Research Article |
Corresponding author: Ingi Agnarsson ( iagnarsson@gmail.com ) Academic editor: Cor Vink
© 2015 Ingi Agnarsson, Brian B. Jencik, Giselle M. Veve, Sahondra Hanitriniaina, Diego Agostini, Seok Ping Goh, Jonathan Pruitt, Matjaž Kuntner.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Agnarsson I, Jencik B, Veve G, Hanitriniaina S, Agostini D, Goh S, Pruitt J, Kuntner M (2015) Systematics of the Madagascar Anelosimus spiders: remarkable local richness and endemism, and dual colonization from the Americas. ZooKeys 509: 13-52. https://doi.org/10.3897/zookeys.509.8897
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Despite the alarming rates of deforestation and forest fragmentation, Madagascar still harbors extraordinary biodiversity. However, in many arthropod groups, such as spiders, this biodiversity remains mostly unexplored and undescribed. The first subsocial Madagascan species of the theridiid spider genus Anelosimus were described in 2005 when six new species were found to coexist in the Périnet forest fragment within Andasibe-Mantadia NP. However, this discovery was based only on a few specimens and the extent of this Madagascan radiation has remained unknown. We here report on a thorough survey of >350 colonies from Périnet, and three pilot surveys into additional Madagascar forests (Ambohitantely, Ranamofana, and Montagne d’Ambre). The morphological, molecular and natural history data from these surveys facilitated a revised taxonomy and phylogenetic hypothesis of Madagascan Anelosimus. This subsocial clade currently comprises six previously known (A. andasibe Agnarsson & Kuntner, 2005, A. may Agnarsson, 2005, A. nazariani Agnarsson & Kuntner, 2005, A. sallee Agnarsson & Kuntner, 2005, A. salut Agnarsson & Kuntner, 2005, A. vondrona Agnarsson & Kuntner, 2005) and 10 new species: A. ata sp. n., A. buffoni sp. n., A. darwini sp. n., A. hookeri sp. n., A. huxleyi sp. n., A. lamarcki sp. n., A. moramora sp. n., A. tita sp. n., A. torfi sp. n., A. wallacei sp. n.. With the exception of A. may and A. vondrona, all other species appear to be single forest endemics. While additional sampling is necessary, these data imply a much higher local richness and endemism in Madagascan forests than in any other comparable area globally. The phylogenetic results establish a sister clade relationship between the subsocial Anelosimus in Madagascar and the American ‘eximius group’, and between the solitary A. decaryi on Madagascar and a solitary American clade. These findings imply duplicate colonizations from America, an otherwise rare biogeographical pattern, calling for more detailed investigation of Anelosimus biogeography.
Cobweb spiders, subsocial, Theridiidae , biogeography, colonization, radiation, congener coexistance
Madagascar is a biodiversity hotspot that has undergone extreme deforestation during the last century. What once was near continuous and vast forest along the eastern slopes of Madagascar is now fragmented, often into discontinuous patches. Many such isolated patches harbor unique diversity of species, with particularly well known vertebrate examples including endemic lemurs, chameleons, geckoes, snakes, frogs, and others (
In spider research, Madagascar has been relatively neglected with the most notable exception being the four year inventory by the California Academy of Sciences under the leadership of Dr. Charles E. Griswold, and a few additional efforts (see the works of
Similarly, the first subsocial species of the spider genus Anelosimus Simon, 1891 were described from Madagascar only 10 years ago (
Spiders were collected in the field from Ambohitantely Special Reserve, Ankazobe district, 28.iv.2008 (Agnarsson and Kuntner), Montagne d’Ambre National Park, Antsiranana district, 4.iv.2008 (Agnarsson and Kuntner), Périnet Special Reserve, 3–20.iv.2008 and 13–26.xi.2008 (Agnarsson, Kuntner, Hanitriniaina and Rabarison), and Ranamofana National Park, Fianarantsoa district, 27.iv.–2.v.2013 (Suppl. material
Specimens were identified to species (
DNA was isolated from one to multiple individuals per putative morphospecies depending on specimen availability using the QIAGEN DNeasy Tissue Kit (Qiagen, Inc., Valencia, CA). We targeted fragments of two mitochondrial (cytochrome c oxidase subunit 1-COI, 16S rRNA) and two nuclear (Internal transcribed spacer-ITS2 and 28S rRNA) loci previously demonstrated to be effective phylogenetic markers at low taxonomic levels for spiders (
Chromatograms were interpreted employing Phred and Phrap (
Species were delimited based on a combination of molecular and morphological diagnosability. Specimens from different areas showing identical or near identical DNA barcoding (COI) haplotypes and sharing detailed genital morphology were treated as conspecific. Specimens differing distinctly in DNA barcodes, generally over 3% sequence divergence (e.g. Hebert et al. 2004) but in some cases as little as 2% (2% is close to minimal distance between closely related previously described Anelosimus species pairs, e.g. Agnarsson 2007, 2012a, b) from other individuals in the analysis, and showing genitalic differences, albeit subtle, were treated as heterospecific. Paucity of specimens of some species prevented establishing a ‘barcoding gap’ (e.g.
Estimates of divergence (Genetic distances) within and among species based on averaging substitutions per site over all sequence pairs under a Maximum Likelihood model with gamma distributed rate variation. The analyses were done including 1011 COI positions for 324 individuals in MEGA6 (
Intraspecific | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | ||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | A. moramora | n/a | X | |||||||||||||||
2 | A. hookeri | n/a | n/a | X | ||||||||||||||
3 | A. lamarcki | 0.002 | 0.111 | 0.032 | X | |||||||||||||
4 | A. tita | n/a | 0.149 | 0.060 | 0.053 | X | ||||||||||||
5 | A. torfi | n/a | 0.162 | 0.051 | 0.076 | 0.078 | X | |||||||||||
6 | A. andasibe | 0.000 | 0.118 | 0.038 | 0.022 | 0.054 | 0.080 | X | ||||||||||
7 | A. wallacei | 0.002 | 0.113 | 0.028 | 0.022 | 0.055 | 0.070 | 0.023 | X | |||||||||
8 | A. buffoni | 0.001 | 0.119 | 0.029 | 0.023 | 0.048 | 0.074 | 0.021 | 0.019 | X | ||||||||
9 | A. ata | 0.002 | 0.129 | 0.055 | 0.058 | 0.056 | 0.076 | 0.056 | 0.055 | 0.052 | X | |||||||
10 | A. darwini | 0.000 | 0.128 | 0.055 | 0.055 | 0.057 | 0.059 | 0.053 | 0.048 | 0.046 | 0.052 | X | ||||||
11 | A. huxleyi | 0.010 | 0.123 | 0.043 | 0.049 | 0.047 | 0.078 | 0.053 | 0.046 | 0.045 | 0.055 | 0.056 | X | |||||
12 | A. may | 0.010 | 0.123 | 0.065 | 0.063 | 0.066 | 0.076 | 0.067 | 0.057 | 0.057 | 0.051 | 0.045 | 0.063 | X | ||||
13 | A. nazariani | 0.001 | 0.131 | 0.071 | 0.066 | 0.054 | 0.075 | 0.065 | 0.062 | 0.062 | 0.059 | 0.054 | 0.063 | 0.059 | X | |||
14 | A. sallee | 0.001 | 0.123 | 0.062 | 0.057 | 0.056 | 0.079 | 0.057 | 0.055 | 0.051 | 0.060 | 0.058 | 0.051 | 0.060 | 0.064 | X | ||
15 | A. salut | 0.001 | 0.154 | 0.082 | 0.080 | 0.075 | 0.052 | 0.082 | 0.080 | 0.075 | 0.091 | 0.072 | 0.083 | 0.092 | 0.088 | 0.089 | X | |
16 | A. vondrona | 0.000 | 0.103 | 0.022 | 0.033 | 0.056 | 0.075 | 0.041 | 0.035 | 0.035 | 0.062 | 0.058 | 0.051 | 0.068 | 0.064 | 0.059 | 0.083 | X |
average | 0.003 |
In addition to describing new species, we also redescribe known species to include first descriptions of males, or to correct previous taxonomic errors, and include illustrations and DNA barcodes of all Madagascan Anelosimus to facilitate future identification from a single source.
Our total dataset contained specimens from >400 colonies and sequence data from 357 Madagascan individuals, plus global representatives. COI barcodes, totaling 1011 bp, were obtained from most sequenced specimens and 336 individuals were included in the barcode analysis (Supplementary Material). Three additional loci were obtained from a small subset for a phylogenetic matrix of 3409 bp for 114 global terminals (Figure
A Bayesian phylogeny of Madagascar Anelosimus and worldwide relatives. Terminal taxa are replaced by species names, full results including all taxon details are found in Suppl. material
Curiously, our phylogenetic results establish that the subsocial montane forest ‘Madagascar group’ is sister to the most diverse American group, the ‘eximius lineage’, and the solitary group from Madagascar is sister to solitary species also from the Americas (Fig.
The intense survey of Périnet secured fresh samples of all known Madagascan Anelosimus species and led to the discovery of males of several species. These species are all re-illustrated and males described. Several new species were also discovered in Périnet and in pilot surveys of Ambohitantely, Ranamofana, and Montagne d´Ambre. Many of these new species are only known from single or a few female specimens, which is far from ideal for taxonomic purposes. These are nevertheless described here to highlight the diversity of this group in Madagascar and especially to call attention to the uniqueness of the tiny and isolated forest fragment of Ambohitantely. Our findings underline the need to thoroughly survey eastern Madagascan montane forests, and to preserve their extraordinary biodiversity.
DNA delimitation and diagnosis. Given that it can be difficult to delimit and distinguish species of Madagascan Anelosimus based on morphology alone, especially in species where males are unknown, we offer DNA diagnosis in addition to standard morphological diagnosis. In total we obtained 334 COI barcodes for specimens of the 16 species. Average distances among species barcodes ranged from 16.2% to 1.9% (Table
Species diagnoses are based on the standard DNA COI barcodes with a reference alignment starting at base 1 of the routinely used 658 bp fragment and in the matrix submitted as supplementary material (and available from the authors) but extending beyond the standard barcode to cover a 1000 bp fragment. We list 1) unique mtDNA nucleotide substitutions at alignment positions for each species as distinct diagnostic features, e.g. G (100) indicating this species uniquely has a G in position 100, following e.g. Bond and Stockman (2008); 2) and also unique combination of nucleotide substitutions that may be shared with one or maximally two additional species, e.g. G (184, except A. buffoni sp. n. and A. andasibe) indicating this species can be diagnosed from all species except those named in parenthesis by this substitution, and from all species by the combination of multiple such partially shared substitutions. This approach does not exhaust the diagnosability of species based on DNA barcodes. For example, four species (A. may, A. torfi, A. darwini, and A. wallacei), none of which are sister species, can each be diagnosed from their respective closest relatives by A (241). In fact A (241) is one of relatively few features that readily diagnoses A. wallacei from the related and very similar A. buffoni. However, listing every DNA substitution-based diagnosis is not feasible and we set the arbitrary limit to substitutions shared with no more than two species in our diagnosis sections. The matrix of barcodes is made available as supplementary material for complete diagnoses. Four of the 16 species were represented only by a single sequence such that no variation is known and the diagnoses involving these species are thus preliminary – a common enough predicament with morphological diagnoses in rare species. However, given that the average within species distances among densely sampled species were 0.3% and 0.1% for those species limited to a single forest, there is no a priory reason to expect these rarely collected species to be outliers with abundant intraspecific variation.
Anelosimus socialis Simon, 1891 = Anelosimus eximius (Keyserling, 1884).
Brief diagnosis (see
The species is here redescribed to clarify earlier taxonomic confusion; the female previously described (see
Holotype male from Ambohitantely Special Reserve, Analamanga region, Ankazobe district, Madagascar, (18.161°S, 47.302°E), 17–22.iv.2001, montane forest, 1500 m alt, col. J. J. Rafanomezantsoa et al., in CAS, examined (see
Additional three females from same locality, 28.iv.2008, col. Agnarsson and Kuntner, a male and multiple females from Périnet Special Reserve, Andasibe Mantadia National Park, Madagascar (18.933°S, 48.417°E), montane forest, 900–1000 m alt, 3–20.iv.2008 and 12–28.xi.2008, col. Agnarsson, Kuntner, and Hanitriniaina and eight females from Ranamofana National Park (21.25°S, 47.43°E), montane rainforest, 980–1050 m alt, 27.iv.–2.v.2013, col. Pruitt.
Males are diagnosed from other species by the shape of the theridiid tegular apophysis, bifurcated with the lower branch longer than the upper (Fig.
Female: Total length 6.02 Cephalothorax 2.77 long, 1.94 wide, 1.58 high, brown. Sternum 1.49 long, 1.23 wide, extending half way between coxae IV, brown. Abdomen 3.85 long, 2.74 wide, 2.8 high. Brown base with white line and dot patterns with red near the spinnerets. Eyes subequal in size about 0.14 in diameter. Clypeus height about 2.9 times one AME diameter. Chelicerae with one large tooth, three denticles prolaterally. Leg I femur 3.4, patella 1.06, tibia 3.22, metatarsus 2.92, tarsus 1.18. Leg formula 2314, with leg 4 slightly longer than leg 1. Legs 1 and 2 brown, legs 3 and 4 light brown-yellow with dark brown at junctions between tibia and metatarsus, and metatarsus and tarsus. 4 small trichobothria dorsally on tibia I, 4 on tibia II. Trichobothria on all metatarsi (1–2), 4–5 dorsal trichobothria on female palpal tibia.
Variation: Total length 5.70–6.20, Cephalothorax 2.60–2.80, femur 1 3.00–3.50.
Male (from Ranamofana, see
Variation: Total length 3.25–4.01, Cephalothorax 1.63–2.05, femur I 2.67–3.15.
Eastern Madagascan montane forest. This is the most widespread species of the Madagascar group, documented from Périnet, Ambohitantely and Ranamofana, and can be expected to be found in additional montane forest reserves in eastern Madagascar.
In Ranamofana, eight complete A. may colonies along trails in the forest interior were found. We found two colonies containing one adult female and her egg case and eight colonies containing a female with a group of small juveniles, likely instars I–III post egg sac. Females actively guarded their egg cases by seizing them in their chelicerae. We also noted one instance of a female feeding her young via regurgitation. Our observations indicate that A. may primarily exhibits subsocial behavior, as do other members of the Madagascar group. An unidentified salticid inhabited six of the eight colonies sampled.
We here describe the male of A. vondrona for the first time and illustrate both sexes to facilitate identification.
Holotype female from Périnet Special Reserve (P.N. Andasibe Mantadia), Toamasina Province, Madagascar, (18.935°S, 48.418°E), 7–8.v.2001, montane forest, 900–1000 m, (I. Agnarsson and M. Kuntner), in NMNH, examined.
Multiple additional specimens from same locality, 3–20.iv.2008 and 12–28.xi.2008, col. Agnarsson, Kuntner, and Hanitriniaina, and from Ranamofana National Park (21.25°S, 47.43°E), montane rainforest, 980–1050 m alt, 27.iv. – 2.v.2013, col. Pruitt.
Anelosimus vondrona females can be diagnosed from all other species except A. huxleyi by the relatively broad septum that extends the entire width of the epigynum (Fig.
Male (same locality as holotype): Total length 4.47 Cephalothorax 2.03 long, 1.53 wide, 0.49 high. Sternum 1.11 long, 0.94 wide, extending halfway between coxae IV, dark brown. Abdomen 2.40 long, 1.87 wide, 1.89 high, color (Fig.
Eastern Madagascan montane forest, documented from Périnet and Ranamofana.
In Ranamofana, we sampled ten colonies of A. vondrona. Six colonies contained a singleton female and four colonies contained a singleton female with a discolored, collapsed egg sac. All of these colonies were found along roadsides and ornamental shrubbery. In Périnet a large number of colonies were collected, almost exclusively in open forest, including many with female and up to 53 spiderlings coexisting. An adult female was more commonly present in webs with small juveniles but also found in some nests containing antepenultimate and subadult (5th-6th instar) juveniles, suggesting prolonged cohabitation of mother and young. Foreign spiders were abundant in A. vondrona colonies, including several saliticids, a sparassid, a thomisid, and many theridiids.
New material of males of this species allowed a more detailed study of the palpal organ and we provide new illustrations and diagnosis of the male; the original description included a single drawing (see
Holotype male and paratype female, Périnet Special Reserve (P.N. Andasibe Mantadia), Toamasina Province, Madagascar, (18.935°S, 48.418°E), 24.xii.2001, montane forest, 1000 m, col. M. E. Irwin, E. I. Schlinger, H.H. Rasolondalao, in CAS, examined.
Additional specimens from same locality, 3–20.iv.2008 and 12–28.xi.2008, col. Agnarsson, Kuntner, and Hanitriniaina.
Anelosimus salut females can be diagnosed by having a broad ‘inverted T-shape’ septum that differs from A. vondrona in not extending the entire length of the epigynum (Fig.
Only known from type locality.
As other species in this group A. salut appears to be subsocial with colonies consisting of single females and up to 39 spiderlings.
The male of A. nazariani is here described and diagnosed for the first time, the female epigynum is re-illustrated.
Holotype and paratype females from Périnet Special Reserve (P.N. Andasibe Mantadia), Toamasina Province, Madagascar, (18.935°S, 48.418°E), 7–8.v.2001, montane forest, 900–1000 m, (I. Agnarsson and M. Kuntner), in NMNH, examined.
Additional specimens from same locality, 3–20.iv.2008 and 12–28.xi.2008, col. Agnarsson, Kuntner, and Hanitriniaina.
Anelosimus nazariani differs from other species in being distinctly the largest Anelosimus species recorded to date with female total length exceeding 7 mm, with other species ranging from 1.9–5.5 mm. The males are easily diagnosed by the dark, bulky, and comparatively smooth Eb (Fig.
Male: Total length 5.89 Cephalothorax 2.70 long, 1.99 wide, 0.27 high. Sternum 1.40 long, 1.17 wide, extending halfway between coxae IV, light brown. Abdomen 3.19 long, 2.31 wide, 2.08 high (add color). Eyes subequal in size about 0.15 in diameter. Clypeus height about times one AME diameter Chelicerae with one large tooth, 4–5 denticles retrolaterally Leg 1 femur 3.71, patella 1.18, tibia 3.94, metatarsus 3.45, tarsus 1.23 Leg formula 1243 Legs light brown-yellow with brown at junctions between tibia and metatarsus, and metatarsus and tarsus. 7 small trichobothria dorsally on tibia I and II, 3 dorsally on metatarsi.
Only known from type locality.
As in other species of this group a female can be found in its web with close to 50 juveniles and juveniles appear to cohabit in the web until close to adulthood.
The species is rediagnosed and genitalia re-illustrated.
Holotype male, paratype female from Périnet Special Reserve (P.N. Andasibe Mantadia), Toamasina Province, Madagascar, (18.935°S, 48.418°E), 24.xii.1999 (M.E. Irwin et al.), in CAS, examined.
Additional specimens from same locality, 3–20.iv.2008 and 12–28.xi.2008, col. Agnarsson, Kuntner, and Hanitriniaina.
Males are readily diagnosed from all species other than A. nazariani by the elongate upper branch of the TTA (Fig.
Only known from type locality.
This species is rare at the type locality, and too few colonies have been sampled to comment on its natural history, though it is expected to be subsocial like related species.
The species, known only from females, is rediagnosed and genitalia re-illustrated.
Holotype female from Périnet Special Reserve (P.N. Andasibe Mantadia), Toamasina Province, Madagascar, (18.935°S, 48.418°E), 7–8.v.2001, montane forest, 900–1000 m, (I. Agnarsson and M. Kuntner), in NMNH, examined.
Additional specimens from same locality, 3–20.iv.2008 and 12–28.xi.2008, col. Agnarsson, Kuntner, and Hanitriniaina.
Anelosimus andasibe differs from all but A. nazariani, A. buffoni sp. n., and A. wallacei sp. n. by the W-shaped septum (Fig.
Only known from type locality.
As in other species of this group a female can be found in its web with close to 50 juveniles and juveniles appear to cohabit in the web until close to adulthood.
Holotype female from Ambohitantely Special Reserve (18.161°S, 47.302°E), 1500 m alt, Analamanga region, Ankazobe district, Madagascar, 28.iv.2008, montane forest, col. Agnarsson and Kuntner, in NMNH.
Only known from holotype.
The species epithet is a noun in apposition and honors Torfi Agnarsson, the senior author´s brother.
Anelosimus torfi can be diagnosed from all other Anelosimus based on the distinctly dark coloration and from all but A. vondrona based on its pendulum-like septum. Anelosimus torfi can be diagnosed from other Madagascan Anelosimus on the basis of the following unique mtDNA nucleotide substitutions at the following standard DNA barcode alignment positions: G (43), C (620), A (764), G (952), T (953), G (955). It can also be readily diagnosed from most other Anelosimus based the following partially shared nucleotide substitutions, and all other species by their unique combination: A (46, except A. nazariani), A (256, except A. salut and A. hookeri), T (364, except A. darwini), T (370, except A. salut), T (412, except A. salut), A (469, except A. salut), T (484, except A. may and A. nazariani), A (622, except A. salut), G (625, except A. ata and A. huxleyi), A (754, except A. salut), G (817, except A. huxleyi), G (841, except A. nazariani), T (940, except A. salut), A (943, except A. moramora), A (961, except A. salut).
Female: Total length 4.1. Cephalothorax 1.95 long, 1.4 wide, 1.06 high, dark black-brown. Sternum 1.13 long,. 99 wide, extending half way between coxae IV, brown. Abdomen 2.67 long, 1.76 wide, 1.67 high.black base with yellow patterns. Eyes subequal in size about 0.12 in diameter. Clypeus height about 2.1 times one AME diameter. Chelicerae with one large tooth, three denticles not visible on specimen. Leg I femur 2.21, patella 0.76, tibia 2.81, metatarsus 2.47, tarsus 1.08. Leg formula 3214, with leg 4 significantly longer than leg 1. Legs primarily black-brown with yellow bands, dark at junction between each leg segment. 4 small trichobothria dorsally on all tibia. Trichobothria on all metatarsi (2), single tricobothria on tarsi. Four dorsal trichobothria on female palpal tibia.
Variation: Total length 4.1–4.32. Abdomen 2.67–2.84 long, 1.76–1.9 wide, 1.67–2.04 high. Femur 2.21–2.47.
Only known from type locality.
Unknown, predicted to be subsocial.
Holotype female from Ambohitantely Special Reserve (18.161°S, 47.302°E), 1500 m alt, Analamanga region, Ankazobe district, Madagascar, 28.iv.2008, montane forest, col. Agnarsson and Kuntner, in NMNH.
Only known from holotype.
The species epithet is a noun in genitive case that honors the evolutionary biologist Joseph Dalton Hooker, who was among the first scientists to publish work announcing support for Darwin´s theory of evolution by natural selection.
Anelosimus hookeri differs from all other Anelosimus by the combination of pale coloring (Fig.
Female: Total length 4.76. Cephalothorax 2.17 long, 1.43 wide, 1.26 high, dark brown. Sternum 1.26 long, 0.99 wide, extending half way between coxae IV, brown. Abdomen 2.99 long, 2.05 wide, 2.17 high. White base with black/brown spots, red marks near spinnerets, dark brown around genitalia. Eyes subequal in size about 0.12 in diameter. Clypeus height about 2.1 times one AME diameter. Chelicerae with one large tooth, three denticles prolaterally. Leg I femur 1.76, patella 0.63, tibia 1.99, metatarsus 1.89, tarsus 0.88. Leg formula 1243, with leg 2 slightly longer than leg 1 and leg 3 slightly longer than leg 4. Leg light orange-brown, with alternating light and dark shaded bands, and very dark at metatarsus/tarsus junction and distal tip of tarsus. Numerous (4–5) small trichobothria dorsally on all tibia, 4 on tibia II, 5 on tibia I. Trichobothria on all metatarsi (2–3). Four dorsal trichobothria on female palpal tibia.
Variation: only known from holotype.
Only known from type locality.
Unknown, predicted to be subsocial.
Holotype female from Ranamofana National Park (21.25°S, 47.43°E), montane rainforest, 9801050 m alt, 27.iv.–2.v.2013, col. Pruitt, in NMNH.
Same locality and collection, several adult females.
The species epithet is a noun in genitive case that honors the early evolutionary biologist Jean-Babtiste Lamarck, the first scientists to develop a thorough and coherent evolutionary theory, though it was later shown by Darwin to be flawed in major ways.
Anelosimus lamarcki can be diagnosed from other Madagascan Anelosimus by the heavily sclerotized copulatory ducts and small spermathecae that barely exceed the diameter of the copulatory ducts. Anelosimus lamarcki can be diagnosed from other Madagascan Anelosimus on the basis of the following unique mtDNA nucleotide substitutions at the following standard DNA barcode alignment positions: G (280), C (562). It can also be readily diagnosed from most other Anelosimus based the following partially shared nucleotide substitutions, and all other species by their unique combination: G (502, except rarely in A. may), G (514, except A. hookeri and most A. vondrona), G (553, except some A. huxleyi), G (766, except some A. may), G (772, except A. andasibe), G (814, except most A. vondrona).
Female (holotype): Total length 5.16. Cephalothorax 2.32 long, 1.70 wide, 0.98 high, dark brown. Abdomen 2.88 long, 2.04 wide, 1.90 high. Light brown base with black/white spots, black and white longitudinal band extending just beyond half of abdomen, red marks near spinnerets. Eyes subequal in size about 0.14 in diameter. Leg I femur 2.77, patella 0.84, tibia 2.34, metatarsus 2.28, tarsus 0.91. Leg formula 1423. Leg light orange-brown, with alternating light and dark shaded bands, and very dark at distal tips of femur, patella, tibia and metatarsus. Numerous (6 – 7) small trichobothria dorsally on all tibia, 7 on tibia I, 6 on tibia II, 7 on tibia III, 6 on tibia IV.
Variation: Total length 5.00–6.80. Prosoma 2.30–2.90 long. Abdomen 2.70–3.20 long. Femur I 2.70–3.20.
Only known from type locality.
We sampled twelve colonies of A. lamarcki. Colonies were found both along trails in the forest interior and along roadsides and ornamental shrubbery. The ten colonies in the forest interior contained females with groups of small juveniles, likely instars I–II, and colonies along road sides contained one penultimate or mature female. Like A. vondrona, A. lamarcki webs contained an impressive diversity of foreign spiders including multiple theridiids, saliticids, sparassids, a thomisid, and several linyphiids. We observed multiple co-feedings events between A. lamarcki and its web associates during staged prey capture events. Whether A. lamarcki or its web associate was the first to subdue the prey differed across trials.
Holotype female from Ambohitantely Special Reserve (18.161°S, 47.302°E), 1500 m alt, Analamanga region, Ankazobe district, Madagascar, 28.iv.2008, montane forest, col. Agnarsson and Kuntner, in NMNH.
Only known from holotype.
The species is a noun in apposition named in the honor of the first author’s mother-in-law Yadira Collado Ulloa, affectionately known to her grandchildren as ‘Tita’.
Anelosimus tita can be diagnosed from other Madagascan Anelosimus by the triangular shape of the septum (Fig.
Female: Total length 3.87 Cephalothorax 1.9 long, 1.34 wide, 1.09 high, brown. Sternum 1.02 long, 0.87 wide, extending half way between coxae IV, orange. Abdomen 2.44 long, 1.68 wide, 1.33 high. Mixed pattern of white, grey, and black. Eyes subequal in size about 0.11 in diameter. Clypeus height about 2 times one AME diameter. Chelicerae with one large tooth, three denticles prolaterally. Leg I femur 2.01, patella 0.66, tibia 2.02, metatarsus 1.84, tarsus 0.91. Leg formula 3421, with leg 1 significantly longer than leg 2. Legs alternating between light orange and dark brown bands. 3–4 small trichobothria dorsally on tibia, 3 on tibia 1. 3 or 4 dorsal trichobothria on female palpal tibia.
Variation: only known from holotype.
Only known from type locality.
Unknown, predicted to be subsocial.
In 2005 we described Anelosimus may Agnarsson, based on a holotype male and females both from Ambohitantely and Périnet (
Holotype female from Périnet Special Reserve (P.N. Andasibe Mantadia), Toamasina Province, Madagascar, (18.935°S, 48.418°E), 7–8.v.2001, montane forest, 900–1000 m, (I. Agnarsson and M. Kuntner) (NMNH), based on the paratype originally attributed to A. may, see
Several female specimens from same locality.
The species epithet is a noun in apposition named in the honor of the first author’s father-in-law Jorge May-Barquero, affectionately known to his grandchildren as ‘Ata’.
Anelosimus ata can be diagnosed from all other Anelosimus, expect A. may, by the anchor-shaped septum (Fig.
Female: Total length 5.01. Cephalothorax 2.28 long, 1.82 wide, 1.45 high, brown. Sternum 1.35 long, 1.16 wide, extending halfway between coxae IV, brown. Abdomen 2.93 long, 2.44 wide, 2.52 high. Pattern as in Fig.
Variation: female total length 4.90–5.15.
Only known from type locality.
This species is common at its type locality and webs have been found with females and up to 80 spiderlings. Juveniles cohabit in the web with the mother until she dies and appear to disperse close to adulthood. Webs without adult females generally contained instar 4–6 juveniles.
Holotype female holotype from Ambohitantely Special Reserve (18.197°S, 47.285°E), 1600 m alt, Analamanga region, Ankazobe district, Madagascar, 28.iv.2008, montane forest, col. Agnarsson and Kuntner, in NMNH.
Juveniles from same locality.
The species epithet is a noun in the genitive case and honors Charles Darwin, the father of evolutionary biology.
Anelosimus darwini can be diagnosed from all other Anelosimus, expect A. may, and A. ata, by the anchor-shaped septum (Fig.
Female (holotype): Total length 3.70. Cephalothorax 1.88 long, 1.27 wide, 0.93 high. Red-brown. Sternum 1.04 long, 0.82 wide, extending between coxae IV, dark brown. Abdomen 1.79 long, 1.63 wide, 2.45 high. Brown pattern with 2 white streaks. Eyes subequal in size about 0.11 in diameter. Chelicerae each with 1 large tooth, 3 denticles located prolaterally. Clypeus height about 2.3 times one AME diameter. Leg I femur 2.10, patella 0.62, tibia 1.86, metatarsus 1.49, tarsus 0.93. Legs roughly same color as cephalothorax. Leg formula 1432. Numerous (3–4) small trichobothria dorsally on all tibiae. 2–3 trichobothria on metatarsus, absent on tarsus.
Variation: only known from holotype.
Only known from type locality.
Unknown, predicted to be subsocial.
Holotype female from Périnet Special Reserve (P.N. Andasibe Mantadia), Toamasina Province, Madagascar, (18.935°S, 48.418°E), 12–28.xi.2008, montane forest, 900–1000 m, col Hanitriniaina, in NMNH.
Additional specimens from same locality, 3–20.iv.2008 and 12–28.xi.2008, col. Agnarsson, Kuntner, and Hanitriniaina.
The species epithet is a noun in the genitive case and honors the evolutionary biologist Alfred Russel Wallace, a contemporary of Darwin and co-author of the first paper on natural selection.
Anelosimus wallacei can be diagnosed from all other Anelosimus, expect A. andasibe and A. buffoni by the W pattern of the septum (Fig.
Female: Total length 4.72 Cephalothorax 2.14 long, 1.57 wide, 0.44 high. Sternum 1.26 long, 1.05 wide, extending halfway between coxae IV, dark brown. Abdomen 2.58 long, 2.01 wide, 1.78 high, color and pattern as in Fig.
Variation: Total length 4.72–4.8. Cephalothorax 2.14–2.25 long. Femur I 1.76–2.35.
Only known from type locality.
This species occurs almost exclusively in closed forest at its type locality. Like other species of the group it makes webs with females and spiderlings cohabiting, with up to 83 spiderlings found in a single web. Webs without adult females generally contained instar 4–6 juveniles.
Holotype female from Périnet Special Reserve (P.N. Andasibe Mantadia), Toamasina Province, Madagascar, (18.935°S, 48.418°E), 12–28.xi.2008, montane forest, 900–1000 m, col Hanitriniaina, in NMNH.
Additional specimens from same locality, 3–20.iv.2008 and 12–28.xi.2008, col. Agnarsson, Kuntner, and Hanitriniaina.
The species epithet is a noun in the genitive case and honors the evolutionary biologist Thomas Henry Huxley; ‘Darwin´s bulldog’.
Anelosimus huxleyi females can be diagnosed from all other species except A. vondrona, by the relatively broad septum that extends the entire width of the epigynum (Fig.
Female: Total length 5.64 Cephalothorax 2.54 long, 1.79 wide, 0.63 high. Sternum 1.30 long, 1.11 wide, extending halfway between coxae IV, dark brown. Abdomen 3.10 long, 2.45 wide, 2.63 high, color and pattern as in Fig.
Variation: Total length 5.50–5.70. Cephalothorax 2.50–2.55 long. Femur I 3.10–3.20.
Only known from type locality.
As in other species of this group a female can be found in its web with close to 50 juveniles and juveniles appear to cohabit in the web until close to adulthood.
Unfortunately most adult specimens of this species, almost all of which were collected in April 2008, were lost during the transport of the Agnarsson lab from UPR to UVM. Of the only two remaining adult females the carapace and legs had been consumed for DNA extraction, though total length was measured before specimens were processed for DNA extraction. The species description is therefore abbreviated and limited to the abdomen, genitalia, and DNA barcode.
Holotype and paratype female from Périnet Special Reserve (P.N. Andasibe Mantadia), Toamasina Province, Madagascar, (18.935°S, 48.418°E), 12–28.xi.2008, montane forest, 900–1000 m, col Hanitriniaina, in NMNH.
The species epithet is a noun in the genitive case and honors the great naturalist Georges-Louis Leclerc, Comte de Buffon.
Anelosimus buffoni females can be diagnosed from all other species expect A. andasibe and A. wallacei by the W pattern of the septum (Fig.
Total length 4.1, Abdomen 2.59 long, 1.96 wide, color and pattern as in Fig.
Only known from type locality.
As in other species of this group a female can be found in its web with close to 50 juveniles and juveniles appear to cohabit in the web until close to adulthood.
Holotype female from Montagne d’Ambre National Park (12.516972°S, 49.178778°E), 1005 m alt, Antsiranana district, Madagascar, 4.iv.2008, montane forest, col. Agnarsson and Kuntner, in NMNH.
The species epithet is a Madagascan aphorism or motto meaning ‘no rush’ or ‘take it easy’.
Anelosimus moramora females can be diagnosed from all other species except A. ata by the relatively small and pointy shape of the septum and from A. ata by its smaller size. Anelosimus moramora can be diagnosed from other Madagascan Anelosimus on the basis of the following unique mtDNA nucleotide substitutions at the following standard DNA barcode alignment positions (note that only a short fragment of the divergent A. moramora barcode is available starting at position 824): C (843), C (888), T (897), A (901), C (906), A (914), C (924), C (939), C (967), A (979). It can also be diagnosed from all Anelosimus except A. torfi based on A (943).
Female: Total length 3.31. Cephalothorax 1.4 long, 1.06 wide, 0.87 high, brown. Sternum 0.78 long, 0.67 wide, extending half way between coxae IV, brown. Abdomen 2.02 long, 1.6 wide, 2.26 high. Red-brown with 2 white streaks. Eyes subequal in size about 0.09 in diameter. Clypeus height about 2.5 times one AME diameter. Chelicerae with one large tooth, three denticles prolaterally. Leg I femur 1.67, patella 0.5, tibia 1.41, metatarsus 1.1, tarsus 0.65. Leg formula 1243. Legs light brown-yellow with dark brown at junctions between tibia and metatarsus, and metatarsus and tarus. 4 small trichobothria dorsally on tibiae, 3 on all metatarsi. 3–4 dorsal trichobothria on female palpal tibia.
Variation: only known from holotype.
Only known from type locality.
Unknown, predicted to be subsocial.
Anelosimus decaryi does not belong to the ‘Madagascar group´ of subsocial montane species but rather to the ´solitary clade´ of Anelosimus (see Agnarsson et al. 2010). It was recently redescribed (see Agnarsson et al. 2010) and is here only re-illustrated for completeness so that all Anelosimus species currently known to occur in Madagascar can be identified from a single source.
Orangea Peninsula (N Madagascar), Ranamofana (Central Madagascar), Comoros Islands, and Aldabra atoll.
Anelosimus decaryi is solitary with very brief cohabitation between mother and offspring, which disperse at early instars (Agnarsson et al. 2010). The species was previously thought to be restricted to coastal habitats in the north, however, it also occurs in Ranamofana. Seven colonies of A. decaryi were sampled along the riparian zones directly flanking the Namorona River. A. decaryi has previously only been known from coastal habitats at low elevations. At Ranomafana (600–800m elevation) we found six colonies containing singleton females and one colony containing a female with an egg case. In contrast to the other species of Anelosimus at Ranomafana, A. decaryi colonies did not contain any foreign spiders.
Thanks to Patricia Wright, Fredrica van Berkum, Benjamin Andriamihaja and all the ANGAP/MICET/MNP crew in Antananarivo and Ranomafana for logistical help. We are grateful to Charles Griswold and Brian L Fisher for help in establishing contacts in Madagascar. Honoré Rabarison (Nono) assisted with field collection. Yadira Ortiz Ruiz and Carol Yablonsky assisted with the molecular work. Funding for this work came from the Slovenian Research Agency (ARRS Z1-9799-0618-07). Additional funds came from the National Geographic Society (8655-09), the University of Puerto Rico, and the National Science Foundation (DEB-1050187-1050253, 1314749) to IA and G. Binford. We are grateful to Cor Vink, Miquel Arnedo and an anonymous reviewer for constructive comments that improved the manuscript.
Data matrix
Data type: NEXUS file
Explanation note: Data matrix set of five aligned and concatenated mtDNA and nuDNA loci.