CSIRO PUBLISHING Invertebrate Systematics, 2020, 34, 474–503 https://doi.org/10.1071/IS19037 Cladistic analysis of the Brazilian troglobitic harvestmen genus Iandumoema Pinto-da-Rocha (Opiliones : Gonyleptidae) with the description of three new species: a brief exercise over the use of troglomorphisms in cladistic analysis Ludson Neves de Ázara A,D, Marcos Ryotara Hara B and Rodrigo Lopes Ferreira C ALaboratório de Aracnologia, Departamento de Invertebrados, Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, São Cristóvão, 20.940-040, Rio de Janeiro, RJ, Brazil. BEscola de Artes, Ciências e Humanidades, Universidade de São Paulo, Avenida Arlindo Béttio 1000, Ermelino Matarazzo, 03828-000, São Paulo, SP, Brazil. CCentro de Estudos em Biologia Subterrânea, Departamento de Biologia, Setor de Zoologia Geral, Universidade Federal de Lavras, Lavras, MG, Brazil. DCorresponding author. Email: [email protected] Abstract. From an ecological and evolutionary standpoint, troglobitic organisms are of special interest because they have evolved in, and are restricted to, the subterranean environment. Iandumoema Pinto-da-Rocha, 1997 stands out for being the only Brazilian harvestmen genus with more than one troglobitic species, with three species described from caves in Minas Gerais state. Traditionally, testing the monophyly of troglobitic groups is more challenging than testing groups that do not include troglobites. Many of their shared features might be the result of convergence or parallelism imposed by the cave environment, such as the absence of light, limited and infrequent availability of food resources and low population density, among others. In the case of Iandumoema, this becomes even more difficult because the genus is currently included in the species-rich and polyphyletic subfamily Pachylinae. This study tested the monophyly of this troglobitic genus and proposed the first phylogenetic hypothesis for Iandumoema based on cladistic analysis using morphological data. The analysis included all described species of Iandumoema and three new troglobitic species: I. cuca, sp. nov. (type locality: Itacarambi, Gruta da Água do João Ferreira); I. gollum, sp. nov. (type locality: Presidente Juscelino, Lapa D’Água); and I. stygia, sp. nov. (type locality: Montes Claros, Gruta do Cedro). The matrix comprises 79 characters and 28 terminal taxa: six species of Iandumoema; 14 of Pachylinae; six from other Gonyleptidae subfamilies; one species of Cosmetidae; and one of Metasarcidae. The cladistic analysis resulted in one parsimonious tree (339 steps, consistency index = 0.35, retention index = 0.56). Iandumoema is a monophyletic and well supported genus, nestled among Brazilian ‘Pachylinae’. Three new species are described and an identification key and ecological remarks for all six species of the genus Iandumoema is provided. Additional keywords: Arachnida, caves, Neotropical fauna, taxonomy. Received 3 July 2019, accepted 17 January 2020, published online 26 June 2020 Introduction Pachylinae also includes most of the Brazilian cave- Gonyleptidae Sundevall, 1833 is the largest family of dwelling species (more than 50 from 155 recorded species; harvestman in the Neotropical region, with 16 subfamilies de Ázara and Ferreira 2018). and 830 species in 272 genera (Kury 2013, 2016). Pachylinae The only non-monotypic cave-restricted Pachylinae genus is the richest subfamily, including ~400 species (Kury 2016) is Iandumoema Pinto-da-Rocha, 1997, which is restricted to with four scutal areas and lacking the diagnostic characters limestone caves in Minas Gerais state, Brazil. It was proposed by of the other subfamilies (Hara et al. 2018). It is polyphyletic, Pinto-da-Rocha (1997) to include I. uai from Gruta Olhos and most of the genera are poorly described for D’Água Cave, Itacarambi, Minas Gerais, and was the third- modern standards (Pinto-da-Rocha et al. 2014), which known troglobitic harvestmen species from Brazil (the first being hinders comparative studies, including phylogenetic ones. Spaeleoleptes spaeleus H. Soares, 1966, and the second, Journal compilation Ó CSIRO 2020 Open Access CC BY-NC-ND www.publish.csiro.au/journals/is Cladistic analysis of Iandumoema Invertebrate Systematics 475 Pachylospeleus strinatii Šilhavý, 1974). Pinto-da-Rocha (1997) Materials and methods tentatively placed it in the Pachylinae based on a classification proposed by Roewer (1913). However, he refrained from Abbreviations of the repositories cited include the following. proposing further phylogenetic relationships owing to the ISLA, Colecão¸ de Invertebrados Subterrâneos de Lavras, lack of data on the genital features of other Pachylinae Universidade Federal de Lavras, Lavras, Minas Gerais genera and the unarmed nature of the dorsal scutum and ISNB, Institut Royal des Sciences Naturelles de Belgique free tergites. Twelve years later, Hara and Pinto-da-Rocha MNRJ, Museu Nacional da Universidade Federal do Rio de (2008) described I. setimapocu from Lapa do Zú Cave, São Janeiro, Rio de Janeiro João da Lagoa (erroneously cited as Coracão¸ de Jesus in the MZSP, Museu de Zoologia, Universidade de São Paulo, São original description), Minas Gerais. In that article, the authors Paulo proposed that the distribution of the genus was restricted to SMF, Naturmuseum Senckenberg Sektion Arachnologie, northern Minas Gerais. In 2015, Pinto-da-Rocha et al. Frankfurt am Main. described the first eyeless species of the genus, I. smeagol, Abbreviations used in tables include: Fe, femur; Mt, from Toca do Geraldo Cave and Lapa do Santo Antônio Cave, metatarsus; Pa, patella; Ta, tarsus; Ti, tibia; and Tr, both in Monjolos, Minas Gerais. They suggested that trochanter. The following abbreviations are used in I. smeagol and I. setimapocu might be closely related, but synonymies: cat, catalogue; cit, citation; dis, notes on stressed the need for a proper cladistic analysis to corroborate geographical distribution; and sys, systematic note. We use this relationship. Later papers related to Iandumoema focused the notation #X(Y) in results, where #X means the number of mainly on ecological and conservation aspects, highlighting the character, and (Y), the character state. their vulnerability to anthropogenic actions. All types designated here as destroyed were lost in a fire on Currently, Iandumoema is composed of three species 2 September 2018 along with the bulk of the arachnological (Pinto-da-Rocha et al. 2015), all of them troglobitic, that is, collection of MNRJ (Kury et al. 2018). There is no formal restricted to subterranean environments. Despite the small impediment according to International Commission on number of species, the phylogenetic relationships and Zoological Nomenclature rules to describing a species for monophyly of Iandumoema remain untested. which the holotype was lost before publication. Article One difficulty in including troglobitic taxa in cladistic 73.1.4. (International Commission on Zoological analysis might be related to the apparent controversy Nomenclature 1999) states that ‘Designation of an about using troglomorphisms (or troglobiomorphisms, illustration of a single specimen as a holotype is to be i.e. apomorphic character states related to the hypogean life; treated as designation of the specimen illustrated; the fact Trajano 2012) as characters. According to Marques and Gnaspini that the specimen no longer exists or cannot be traced does not (2001), the inclusion of characters subject to parallel evolution of itself invalidate the designation’. The International would result in error and should be treated in a different manner Commission on Zoological Nomenclature (2017) provides analytically. Desutter-Grandcolas et al.(2003), as well as other more recommendations and explanation regarding this researchers, heavily criticised the approach of Marques and matter. For further discussion on this topic, see Marshall Gnaspini (2001). The criticism was based on the different and Evenhuis (2015), Krell and Marshall (2017)and treatment of those characters before analysis, as well as some references therein. technical flaws (Harris et al. 2003). Desutter-Grandcolas et al. We used the standard names and numbers of the 267 colour (2003) recommended evaluating the outcome of analysis centroids of the National Bureau of Standards Inter-Society including v. excluding the characters associated with Colour Council Colour System (see http://people.csail.mit. troglomorphism. edu/jaffer/Color/Dictionaries#nbs-iscc, accessed 2 November The few examples of cladistic analysis including troglobitic 2018) in the (re)descriptions as described in Kury and Orrico Neotropical harvestmen using morphological data are Pinto- (2006). Scanning electron microscopy was carried out with a da-Rocha (2002) (with Pachylospeleus strinatii Šilhavý, 1974) JSM-6390LV (JEOL, Tokyo) at the Center for Scanning and, recently, Acosta (2019)(withOtilioleptes marcelae Electron Microscopy of Museu Nacional, Universidade Acosta, 2019). Unfortunately, Pinto-da-Rocha (2002)did Federal do Rio de Janeiro, with an accelerating voltage of not provide the matrix or the tree search routine; hence, his 10 kV after sputter-coating with gold–palladium. treatment of troglomorphisms is unknown. Acosta (2019), on Topological nomenclature and integumentary the other hand, included a matrix that is a different version of ornamentation follows Acosta et al.(2007). Terminology that made by Kury and Villarreal (2015). Nevertheless, no for the outline of the dorsal scutum follows Kury and character