Biodiversity baseline of the French Guiana spider fauna.

The need for an updated list of spiders found in French Guiana rose recently due to many upcoming studies planned. In this paper, we list spiders from French Guiana from existing literature (with corrected nomenclature when necessary) and from 2142 spiders sampled in 12 sites for this baseline study. Three hundred and sixty four validated species names of spider were found in the literature and previous authors' works. Additional sampling, conducted for this study added another 89 identified species and 62 other species with only a genus name for now. The total species of spiders sampled in French Guiana is currently 515. Many other Morphospecies were found but not described as species yet. An accumulation curve was drawn with seven of the sampling sites and shows no plateau yet. Therefore, the number of species inhabiting French Guiana cannot yet be determined. As the very large number of singletons found in the collected materials suggests, the accumulation curve indicates nevertheless that more sampling is necessary to discover the many unknown spider species living in French Guiana, with a focus on specific periods (dry season and wet season) and on specific and poorly studied habitats such as canopy, inselberg and cambrouze (local bamboo monospecific forest).

Background

Under the Streamline European Biodiversity Inventory 2010 protocols (SEBI) (Butchardt et al. 2010; Jones et al. 2011), species occurrences and abundances are currently only being assessed through survey of birds and butterflies. While there is a general agreement that those groups should continue to be monitored (EEA technical report No 11/2012) (EEA (2005), the Group on Earth Observations Biodiversity Observation Network (GEO BON), the European Biodiversity Observatory Network (EBON) (Reviewed in Scholes et al. 2008) and many authors specialized in this field (De Baan et al. 2012; Cardoso et al. 2011; Feest 2013; Feest et al. 2011) have recommended the survey and monitoring of additional groups to fill the taxonomic and ecological gaps.

Spiders have been identified as a meaningful additional indicator taxon by the European Commission FP7-BioBio project (Targetti et al. 2012) not only because they represent well the local micro-fauna richness, but also because they are easy and cheap to sample, sensitive to changes (Cardoso et al. 2008), have little dispersal potential (New 1999), are abundant and diverse (Foelix 1996), represent differences in other species richness and diversity (Cardoso et al. 2008) and are recognized by stakeholders. Moreover, rigorous sampling protocols have just been set up (Cardoso 2009) and locally adapted (Vedel and Lalagüe 2013). They provide a complementary alternative to Lepidoptera in term of distribution and ecological functions as top predators of soil and lower vegetation communities (Cardoso et al. 2008) and are extremely diverse in tropical rain forest (Sørensen et al. 2002; Pinkus-Rendón et al. 2006; Coddington et al. 2009).

French Guiana is 97% covered by primary forest and hosts an exceptionally diverse and distinctive equatorial forest, part of the Amazonian tropical rainforest. This region also has an increasing demographic and economic development, which will raise conservation issues in the near future. As such it deserves special attention from the scientific community. The last integrative spider species list for French Guiana is almost 70 years old (Di Caporiacco 1954) with few later additions (Drolshagen and Bäckstam 2011; Lopez 1988). In this study, our goal is to establish a baseline biodiversity reference for the spider fauna of French Guiana to enable further studies which will set spider monitoring as an efficient “tool” for assessment and monitoring local biodiversity.

Results and discussion

2142 spider specimens were sampled and sent for identification during this study. Identification results are summarized in Table 1. About 692 Morphospecies (M-S from hereonin) were singled out from this material with many M-S represented only by singletons. Many of these M-S could not be identified yet, and therefore are not included in the species list. In addition, many individuals could not be identified because they were either juveniles or undescribed, and they were therefore excluded from this list. Individuals identified only at the genus level are mainly species which are either not recognized yet, even with the sexual organs (often just one sex represented), or are a species new to science and therefore not described and not named yet. In any case they represent a species not found in the region until now.

Table 1

Number of specimens collected for each location with the number of morpho-species recognized

Sampling site	Coordinates	Season	Number of	Number of	Type of	Sampling
			collected individuals	morpho-species	habitats	methods
Crique Baggot	22N0329797-0501628	Wet	24	23	FF	B(1), SN(1), H(1)
Gentry plots (Petite Montagne Tortue, Régina)	22N0362289-0477672	Wet, Dry	97	58	WS, FF, TF	MT, WP
Gentry plots (Laussat Ouest)	22N0213521-0605836	Wet, Dry	76	42	WS, FF, TF	MT, WP
Grand Connétable Island	22N0396505-0534312	Wet	15	10	OI	H(2)
Kaw	22N0315898-0556000	Wet	78	60	WF	B(2), SN(2), S(2)
La Trinité	22N0232748-0510994	Dry	439	242	FF, TF, I	B (6), SN(6), S(3), WP
Mont Itoupé	-	Wet	74	61	I	WP, MT
Nouragues	22N0314321-0446496	Wet	338	175	FF, TF, I	B(6), SN(6), S(3), WP
Nouragues	22N0307547-0450440	Dry	375	270	FF, TF, I	B(10), SN(10), S(5), WP
Piste des compagnons	22N0310766-0564719	Dry	27	25	TF	MT
Saül	22N0253843-0400740	Wet	482	347	FF, TF, I	B(6), SN-6), S(3),
Savane-roche Virginie	22N0257866, W0731672	Dry	117	43	I	SN(2), H(2)
Total			2142	NA

Abbreviations: (FF Flooded Forest, TF Terra Firme, I Inselberg, WF Wet Forest, OI Oceanic Island, WS White Sand, B Beating, SN Sweep Net, S Sieve, H by Hand, WP Window Pane trap, MT Malaise Trap. Numbers in brackets reflect the units of sampling effort for the active techniques applied. The wet season lasts from December until June and the dry season from July until November with some little variations. The total number of M-S cannot be determined (and it is therefore noted NA=Not Applicable) because at some sites spiders were not photographed and could not be compared with other sites (those sites are the ones not used for the following analyses).

After adding to Caporiacco (1954) list the sampling from this study and the previously identified materials from the two last authors, we obtained a total number of 515 species belonging to 45 families (Table 2). Therefore, 151 new species were added in this study and nine new families for French Guiana were also found: Amaurobiidae, Cyrtaucheniidae, Hersiliidae, Linyphiidae, Miturgidae, Oonopidae, Prodidomidae, Senoculidae and Synotaxidae (see Table 3 for the detailed list of species). From these 151 new species 89 species were named at the species level (Table 2), which indicates this study added 20% more species names to the French Guianan total. Only 137 species described in Caporiacco’s work (1954), which represent about 40% of the species number, were resampled in our study. This number is probably largely underestimated due to the lack of certain identification for many specimens.

Table 2

Details of number of species from the existing literature added now from the ones found in this study

Sources	Species level	M-S identified at the
		Genus level
Former list published: (Caporiacco 1954)	364	0
Brescovit’s review (Brescovit et al. 2011)	34	2
Present study’s samples	55	60
Total	453	62

Table 3

Current list of identified spiders from French Guiana with notes about the current names

Guyane+espèces
Familyx	Species	New finding	Notes
Amaurobiidae	Amaurobius brevis (Taczanowski, 1874)	B	incertae sedis/ Corinnidae
Amaurobiidae	Amaurobius cayanus (Taczanowski, 1874)	B	incertae sedis/ Corinnidae
Amaurobiidae	Amaurobius hirtus (Taczanowski, 1874)	B	incertae sedis/ Corinnidae
Amaurobiidae	Amaurobius rufipes (Taczanowski, 1874)	B	incertae sedis/ Corinnidae
Anyphaenidae	Aljassa n. sp.1	V
Anyphaenidae	Anyphaenoides n. sp.1	V
Anyphaenidae	Hibana melloleitaoi (Caporiacco, 1947)	V
Anyphaenidae	Katissa n. sp.1	V
Anyphaenidae	Mesilla anyphaenoides (Caporiacco 1954)
Anyphaenidae	Patrera armata (Chickering, 1940)	V
Anyphaenidae	Patrera n. sp.1	V
Anyphaenidae	Patrera n. sp.2	V
Anyphaenidae	Patrera n. sp.3	V
Anyphaenidae	Patrera n. sp.4	V
Anyphaenidae	Sillus furciger (Caporiacco 1954)
Anyphaenidae	Wulfila n. sp.1	V
Araneidae	Actinosoma pentacanthum (Walckenaer, 1841)
Araneidae	Acacesia hamata (Hentz, 1847)
Araneidae	Acacesia tenella (Koch, 1871)
Araneidae	Alpaida deborae (Levi, 1988)
Araneidae	Alpaida erythrothorax (Taczanowski, 1873)
Araneidae	Alpaida graphica (Cambridge, 1889)
Araneidae	Alpaida marmorata (Taczanowski, 1873)
Araneidae	Alpaida sulphurea (Taczanowski, 1873)
Araneidae	Alpaida truncata (Keyserling, 1865)
Araneidae	Alpaida truncata obscura (Caporiacco 1954,1948)
Araneidae	Alpaida truncata sexmaculata (Caporiacco 1954, 1948)
Araneidae	Alpaida veniliae (Keyserling, 1865)
Araneidae	Araneus appendiculatus (Taczanowski, 1873)
Araneidae	Araneus contestationis (Caporiacco 1954)		Nomem dubium
Araneidae	Araneus decaspinus (Taczanowski, 1873)		Nomem dubium
Araneidae	Araneus guttatus (Keyserling, 1865)
Araneidae	Araneus nigrocellatus (Caporiacco 1954)		Nomen dubium
Araneidae	Araneus venatrix (Koch, 1838)
Araneidae	Argiope argentata (Fabricius, 1775)
Araneidae	Argiope trifasciata (Forsskel, 1775)
Araneidae	Cercidia n. sp.1
Araneidae	Chaetacis abrahami (Mello-Leitão , 1948)	B
Araneidae	Chaetacis aureola (Koch, 1836)
Araneidae	Chaetacis cornuta (Taczanowski, 1873)
Araneidae	Chaetacis necopinata (Chickering, 1960)	V
Araneidae	Cyclosa fililineata (Hingston, 1932)	V
Araneidae	Cyclosa nodosa (Cambridge, 1889)
Araneidae	Cyclosa walckenaeri (Cambridge, 1889)
Araneidae	Enacrosoma anomalum (Taczanowski, 1873)
Araneidae	Epeiroides bahiensis (Keyserling, 1885)
Araneidae	Eriophora edax (Blackwall, 1863)
Araneidae	Eriophora fuliginea (Koch, 1838)
Araneidae	Eriophora nephiloides (Cambridge, 1889)
Araneidae	Eustacesia albonotata (Caporiacco 1954)
Araneidae	Eustala albicans (Caporiacco 1954)
Araneidae	Eustala anastera (Walckenaer, 1841)
Araneidae	Eustala clavispina (Cambridge, 1889)
Araneidae	Eustala fuscovittata (Keyserling, 1863)
Araneidae	Eustala guianensis (Taczanowski, 1873)
Araneidae	Eustala lunulifera (Mello-Leitão, 1939)
Araneidae	Eustala sagana (Keyserling, 1893)
Araneidae	Eustala scutigera (Cambridge, 1898)
Araneidae	Eustala semifoliata (Cambridge, 1899)
Araneidae	Eustala tridentata (Koch, 1838)
Araneidae	Eustala vegeta (Keyserling, 1865)
Araneidae	Gasteracantha cancriformis (Linnaeus, 1758)
Araneidae	Hingstepeira folisecens (Hingston, 1932)
Araneidae	Hypognatha deplanata (Taczanowski, 1873)
Araneidae	Hypognatha saut (Levi, 1996)
Araneidae	Hypognatha scutata (Perty, 1833)
Araneidae	Kapogea sexnotata (Simon, 1895)
Araneidae	Mangora melanocephala (Taczanowski, 1874)
Araneidae	Mangora saut (Levi, 2007)	B
Araneidae	Mangora n. sp.1	V
Araneidae	Manogea porracea (Koch, 1838)
Araneidae	Metazygia n. sp.1
Araneidae	Metepeira brunneiceps (Caporiacco 1954)
Araneidae	Metepeira labyrinthea (Hentz, 1847)
Araneidae	Micrathena acuta (Walckenaer, 1841)
Araneidae	Micrathena gracilis (Walckenaer, 1805)
Araneidae	Micrathena cyanospina (Lucas, 1835)
Araneidae	Micrathena clypeata (Walckenaer, 1805)
Araneidae	Micrathena evansi (Chickering 1960)
Araneidae	Micrathena excavata (Koch, 1836)
Araneidae	Micrathena fissispina (Koch, 1836)
Araneidae	Micrathena flaveola (Perty, 1839)
Araneidae	Micrathena hamifera (Simon, 1897)	B
Araneidae	Micrathena horrida (Taczanowski, 1873)
Araneidae	Micrathena kirbyi (Perty, 1833)
Araneidae	Micrathena lata (Chickering, 1960)
Araneidae	Micrathena plana (Koch, 1836)
Araneidae	Micrathena pungens (Walckenaer, 1841)
Araneidae	Micrathena saccata (Koch, 1836)
Araneidae	Micrathena schreibersi (Perty 1833)
Araneidae	Micrathena sexspinosa (Hahn, 1822)
Araneidae	Micrathena spinosa (Linnaeus, 1758)
Araneidae	Micrathena triangularis (Koch, 1836)
Araneidae	Micrathena triangularispinosa (De Geer, 1778)
Araneidae	Micrepeira hoeferi (Levi, 1995)
Araneidae	Micrepeira tubulofaciens (Hingston, 1932)
Araneidae	Neoscona benjamina (Walckenaer, 1841)		Nomem dubium
Araneidae	Neoscona nautica (Koch, 1875)
Araneidae	Neoscona theisi (Walckenaer, 1841)
Araneidae	Ocrepeira albopunctata (Taczanowski, 1879)
Araneidae	Ocrepeira covillei (Levi, 1993)
Araneidae	Ocrepeira n. sp.2
Araneidae	Parawixia audax (Blackwall, 1863)
Araneidae	Parawixia kochi (Taczanowski, 1873)
Araneidae	Parawixia velutina (Taczanowski, 1878)
Araneidae	Scoloderus tuberculifer (Cambridge, 1889)
Araneidae	Testudinaria quadripunctata (Taczanowski, 1879)	B
Araneidae	Verrucosa arenata (Walckenaer, 1841)
Araneidae	Verrucosa septemmammata (Caporiacco 1954)
Araneidae	Wagneriana jelskii (Taczanowski, 1873)
Araneidae	Wagneriana tayos (Levi, 1991)	V
Araneidae	Wagneriana tauricornis (Cambridge, 1889)
Araneidae	Wagneriana transitoria (Koch, 1839)
Araneidae	Witica cayanus (Taczanowski, 1873)
Araneidae	Wixia n. sp.1
Araneidae	Xylethrus n. sp.1
Barychelidae	Psalistops gasci (Maréchal, 1996)
Caponiidae	Nops branicki (Taczanowski, 1874)
Clubionidae	Elaver sericea (Cambridge, 1898)
Clubionidae	Elaver n. sp.2	V
Corinnidae	Apochinomma n. sp.1	V
Corinnidae	Castianeira salticina (Taczanowski, 1874)
Corinnidae	Castianeira n. sp.1	V
Corinnidae	Castianeira n. sp.2	V
Corinnidae	Corinna annulipes (Taczanowski, 1874)
Corinnidae	Corinna anomala (Schmidt, 1971)
Corinnidae	Corinna kochi (Petrunkevith, 1911)	V
Corinnidae	Corinna n. sp.4	V
Corinnidae	Corinna n. sp.5	V
Corinnidae	Corinna n. sp.6	V
Corinnidae	Corinna n. sp.7	V
Corinnidae	Medmassa septentrionalis (Caporiacco 1954)		Nomem dubium
Corinnidae	Methesis brevitarsa (Caporiacco 1954)
Corinnidae	Myrmecium n. sp.1	V
Corinnidae	Myrmecium n. sp.2	V
Corinnidae	Myrmecium n. sp.3	V
Corinnidae	Myrmecium n. sp.4	V
Corinnidae	Myrmecium bifasciatum (Taczanowski, 1874)
Corinnidae	Myrmecotypus n. sp.1	V
Corinnidae	Parachemmis hassleri (Gertsch, 1942)	V
Corinnidae	Parachemmis n. sp.1	V
Corinnidae	Paradiestius n. sp.1	V
Corinnidae	Tupirinna n. sp.1	V
Corinnidae	Trachelas anomalus (Taczanowski, 1874)
Corinnidae	Trachelas n. sp.1	V
Corinnidae	Trachelas n. sp.2	V
Corinnidae	Trachelas n. sp.3	V
Ctenidae	Ancylometes bogotensis (Keyserling, 1876)	B
Ctenidae	Ancylometes rufus (Walckenaer, 1837)
Ctenidae	Centroctenus auberti (Caporiacco 1954)
Ctenidae	Ctenus ellacomei (Cambridge, 1902)
Ctenidae	Ctenus n. sp.1	V
Ctenidae	Ctenus n. sp.2	V
Ctenidae	Ctenus n. sp.3
Ctenidae	Ctenus villasboasi (Mello-Leitao, 1949)	V
Ctenidae	Ctenus crulsi (Mello-Leitao, 1930)	V
Ctenidae	Ctenus dubius (Walckenaer, 1805)
Ctenidae	Cupiennius bimaculatus (Taczanowski, 1874)	V
Ctenidae	Cupiennius foliatus (Cambridge, 1901)
Ctenidae	Isoctenus latevittatus (Caporiacco 1954)		Nomen nudum
Ctenidae	Phoneutria fera (Perty, 1833)
Ctenidae	Phoneutria reidyi (Cambridge, 1897)
Cyrtaucheniidae	Fufius n. sp.1	V
Deinopidae	Deinopis guianensis (Taczanowski, 1874)
Dictynidae	Phantyna mandibularis (Taczanowski, 1874)
Dipluridae	Harmonicon audeae (Maréchal & Marty, 1998)
Dipluridae	Harmonicon oiapoqueae (Drolshagen & Bäckstam 2011)
Dipluridae	Harmonicon rufescens (Cambridge, 1897)
Dipluridae	Diplura nigra (Cambridge, 1897)
Dipluridae	Ischnothele guianensis (Walkenaer, 1837)
Dysderidae	Dysdera bicolor (Taczanowski, 1874)
Eresidae	Eresus n. sp.1	V
Eresidae	Eresus n. sp.2	V
Filistatidae	Kukulcania hibernalis (Hentz, 1842)
Gnaphosidae	Echemographis distincta (Caporiacco 1954)
Hersiliidae	Neotama n. sp.1	V
Hersiliidae	Ypypuera n. sp.1	V
Idiopidae	Idiops opifex (Simon, 1889)
Linyphiidae	Ceratinopsis jelskii (Keyserling, 1886)	B	Nomem dubium
Linyphiidae	Meioneta n. sp.1	V
Lycosidae	Agalenocosa denisi (Caporiacco, 1947)
Lycosidae	Aglaoctenus castaneus (Mello-Leitao, 1942)	V
Lycosidae	Aglaoctenus guianensis (Caporiacco 1954)		Nomen dubium
Lycosidae	Trochosa n. sp.1	V
Lycosidae	Allocosa n. sp.1	V
Lycosidae	Hogna vachoni (Caporiacco 1954)
Lycosidae	Hogna ventrilineata (Caporiacco 1954)
Lycosidae	Pardosa cayennensis (Taczanowski, 1874)
Mimetidae	Ero n. sp.1	V
Mimetidae	Ero n. sp.2	V
Mimetidae	Gelanor mabelae (Chickering, 1947)	V
Mimetidae	Gelanor zonatus (Koch 1845)
Miturgidae	Cheiracanthium inclusum (Hentz, 1847)	B
Miturgidae	Teminius insularis (Lucas, 1857)	B
Nephilidae	Nephila clavipes (Linnaeus, 1767)
Nephilidae	Nephila cornuta (Pallas, 1772)
Nephilidae	Nephilengys cruentata (Fabricius, 1775)
Nesticidae	Nesticus citrinus (Taczanowski, 1874)
Ochyroceratidae	Ochyrocera caeruleoamethystina (Lopez & Lopez, 1997)
Oonopidae	Neoxyphinus hispidus (Dumitresco & Georgescu, 1987)	V
Oonopidae	Oonops n. sp.1	V
Oxyopidae	Hamataliwa barroana (Keyserling 1887)
Oxyopidae	Oxyopes haemorrhous (Mello-Leitao, 1929)
Oxyopidae	Oxyopes maripae (Caporiacco 1954)
Oxyopidae	Oxyopes masculinus (Caporiacco 1954)
Oxyopidae	Oxyopes salticus (Hentz, 1845)	V
Oxyopidae	Peucetia macroglossa (Mello-Leitão, 1929)
Oxyopidae	Tapinillus longipes (Taczanowski, 1872)
Paratropididae	Paratropis papilligera (Cambridge, 1896)
Philodromidae	Cleocnemis punctulata (Taczanowski, 1872)
Philodromidae	Philodromus cayanus (Taczanowski, 1872)
Pholcidae	Artema atlanta (Walckenaer, 1837)
Pholcidae	Litoporus saul (Huber, 2000)
Pholcidae	Mesabolivar cyaneus (Taczanowski, 1874)
Pholcidae	Metagonia auberti (Caporiacco 1954)
Pholcidae	Physocyclus globosus (Taczanowski, 1874)	B
Pholcidae	Smeringopus pallidus (Blackwall, 1858)	B
Pisauridae	Architis spinipes (Taczanowski, 1874)
Pisauridae	Architis tenuis (Simon, 1898)	B
Pisauridae	Dolomedes elegans (Taczanowski, 1874)
Pisauridae	Thaumasia benoisti (Caporiacco 1954)
Pisauridae	Thaumasia marginella (Koch, 1847)
Pisauridae	Tinus nigrinus (Cambridge, 1901)
Prodidomidae	Zimiris doriai (Simon, 1882)	B
Salticidae	Acragas flavescens (Caporiacco 1954)		Nomen dubium
Salticidae	Albionella guianensis (Caporiacco 1954)	V
Salticidae	Alcmena trifasciata (Caporiacco 1954)		Nomen dubium
Salticidae	Amycus ectipus (Simon, 1900)	V
Salticidae	Amycus effeminatus (Caporiacco 1954)	V
Salticidae	Amycus favicomis (Simon, 1900)	V
Salticidae	Amycus patellaris (Caporiacco 1954)		Nomen dubium
Salticidae	Anasaitis canosa (Walckenaer, 1837)
Salticidae	Beata rustica (Peckham & Peckham, 1895)
Salticidae	Breda apicalis (Simon, 1901)	V
Salticidae	Capidava variegata (Caporiacco 1954)		Nomen dubium
Salticidae	Chinoscopus gracilis (Taczanowski, 1872)
Salticidae	Chinoscopus maculipes (Crane, 1943)
Salticidae	Chira guianensis (Taczanowski, 1871)
Salticidae	Chira simoni (Galiano, 1961)	V
Salticidae	Chira spinipes (Taczanowski, 1871)
Salticidae	Chira thysbe (Simon, 1902)	V
Salticidae	Chira trivittata (Taczanowski, 1871)
Salticidae	Chirothecia crassipes (Taczanowski, 1878)
Salticidae	Chloridusa n. sp.1	V
Salticidae	Chloridusa n. sp.2	V
Salticidae	Cobanus n. sp.1	V
Salticidae	Corythalia heliophanina (Taczanowski, 1871)
Salticidae	Corythalia luctuosa (Caporiacco 1954)
Salticidae	Corythalia tropica (Mello-Leitão, 1939)
Salticidae	Corythalia variegata (Caporiacco 1954)		Nomen dubium
Salticidae	Corythalia walecki (Taczanowski, 1871)
Salticidae	Cyllodania fasciata (Caporiacco 1954)	V
Salticidae	Cyllistella n. sp.1	V
Salticidae	Dendryphantes coccineocinctus (Caporiacco 1954)		Nomen dubium
Salticidae	Dendryphantes spinosissimus (Caporiacco 1954)		Nomen dubium
Salticidae	Euophrys ambigua (Koch, 1846)
Salticidae	Eustiromastix bahiensis (Galiano, 1979)	V
Salticidae	Eustiromastix guianae (Caporiacco 1954)
Salticidae	Eustiromastix major (Simon, 1902)
Salticidae	Fluda n. sp.1	V
Salticidae	Freya decorata (Koch, 1846)
Salticidae	Freya disparipes (Caporiacco 1954)
Salticidae	Freya grisea (Cambridge, 1901)	V
Salticidae	Freya perelegans (Simon, 1902)	V
Salticidae	Frigga coronigera (Koch, 1846)	V
Salticidae	Frigga kessleri (Taczanowski, 1872)
Salticidae	Habronattus paratus (Peckham & Peckham, 1896)	V
Salticidae	Helvetia cancrimana (Taczanowski, 1872)
Salticidae	Hypaeus flavipes (Simon, 1900)	V
Salticidae	Hypaeus porcatus (Taczanowski, 1871)
Salticidae	Hypaeus taczanowskii (Mello-Leitão, 1948)
Salticidae	Kalcerrytus n. sp.1	V
Salticidae	Kalcerrytus kikkri (Galiano, 2000)
Salticidae	Kalcerrytus nauticus (Galiano, 2000)	V
Salticidae	Lurio lethierryi (Taczanowski, 1872)
Salticidae	Lurio splendidissimus (Caporiacco 1954)		Nomem dubium
Salticidae	Lurio solennis (Koch, 1846)
Salticidae	Lyssomanes amazonicus (Peckham & Wheeler, 1889)	B
Salticidae	Lyssomanes elegans (Cambridge, 1900)
Salticidae	Lysomanes ipanemae (Galiano, 1980)
Salticidae	Lyssomanes longipes (Taczanowski, 1871)
Salticidae	Lyssomanes parallelus (Peckham & Wheeler, 1889)
Salticidae	Lyssomanes unicolor (Taczanowski, 1872)
Salticidae	Maeota dichrura (Simon, 1901)	V
Salticidae	Mago acutidens (Simon, 1900)
Salticidae	Mago barbatus (Caporiacco 1954)		Nomen dubium
Salticidae	Mago chickeringi (Caporiacco 1954)
Salticidae	Mago dentichelis (Crane, 1949)
Salticidae	Mago fasciatus (Mello-Leitao, 1940)	V
Salticidae	Mago fulvithorax (Caporiacco 1954)		Nomen dubium
Salticidae	Mago longidens (Simon, 1900)
Salticidae	Mago silvae (Crane, 1943)
Salticidae	Menemerus bivittatus (Dufour, 1831)	V
Salticidae	Myrmarachne obscura (Taczanowski, 1872)		Nomen dubium
Salticidae	Nagaina modesta (Caporiacco 1954)		Nomem dubium
Salticidae	Noegus bidens (Simon, 1900)
Salticidae	Noegus fuscimanus (Simon, 1900)	V
Salticidae	Noegus petrusewiczi (Caporiacco 1954)
Salticidae	Noegus rufus (Simon, 1900)	V
Salticidae	Noegus n. sp.1	V
Salticidae	Nycerella n. sp.1	V
Salticidae	Pachomius dybowskii (Taczanowski, 1872)
Salticidae	Parnaenus cyanidens (Koch, 1846)	V
Salticidae	Phiale crocea (Koch, 1846)	V
Salticidae	Phiale cruentata (Walckenaer, 1837)
Salticidae	Phiale rubriceps (Taczanowski, 1871)
Salticidae	Phiale septemguttata (Taczanowski, 1871)
Salticidae	Phiale gratiosa (Koch, 1846)
Salticidae	Phiale guttata ( Koch, 1846)	V
Salticidae	Phiale niveoguttata (Cambridge, 1901)
Salticidae	Phiale simplicicava (Cambridge, 1901)	V
Salticidae	Phiale virgo (Koch, 1846)
Salticidae	Phidippus guianensis (Caporiaco, 1947)
Salticidae	Phidippus triangulifer (Caporiacco 1954)		Nomen dubium
Salticidae	Platycryptus magnus (Peckham & Peckham, 1894)	V
Salticidae	Plexippus paykulli (Audouin, 1826)	V
Salticidae	Psecas bubo (Taczanowski, 1871)
Salticidae	Pseudopartona ornata (Caporiacco 1954)
Salticidae	Rhene jelskii (Taczanowski, 1871)
Salticidae	Romitia n. sp.1	V
Salticidae	Rudra wagae (Taczanowski, 1872)
Salticidae	Salticus albosignatus (Taczanowski, 1849)		Nomen dubium
Salticidae	Salticus bidens (Taczanowski, 1872)		Nomen dubium
Salticidae	Salticus cabanisi (Taczanowski, 1872)		Nomen dubium
Salticidae	Salticus cayanus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus crassipes (Taczanowski, 1871)		Nomen dubium
Salticidae	Salticus cylindricus (Walckenaer, 1837)		Nomem dubium
Salticidae	Salticus deplanatus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus dryocopinus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus elaterinus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus emaciatus (Walckenaer, 1837)		Nomem dubium
Salticidae	Salticus fulvatus (Fabricius, 1896)
Salticidae	Salticus hamatinus (Taczanowski, 1849)		Nomem dubium
Salticidae	Salticus longimanus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus mandibularis (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus marmottani (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus maronicus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus miniaceus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus minutus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus nigerrimus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus olivacens (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus ornatus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus paederinus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus platycephalus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus quadriguttatus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus radoszkowskii (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus rubescens (Walckenaer, 1837)		Nomem dubium
Salticidae	Salticus ruficeps (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus salutanus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus sericeus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus sexfasciatus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus simoni (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus solskii (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus superciliatus (Walckenaer, 1837)		Nomem dubium
Salticidae	Salticus tenebrosus (Walckenaer, 1837)		Nomem dubium
Salticidae	Salticus tenuis (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus trematus (Walckenaer, 1837)		Nomem dubium
Salticidae	Salticus tricinctus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus uassanus (Taczanowski, 1871)		Nomem dubium
Salticidae	Salticus verrauxi (Taczanowski, 1871)		Nomem dubium
Salticidae	Sarinda atrata (Taczanowski, 1871)
Salticidae	Sarinda cayennensis (Taczanowski, 1871)
Salticidae	Sarinda longula (Taczanowski, 1871)
Salticidae	Scopocira melanops (Taczanowski, 1871)
Salticidae	Siloca septentrionalis (Caporiacco 1954)
Salticidae	Soesilarishius n. sp.1	V
Salticidae	Soesilarishius n. sp.2	V
Salticidae	Synemosyna myrmeciaeformis (Taczanowski, 1871)
Salticidae	Synemosyna subtilis (Taczanowski, 1871)		Nomem dubium
Salticidae	Synemosyna lucasi (Taczanowski, 1871)
Salticidae	Thiodina branicki (Taczanowski, 1871)
Salticidae	Thiodina melanogaster (Mello-Leitão, 1917)	V
Salticidae	Thiodina pallida (Koch, 1846)
Salticidae	Tutelina iridea (Caporiacco 1954)		Nomem dubium
Salticidae	Viciria chabanaudi (Fage, 1923)
Salticidae	Wedoquella n. sp.1
Salticidae	Zuniga magna (Peckham & Peckham, 1892)	B
Scytodidae	Scytodes fusca (Walckenaer, 1837)
Scytodidae	Scytodes lineatipes (Taczanowski, 1874)
Scytodidae	Scytodes longipes (Lucas, 1844)
Senoculidae	Senoculus canaliculatus (Cambridge, 1902)	B
Senoculidae	Senoculus maronicus (Taczanowski, 1872)
Sparassidae	Guadana n. sp.1	V
Sparassidae	Olios cayanus (Taczanowski, 1872)
Sparassidae	Olios nigriventris (Taczanowski, 1872)
Sparassidae	Olios quinquelineatus (Taczanowski, 1872)
Sparassidae	Olios roeweri (Caporiacco 1954)
Sparassidae	Olios rubripes (Taczanowski, 1872)
Sparassidae	Olios velox (Simon, 1880)	V
Sparassidae	Polybetes pythagoricus (Holmberg, 1875)
Sparassidae	Pseudosparianthis megalopalpa (Caporiacco 1954)
Sparassidae	Sampaiosia crulsi (Mello-Leitão, 1930)	V
Sparassidae	Sparianthina rufescens (Mello-Leitão, 1940)	V
Sparassidae	Sparianthis amazonica (Simon, 1880)	V
Sparassidae	Thomasettia n. sp.1	V
Sparassidae	Vindullus gracilipes (Taczanowski, 1872)
Synotaxidae	Synotaxus n. sp.1	V
Tetragnathidae	Azilia vachoni (Caporiacco 1954)
Tetragnathidae	Chrysometa minuta (Keyserling, 1883)
Tetragnathidae	Leucauge acuminata (Cambridge, 1889)
Tetragnathidae	Leucauge argyra (Walckenaer, 1849)
Tetragnathidae	Leucauge branickii (Taczanowski, 1874)
Tetragnathidae	Leucauge funebris (Mello-Leitão, 1930)
Tetragnathidae	Leucauge pulcherrima (Keyserling, 1865)
Tetragnathidae	Leucauge saphes (Chamberlain & Ivie, 1936)
Tetragnathidae	Leucauge taczanowskii (Marx, 1893)
Tetragnathidae	Leucauge venusta (Walckenaer, 1841)
Tetragnathidae	Metabus ocellatus (Keyserling, 1864)	B
Tetragnathidae	Opas caudacuta (Taczanowski, 1873)
Tetragnathidae	Opas lugens, (Cambridge 1896)
Tetragnathidae	Tetragnatha filiformata (Roewer, 1942)
Tetragnathidae	Tetragnatha gibbula (Roewer, 1942)
Theraphosidae	Acanthopelma beccarii (Caporiacco 1954)
Theraphosidae	Acanthoscurria simoensi (Vol, 2000)
Theraphosidae	Avicularia avicularia (Linnaeus, 1758)
Theraphosidae	Avicularia avicularia variegata (Cambridge, 1896)
Theraphosidae	Avicularia metallica (Ausserer, 1875)
Theraphosidae	Avicularia holmbergi (Thorell, 1890)
Theraphosidae	Avicularia lycosiformis (Koch, 1846)		Nomen dubium
Theraphosidae	Avicularia surinamensis (Strand, 1907)
Theraphosidae	Ephebopus cyanognathus (West & Marshall, 2000)
Theraphosidae	Ephebopus murinus (Walckenaer, 1837)
Theraphosidae	Ephebopus rufescens (West & Marshall, 2000)
Theraphosidae	Hapalopus guianensis (Caporiacco 1954)
Theraphosidae	Magulla Janeira (Keyserling, 1891)
Theraphosidae	Neostenotarsus (Tesmoingt & Schmidt, 2002)
Theraphosidae	Tapinauchenius gigas (Caporiacco 1954)
Theraphosidae	Tapinauchenius violaceus (Mello-Leitão, 1930)
Theraphosidae	Teraphosa blondi (Latreille, 1804)
Theraphosidae	Vitalius vellutinus (Mello-Leitao, 1923)
Theridiidae	Achaearanea hieroglyphica (Mello-Leitão, 1940)
Theridiidae	Anelosimus chickeringi (Levi, 1956)	B
Theridiidae	Anelosimus eximius (Keyserling, 1884)	B
Theridiidae	Anelosimus jucundus (Cambridge, 1896)	B
Theridiidae	Anelosimus nigrescens (Keyserling 1884)	B
Theridiidae	Anelosimus rupununi (Levi, 1956)	B
Theridiidae	Anelosimus studiosus (Hentz, 1850)	B
Theridiidae	Argyrodes benedicti (Lopez 1988)
Theridiidae	Argyrodes coactatus (Lopez 1988)
Theridiidae	Argyrodes elevatus (Taczanowski, 1873)
Theridiidae	Argyrodes nephilae (Taczanowski, 1873)
Theridiidae	Chrysso albomaculata (Cambridge, 1882)
Theridiidae	Chrysso pulcherrima (Mello-Leitão, 1917)	B
Theridiidae	Coleosoma acutiventer (Keyserling, 1884)	B
Theridiidae	Cryptachaea hirta (Taczanowski, 1873)
Theridiidae	Cryptachaea migrans (Keyserling, 1884)
Theridiidae	Cryptachaea pusillana (Roewer, 1942)
Theridiidae	Cryptachaea rostrata (Cambridge, 1864)
Theridiidae	Dipoena n. sp.1	V
Theridiidae	Dipoena n. sp.2	V
Theridiidae	Episinus n. sp.1
Theridiidae	Faiditus americanus (Taczanowski, 1874)
Theridiidae	Faiditus caudatus (Taczanowski, 1874)
Theridiidae	Faiditus dracus (Chamberlin & Ivie, 1936)	B
Theridiidae	Faiditus globosus (Keyserling, 1884)	B
Theridiidae	Neospintharus triangularis (Taczanowski, 1873)	B
Theridiidae	Parasteatoda tepidariorum (Koch, 1841)	B
Theridiidae	Rhomphaea paradoxa (Taczanowski, 1896)	B
Theridiidae	Steatoda ancorata (Holmberg, 1876)	B
Theridiidae	Nesticodes rufipes (Lucas, 1846)
Theridiidae	Theridion incertissimum (Caporiacco 1954)
Theridiidae	Theridion rubrolineatum (Taczanowski, 1874)		Nomem dubium
Theridiidae	Theridula gonygaster (Simon, 1873)	B
Theridiosomatidae	Naatlo splendida (Taczanowski, 1879)	B
Theridiosomatidae	Plato juberthiei (Lopez, 1996)
Thomisidae	Acentroscelus guianensis (Taczanowski, 1872)
Thomisidae	Acentroscelus nigrianus (Mello-Leitão, 1929)
Thomisidae	Acentroscelus n. sp.1	V
Thomisidae	Bucranium taurifrons (Cambridge, 1881)
Thomisidae	Bucranium n. sp.1	V
Thomisidae	Diaea n. sp.1	V
Thomisidae	Epicadus heterogaster (Guérin, 1829)
Thomisidae	Epicadinus trispinosus (Taczanowski, 1872)
Thomisidae	Erissus truncatifrons (Simon, 1895)
Thomisidae	Misumena citreoides (Taczanowski, 1872)
Thomisidae	Misumena maronica (Caporiacco 1954)
Thomisidae	Misumena nigripes (Taczanowski, 1872)
Thomisidae	Misumenops guianensis (Taczanowski, 1872)
Thomisidae	Monaeses lucasi (Taczanowski, 1872)	V
Thomisidae	Onoculus echinatus (Taczanowski, 1872)
Thomisidae	Onoculus pentagonus (Keyserling, 1880)	V
Thomisidae	Platyarachne episcopalis (Taczanowski, 1872)
Thomisidae	Runcinioides argenteus (Mello-Leitão, 1929)
Thomisidae	Stephanopis quinquetuberculata (Taczanowski, 1872)
Thomisidae	Strophius n. sp.1	V
Thomisidae	Synema aequinoctiale (Taczanowski, 1872)
Thomisidae	Synema bipunctatum (Taczanowski, 1872)
Thomisidae	Synema bishopi (Caporiacco 1954)
Thomisidae	Synema maculatovittatum (Caporiacco 1954)
Thomisidae	Tmarus candefactus (Caporiacco 1954)
Thomisidae	Tmarus geayi (Caporiacco 1954)
Thomisidae	Tmarus grandis (Mello-Leitão, 1929)
Thomisidae	Tmarus hystrix (Caporiacco 1954)
Thomisidae	Tmarus intentus (Cambridge, 1892)
Thomisidae	Tmarus jelskii (Taczanowski, 1872)
Thomisidae	Tmarus littoralis (Keyserling, 1880)
Thomisidae	Tmarus obesus (Mello-Leitão, 1929)
Thomisidae	Tobias albovittatus (Caporiacco 1954)
Thomisidae	Tobias corticatus (Mello-Leitão, 1917)
Thomisidae	Tobias cornutus (Taczanowski, 1872)
Thomisidae	Tobias taczanowskii (Roewer, 1951)	V
Thomisidae	Tobias trituberculatus (Taczanowski, 1872)
Thomisidae	Uraarachne vittata (Caporiacco 1954)
Titanoecidae	Goeldia patellaris (Simon, 1892)
Trechaleidae	Enna jullieni (Simon & Duss, 1898)
Trechaleidae	Paradossenus longipes (Taczanowski, 1874)
Trechaleidae	Rhoicinus n. sp.1	V
Trechaleidae	Syntrechalea reimoseri (Caporiacco, 1947)	V
Trechaleidae	Trechalea n. sp.1	V
Trechaleidae	Trechalea n. sp.2	V
Trechaleidae	Trechalea n. sp.3	V
Uloboridae	Miagrammopes n. sp.1	V
Uloboridae	Philiponnella semiplumosa (Simon, 1893)
Uloboridae	Zosis geniculata (Olivier, 1789)
Zodariidae	Tristichops coerulescens (Taczanowski, 1874)		Nomem dubium

The numbers assigned to the M-S indicate only the order they were examined. B means that this species was not taken into consideration by the former list but was found published in the literature by Brescovit et al. 2011 and therefore added. V means that this species is new for French Guiana and found during the sampling expeditions organized for this study.

The number of M-S found (692 M-S for 1617 spiders sampled) is similar to what was found in Bolivia and Peru; respectively 329 species out of 1109 specimens sampled and 635 species for 1821 specimens (reviewed in Coddington et al. 2009), but represents ten times more than the number of spider species found in temperate forests (Coddington et al. 1996) and much more than found in Tanzania (170 species for 9096 specimens sampled) (Sørensen et al. 2002) and Malaysia (578 species for 6999 specimens collected) (Floren and Deeleman-Reinhold 2005) indicating the high diversity of the Amazonian areas. In Guyana, a neighbourhood country of French Guiana, only 351 species were found out of 5965 specimens collected (Coddington et al. 2009). Nonetheless, these comparisons have to be made with caution due to differences in sampling protocols including different techniques, efforts and the number of different habitats studied.

It is interesting to observe that the most diverse families are representative of most of the main feeding guilds of spiders (Dias et al. 2010; Cardoso et al. 2011): Salticidae with 153 species belong to the diurnal hunting spiders, the Araneidae with 113 species belong to the orb weavers, the Thomisidae with 39 identified species are representative of the ambush spiders, the Theridiidae with 33 species represent the entangled web weavers, the Corinnidae with 26 recognized species belong to the nocturnal hunting spiders and finally the Theraphosidae (the most diverse and numerous Mygalomorphae representative) with 17 species, ambush from their burrows. Nevertheless, the Ctenidae (15 species) and Trechaleidae (7 species) are probably much more diverse than we have found up until now. In this study, we collected about 60 different M-S belonging to the first family and 20 for the second.

The rate of Endemism is quite high, as noted by Caporiacco (1954) with 192 species out of 357 (53.8%) never having been found outside French Guiana. In this study we cannot accurately evaluate endemism because of the bias made during the identification: most of the named species are fully identified because they were previously discovered and described from somewhere else, where spider studies were performed over a longer period of time. In any case, the number of endemic species has to be handled carefully here due to the poor comparison possible due to few studies achieved in the neighbouring regions (Venezuela, Surinam, Guyana and Amapá and Pará States in Brazil).

The accumulation curve shows a constant increase of the number of M-S (Table 4 and Figure 1) and does not reach a plateau, even on the calculated tendency curve. This plateau normally shows the total number of species present in a site or a region. Here, we cannot determine yet this number from the curve which indicates that we have to sample many more individuals to arrive at this plateau.

Table 4

Sampling sites used in the accumulation curve

Sites	Number of individuals	Number of M-S	Number of « new » M-S in each site
Nouragues (dry season)	375	270	270
Crique Baggot	24	23	11
La Trinité	439	242	132
Gentry plots (Laussat Ouest	76	42	25
Gentry plots (Petite Montagne Tortue, Régina)	97	58	52
Saül	482	347	164
Savane roche Virginie	124	50	38
Total	1617		692

Sites were written in the chronological order they were sampled. The fourth column indicates the number of M-S not found in the previous sampled sites, starting from the top. Therefore they are considered as “new” for the sampling.

Figure 1

Accumulation curve showing the slope of the increase of M-S numbers by the number of specimens collected. The tendency curve (light blue) was added, including its equation.

From the estimators, the minimum richness is evaluated at 1241 species by the Chao 1 estimator and the Jackknife estimator calculated 1680 (+/−112) species. These results suggest we only know about one third (515 species identified out of around 1,500 species estimated) of the local spider fauna, which places French Guiana as a region of high diversity of spiders but also in a region where sampling and identification efforts have to be substantially increased to gain a sufficient knowledge in order to be able to use spider as a biodiversity assessment tool.

Now, although the aim of having a list of spiders to start with is reached, those results have to be taken as a first step in the arachnological biodiversity assessment of French Guiana and not as an exhaustive catalog of the spiders inhabiting the area. At each sampled site, although an inclusive sampling protocol was applied, the large number of singletons (between 50 to 70% of the individuals) indicates clearly that those sites are under-sampled (Coddington et al. 2009). A sampling effort index comparing the ratios of abundance to species (N/S) (Colwell and Coddington 1994) gives a result of 54 (9096/170) for Tanzania, 12 for Malaysia, 17 for Guyana, 2.87 for Pérù and 3.37 for Bolivia. In our study, the ratio is 2.34 (1617/692) which shows, in comparison to the other studies both that French Guianan sites are under-sampled and that the diversity is locally high; being comparable to Bolivia and Perù. Tanzania’s study exhibits a high ratio because the sampling was intensive and also because the sites there were poorer in term of diversity.

Moreover, each site should be sampled at different times of the year as the wet and the dry seasons exhibit radical changes in environmental conditions which trigger a change in the communities of animals. In addition, some specific habitats such as canopies, inselbergs (granitic hill specific vegetation) or liana forests were not well sampled and might hold some unknown spider species too. Therefore, in order to assess the total species richness of the spiders of French Guiana, the sampling effort has to be substantially increased, in order that further quantitative studies applying more advanced methods to define the local fauna (Feest & Cardoso 2012). Applying rigorous sampling protocols can be widely applied for local biodiversity assessment using spiders.

Conclusions

This study sets a starting point for the spider richness described and expected for French Guiana, in order to be able to use spiders as a “bioindication tool”, as recommended by several commissions and organizations, for future biodiversity assessments.

After a literature review and several sampling excursions, the total number of spider species found in French Guiana is now at 515. This revision added 151 new species and nine new families for this region, which make a more credible start for upcoming spider studies. Many other M-S were found but not described as species yet. This study shows that few collections in Guianese forestry habitats brought many new species to the list for French Guiana, which suggests both that the area holds a high diversity of spiders and that this diversity was poorly explored.

The accumulation curve does not yet show the maximum of species number inhabiting this equatorial region but the species richness indices shows the tropical rainforest of French Guiana would host between 1241 and 1792 spider species. They also indicate that more sampling is necessary to complement our current knowledge in this regard. Finally, we can speculate that sampling specific periods (dry season and wet season) and specific and poorly studied habitats such as canopy, inselberg, cambrouze would bring many unknown spider species.

Methods

Published data compilation

The official National Natural Patrimony Inventory (INPN: http://inpn.mnhn.fr) currently lists 138 Araneae species for French Guiana. This list was checked and augmented by a complete survey of the literature from a database of Neotropical spiders (Brescovit et al. 2011). Species names were checked with reference to the world catalog of spiders 13.0 (Platnick 2012) and Prószyński’s (2012) catalog of world.

Study sites

Sampling was performed by the authors in 12 sites of forest in French Guiana (Figure 2) at different periods during 3 years (2009–2011), to complement the number of species found in the existing literature. The name of the sites are given to the forest area were samples were collected. All of these sites are undisturbed forestry habitats. These sites were chosen for insect collecting expeditions organized by INRA (Institut National de la Recherche Agronomique) (the two Gentry sites), by the CNRS (Kaw) by the first author (Crique Baggot, Savane Roche Virginie, Piste des compagnons), and the remainder by the SEAG (Société Entomologique des Antilles et de la Guyane) for all the other sites.

Figure 2

Map of French Guiana with the sampling sites.

The sites are located in different part of French Guiana covering almost all the region except the extreme southeast and the west (Figure 2), where most samples of Caporiacco’s study were conducted (Caporiacco 1954). At each site several habitats (such as river side, swamps and terra firme) were sampled (Table 1 for details), offering altogether a good geographical coverage of the spiders found in French Guiana.

Sampling protocol

In order to collect the maximum number of spiders from every ecological stratum of each habitat, different active techniques and innovative methods such as traps were used (Vedel et al. 2011). Active techniques consist of sampling spiders using a sieve for filtering the soil and the leaf litter, a triangular sweep net for catching spiders inhabiting the low vegetation from 10 cm to 1.5 m, a beating tray to collect individuals living from 1.5 m to 2.5 m in the higher vegetation and by hand to collect visible spiders on trunk or on silk webs. The innovative methods were Malaise traps and window pane traps, normally used to catch insects, which were recognized as efficient at collecting spiders (Vedel et al. 2011). Because of the heterogeneity of the sampling and the initial aim of the study, which was only to increase the number of spider species found, rigorous standardized protocol (Vedel and Lalagüe 2013) was applied only at only the sites Nouragues (wet season), Nouragues (dry season), Crique Baggot, La Trinité, Saül and Savane Roche Virginie. The sampling effort is an equal mix of the active techniques described above where one unit represents one hour of an active sampling technique. For the two Gentry plots spiders were collected only by traps (six window pane traps and six Malaise traps on each site) over a six months period (dry season). At the Mont Itoupe site, six window pane traps and six Malaise traps over one month (dry season) were used to collect spiders. At the Piste des compagnons site, two Malaise traps were placed over a two month period (dry season). Therefore, because of this non-standardization of sampling effort and methods, only a global estimation of total number of species was statistically feasible and no advanced biodiversity studies on spiders (Feest & Cardoso 2012; Cardoso et al. 2009) were possible.

Storage and identification

Spiders were stored in labeled tubes containing 70% ethanol. Material was identified first as Morphospecies (M-S) by the authors and when possible, identified at the species level by them. Otherwise, material was sent to family specialists (see Acknowledgments) for a complete identification or description. Juveniles were excluded from the list. Specimens are noted as “sp. n” only when recognized as a species new to science by a specialist of the family who will describe it in a further publication.

Data analysis

An accumulation curve plotting the number of collected individuals by the number of M-S found was drawn to assess the species richness found in French Guiana. This accumulation curve was drawn with only seven of the sampling sites, because a quantitative protocol accompanied with photography of each specimen were applied only at those sites (Vedel and Lalagüe 2013). Although the number of sites (seven) for any statistical study is low, a rough estimation of the total number of spider species found can be nevertheless computed with a high standard deviation to consider. A logarithmic tendency curve (Colwell and Coddington 1994) (and its equation) was also drawn by Excel open office to derive the rate of the M-S number increase from our samplings (Table 4 and Figure 1).

In addition, to estimate the total species richness of French Guiana we computed, from our sampling, the two most widely used estimators: the Chao 1 (Chao 2005, Gotelli and Colwell 2010) was manually calculated, and the Jackknife computed online (http://www.mbr-pwrc.usgs.gov/software/specrich.html) (Burnham and Overton 1979). Chao 1 is a minimum estimator of the species richness particularly adapted when the number of singletons and doubletons are high, and therefore well adapted to our case. Jackknife allows a non-biased estimation of the richness which is complementary of the first estimator used.