Morphology of respiratory organs in South American Oniscidea (‘Philosciidae’)

Respiratory organs are widespread among the Oniscidea. Especially within the Crinocheta, different developmental stages can be found in several phyletic lineages as an adaptation to their terrestrial habitat. From the New World, there are few genera known to possess pleopodal lungs. The genera of Balloniscidae, Balloniscus and Plataoniscus are known to have pleopodal lungs; nonetheless, their structure is virtually undescribed. Among the philosciids, Benthana, Benthanoscia longicaudata, Atlantoscia floridana are said to have respiratory areas on their pleopod exopods. All these taxa are found in temperate and eastern South America, where recently a new species of Atlantoscia was discovered. In this work, the lungs of Balloniscus sellowii, Benthana picta, Atlantoscia floridana, and a new species of Atlantoscia ait examined by means of a Scanning Electron Microscope and semi-thin sections. The morphology of the respiratory structures of the South American species is described and discussed.