Molecular analyses reveal the occurrence of three new sympatric lineages of velvet worms (Onychophora: Peripatidae) in the eastern Amazon basin

Abstract

In the present study, we investigated the possible existence of new lineages of peripatids through comparisons between known Neotropical species and specimens obtained from two locations in Pará, a state in eastern Brazilian Amazonia using a molecular approach based on sequences of the mtDNA genes COI, 16Sr RNA, and 18S RNA. The analyses included also sequences of Asian and African taxa for a more systematic understanding of the phylogenetic relationships within the group. The analysis of the COI, 16S rRNA and 18S RNA sequences permitted the identification of three distinct lineages (A, B and C) based on two different phylogenetic approaches (Bayesian methods and ML). The three lineages presented here are completely distinct from all other peripatid taxa so far defined by molecular data. The presence of specimens of three independent onychophoran lineages occurring in sympatry in the Amazon basin was confirmed in all the analyses, providing consistent support for the phylogenies presented in this study. These findings reinforce the importance of the Amazon region in the diversification of Neotropical peripatids, and indicate that onychophoran diversity is much greater than previously thought, given that the number of taxa found at a single site was equivalent to the total number of allopatric species described for the entire region.

A new giant velvet worm from Costa Rica suggests absence of the genus Peripatus (Onychophora: Peripatidae) in Central America

“…It is important to point out that Macroperipatus and Epiperipatus are problematic genera (Oliveira & Wieloch, 2005, Oliveira et al, 2010, 2012a: considering the general onychophoran biology, they exhibit an unlikely broad distribution (Oliveira et al, 2011;Daniels et al, 2016;Cunha et al, 2017;Sato et al, 2018;Barnes & Daniels, 2019), which causes an overlap in characters with those of other genera. This is especially true in Epiperipatus (Sampaio-Costa et al, 2018), as its diagnostic characters are present in most species.…”

“…Except for the pioneer works of Trewick (1998Trewick ( , 1999Trewick ( , 2000, none other onychophoran's taxonomist has recognized that molecular genetics is the best tool available to identify taxa within this phylum (see Gleeson & Ruhberg, 2010). Particularly, for cryptic species, this is possibly the only way (Briscoe, & Tait, 1995;Daniels et al, 2016;Cunha et al, 2017;Sato et al, 2018). Certainly, morphology and biogeography should be used as auxiliary tools.…”

“…Additionally, some of those characteristics -like interpedal structures, pre-ventral and ventral organs -depend on the contraction of preserved specimens. Moreover, the discovery of cryptic species in both families (Briscoe, & Tait, 1995;Trewick, 1998Trewick, , 1999Trewick, , 2000Ruhberg, & Hamer, 2005;Daniels, Picker, Cowlin, & Hamer, 2009;Daniels, & Ruhberg, 2010;Oliveira et al, 2010;Daniels, 2011;Oliveira, Lacorte, Fonseca, Wieloch, & Mayer, 2011;Daniels, McDonald, & Picker, 2013;Ruhberg, & Daniels, 2013;Myburgh, & Daniels, 2015;Daniels, Dambire, Klaus, & Sharma, 2016;Cunha et al, 2017;Sato, Buckman-Young, Harvey, & Giribet, 2018) has complicated taxonomic distinctions.…”

<strong>History of Onychophorology, 1826-2020</strong><strong> </strong>

“…In this decade, onychophorans were found in unexpected places, like Vietnam (Bá i & Anh, 2012), lava tubes (Espinasa et al, 2015) and urban vegetation (Barrett, 2013), and the first model to explain and predict their survival in highly disturbed habitats, based on their size and habits, was published (Monge-Ná jera, 2018). The only tropical African species was collected again after more than a century (Costa & Giribet, 2016), and the period was also marked by advances in the study of onychophoran genetics and conservation in Brazil (Lacorte, De Sena Oliveira, and Da Fonseca, 2011;Costa, 2016;Cunha et al, 2017;Costa et al, 2018).…”

Cytogenetics and DNA barcode reveal an undescribed Apareiodon species (Characiformes: Parodontidae)

“…Integrative cytogenetic and DNA barcoding studies were effective in detecting chromosome evolution and species richness within supposedly homogeneous taxa of A. affinis (do Nascimento et al , 2018). Indeed, molecular analysis contributes to reveal a hidden biodiversity (Cunha et al , 2017; Ramirez et al , 2017; do Nascimento et al , 2018) and has been widely used for identification and delimitation of neotropical fish species (Carvalho et al , 2011; Pereira et al , 2011, 2013; Ramirez and Galetti Jr, 2015; Machado et al. , 2016).…”