Gastrotricha: A Marine Sister for a Freshwater Puzzle


Autoria(s): Todaro, M. Antonio; Dal Zotto, Matteo; Jondelius, Ulf; Hochberg, Rick; Hummon, William D.; Kanneby, Tobias; Rocha, Carlos E. F.
Contribuinte(s)

UNIVERSIDADE DE SÃO PAULO

Data(s)

06/08/2013

06/08/2013

01/02/2012

Resumo

Background: Within an evolutionary framework of Gastrotricha Marinellina flagellata and Redudasys fornerise bear special interest, as they are the only Macrodasyida that inhabit freshwater ecosystems. Notwithstanding, these rare animals are poorly known; found only once (Austria and Brazil), they are currently systematised as incertae sedis. Here we report on the rediscovery of Redudasys fornerise, provide an account on morphological novelties and present a hypothesis on its phylogenetic relationship based on molecular data. Methodology/Principal Findings: Specimens were surveyed using DIC microscopy and SEM, and used to obtain the 18 S rRNA gene sequence; molecular data was analyzed cladistically in conjunction with data from 42 additional species belonging to the near complete Macrodasyida taxonomic spectrum. Morphological analysis, while providing new information on taxonomically relevant traits (adhesive tubes, protonephridia and sensorial bristles), failed to detect elements of the male system, thus stressing the parthenogenetic nature of the Brazilian species. Phylogenetic analysis, carried out with ML, MP and Bayesian approaches, yielded topologies with strong nodal support and highly congruent with each other. Among the supported groups is the previously undocumented clade showing the alliance between Redudasys fornerise and Dactylopodola agadasys; other strongly sustained clades include the densely sampled families Thaumastodermatidae and Turbanellidae and most genera. Conclusions/Significance: A reconsideration of the morphological traits of Dactylopodola agadasys in light of the new information on Redudasys fornerise makes the alliance between these two taxa very likely. As a result, we create Anandrodasys gen. nov. to contain members of the previously described D. agadasys and erect Redudasyidae fam. nov. to reflect this novel relationship between Anandrodasys and Redudasys. From an ecological perspective, the derived position of Redudasys, which is deeply nested within the Macrodasyida clade, unequivocally demonstrates that invasion of freshwater by gastrotrichs has taken place at least twice, in contrast with the single event hypothesis recently put forward.

Identificador

PLOS ONE, SAN FRANCISCO, v. 7, n. 2, supl. 1, Part 2, pp. 1127-1131, FEB 14, 2012

1932-6203

http://www.producao.usp.br/handle/BDPI/32514

10.1371/journal.pone.0031740

http://dx.doi.org/10.1371/journal.pone.0031740

Idioma(s)

eng

Publicador

PUBLIC LIBRARY SCIENCE

SAN FRANCISCO

Relação

PLOS ONE

Direitos

openAccess

Copyright PUBLIC LIBRARY SCIENCE

Palavras-Chave #RIBOSOMAL-RNA GENES #4 MOLECULAR LOCI #INTERRELATIONSHIPS #MACRODASYIDA #MORPHOLOGY #PHYLOGENY #MULTIDISCIPLINARY SCIENCES
Tipo

article

original article

publishedVersion