New data on freshwater psammic Gastrotricha from Brazil

Abstract

Current knowledge of freshwater gastrotrich fauna from Brazil is underestimated as only two studies are available. The present communication is a taxonomic account of the first-ever survey of freshwater Gastrotricha in Minas Gerais State. Samplings were carried out yielding six species of three Chaetonotidae genera: Aspidiophorus cf. pleustonicus, Ichthydium cf. chaetiferum, Chaetonotus acanthocephalus, Chaetonotus heideri, Chaetonotus cf. succinctus, Chaetonotus sp., and also an undescribed species belonging to the genus Redudasys (incertae sedis): this is the first finding of specimens of Redudasys outside of original type locality. These preliminary observations suggest that the knowledge of the biodiversity of Gastrotricha in the Minas Gerais State, as well as in the whole Brazil, will certainly increase as further investigations are undertaken, and that freshwater Macrodasyida may be more common than previously thought.

1. Gastrotricha

“…The body is slender (Kisielewski 1987a) to tenpin-shaped (Todaro et al 2012b), probably due to the presence of mature eggs. Recently, Garraffoni et al (2010) reported the discovery of several specimens of Redudasys that possibly belong to another species. At the posterior end of the animals, two TbP are present on each side.…”

Integrative taxonomy of a new Redudasys species (Gastrotricha: Macrodasyida) sheds light on the invasion of fresh water habitats by macrodasyids

“…nov. Garraffoni et al . 11 . also reported an unnamed species of Redudasys with a single TbA per side from Brazil, but in this case that observation was a misinterpretation.…”

“…also reported an unnamed species of Redudasys with a single TbA per side from Brazil, but in this case that observation was a misinterpretation. During the present study we had the opportunity to collect fresh material and analyze Redudasys specimens from one of the sites previously investigated 11 . This allowed us to verify that these individuals in fact had 2 TbA of unequal size per side arising from a common base just like in R. fornerise .…”

“…Thus, we considered that the Redudasys specimens found by Garraffoni et al . 11 . can be treated as R. fornerise .…”

“…Recently, Garraffoni et al . 11 found many specimens belonging to the genus Redudasys showing some minor differences from Redudasys fornerise , and Araújo et al . 10 reported the occurrence of an undescribed species provisionally assigned to the genus Marinellina in South America for the first time.…”