A new genus and new species of freshwater Chaetonotidae (Gastrotricha: Chaetonotida) from Brazil with phylogenetic position inferred from nuclear and mitochondrial DNA sequences

Abstract

Most studies of South American freshwater Gastrotricha have focused on the inland waters of Brazil including São Paulo State, Mato Grosso do Sul State, and Pará State. In this paper, we describe a new genus and species, Cephalionotus kisielewskii gen. et. sp. nov. (Chaetonotida, Chaetonotidae), from Minas Gerais State using morphological data and DNA sequence data (18S rDNA and COI genes). The new genus contains a single psammic species collected from high altitude streams. Cephalionotus gen. nov. exhibits a set of autapomorphic characters that easily distinguish it from all other genera of Chaetonotida: extremely large cephalion and hypostomium that completely cover the dorsal and ventral sides of the head, respectively; a single pair of pleurae; peculiar shape and arrangement of dorsal and ventral scales in the posterior trunk region; one paired, very large, keeled scale at the ventral posterior end; and very long adhesive tubes divided into three parts. Affinity of Cephalionotus kisielewskii gen. et sp. nov. with other Chaetonotida (Paucitubulatina) is discussed from morphological and molecular perspectives.

http://zoobank.org/urn:lsid:zoobank.org:pub:5E324696-AB33-42C2-A27A-609B1983D540

Key words:

• inland waters
• meiofauna
• Neotropical biogeographic region
• phylogeny
• psammic
• systematics

Acknowledgements

We express our gratitude to FAPEMIG (ETC 00017-13), Rede ComCerrado (CNPq – 50.6121/2008-09), CNPQ (478825/2013-7), FAPESP (2014/23856-0), and FAEPEX-UNICAMP (2031/15) for financial support; to the staff of the Life Sciences Core Facility (LaCTAD) at the University of Campinas (UNICAMP) for DNA sequencing; to Dr Cecilia Amaral for the use of optical equipment; to Dr Maikon di Domenico and MSc. Noemy Seraphim Pereira for their help with the phylogenetic analyses; and to Laura Hafner for editing the English text. Drs Tobias Kånneby, Antonio Todaro, Rick Hochberg, and Małgorzata Kolicka are also acknowledged for offering suggestions that greatly improved the paper.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

FAPESP [grant number 2014/23856-0], FAEPEX-UNICAMP [grant number 2031/15], CNPQ [grant number 478825/2013-7], Rede ComCerrado/CNPq [grant number 50.6121/2008-09], FAPEMIG [grant number ETC 00017-13].