Thesis (doctoral)--Rijksuniversiteit te Leiden, 1929. / "Stellingen": p. [117-119]. Includes bibliographical references (p. 109-116).

Em 2016, descobrimos que o material-tipo de 10 das 15 espécies de planárias terrestres (Platyhelminthes, Tricladida, Geoplanidae) brasileiras descritas por Schirch (1929) não estava perdido, mas sim depositado no Museu Nacional do Rio de Janeiro (MNRJ). Schirch somente descreveu a morfologia externa destas espécies. Originalmente no gênero Geoplana, as 15 espécies sofreram revisão taxonômica e atualmente são conhecidas como Issoca ezendei, Obama itatiayana, Pasipha plana, Paraba goettei, Pseudogeoplana arpi, Ps. bonita, Ps. blaseri, Ps. bresslaui, Ps. cardosi, Ps. doerdeleini, Ps. lumbricoides, Ps. obscura, Ps. riedeli, Ps. theresopolitana e Ps. wetzeli. Ainda, Geoplana maximiliani sensu Schirch, 1929 foi renomeada como Ps. schirchi Ogren & Kawakatsu, 1990. Pseudogeoplana foi proposto para espécies de Geoplaninae cuja morfologia interna se desconhece, especialmente a do aparelho copulador, órgão fundamental para a determinação inequívoca das espécies. Neste trabalho fizemos uma revisão taxonômica das espécies cujo material-tipo ainda existe, ou seja, Pasipha plana, Pseudogeoplana arpi, Ps. bonita, Ps. blaseri, Ps. bresslaui, Ps. doerdeleini e Ps. wetzeli. Excluímos do estudo Obama itatiayana por não atender aos requisitos de análise adotados (existência de material-tipo maduro e espécie não revisada anteriormente) e Issoca rezendei por ser objeto de estudo de outra dissertação. Estudamos o material-tipo e espécimes adicionais coletados recentemente de algumas das espécies. Obtivemos os dados morfológicos a partir de preparações histológicas e, quando viável, a partir de cortes virtuais obtidos por microtomografia computadorizada de raios-X (mCT), técnica que não destrói os espécimes. Esta abordagem resultou na preservação do corpo inteiro de, pelo menos, um parátipo de cada espécie e do holótipo, por monotipia, de Ps. bresslaui. Os espécimes-tipo de algumas espécies são jovens, sem aparelho copulador desenvolvido (Ps. arpi, Ps. doederleini e Ps. wetzeli); os de outra espécie não pode ser estudado em detalhe por conta da preservação deficiente (Ps. doederleini, Capítulo 1). Nesta revisão taxonômica, propomos a mudança de gênero para duas espécies: Paraba bresslaui (Capítulo 1) e Imbira bonita (Capítulo 2). Dadas as semelhanças entre Geoplana goetschi Riester, 1938 e I. bonita (Capítulo 2), também foi estudado o material tipo e espécimes adicionais de G. goetschi. O estudo levou à conclusão de que G. goetschi é sinônimo júnior de I. bonita (Capítulo 2). Por último, também descrevemos uma espécie nova de Imbira, simpátrica com I. marcusi, e propomos uma nova diagnose para este gênero (Capítulo 2). A mCT foi uma técnica valiosa para o estudo sistemático de várias espécies de Schirch sem destruir os espécimes-tipo. / In 2016, we found that the type-material of 10 of the 15 Brazilian land planarians (Platyhelminthes, Tricladida, Geoplanidae) described by Schirch (1929) were not lost but deposited in the Museu Nacional do Rio de Janeiro (MNRJ). Schirch only described the external morphology of these species. Originally in the genus Geoplana, the 15 species underwent taxonomic revision and their current names are Issoca rezendei, Obama itatiayana, Pasipha plana, Paraba goettei, Pseudogeoplana arpi, Ps. bonita, Ps. blaseri, Ps. bresslaui, Ps. cardosi, Ps. doerdeleini, Ps. lumbricoides, Ps. obscura, Ps. riedeli, Ps. theresopolitana. Also, Geoplana maximiliani sensu Schirch, 1929 was renamed as Ps. Schirchi Ogren & Kawakatsu, 1990. Pseudogeoplana was proposed for species of Geoplaninae whose internal morphology is unknown, especially that of the copulatory apparatus, organ essential for the unequivocal determination of the species. In this work we carried out a taxonomic revision of the species having type-material available, namely Pasipha plana, Pseudogeoplana arpi, Ps. bonita, Ps. blaseri, Ps. bresslaui, Ps. doerdeleini and Ps. wetzeli. We excluded from the work Obama itatiayana for it does not fulfill the requirements adopted (both existing mature type-material, and species not revised previously) and Issoca rezendei, since this species is currently being studied elsewhere. We studied the type-material and additional specimens collected recently, of some of the species. We obtained the morphological data from histological preparations and, when feasible, from virtual sections obtained through X-ray computed microtomography (mCT), a technique that does not destroy the specimens. This approach resulted in the preservation of the entire body of, at least, one paratype of each species, and the holotype, by monotypy, of Ps. bresslaui. The type specimens of several species are young, without copulatory apparatus (Ps. arpi, Ps. doederleini and Ps. wetzeli), or are poorly preserved, and hence could not be studied in detail (Chapter 1). As a result of the taxonomic revision, we propose the transfer of two species to other genera: Paraba bresslaui (Chapter 1) and Imbira bonita (Chapter 2). Given the similarities between Geoplana goetschi Riester, 1938 and I. bonita (Chapter 2), we also studied the type-material and additional specimens of G. goetschi. The study led us to the conclusion that G. goetschi is a junior synonym of I. bonita (Chapter 2). Finally, we also describe a new species of Imbira, sympatric with I. marcusi, and propose a new diagnosis for this genus (Chapter 2). mCT was a valuable technique for the systematic study of several type-specimens of Schirch\'s species without destroying them.

To show how predaceous fish and dragonflies affect benthic community structure, we conducted enclosure experiments in the littoral zone of Bays Mountain Lake, Tennessee. A 'natural' benthic assemblage was subjected to all combinations of 2 densities of 3 predator treatments - small sunfish, 0 or 4/m2; large dragonfly larvae, 0 or 15/m2; and dragonfly eggs at 2 densities, 90 or 900/m2. Treatments were assigned randomly in each of 6 spatiotemporal blocks. Net effects of predation over 4 mo show that small sunfish had 'strong' effects (>50% reduction of densities) on triclads, large daphnid cladocerans, and snails, and 'moderate' effects (50% > reduction > 25%) on small dragonflies and ostracods; all these effects were statistically significant, except the one on ostracods. Large dragonflies had moderate non-significant effects on triclads and ostracods. There were no significant increases in prey density associated with fish predation; but chydorid cladocerans and midge larvae showed 'weak' non-significant increases that might be caused by 'indirect effects' of fish predation on invertebrate predators or grazers. There were only 2 significant interaction terms indicative of 'higher-order interactions': Fish X Dragonfly on the large daphnid Simocephalus, and Fish X Egg Density on snails, which were associated with relatively low probabilities. In both cases, the net effect of dragonflies was to reduce prey densities more when fish were present.