemerus bivittatus, Plexippus paykulli, P. pe- largely the result of habitat variability and ¯o- tersi) are found on the islands. It is likely that ristic diversity. The islands, being poor in also other island species (e.g., Cytaea plum- plant communities, are mostly inhabited by beiventris, Cosmophasis thalassina) can dis- eurytopic species. However, until the material perse this way. is more complete, it is premature to reliably discuss such ``island problems'' as size effect, CONCLUSIONS distance from the source of the fauna, island Only 10% of all continental Australian sal- age, plant communities and topographic in¯u- ticid species are found on the analyzed is- ence. For the majority of islands only one or lands, indicating they are either poorly stud- two species are listed. Even for the richest (Fi- ied, scanty in species and/or ecologically tzroy) only eight species are recorded. Of all 232 THE JOURNAL OF ARACHNOLOGY

Table 2.ÐThe distribution of species recorded on islands off Australia. WA ϭ Western Australia, NT ϭ Northern Territory, SA ϭ South Australia, TAS ϭ , QLD ϭ Queensland, NSW ϭ , NG ϭ New Guinea, PNG ϭ , C ϭ central, M ϭ middle, S ϭ south, W ϭ west, NE ϭ north-east, E ϭ east, N ϭ north.

Records in continental Australia Species Islands WA NT QLD NSW Other records Abracadabrella elegans Binstead NE, E E Astia hariola Fraser E ENG Bavia aericeps Horn, Campbell NE NG, C and W Paci®c Archipelagoes Bianor maculatus Gannett Cay, Motmot S E New Caledonia, Sa- moa, severus Yam, Horn ϩ E E S PNG Fitzroy E E PNG, Aru Is. Cosmophasis micarioides Motmot NE Cosmophasis thalassina Cairncross West, Fitzroy, N Malay Arch., NG Hannibal East Cyrba ocellata Barrow, Masthead from Africa to Oriental Region and Australia Cytaea mitellata Campbell Aru Is., Yule Is., Sun- da Arch. Cytaea frontaligera Darnley E N PNG, Aru Is. Cytaea plumbeiventris Fitzroy, Hannibal East, NE Aru Is., PNG, New Heron, Horn, Little Fitz- Mecklenburg roy, Lizard, Low, Mast- head, Murray, Pethe- bridge, Stephens, Tryon Cytaea severa Barrow, Lizard, Masthead, ϩ Yam Ergane cognata Pellew Ergane insulana Pellew Euryattus bleekeri Cairncross West, Fitzroy, NE, M NG, Ambon, Aru, Ma- Thursday laysia Evarcha infrastriata Horn NE, E Gangus longulus Motmot ϩ Hasarius adansoni Heron, Masthead, North Pantropical West, Percy, Wilson Helpis minitabunda Fitzroy SE colemani Lizard, Masthead ϩ ϩ Holoplatys complanata Fitzroy, Masthead, Tryon N E PNG Ligurinus bipenicilatus Fraser ϩϩ Menemerus bivittatus Barrow, Heron, Masthead Pantropical Mopsolodes australiensis Horn ϩ N, NE, SE Mopsus mormon Fitzroy, North West, Saibai ϩ NNG Opisthoncus abnormis Wharton Reef ϩ ϩ Plexippus paykulli Hannibal East Pantropical Plexippus petersi Thursday Pantropical Servaea vestita Yorke E ϩ Tasmania Simaetha atypica Pethebridge ϩ Simaetha robustior Stephen NE Aru Simaetha tenuidens Friday, Heron, Horn, More- E PNG ton Simaetha tenuior Barrow, Heron, Masthead E PATOLETA & ZÇ ABKAÐSALTICIDS OF AUSTRALIAN ISLANDS 233

Table 2.ÐContinued

Records in continental Australia Species Islands WA NT QLD NSW Other records Tauala minutus Murray ``Trite'' longula Cairncross West, Darnley, NE Motmot, Rocky Zenodorus arcipluvius Tana Zenodorus metallescens Horn E E Zenodorus orbiculatus Fitzroy, Fraser, Friday, Liz- E E ard

39 species, three zoogeographic groups are ACKNOWLEDGMENTS distinguished: Australian endemics, Oriental Drs. V.T. Davies, R. Raven, M. Gray, R.B. and New Guinean immigrants, and cosmopol- Halliday and Ms. J. Waldock are acknowl- itan/pantropical elements. We hypothesize that edged for their generous help and cooperation no island endemics are found, unless con- during stay of one of us (MZÇ ) in their de- ®rmed by further research. Ballooning and partments. V. Davies and R. Raven provided man agency seem possible ways of dispersal; useful data on the studied islands and Drs. P. however, it is more likely that, at least some Selden, J. Berry and Mr. G. Wishart (Gerrin- islands were colonized via past land bridges. gong) corrected the manuscript. The Torres Strait islands are the barrier for LITERATURE CITED northern tropical (rainforest) species and the Baert, L. & R. JocqueÂ. 1993. A tentative analysis passage for southern savannah and Eucalyptus of the spider fauna of some tropical oceanic is- forest inhabitants. lands. Mem. Queensland Mus., 33(2):447±454.

Table 3.ÐIsland species and their zoogeographic distribution.

Australian endemics Widely distributed Cosmopolitan/pantropical Abracadabrella elegans Bavia aericeps Hasarius adansoni Astia hariola Bianor maculatus Menemerus bivittatus Clynotis severus Cosmophasis bitaeniata Plexippus paykulli Cosmophasis micarioides Cosmophasis thalassina Plexippus petersi Cytaea severa Cyrba ocellata Ergane cognata Cytaea frontaligera Ergane insulana Cytaea mitellata Evarcha infrastriata Cytaea plumbeiventris Gangus longulus Euryattus bleekeri Helpis minitabunda Zenodorus arcipluvius Holoplatys colemani Zenodorus orbiculatus Holoplatys complanata Mopsus mormon Ligurinus bipenicilatus Mopsolodes australiensis Opisthoncus abnormis Servaea vestita Simaetha atypica Simaetha robustior Simaetha tenuidens Simaetha tenuior Tauala minutus ``Trite'' longula Zenodorus metallescens 234 THE JOURNAL OF ARACHNOLOGY

Table 4.ÐIsland genera in comparison with the Table 4.ÐContinued continental fauna (after ZÇ abka 1991, unpubl.). Number of species on Number of species on the the the the Australian genera Continent Islands Australian genera Continent Islands Servaea 3 1 Abracadabrella 3 1 Simaetha 10 4 Adoxotoma 2 Simaethula 8 Afra¯acilla 5 Sondra 11 Arasia 2 Tara 3? Ascyltus 1 Tauala 7 1 Astia 2 1 Trite 5? 1 Bavia 3 1 Zebraplatys 4 Bianor 2 1 Zenodorus 14 3 Canama 1 Clynotis 1 1 Cocalus 1 Baert, L., J.P. Maelfait & K. Desender. 1989. Re- Coccorchestes 1 sult of the Belgian 1986-expedition: Araneae, Copocrossa 1 Cosmophasis 6 3 and provisional checklist of the spiders of the Cyrba 1 1 GalapaÂgos archipelago. Bull. Inst. Sci. Nat. Bel- Cytaea 5 4 gique, 58:29±54. Damoetas 1 Berland, L. 1934. Les AraigneÂes du Paci®que. In Diolenius 1? Contribution a l'etude du peuplement zoologique Ergane Ð 2 et botanique des ``les du Paci®que.'' Publ. Soc. Euryattus 4 1 Biogeogr., 4:155±180. Evarcha 1 1 Berry, J.W., J.A. Beatty & J. ProÂszynÂski. 1996. Sal- Frigga 1 ticidae of the Paci®c Islands. I. Distribution of Gangus 2 1 twelve genera, with descriptions of eighteen new Grayenulla 5 species. J. Arachnol., 24:214±253. Harmochirus 1 Berry, J.W., J.A. Beatty & J. ProÂszynÂski. 1997. Hasarius 2 1 Salticidae of the Paci®c Islands. II. Distribution Helpis 3 1 of nine genera, with descriptions of eleven new Holoplatys 36 2 species. J. Arachnol., 25:109±136. 3 Carlquist, S. 1965. Island Life. A Natural History Jacksonoides 7 of the Islands of the World. The Natural History 1 Press, New York. Lauharulla 1 Carlquist, S. 1974. Island Biology. Columbia Uni- Ligonipes 4 versity Press, New York. Lycidas 22? Davies, V.T. & M. ZÇ abka. 1989. Illustrated keys to 7 the genera of jumping spiders (Araneae: Saltici- Margaromma 1 dae) in Australia. Mem. Queensland Mus., 27: Megaloastia 1 189±266. Menemerus 2 1 Forster, R.R. 1975. The spiders and harvestmen. Mintonia 1 Pp. 493-506. In Biogeography and Ecology of Mopsolodes 1? 1 New Zealand, Junk, Den Haag. Mopsus 1 1 Gillespie, R.G. 1993. Biogeographic pattern of Myrmarachne 10 phylogeny in a clade of endemic Hawaiian spi- Ocrisiona 8 ders (Araneae, Tetragnathidae). Proc. XII Int. Omoedus 1 Congr. Arachnol. Brisbane. Mem. Queensland Opisthoncus 31 1 Mus., 33(2):519±526. Palpelius 2 Gillespie, R.G., H.B. Croom & S.R. Palumbi. 1994. Paraplatoides 5 Multiple origins of a spider radiation in Hawaii. Plexippus 2 2 Proc. Nat. Acad. Sci., 91:2290±2294. Portia 1 Greenstone, M.H., C.E. Morgan, A.L. Hultsch, R.A. Prostheclina 1 Farrow & J.E. Dowse. 1987. Ballooning spiders Pseudomaevia 1 in Missouri, USA, and New South Wales, Aus- Pseudosynagelides 6 tralia: family and mass distribution. J. Arachnol., Rombonatus 1 15:163±170. PATOLETA & ZÇ ABKAÐSALTICIDS OF AUSTRALIAN ISLANDS 235

Horner, N.V. 1975. Annual aerial dispersal of tion over Indonesian and Paci®c Islands. Rev. jumping spiders in Oklahoma (Araneae, Saltici- Suisse Zool., hors seÂrie:531±536. dae). J. Arachnol., 2:101±105. Salmon, J.T. & N.V. Horner. 1977. Aerial disper- Lehtinen, P.T. 1980. Arachnological zoogeography sion of spiders in North Central Texas. J. Arach- of the Indo-Paci®c Region. Proc. 8th Int. Congr. nol., 5:153±157. Arachnol., Pp. 499±504. ZÇ abka, M. 1988. Salticidae (Araneae) of Oriental, Lehtinen, P.T. 1996. Origin of the Polynesian spi- Australian and Paci®c Regions, III. Ann. Zool., ders. Rev. Suisse Zool., hors seÂrie:383±397. 41:421±479. MacArthur, R.H. & E.O. Wilson. 1967. The The- ZÇ abka, M. 1990. Remarks on Salticidae (Araneae) ory of Island Biogeography. Princeton Univ. of Australia. Ann. Zool. Fennici, 190:415±418. Ç Press, Princeton. Zabka, M. 1991. Studium taksonomiczno-zoogeo- Main, B.Y. 1981. Australian spiders: Diversity, dis- gra®czne nad Salticidae (Arachnida: Araneae) tribution and ecology. Pp. 808±852, In Ecologi- Australii. Rozprawa naukowa nr 32., WSR-P cal Biogeography of Australia. (A. Keast, ed.). Siedlce. ZÇ abka, M. 1993. Salticidae (Arachnida: Araneae) Junk, The Hague, Boston, London. of New Guinea, Australia and adjacent areas. ProÂszynÂski, J. 1992. Salticidae (Araneae) of the Boll. Acc. Gioenia Sci. Nat., 26:389±394. Old World and Paci®c Islands in several US col- lections. Ann. Zool., 44:87±163. Manuscript received 1 May 1998, revised 24 Oc- ProÂszynÂski, J. 1996. Salticidae (Araneae) distribu- tober 1998.