Systematic and phylogenetic analysis of Epiperipatus Clark, 1913 (Onychophora: Peripatidae) based on molecular and morphological data

Author(s)

Cristiano Sampaio Costa

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2016-05-05

Examining board members

Ricardo Pinto da Rocha; Marcos Ryotaro Hara; Daniel José Galafasse Lahr; Marcio Bernardino da Silva; Sergio Antonio Vanin

• Advisor: Ricardo Pinto da Rocha; Fernando Portella de Luna Marques

Abstract

The \"caraibes\" onychophorans present both a large diversity and weakly defined genera. Epiperipatus Clark, 1913 is the largest genus, but it has not been revised so far. This genus is herein incorporated into the currently most comprehensive molecular phylogenetic analysis of Peripatidae, assisted by morphology. Four markers were used: cytochrome c oxidase subunit I (COI), 12S rRNA, 16S rRNA (mitochondrial) and 18S rRNA (nuclear). Moreover, 33 morphological characters were obtained. The dataset was used in two Maximum Parsimony (MP) and one Maximum Likelihood (ML) analyses. In a total of 175 specimens of Onychophora, nine genera and twenty-nine species were examined, eighteen of them belonging to Epiperipatus. We adopted as work hypothesis the MP based on total evidence. The result showed that morphological by itself cannot be used to resolve the phylogenetic relationships of this group, because the number of characters is smaller than the number of terminals examined. Here, Peripatidae was based on molecular data and this conflicts with the characters traditionally used to define genera in the family. It means that clades supported by molecular data shows high morphological disparity which might be reflected on the adaptation to different environments in the Caribbean clade. Also, the result suggests that Epiperipatus seems to be not monophyletic, as it includes others genera and these genera should be synonymized. Epiperipatus presented stable relationships across three clades of Neotropical onychophorans, but it was observed the unstable position of Epiperipatus edwardsii (Blanchard, 1847) and four groups also. To reconcile Epiperipatus systematics with the phylogeny, the monotypic genera Principapillatus Oliveira et al., 2014 and Cerradopatus Oliveira et al., 2015 should be considered as junior synonyms of Epiperipatus. Hence, the new combinations were proposed: Epiperipatus hitoyensis (Oliveira et al., 2012) n. comb. and Epiperipatus sucuriuensis (Oliveira et al., 2015) n. comb.. Moreover, the new species Epiperipatus [sp1] n. sp., Epiperipatus [sp2] n. sp., Epiperipatus [sp10] n. sp., Epiperipatus [sp16] n. sp. and Epiperipatus [sp17] n. sp. were presented and described here. Rooting the Onychophora phylogeny in Peripatopsidae resulted in the Neotropical group as the sister group relationship to the African species, and an apparently ancestral group from Asia. The demonstrated Epiperipatus monophily confirmed its widespread distribution, in the same way as Peripatus. Both are recorded from Central America to Brazil. However, in Brazil, while Peripatus occurs only until the Central-West region, Epiperipatus is found in all Brazilian territories, except in the South region (AU)

• FAPESP's process: 11/20211-0 - Systematic and phylogenetic analysis of Epiperipatus Clark, 1913 based on molecular and morphological data (Onychophora, Peripatidae)
• Grantee: Cristiano Sampaio Costa
• Support Opportunities: Scholarships in Brazil - Doctorate