Keywords

4.1 Introduction

In a broad sense, the Aviculariinae spiders are considered as the group of arboreal theraphosids of the Neotropics (Fig. 4.1), represented by species of a variety of sizes and colors; some even have metallic-color patterns. The group is traditionally known as the bird-eating spiders. These curious habits have been documented for centuries. The first documented observation of an aviculariine eating a bird is attributed to the naturalist and scientific illustrator Maria Sibylla Merian (1705), who published in Metamorphosis Insectorium Surinamensis the representation of an arboreal tarantula feeding on a hummingbird (Fukushima and Bertani 2017). According to Madame Merian, these spiders surprise small birds that are in their nests, and suck their blood with avidity. The illustration and description initially was controversial and considered as a senseless idea, but it was probably the story that Lamarck (1818) took into account for naming these spiders as Avicularia , referring to the fact that these tarantulas prey on birds (“avis” in Latin) (Fukushima and Bertani 2017).

Fig. 4.1
figure 1

Aviculariinae arboreal spider habitus. (a, b) Antillena rickwesti, (a) male, (b) female. (c, d) Caribena versicolor, (c) juvenile, (d) female. (e) Avicularia avicularia, female. (f) Avicularia minatrix, female. (Photos: courtesy of Rick West)

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Aviculariinae sensu lato can be distinguished morphologically from the other theraphosids primarily by having legs with few or no spines, and laterally extended tarsal and metatarsal scopulae, resulting in a spatulate appearance of the appendices (Fig. 4.2). Other additional features presented are: the absence of spiniform setae on the prolateral maxillae, females with completely separated spermathecae, males with palpal bulb with subtegulum not extended, and long and thin embolus without keels (except Antillena Bertani, Huff and Fukushima 2017) (Raven 1985; Fukushima and Bertani 2017).

Fig. 4.2
figure 2

Tarsal and metatarsal scopulae, and claw tufts in Neotropical arboreal tarantulas. (a) Caribena versicolor, ventral view. (b, c) Detail of the adhesive pads in Avicularia sp., (b) Lateral view, (c) Ventral view. (Photos: courtesy of Julian Kamzol)

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4.1.1 Aviculariinae

The taxonomic history of the aviculariines goes back to the first arachnological studies, beginning with the first system of spider classification proposed by the Baron Walckenaer (1802), who used the term “Mygale” (a nonscientific name) to distinguish the “mineuses” and “aviculaires” spiders (where it included species with two pairs of book lungs and paraxial chelicerae) from the other spiders. The name Mygale was subsequently used by Latreille (1802) to designate a spider genus, where he described the most mygalomorph spiders known until then. Later, Olivier (1811) following Walckenaer’s system adopted the genus Mygale separated from Aranea, but he restricted Mygale to “les Araignées mineuses,” excluding all the other Mygale species or “les Araignées aviculaires,” which he referred to Aranea (Thorell 1870). Then, Lamarck (1818) followed the Olivier proposal, but for “les Araignées aviculaires” proposed a separated genus, Avicularia Lamarck, 1818; at this time Avicularia included three species, A. canceridea (Latreille 1806), A. blondii (Latreille 1804), and A. fasciata (Latreille 1804) (Fukushima and Bertani 2017). Several years later, Latreille (1802) named Ctenize to “les Araignées mineuses,” and in opposition to Olivier (1811) and Lamarck (1818) gave to “les Araignées aviculaires” the name Mygale, which was unavailable later (Thorell 1870), because it is a junior homonym of a mammal genus described by Cuvier (1800).

Simon (1892) in his famous work “Histoire naturelle des Araignées” established a classification for the order Araneae where he proposed two suborders “Araneae theraphosae” and “Araneae verae.” The first was composed of the Mesothelae and mygalomorph spiders, and divided into Liphistiidae, Aviculariidae, and Atypidae. At the same time, he configured some subfamilies, one of them the Aviculariinae subfamily (which corresponds currently to the family Theraphosidae Thorell, 1869) divided into 10 groups. One of these groups was named Avicularieae, which was composed by two genera, Avicularia and Tapinauchenius Ausserer, 1871. Additionally, Simon (1892) synonymized Typhochlaena C.L. Koch, 1850 with Avicularia. Afterwards, Pocock (1901) included Ephebopus Simon, 1892, Psalmopoeus Pocock, 1895, Pachistopelma Pocock, 1901, and Iridopelma Pocock, 1901 into Avicularieae, and also suggested the inclusion of the African genera Scodra Becker, 1879 (currently Stromatopelma Karsch, 1881) and Heteroscodra Pocock, 1899 (Pocock 1901). Soon after, Simon (1903) following Pocock (1901) included the African genera mentioned, transferred Ephebopus to Phoneyuseae (currently part of Eumenophorinae), and synonymized Iridopelma with Avicularia . Sometime later, Mello-Leitao (1923) considered only American genera as valid taxa within the “Avicularias” group, added Ancylochiros Mello-Leitao, 1920, revalidated Typhochlaena , and synonymized Iridopelma with this genus. Finally, Roewer (1942) used for his catalog the taxonomic category of subfamily for spiders Avicularieae, additionally transferred Heteroscodra and Scodra back to this group, included the genera Avicuscodra Strand, 1908 (currently Avicularia ), synonymized Typhochlaena with Avicularia again, transferred Ancylochiros to Ischnocolinae subfamily and Ephebopus to Eumenophoriinae subfamily.

It is well known that in 1985 Raven performed the first taxonomic revision and phylogenetic analysis of the infraorder Mygalomorphae based on morphological characters and without cladistics software. Within his results, Raven (1985) established Avicularia , Iridopelma , Pachistopelma , and Tapinauchenius genera as the Aviculariinae subfamily. Likewise, he transferred Ephebopus to Theraphosinae; Stramatopelma and Heteroscodra to Eumenophorinae; and Psalmopoeus to Selenocosmiinae. Raven (1985) considered the following characteristics as diagnostic of the Aviculariinae subfamily: presence of a spinose process between the lobes of the male palpal tarsus (except Tapinauchenius ), tarsi broad as or broader than the metatarsi, and legs with few spines or absent. Lucas et al. (1991) described the male of E. murinus and, based on the possession of a sinuous embolus without keels, together with the characters used by Raven (1985), transferred Ephebopus to Aviculariinae. Additionally, they noted that males of both Ephebopus and Tapinauchenius lacked the spinose process on the palpal tarsi, but considered the wide tarsal pads, elongated embolus, and absence of spines on the legs as synapomorphies of Aviculariinae, allowing as a consequence the inclusion of these genera within the subfamily (West et al. 2008).

The first approximation to the study of the phylogenetic relationships into the Aviculariinae subfamily was carried out by West et al. (2008), with the taxonomic review and cladistic analysis of Ephebopus . Aviculariinae was considered as a monophyletic group which includes various lineages, supported by the presence of a “well-developed scopulae” that extends laterally on tarsi and metatarsi, mainly those of legs I and II (with parallelism in Poecilotheria : Selenocosmiinae subfamily). According to West et al. (2008), Aviculariinae includes two West African genera, Stromatopelma and Heteroscodra , and the New World genera Avicularia , Ephebopus , Iridopelma , Pachistopelma , Psalmopoeus , and Tapinauchenius . This composition is in complete harmony with Pocock’s (1901) previous proposal. However, according to their cladogram obtained, the conformation of two subfamilies could be inferred: one of them composed by Avicularia , Heteroscodra , Iridopelma , Pachistopelma , and Stromatopelma , and the other by Ephebopus , Psalmopoeus , and Tapinauchenius (Fig. 4.3a; West et al. 2008: Fig. 9).

Fig. 4.3
figure 3

Preferred phylogenetic hypothesis of the arboreal tarantulas and their allies. (a) West et al. (2008). (b) Bertani (2012). (c) Fukushima and Bertani (2017). (d) Hüsser (2018)

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Bertani (2012) performed the taxonomic review of the genera Iridopelma , Pachistopelma , and Typhochlaena , revalidating again this last problematic genus. His results recovered Aviculariinae as a paraphyletic group in the majority of obtained trees, with a clade (Ephebopus (Psalmopoeus + Tapinauchenius )) as sister group of Pelinobius (Eumenophorinae) + Phlogiellus (Selenocosmiinae); and another clade composed by Avicularia , Heteroscodra , Iridopelma , Typhochlaena , Pachistopelma , and Stromatopelma , as sister group of Encyocratella (Stromatopelminae), Haplopelma (Ornithoctoninae), and Poecilotheria (Selenocosmiinae) (Fig. 4.3b; Bertani 2012: Figs. 177, 178). The author mentioned the possibility of changes in the Aviculariinae composition, which could be supported with the revision of other genera such as Avicularia and Psalmopoeus and additional information of the outgroups (Bertani 2012).

The genus Avicularia was recently revised by Fukushima and Bertani (2017), who also described three new genera in Aviculariinae: Antillena , Caribena , and Ybyrapora . They stated the monophyly of the subfamily, agreeing with West et al. (2008) and based on the following homoplastic characters: presence of well-developed scopulae on tarsi, and metatarsi very extended laterally. According to Fukushima and Bertani (2017), Aviculariinae is composed of: Antillena , Avicularia, Caribena , Ephebopus , Heteroscodra , Iridopelma , Pachistopelma , Psalmopoeus , Stromatopelma , Tapinauchenius , Typhochlaena , and Ybyrapora . The clade (Ephebopus (Psalmopoeus + Tapinauchenius )) was retrieved as sister group to all the remaining Aviculariinae (Fig. 4.3c; Fukushima and Bertani 2017: Fig. 325).

The monophyly and the relationships within Aviculariinae have been extensively debated in the last decade, and the classification of the node (Ephebopus (Psalmopoeus + Tapinauchenius )) has been controversial (West et al. 2008; Bertani 2012, Fukushima and Bertani 2017; Foley et al. 2019). Recent phylogenetic analyses with molecular data consider this clade out of Aviculariinae, as another subfamily Psalmopoeinae (Foley et al. 2019; Hüsser 2018; Lüddecke et al. 2018; Turner et al. 2018). The cladograms obtained by Hüsser (2018), Lüddecke et al. (2018), and Turner et al. (2018) recover the clade composed by Aviculariinae taxa as the sister group of a clade composed by Schismatothelinae + Psalmopoeinae (Fig. 4.3d). Additionally, Foley et al. (2019) recover the same evidence from transcriptome data: Aviculariinae as sister group of Schismatothelinae + Psalmopoeinae.

4.1.2 Psalmopoeinae

The genus Psalmopoeus Pocock, 1895 has had a controversial history of changes between Theraphosidae subfamilies. Initially, Pocock (1901), followed by other authors, allocated Psalmopoeus in Aviculariinae, but later Raven (1985) transferred it to Selenocosmiinae, based on the presence of numerous bacilliform setae in the prolateral surface of the maxillae (lyriform organ ) (Fig. 4.4a). Samm and Schmidt (2008) proposed the Sinurticantinae subfamily, composed by Psalmopoeus and Tapinauchenius , based on the absence of urticating setae, presence of male tibial apophysis bipartite, and differences on the copulatory palpal bulbs regarding Selenocosmiinae males. However, Sinurticantinae was considered an invalid nomenclatural proposal because no type genus was specified and none corresponded with the “subfamily” name. Then, Schmidt (2010) modified the subfamily name to Psalmopoeinae, but did not present a phylogenetic analysis to justify the new group, although he endorsed the nature of the group by the lacking abdominal urticating setae, morphology of the tibial apophysis and palpal bulb , as well as other aspects such the Neotropical distribution. Additionally, Schmidt (2010) proposed that Psalmopoeus and Tapinauchenius are more closely related phylogenetically with Aviculariinae. This last proposal did not have a place in the academic community, perhaps due to the lack of a robust phylogenetic analysis, the fact that the absence of urticating setae would not be enough to create a subfamily, and in some sense this would be far from solving the group’s taxonomic problems.

Fig. 4.4
figure 4

Stridulatory organ in Psalmopoeinae. (a, b) Psalmopoeus cambridgei, (a) Maxillary lyra, composed by one row of thick bristles, (b) Base of chelicerae, ventral view. (c, d) Pseudoclamoris gigas, (c) Maxillary lyra, composed by a group of slender bristles, (d) Base of chelicerae, ventral view. White arrows point to the rows of filiform setae strikers

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On the other hand, Ephebopus also has been a theraphosid genus that has had a very uncertain taxonomic position over the decades. Summarized, first, Ephebopus was included in the Selenocosmieae by Simon (1892), and then it was transferred variously to the Avicularieae (Pocock 1901), Phoneyuseae (Simon 1903), back to Aviculariinae (Mello-Leitão 1923), Eumenophorinae (Roewer 1942), Theraphosinae (Raven 1985), again to Aviculariinae (Lucas et al. 1991; West et al. 2008; Fukushima and Bertani 2017), and recently in Psalmopoeinae (Hüsser 2018).

Cladistic analyses carried out by West et al. (2008), Bertani (2012), and Fukushima and Bertani (2017) considered Ephebopus , Tapinauchenius , and Psalmopoeus as Aviculariinae genera. However, other studies validate the inclusion of Psalmopoeus and Tapinauchenius, and recently Ephebopus, into Psalmopoeinae subfamily (Lüddecke et al. 2018; Turner et al. 2018; Hüsser 2018). Recently molecular analyses of Theraphosidae have supported the hypothesis that Psalmopoeinae is closely related to Schismatothelinae, forming the clade sister of Aviculariinae. Lüddecke et al. (2018) and Turner et al. (2018) suggest (Psalmopoeus + Tapinauchenius ) as the sister group of Schismatothelinae, and paraphyletic with respect to Aviculariinae. Lüddecke et al. (2018) also discussed the position of the two African genera Stromatopelma and Heteroscodra , transferred out of Aviculariinae, and proposed Stromatopelmatinae as the sister group of Harpactirinae, with a phylogenetic analysis strongly supported.

A phylogenetic study focused on Tapinauchenius and Psalmopoeus based on morphological and molecular data, conducted by Hüsser (2018), suggests Psalmopoeinae as a paraphyletic group (=morphological data) or monophyletic group (=molecular data), including Ephebopus , Tapinauchenius, Psalmopoeus, and a new genus described Pseudoclamoris (Fig. 4.3d; Hüsser 2018: Figs. 16–17). The obtained tree with morphological data recovered Psalmopoeus as the sister group of (Tapinauchenius (Ephebopus (Pseudoclamoris + Aviculariinae))), while with molecular data recovered the clade (Psalmopoeinae + Schismatothelinae) as sister group of Aviculariinae, as follow (Aviculariinae (Schismatothelinae (Psalmopoeus (Pseudoclamoris (Ephebopus + Tapinauchenius))))) (Hüsser 2018). The last tree recovered Psalmopoeus as paraphyletic group. Cifuentes (2018) in a taxonomic revision and cladistic analysis of Psalmopoeus and Tapinauchenius , based on morphological characters, recovered the clade (Ephebopus (Tapinauchenius + Psalmopoeus )) as monophyletic, related as the sister group of the Aviculariinae. Both genera Tapinauchenius and Psalmopoeus were recovered as monophyletic; nevertheless, no Schismatothelinae taxa were included in the analysis (Cifuentes 2018).

Traditionally, several authors have highlighted the taxonomic difficulties of Theraphosidae and the problems to delimit species, because of its great morphological homogeneity (Raven 1990, Bertani 2000; Perafán and Pérez-Miles 2014); Aviculariinae is no exception. Therefore, deep taxonomic studies and additional molecular analyses are necessary in order to know the identity of the species and attain better resolution of the relationships inside this group. Tapinauchenius and Psalmopoeus have variety and stability in some characters (sexual characters, setae of the legs, morphology of the maxillae lyra, and strikers) that permit the identification of groups and species. The addition of those characters in cladistic analyses will therefore attempt to better resolve the trees and improve the comparison with earlier hypotheses (Cifuentes 2018).

The validity of Psalmopoeinae as a monophyletic subfamily, as well as the phylogenetic relationships within the group are still questionable. However, we have preferred to maintain the two proposed subfamilies within the group of Neotropical arboreal tarantulas and their kin, according to the recent molecular evidence, for taxonomic treatment within this chapter: Aviculariinae and Psalmopoeinae.

4.2 Taxonomy

4.2.1 Aviculariinae Simon, 1892

Type species: Avicularia avicularia (Linnaeus, 1758).

Genera included: Antillena Bertani, Huff and Fukushima, 2017, Avicularia Lamarck, 1818, Caribena Fukushima and Bertani, 2017, Iridopelma Pocock, 1901, Pachistopelma Pocock, 1901, Typhochlaena C.L. Koch, 1850 and Ybyrapora Fukushima and Bertani, 2017.

Note: recent molecular study carried out by Lüddecke et al. (2018) considered Stromatopelma and Heteroscodra , distributed in West and Central Africa, out of Aviculariinae, composing the family Stromatopelminae together with Encyocratella . Foley et al. (2019), Hüsser (2018), and Lüddecke et al. (2018) recovered Ephebopus , Psalmopoeus and Tapinauchenius in a clade closely related to Schismatothelinae before with the rest of the Aviculariinae taxa.

Diagnosis: Aviculariinae subfamily can be recognized by the conjunction of the following characters: legs without spines; scopulae in tarsus and metatarsus laterally extended, mainly on anterior legs, giving a spatulate appearance (Fig. 4.2); absence of spiniform setae on prolateral maxillae and presence of abdominal urticating setae type II (most species, absent in adult females of both I. marcoi Bertani, 2012 and Pachistopelma ). Females with spermathecae long and completely separated. Males with tibia I with a spinose spur (Fig. 4.5a) (except Typhochlaena , Ybyrapora and some Avicularia , in which it’s lacking), and palpal bulb with subtegulum not extended, and embolus long and thin without keels (except Antillena ) (Bertani 2012; Fukushima and Bertani 2017).

Fig. 4.5
figure 5

Male tibial apophysis in Aviculariinae and Psalmopoeinae, ventral view. (a) Avicularia sp. (b) Psalmopoeus sp.

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Distribution: Southern Mexico, Central America, some Caribbean islands, and northern and central South America.

Taxonomic Key for the New World Aviculariinae

(Based on Bertani 2012; Fukushima and Bertani 2017)

  1. 1.

    Adults with sternum as long as wide, truncated behind; posterior lateral spinnerets with domed, short distal article. Males without both tibial spur and spiniform process on the cymbium (Bertani 2012: Figs. 1–28) .......................Typhochlaena

    • Sternum longer than wide; posterior lateral spinnerets with digitiform distal article. Males with tibial spur and spiniform process on the cymbium ..............................................................................................................................2

  2. 2.

    Anterior row of eyes straight or slightly procurved. Females with abdomen dorso-ventrally flattened and without urticating setae (Bertani 2012: Figs. 29–80) ........................................................................................................Pachistopelma

    • Anterior row of eyes strongly procurved. Females with abdomen not flattened and with urticating setae type II (Fukushima and Bertani 2017: Figs. 13, 15–17) ............................................................................................................3

  3. 3.

    Spermathecae very short and broad, with distal half strongly sclerotized (Fukushima and Bertani 2017: Fig. 284). Male palpal bulb with very flattened embolus and well-developed keels (Fukushima and Bertani 2017: Figs. 285–288) ....................................................................................................................... Antillena

    • Spermathecae long, not strongly sclerotized. Male palpal bulb lacking keels ....................................................................................................................…4

  4. 4.

    Urticating setae type II very slender on a conspicuous patch on abdomen dorsum (Fukushima and Bertani 2017: Figs. 18, 254) ........................................Caribena

    • Urticating setae type II stout spread over most abdominal area (Fukushima and Bertani 2017: Figs. 15–17, 302–304.) .....................................................5

  5. 5.

    Spermathecae lacking an accentuated outwards curvature medially, with distal portion far from the base (Fukushima and Bertani 2017: Fig. 14). Male withtibial spur on legs I and II (Bertani 2012: Figs. 85, 86) .............................… Iridopelma

    • Spermathecae with an accentuated outwards curvature medially (Fukushima and Bertani 2017: Fig. 21). Males lacking tibial apophysis on leg II .............6

  6. 6.

    Spermathecae virtually non-sclerotized (Fukushima and Bertani 2017: Figs. 257–259). Male cymbium with or without a process on retrolateral lobe, tibial spur on leg I absent (Fukushima and Bertani 2017: Fig. 308) (southeastern and part of northeastern Brazil) ..................................................................................Ybyrapora

    • Spermathecae with a well-sclerotized area (Fukushima and Bertani 2017: Fig. 21). Male cymbium with or without a process on retrolateral lobe, tibial spur on leg I well-developed or tibia with a discrete elevation covered by a cluster of setae on apical portion (Fukushima and Bertani 2017: Figs. 309–311) (México, Central America and South America) ...............................Avicularia

Antillena Bertani, Huff and Fukushima, 2017

Type species: Antillena rickwesti (Bertani and Huff, 2013)

Species included: Antillena rickwesti

Diagnosis: Antillena females can be distinguished by having two very short, broad, and apically sclerotized spermathecae (Fukushima and Bertani 2017: Fig. 284), and by spiniform setae in prolateral and/or retrolateral side of coxae I–IV. Males differ by the copulatory palpal bulb with embolus very flattened and with keels (Fukushima and Bertani 2017: Figs. 285–288). Additionally, males are characterized by abdominal leaf pattern coloration (Fukushima and Bertani 2017: Fig. 294) (Fukushima and Bertani 2017).

Distribution: Dominican Republic (Bertani and Huff, 2013)

Avicularia Lamarck, 1818

Type species: Avicularia avicularia (Linnaeus, 1758)

Species included: Avicularia avicularia, Avicularia caei Fukushima and Bertani, 2017, Avicularia glauca Simon, 1891, Avicularia hirschii Bullmer, Thierer-Lutz and Schmidt, 2006, Avicularia juruensis Mello-Leitão, 1923, Avicularia lynnae Fukushima and Bertani, 2017, Avicularia merianae Fukushima and Bertani, 2017, Avicularia minatrix Pocock, 1903, Avicularia purpurea Kirk, 1990, Avicularia rufa Schiapelli Gerschman, 1945, and Avicularia taunayi (Mello-Leitão, 1920), and Avicularia variegata F. O. Pickard-Cambridge, 1896.

Diagnosis: Avicularia can be distinguished from some Aviculariinae, except Caribena , Iridopelma , Typhochlaena , and Ybyrapora, by having the anterior row of eyes procurved (Fukushima and Bertani 2017). It can be recognized from those groups by the following: from Caribena by stout urticating setae on abdomen dorsum and rounded process of cymbium (Fukushima and Bertani 2017: Figs. 15–17, 307); from Iridopelma males by lacking tibial apophysis on tibiae II and females by spermathecae long with accentuated medial curvature directed outward (Fukushima and Bertani 2017: Fig. 21); from Typhochlaena by digitiform apical article in PLS (Fukushima and Bertani 2017: Fig. 10); and from Ybyrapora by the sclerotized spermathecae in females and the presence of developed tibial apophysis in males (Fukushima and Bertani 2017: Figs. 309–311), except A. minatrix, A. lynnae, A. caei, and A hirschii. Males of these species can be differentiated from Y. diversipes by the embolus less curved in frontal view (Fukushima and Bertani 2017: Fig. 30), from Y. sooretama and Y. gamba by the presence of a well-developed process on cymbium (Fukushima and Bertani 2017: Fig. 307), except A. minatrix; A. minatrix can be distinguished from the last Ybyrapora species mentioned by the abdomen coloration, dorsum black with orange spots on its side (Fukushima and Bertani 2017: Fig. 89).

Distribution: Mexico; Central America: Costa Rica, Panama; South America: Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, Trinidad and Tobago and Venezuela. In Brazil, it occurs in the states of Roraima, Amapá, Amazonas, Pará, Maranhão, Tocantins, Acre, western Bahia, Rondônia, Mato Grosso, Goiás, Minas Gerais, São Paulo, and The Distrito Federal (Fukushima and Bertani 2017).

Caribena Fukushima and Bertani, 2017

Type species: Caribena laeta (C. L. Koch, 1842)

Species included: Caribena laeta, and Caribena versicolor (Walckenaer, 1837).

Diagnosis: Caribena species are characterized by the presence of a conspicuous abdominal patch of type II urticating setae, setae long and slender (more than 1 mm long and less than 0.009 mm wide) (Fukushima and Bertani 2017: Figs. 18, 243, 241, 254). Additionally, males have a sharp spiniform process in the retrolateral lobe of cymbium (Fukushima and Bertani 2017: Fig. 306) (Fukushima and Bertani 2017).

Distribution: Puerto Rico, the U. S. Virgin Island , and Martinique (Fukushima and Bertani 2017).

Iridopelma Pocock, 1901

Type species: Iridopelma hirsutum Pocock, 1901

Species included: Iridopelma hirsutum, Iridopelma katiae Bertani, 2012, Iridopelma marcoi Bertani, 2012, Iridopelma oliverai Bertani, 2012, Iridopelma vanini Bertani, 2012 and Iridopelma zorodes (Mello-Leitao, 1926).

Diagnosis: Iridopelma males are characterized by having tibial spurs on leg I and II (Bertani 2012: Figs. 85, 86) and females by having the anterior row of eyes strong procurved (Fukushima and Bertani 2017: Fig. 13). The last characteristic is shared with Avicularia and Typhochlaena , but it can be recognized from those genera, respectively, by having spermathecae lacking accentuated curvature (Fukushima and Bertani 2017: Fig. 14), and by the distal PLS segment digitiform (Fukushima and Bertani 2017: Fig. 10) (Bertani 2012).

Distribution: Northeastern Brazil, from the state of Bahia, northwards, and some records for states of Para and Tocantins (Bertani 2012).

Pachistopelma Pocock, 1901

Type species: Pachistopelma rufonigrum Pocock, 1901

Species included: Pachistopelma bromelicola Bertani, 2012, and Pachistopelma rufonigrum.

Diagnosis: Pachistopelma differs from those of other aviculariines by having the anterior row of eyes straight or slightly procurved (Bertani 2012: Fig. 37).

Note: It is worth noting that the characteristic of anterior row of eyes straight or slightly procurved is shared with Ephebopus , Tapinauchenius , and Psalmopoeus genera (Psalmopoeinae). However, Pachistopelma can be recognized from those genera by having legs aspinose, abdominal urticating setae (except in mature female), males with a spinose spur on tibia I, and females with abdomen dorso-ventral flattened (Bertani 2012: Fig. 34) and paired long spermathecae with slight curvature medially, without any constriction (Bertani 2012: Figs. 58–65) (Bertani 2012). Distribution: Northeastern Brazil, from the state of Rio Grande do Norte to state of Bahia, mostly in the coastal region (Bertani 2012).

Typhochlaena C. L. Koch, 1850

Type species: Typhochalena seladonia (C.L. Koch 1841)

Species included: Typhochalena amma Bertani, 2012, Typhochalena costae Bertani, 2012, Typhochalena curumin Bertani, 2012, Typhochalena seladonia, and Typhochalena paschoali Bertani, 2012.

Diagnosis: Typhochlaena can be differentiated from other aviculariines by the short, domed apical segment of PLS (Bertani 2012: Fig. 21), and adults with a sternum as long as wide, truncated behind (Bertani 2012: Fig. 20). They are characterized by small sizes. Additionally, males lack tibial spurs and spiniform process in the cymbium (Bertani 2012).

Distribution: Brazil: Northeastern, part of Central-West (Tocantins state), and part of southeastern (Espirito Santo state) (Bertani 2012).

Ybyrapora Fukushima and Bertani, 2017

Type species: Ybyrapora sooretama (Bertani and Fukushima 2009).

Species included: Ybyrapora diversipes (C.L. Koch 1842), Ybyrapora gamba (Bertani and Fukushima 2009), and Ybyrapora sooretama.

Diagnosis: Ybyrapora species can be distinguished from some aviculariine by having an anterior row of eyes procurved; a characteristic that is shared with Avicularia , Caribena , Iridopelma , and Typhochlaena . It can be distinguished from Avicularia by the presence of virtually non-sclerotized spermathecae in females (Fukushima and Bertani 2017: Figs. 257–259), while males differ by lacking developed tibial apophysis (Fukushima and Bertani 2017: Fig. 308), except from A. minatrix, A. lynnae, A. caei, and A hirschii. Males of Y. diversipes can be differentiated from those four species by the presence of a very long embolus, strongly curved in the frontal view (Fukushima and Bertani 2017: Fig. 278); Y. sooretama and Y. gamba differ from those of A. lynnae, A. caei, and A. hirschii by lack a well-developed process on cymbium (Fukushima and Bertani 2017: Fig. 305); Ybyrapora males can be distinguished from A. minatrix by the presence of a single red or dark longitudinal stripe on the abdomen dorsum (Fukushima and Bertani 2017: Fig. 297). Ybyrapora can be distinguished from Caribena by the presence of stout urticating setae on the abdomen dorsum in both males and females, and the absence of a sharp process with thin setae on the retrolateral lobe of the cymbium in males; from Iridopelma by males lacking a tibial apophysis on tibiae II and females by the presence of a long spermathecae medially curved and directed outwards; and from Typhochlaena by the presence of a digitiform apical article in PLS (Fukushima and Bertani 2017).

Distribution: Brazil, from Bahia to southern Rio de Janeiro (Fukushima and Bertani 2017).

4.2.2 Psalmopoeinae Samm and Schmidt (2008)

Type species: Psalmopoeus cambridgei Pocock, 1895

Genera included: Ephebopus Simon, 1892, Psalmopoeus Pocock, 1895, Pseudoclamoris Hüsser, 2018, and Tapinauchenius Ausserer, 1871 (Fig. 4.6).

Fig. 4.6
figure 6

Psalmopoeinae spiders habitus. (a) Ephebopus murinus, male. (b) Ephepobus cyanognathus, female. (c) Pseudoclamoris gigas, female. (d) Tapinauchenius polybtes, female. (e, f) Psalmopoeus ecclesiasticus, (e) juvenil, (f) female. (Photos: a–d courtesy of Rick West; e–f Carlos Perafán)

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Diagnosis: Males and females of Psalmopoeinae can be distinguished from the majority of Theraphosidae subfamilies, except Aviculariinae, by the scopulae in tarsus and metatarsus laterally extended, giving a spatulate appearance. They differ from most Aviculariinae species by the absence of abdominal urticating setae; urticating setae only present in palpal femur of Ephebopus . Also, by the anterior row of eyes straight (except from Pachistopelma ). Additionally, Psalmopoeus , Tapinauchenius , and Pseudoclamoris males can be distinguished by the long covering setae laterally directed in their legs (Fig. 4.7a) and tibial apophysis composed by two branches (Fig. 4.5b) (Hüsser 2018).

Fig. 4.7
figure 7

(a) Psalmopoeus ecclesiasticus, showing the long lateral setae in the legs. (b) Psalmopoeus cambridgei, dorsal view of palp and leg I, showing the group of smooth short setae. Arrows point to the lateral setae and the group of smooth short setae in legs

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Distribution: Mexico; Central America: Belize, Costa Rica and Panama, Caribbean islands: Saint Vincent Island , Saint Lucia island , Union island , The Grenadines, Trinidad and Tobago islands and South America: Brazil, Colombia, Ecuador, French Guiana, Peru, and Venezuela (World Spider Catalog 2020; West 1983).

Taxonomic Key for Psalmopoeinae

  1. 1.

    Presence of a patch of urticating setae (type V) on prolateral distal palpal femora (West et al. 2008: Figs. 19–20; Fukushima and Bertani 2017: Fig. 4) ..............................................................................................................................Ephebopus

    • Absence of a patch of urticating setae on femora ..........................................2

  2. 2.

    Stridulatory setae forming a lyriform organ on prolateral maxillae (Fig. 4.4a, c; Fukushima and Bertani 2017: Fig. 11) ................................................................3

    • Stridulatory setae absent on maxillae ........................................Tapinauchenius

  3. 3.

    Thick bristles on the maxillary lyra disposed in one row (Fig. 4.4a; Fukushima and Bertani 2017: Fig. 11) ............................................................... Psalmopoeus

  4. 4.

    Slender bristles on the maxillary lyra arranged in an oval patch, composed by several rows of slender setae (Fig. 4.4c; Hüsser 2018: Fig. 2) .....................................................................................................Pseudoclamoris

Ephebopus Simon, 1892

Type species: Ephebopus murinus (Walckenaer, 1837)

Species included: Ephebopus cyanognathus West and Marshall, 2000, Ephebopus foliatus West, Marshall, Fukushima and Bertani, 2008, Ephebopus murinus, Ephebopus rufescens West and Marshall, 2000, and Ephebopus uatuman Lucas, Silva and Bertani, 1992.

Diagnosis: Ephebopus can be distinguished from all Theraphosidae genera by the presence of a patch of urticating setae (type V) on prolateral distal palpal femora (West et al. 2008: Figs. 19–20; Fukushima and Bertani 2017: Fig. 4).

Distribution: Northeastern and Central Brazilian Amazon, French Guiana, Southern Suriname, and Southwestern Guyana (West et al. 2008).

Psalmopoeus Pocock, 1895

Type species: Psalmopoeus cambridgei Pocock, 1895

Species included: Psalmopoeus cambridgei, Psalmopoeus ecclesiasticus Pocock, 1903, Psalmopoeus emeraldus Pocock, 1903, Psalmopoeus intermedius Chamberlin, 1940, Psalmopoeus irminia Saager, 1994, Psalmopoeus langenbucheri Schmidt, Bullmer and Thierer-Lutz, 2006, Psalmopoeus plantaris Pocock, 1903, Psalmopoeus pulcher Petrunkevitch, 1925, Psalmopoeus reduncus (Karsch, 1880), and Psalmopoeus victori Mendoza, 2014.

Diagnosis: The species of Psalmopoeus can be distinguished by the presence of a lyriform organ composed by one row of thick bristles on prolateral maxillae in conjunction with a row of long filiform setae strikers on the base of chelicerae (Fig. 4.4a, b). Additionally, Psalmopoeus have a group of short and smooth hair on the retrolateral side of the palpal trochanter and femur, and on prolateral and retrolateral sides of trochanter and femur of leg I (Fig. 4.7b) (Absent in Tapinauchenius and Pseudoclamoris ) (Cifuentes 2018).

Distribution: Mexico; Central America: Belize to Panama; Caribbean: Trinidad and Tobago islands; South America: Colombia, Ecuador, Venezuela, Guyana, and Brazil.

Pseudoclamoris Hüsser, 2018

Type species: Pseudoclamoris gigas (Caporiacco, 1954)

Species included: Pseudoclamoris elenae (Schmidt, 1994), Pseudoclamoris gigas, and Pseudoclamoris burgessi Hüsser, 2018.

Diagnosis: Pseudoclamoris species resemble Psalmopoeus genus by the presence of a lyriform organ on prolateral maxillae. However, Pseudoclamoris can be distinguished by having an oval maxillary lyra composed by several rows of slender setae (thick bristles on Psalmopoeus ) (Fig. 4.4c). Additionally, females have spermathecae with one subsegmented apical lobule (Fig. 4.8e) or with multiple apical lobules (Fig. 4.8f).

Fig. 4.8
figure 8

Morphology of the female’s spermatheca in Avicularia and Psalmopoeinae. (a) Avicularia sp. (b) Ephebopus rufescens. (c) Psalmopoeus irminia. (d) Tapinauchenius polybotes. (e) Pseudoclamoris gigas. (f) Pseudoclamoris elenae (Photos: a, c–f Yeimy Cifuentes; b courtesy of Rick West)

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Distribution: Colombia, Ecuador, Brazil, Peru, and French Guiana.

Tapinauchenius Ausserer, 1871

Type species: Tapinauchenius plumipes (C. L. Koch, 1842)

Species included: Tapinauchenius brunneus Schmidt, 1995, Tapinauchenius concolor (Caporiacco, 1947), Tapinauchenius cupreus Schmidt and Bauer, 1996, Tapinauchenius latipes L. Koch, 1875, Tapinauchenius plumipes (C. L. Koch, 1842), Tapinauchenius polybotes Hüsser, 2018, Tapinauchenius rasti Hüsser, 2018, Tapinauchenius sanctivincenti (Walckenaer, 1837), and Tapinauchenius violaceus (Mello-Leitão, 1930).

Diagnosis: Tapinauchenius can be distinguished from Ephebopus by lack urticating setae, and from Psalmopoeus and Pseudoclamoris by the absence of a maxillary lyra. Additionally, males have palpal bulb embolus with an apical constriction, small and curved ventrally tip (Fig. 4.9b) (except in T. cupreus), and known females have spermathecae with one apical lobule (Fig. 4.8d) (Cifuentes 2018).

Fig. 4.9
figure 9

Morphology of copulatory palpal bulb in Aviculariinae and Psalmopoeinae. (a) Avicularia sp. (b) Tapinauchenius plumipes

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Distribution: Caribbean: Saint Vincent island , Saint Lucia island , Union island , Trinidad and Tobago island ; South America: Colombia, Ecuador, Venezuela, Guyana, Suriname, French Guiana, and Brazil.

4.3 Distribution and Natural History

One of the most important and conspicuous characteristics in the arboreal tarantulas is the presence of very well-developed claw tufts and scopulae on the tarsi and metatarsi. These structures participate in the adhesion mechanisms, transcendental in predatory and locomotory function, which facilitate the climbing and descending ability on vertical surfaces. Likewise, claw tufts and scopulae played an important role in the arboreal spiders' evolution, maybe because it was involved in the colonization from the ground to vegetation (Pérez-Miles et al. 2015). On the other hand, most aviculariines species possess urticating setae as a defense mechanism, an evolutionary novelty that appeared only in tarantulas of the New World. A detailed analysis of function and morphology of adhesive setae and urticating setae is found in the Chapters 12 and 9, respectively.

The majority of Neotropical arboreal aviculariine species present an outstanding ontogenetic differentiation in the coloration patterns. Usually, juveniles present abdominal patterns of longitudinal and/or transverse stripes, with striking colors, while in adults these patterns tend to disappear and black, bluish, and reddish colors are predominant. There is also sexual dimorphism in the coloration of mature individuals (Figs 4.1a–d). However, contrary to most aviculariines, ontogenetic changes are not known in species of Typhochlaena (Bertani 2012). The ontogenetic and sexual differences in color contributed in the past to erroneous descriptions of different species, because the coloration patterns were used before sexual structures as valid characters to separate species. This has brought difficulties for the current taxonomy and the consequent long list of synonymized species.

Aviculariinae species inhabit predominantly tropical lowland wet forest. Avicularia is distributed in the tropical areas of the Americas, from Costa Rica to Bolivia and Brazil, although there are also some unofficial records from southern Mexico (Fukushima and Bertani 2017). In addition to their arboreal habits, usually they make their silk retreats on vegetation but they also tend to use the human structures for establishing their retreats. These habits can change throughout their life development , as is known for many tarantulas. Stradling (1994) reported that A. avicularia , in a population closely related to human settlements in Trinidad, use leaves of herbaceous plants, tree barks, branches of tree trunks for their silk retreats, and that the juveniles in first instars use leaves of low growing plants.

Avicularia has type II abdominal urticating setae which present a peculiar defense mechanism. These setae are transferred by direct contact when the spider is disturbed, from the abdomen against the target (Bertani and Marques 1996), and are not expelled into the air, as in the majority of Theraphosinae (except Kankuamo Perafán, Galvis and Gutiérrez 2016). Urticating setae type II and VII (present in Kankuamo) have a different shape and size in relation to other urticating setae; they are thicker and heavier than the slender setae of theraphosines, preventing them from being carried by the air (Cooke et al. 1972; Bertani and Marques 1996; Perafán et al. 2016). A particularity of the urticating setae type II is the basal localization of the penetrating tip being very close to the supporting stalk, which gives it a special release mechanism: In contact, the urticating setae pivots on its stalk, so that the apical end moves away from the target, while the basal penetration tip instead lodges into the target as the stalk releases (see Bertani and Marques 1996: Fig. 3). However, there is a curious exception observed in C. versicolor, whereby it has urticating setae type II but its releasing mechanism is similar to theraphosines. According to Bertani et al. (2003), this constitutes a case of convergence between aviculariines and theraphosines. The type II urticating setae of C. versicolor are slender, similar to Theraphosinae urticating setae, and this morphology facilitates to said setae to go airborne.

Iridopelma , Pachistopelma , and Typhochalena are principally distributed in Atlantic forests, Restinga, and Caatinga areas of north and northeastern of Brazil. The majority of Iridopelma species live in dry open environments (Bertani 2012). These spiders generally build their retreats with two leaves connected with silk , or in a rolled single leaf, although I. zorodes and I. katiae use bromeliads as a refuge. This change in the habitat has been considered by Bertani (2012) as a derived condition in the group according to its cladistic analysis, which could have occurred due to climatic changes that carried a shift in the vegetation, forming grasslands on rocky and sandy soils, leading to the use of bromeliads and rocks as the available refuges for those spiders (Bertani 2012). Under this same scenario, Pachistopelma spp. are strictly associated with bromeliads (Santos et al. 2002, 2004; Dias et al. 2000; Dias and Brescovit 2003, 2004; Bertani 2012), as well some Avicularia juveniles that eventually use these refuge plants (Bertani 2012); nonetheless, other aviculariines are uncommon in bromeliads (Bertani 2012).

Pachistopelma rufonigrum is a species from Restinga vegetation and apparently strictly-dependent of bromeliads as a resource of water and as a refuge (Bertani 2012; Almeida-Silva et al. 2008), as well as P. bromelicola, distributed in the Brazilian Atlantic forest, Restinga, and Caatinga areas (Bertani 2012). Typhochlaena species are also found in the Brazilian Atlantic forest, but T. costae have been reported in drier environments (Bertani 2012). Some of these species construct silk retreats under loose tree bark, or under low tree leaves (Bertani 2012), and there is evidence that T. seladonia and T. costae close their shelters with a thin lid (Andre and Hüsser 2018).

Ephebopus species are distributed in the Amazonian rainforest, from northeastern and central Brazilian Amazon, French Guiana, southern Suriname, and southwestern Guyana (West et al. 2008). In relation to their shelters, West et al. (2008) described older juvenile and adult E. murinus refuges as fossorial channels ending in a blind chamber with a burrow entrance that has a large and elaborate trumpet-shaped turret of silk , in contrast to juveniles that build silk refuges inside terrestrial bromeliads. Other species have been found in retreats in hollow logs and stems, both on and above the ground, in holes and hollows of standing trees, in arboreal termite nests, and in mosses on the sides of shaded rock faces; additionally, they can extend its retreat with tubular silk and camouflage it with soil and vegetative debris (West et al. 2008). Marshall and West (2008) made emphasis in the ontogenetic habitat shift behavior presented by E. murinus in a study made in a population in French Guiana. They observed that early instars spiderlings constructed tubular silk refuges in the vegetation above the ground (this correlated with the presence of bromeliads), and the older juveniles and adult females were found in retreats in the ground. They theorized that the ontogenetic habitat shift can be considered as a strategy for avoiding intraspecific competition and cannibalism, but they also suggested that it is possible that the early instars retrieve an ancestry habit (Marshall and West 2008). Retreats of E. uatuman and E. cyanognathus have been found in damp soil covered by litter and were described as flare-mouth burrows, with the entrance surrounded by a collar of leaves attached by silk and the channel ending in a deep chamber (West et al. 2008). E. rufescens was found above the ground (1–4 m) with no evidence of retreats on the soil, and E. foliatus has been reported as arboreal (West et al. 2008).

Ephebopus represents an exceptional case in the evolution of urticating setae in tarantulas of the New World. It presents an urticating setae patch on the distal prolateral face of palpal femora, composed by setae described as type V (Marshall and Uetz 1990). In contrast to the majority of aviculariines, these setae are released to the air by the movement of the basal segment of the chelicerae against the area of the urticating setae (Lucas et al. 1991; Foelix et al. 2009).

Psalmopoeus has a fairly wide Neotropical distribution, inhabiting Amazonian forest from Ecuador, Colombia, Brazil and Venezuela; Andean and Pacific regions from Ecuador and Colombia; dry forest from Andean and Caribbean regions in Colombia; tropical forest of Panama, Costa Rica, Belize, México, and Trinidad and Tobago islands. In addition, they are the only known arboreal tarantulas found in the Andean forest. Psalmopoeus is recognized by its arboreal habits and abilities as an opportunistic taxon. Mendoza-M (2014) reported that P. victori construct retreats in tree cavities in rainforest of Veracruz, Mexico, from an area that is under pressure from human activities; P. pulcher has been reported as opportunistic, adapting an arboreal lifestyle (Gabriel and Sherwood 2018), and has been observed living in environments close to human settlements (personal observations). Records in Colombia indicate that they construct retreats in palm trees, and are associated with dry forest remnants of Caribbean regions (information of museum specimens).

Valerio (1979) recorded P. reduncus as an arboreal species, living up to 4 m above the ground, hidden in trunk cavities and bases of palm trees in forested areas in Costa Rica; P. irminia was reported in the Paracaima region of the Amazonian area of Brazil at 900 m.a.s.l., predominantly covered by savanna vegetation, in a tubular silk retreats at 1.60 m above into rocky cavities (Bertani et al. 2016). Saager (1994) described this species from the “Gran Sabana” in Venezuela, an area surrounded by tropical forest galleries inside Mahogany and other tree roots, in cavities, lianas, and under tree barks (Saager 1994). P. ecclesiasticusis distributed in Colombia and Ecuador, in the biogeographic Chocó region , it has been found in the Pacific foggy forest at 1400 m.a.s.l. from Nariño, Colombia, living over trunks, and juveniles in retreats inside mosses that cover standing trees. This data constitutes the highest altitudinal limit registered for the genus.

Tapinauchenius has been reported as opportunistic, even constructing retreats in abandoned human constructions (personal communication with R. Bertani). Apparently, Pseudoclamoris species are restricted to the Amazonian rainforest, but information about microhabitats has not been reported.

4.4 Conservation

It is widely known that large theraphosids are commonly sold and kept as exotic pets in many countries, due to their exotic beauty, highlighted by their colors, easy maintenance, and long life in captivity. Although, some tarantula dealers act under legal regulations, most of the trade is illegal through animal trafficking (Cifuentes and Perafán personal observations). This activity that is not only used as a lucrative business but also used as scientific traffic. These activities, added to the environmental pressures that all biota of the Earth face due to contamination and reduction of natural habitats, have more than one Aviculariinae species on alert. Unfortunately, we are still far from calculating the full scale of these problems.

Bertani and Fukushima (2009) discussed some traits about the conservation status of the endemic species from Brazilian Atlantic Forest, Y. diversipes, Y. sooretama, and Y. gamba. As expected, the three species are considered as affected, especially by the reduction and fragmentation of their habitat range caused by deforestation in the ecosystems. The Atlantic Forest is one of the most emblematic biogeographic regions of South America, considered as one hotspot of biodiversity and probably the most endangered ecosystem in the planet (Galindo-Leal and Câmara 2003); it is an area of high endemicity, and is considered to house at least 60% of the planet’s diversity (Galindo-Leal and Câmara 2003). Bertani and Fukushima (2009) also considered the illegal wildlife trafficking of Y. diversipes as one factor that can be affecting the populations; they reported in 2009 that the species was commercialized in Europe, Asia, and United States, with high online sales demand. They consider that, due to the illegal collection, the restricted distributions and the altered habitats, all gravely affecting the populations, the inclusion of these species in the CITES and IUCN threatened list of species should be considered (Bertani and Fukushima 2009).

According to Bertani (2012), some species of Pachistopelma , Iridopelma , and Typhochlaena are very endemic : rare (Typhochlaena spp.), specialist (Pachistopelma spp. as a result of being strictly bromeliaceous), and scarcely studied (Iridopelma are distributed only in threatened areas of Brazilian Atlantic forest, Restinga, and Caatinga). These species can be affected by the reduction of the distribution areas and threatened microhabitats as the bromeliad species of the distribution regions (Bertani 2012).

Wildlife trafficking is one of the most lucrative illegal activities, and it has been reported that only 10% of the captured animals arrive alive to the destination, due to the stress and mistreatment of the animals in the transportation (Caldas et al. 2018). It is considered that the rate of survival of rescued animals, along with the successful reintroduction to their natural habitats, is low or without benefit for the species (Caldas et al. 2018). An extraordinary case was reported by Caldas et al. (2018) where they recorded the study over a case of wildlife trafficking of 52 individuals of Pachistopelma bromelicola (Aviculariinae) that were found by the Brazilian Institute of the Environment and Renewable Natural Resources (IBAMA, portuguese acronym) in cruel and poor conditions, transported inside matchboxes and presumably for being sold in Slovakia. Of the 52 individuals found captive, only 22 were alive. During the rehabilitation process 12 of them died and from the remainder, only 4 presented traits of good health (molting). After monitoring the live animals, the researchers realized that some of those spiders presented protuberances “tumor-like” on their opisthosoma, a zoonotic concern for being reintroduced to their natural habitat . Finally, from the total of individuals only 7 (13%) survived (Caldas et al. 2018).

Studies in Aviculariinae and Psalmopoeinae populations are not developed, so the state of the species inside the principal list for animal conservation is generally lacking in information; this information vacuum does not permit the regulation in the use of the natural resources of the region .

4.5 Final Considerations

There is an interesting and deep discussion currently about the monophyly of the Neotropical arboreal theraphosids. As it happens widely in the animal world, the evidence suggests that adaptation to arboreal life to be an evolutionary convergence in tarantulas. The latest phylogenetic analyses also suggest a close relationship of these taxa with South American lineages, and each other, rather than with lineages of African or Asian arboreal theraphosids. The evolutionary evidence theorized that the South American theraphosids make up a unique and ancient lineage . Although the growing interest in the study of Neotropical arboreal tarantulas has improved their taxonomic knowledge, there are still few works related to their natural history and there are still many unsolved questions about the ecology and evolution of the urticating setae, as well as the stridulatory structures. Deepening these fields of research will not only expand the knowledge of this fascinating group but also affect the decision-making related to its conservation and the environments it occupies, which are generally just relicts of natural environments.