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Most Neotropical land flatworm species are known from areas of the Atlantic Forest. Herein, we describe two new land planarian species from areas of semideciduous forest in the Cerrado biome in southwestern Brazil. Paraba aurantia Marques & Leal-Zanchet, sp. nov. can be distinguished from its congeners by the wide black median band on the dorsum, eyes occupying almost the entire dorsal surface, prostatic vesicle twisted and asymmetrical with proximal portions forked, and female atrium with an ample lumen lined by a low epithelium with stratified appearance. Pasipha liviae Marques & Leal-Zanchet, sp. nov. shows a narrow longitudinal dorsal stripe, collar-shaped pharynx, and prostatic vesicle with a pear-shaped proximal portion and a globose distal portion separated by a constriction. In addition, P. liviae can be distinguished from its congeners by molecular analyses from the cytochrome c oxidase subunit I gene (COI). Phylogenetic analyses suggest that P. liviae is closely related to P. hauseri, which occurs in areas of semidseciduous forest in southern Brazil.

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Although most land planarians are sensitive to environmental changes, some species are well adapted to human-disturbed areas and are easily transported to new places, having the potential to threaten native ecosystems. We investigated growth and survival in a land planarian common in human-disturbed areas in southern Brazil. Specimens of Obama anthropophila were divided into three groups that received different diets: (1) only the land planarian Luteostriata abundans (N=13), (2) only the slug Deroceras leave (N=12), and (3) alternating both prey types (N=13). We monitored the weight of the specimens for a month and counted and weighed egg capsules. Planarians receiving a mixed diet tended to survive less than the groups receiving a single prey type; there were significant differences between those feeding on D. laeve and the other groups. Planarians with the mixed diet ate L. abundans more often than D. laeve, and those feeding only on L. abundans tended to eat more than the other groups. Most egg capsules were laid by specimens with a diet based on D. laeve but the mixed-diet group laid heavier capsules. Both prey species are suitable as food for O. anthropophila, although it prefers planarians when both food items are available. The constant alternation between food items seems to have adverse effects, perhaps related to physiological changes to digest different food items. The heavier egg capsules of the mixed-diet group, considering its lower survival, suggest terminal investment, i.e., an increased reproductive effort when approaching death. The ability to feed on both snails and planarians, combined with its proximity to humans, make O. anthropophila a potentially invasive species.

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We describe two new species of Neotropical land planarians found in protected areas of the Atlantic Forest in southern Brazil. Cratera obsidiana Amaral, Boll Leal-Zanchet, sp. nov., found in the State Park of Turvo, is the first species of the genus Cratera described from an area of deciduous seasonal forest. It can be distinguished from its congeners by the uniformly black dorsal color and the prostatic vesicle with proximal portion laterally expanded and directed upward. Luteostriata subtilis Boll, Amaral Leal-Zanchet, sp. nov., found in the National Park of Aparados da Serra, in an area covered by Araucaria moist forest, is distinguished from its congeners by only two conspicuous longitudinal stripes on the dorsal surface of the body and a large fold in the male atrium below the opening of the ejaculatory duct. We also provide an updated key for species of Cratera and the first key for species of Luteostriata.

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The genus Obama Carbayo et al., 2013 includes 38 species, being the most species-rich within Geoplaninae. Species of this genus show a similar anatomy regarding their copulatory apparatus, which may hinder species differentiation. In this study, we describe two new species, presenting a marbled colour pattern, found in two different phytophysionomies of the Atlantic Forest, namely Semi-deciduous Forest and Araucaria Forest. Both species can be distinguished from their congeners, as well from each other, by colour pattern and eye arrangement combined with characteristics of the pharynx, penis papilla and prostatic vesicle, confirmed by molecular analyses from cytochrome c oxidase subunit I gene (COI). Phylogenetic analyses suggest that both species herein studied are closely related to another species that occurs in areas of Araucaria Forest (O. maculipunctata). Results also indicate the need to use at least 600 bp of the gene COI in the definitions of interspecific divergences and for species delineation, at least for the genus Obama.

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The Areias System, situated in the Atlantic Forest, is considered a hotspot of troglobitic diversity in Brazil. Herein we describe two new sympatric, troglobitic species of Girardia occurring in this system. Both species show minute eyes; one of them has a whitish body, and the other scattered, fine pigmentation over the dorsal surface. Regarding the copulatory apparatus, one of the species shows a bulbar cavity with multiple diverticula and a bursal canal of the angled type, whereas the other has a single, ovoid bulbar cavity and a smoothly curved bursal canal, among other distinguishing features. Thus, each species can be differentiated by a unique combination of features in its external morphology and copulatory apparatus. Both present a restricted distribution, occurring in a group of pools in travertine rock formed by water from the epikarst. The morphological features of both species and this sampling location indicate that both species are stygobionts.

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Land planarians have a simple anatomy and simple behavioral repertoire in relation to most bilaterian animals, which makes them adequate for the study of biological processes. In this study, we investigate the behavior of land planarians during interaction events with other invertebrates found in the same environment. We observed 16 different behavioral units, including seven different capture behaviors and three different prey ingestion behaviors. The capture behavior varied from very simple, such as simply covering the prey with the body, to more complex ones, including two forms of tube formation that are described for the first time. In general, the capture behaviors were similar among different predators but different for different prey. Similarly, prey ingestion type was more related to prey type than to predator species, with small soft prey being swallowed without fragmentation, large prey being crushed, and prey with a hard skeleton being perforated. Considering that land planarians face limitations due to their lack of efficient ways to retain water, thus being highly dependent on a moist environment, the set of behaviors shown by them in this study was considerably rich, especially concerning strategies to capture prey.

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Two new species of Geoplaninae from southern Brazil are described herein. The new species, belonging to the genus Pasipha Ogren & Kawakatsu, 1990, can be distinguished from each other and from their congeners by colour pattern and characteristics of the copulatory apparatus, especially regarding the female organs and prostatic vesicle. Both new species seem to be endemic to areas covered by deciduous forest.

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Land planarians are recognized as important predators, yet studies on their feeding habits are usually restricted to invasive species. Thus, it is difficult to determine the real ecological role of this group in ecosystems and how their communities are structured. In the present study, we analyzed the diet of six co-occurring Neotropical land planarians and their success in capturing prey, based on experiments in the laboratory, in order to determine how they share resources in the same environment. We also calculated indices of food niche breadth and food niche overlap for land planarians for the first time. The diet of Luteostriata abundans comprises only woodlice and the diets of Obama ficki and Obama ladislavii are composed only of gastropods, while Paraba multicolor and Obama anthropophila feed on both gastropods and other land planarians. An invasive species recently found in Western Europe, Obama nungara, showed the highest food niche breadth, feeding on gastropods, earthworms and planarians. We found the highest niche overlap between O. anthropophila and P. multicolor. The results suggest that land planarians are frequent predators of woodlice and land gastropods in the Neotropical ecozone and thus are important for the maintenance of native ecosystems and for the control of invasive species. The coexistence of several species in the same habitat is possible due to the use of different species as main prey, which reduces interspecific competition.

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Brazilian cave diversity, especially of invertebrates, is poorly known. The Bodoquena Plateau, which is located in the Cerrado Biome in central Brazil, has approximately 200 recorded caves with a rich system of subterranean water resources and high troglobitic diversity. Herein we describe a new troglobitic species of Girardia that represents the first obligate cave-dwelling species of the suborder Continenticola in South America. Specimens of the new species, which occur in a limestone cave in the Bodoquena Plateau, in the Cerrado biome, are unpigmented and eyeless. Species recognition in the genus Girardia is difficult, due to their great morphological resemblance. However, the new species can be easily recognized by a unique feature in its copulatory apparatus, namely a large, branched bulbar cavity with multiple diverticula.

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BACKGROUND: The subfamily Geoplaninae (Geoplanidae) includes land planarian species of the Neotropical Region. In Argentina, the knowledge about land planarian diversity is still incipient, although this has recently increased mainly in the Atlantic Forest ecosystem. However, other regions like Chacoan forests remain virtually unexplored. RESULTS: In this paper, we describe a new species of the genus Notogynaphallia of the Chacoan subregion. This species is characterized by a black pigmentation on the dorsum and a dark grey ventral surface. The eyes with clear halos extend to the dorsal surface. The pharynx is cylindrical. The main features of the reproductive system involve testes anterior to the ovaries, prostatic vesicle intrabulbar (with a tubular proximal portion and a globose distal portion) opening broadly in a richly folded male atrium, common glandular ovovitelline duct and female genital canal dorso-anteriorly flexed constituting a "C",female atrium tubular proximally and widening distally. CONCLUSIONS: This is the first report of the genus Notogynaphallia in Argentina (Chacoan subregion, Neotropical Region) which increases its geographic distribution in South America. Also, as a consequence of features observed in species of the genus, we propose an emendation of the generic diagnosis.

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Species diversity of Brazilian cave fauna has been seriously underestimated. A karst area located in Felipe Guerra, northeastern Brazil, which is a hotspot of subterranean diversity in Brazil, has revealed more than 20 troglobitic species, most of them still undescribed. Based on recent samplings in this karst area, we document the occurrence of the suborder Cavernicola (Platyhelminthes) in South American hypogean environments for the first time and describe a new genus and species for this suborder. Hausera Leal-Zanchet & Souza, gen. n. has features concordant with those defined for the family Dimarcusidae. The new genus is characterized by two unique features, viz. an intestine extending dorsally to the brain and ovovitelline ducts located dorsally to the nerve cords, which is complemented by a combination of other characters. The type-specimens of Hauserahauseri Leal-Zanchet & Souza, sp. n. are typical stygobionts, unpigmented and eyeless, and they may constitute an oceanic relict as is the case of other stygobiotic invertebrates found in this karst area in northeastern Brazil.

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Supramontana argentina sp. nov. (Platyhelminthes, Continenticola, Geoplanidae) from north-eastern Argentina is herein described. The new species differs from Supramontana irritata Carbayo & Leal-Zanchet, 2003 from Brazil, the only species of this genus so far described, by external and internal morphological characters. Supramontana argentina sp. nov. is characterized by having a colour pattern with a yellowish median band, thin para-median black stripes, and two dark grey lateral bands on the dorsal surface. The most outstanding features of the internal morphology are a ventral cephalic retractor muscle almost circular in cross section, prostatic vesicle extrabulbar, tubular and very long, and penis papilla conical and blunt with a sinuous ejaculatory duct.

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Land flatworms show high endemism due to their restricted mobility. In southern Brazil, land flatworm communities have been found mainly in areas of ombrophilous forests. Thus, this study documents land planarian species composition in remnants of deciduous seasonal forest in the northeast region of southern Brazil. Direct, diurnal samplings reveal the occurrence of 26 species of land flatworms, of which one belongs to the subfamily Rhynchodeminae and the others to the subfamily Geoplaninae. The Rhynchodeminae genus Rhynchodemus Leidy 1851 and the following Geoplaninae genera occurred: CephaloflexaCarbayo & Leal-Zanchet, 2003, Choeradoplana Graff, 1896, Imbira Carbayo et al., 2013, IssocaFroehlich, 1955, LuteostriataCarbayo, 2010, Obama Carbayo et al., 2013, Paraba Carbayo et al., 2013, Pasipha Ogren & Kawakatsu, 1990 and XerapoaFroehlich, 1955, besides the collective group Pseudogeoplana Ogren & Kawakatsu, 1990. The genus Obama had the highest species richness (S=6), followed by Paraba (S=4) and Pasipha (S=3). Eighteen species were recorded exclusively in one of the two study areas, and eight species occurred in both sites. The known distribution of Luteostriata abundans (Graff, 1899), Choeradoplana iheringiGraff, 1899, Obama ficki (Amaral & Leal-Zanchet, 2012), Imbira guaiana (Leal-Zanchet & Carbayo, 2001) and Pasipha hauseri (Froehlich, 1959) is increased. Results emphasize the relevance of expanding taxonomic studies on land flatworms and including more study areas in southern Brazil.

Os tricladidos terrestres apresentam alto grau de endemismo, devido especialmente è sua capacidade de locomoção reduzida. No Rio Grande do Sul, dados sobre as comunidades de planárias terrestres são principalmente conhecidos de áreas de floresta ombrófila mista. O presente estudo teve como objetivo analisar a composição das espécies de planárias terrestres em remanescentes de floresta estacional decidual, situados na região nordeste do Rio Grande do Sul. Com base em coletas diurnas diretas foram registradas 26 espécies, pertencentes ès subfamílias Geoplaninae e Rhynchodeminae. Foram registrados os seguintes gêneros de Geoplaninae: CephaloflexaCarbayo & Leal-Zanchet, 2003, Choeradoplana Graff, 1896, Imbira Carbayo et al., 2013, IssocaFroehlich, 1955, LuteostriataCarbayo, 2010, Obama Carbayo et al., 2013, Paraba Carbayo et al., 2013, Pasipha Ogren & Kawakatsu, 1990 e XerapoaFroehlich, 1955, além do grupo coletivo Pseudogeoplana Ogren & Kawakatsu, 1990 e do gênero de Rhynchodeminae Rhynchodemus Leidy 1851. O gênero Obama apresentou a maior riqueza de espécies (S=6), seguido por Paraba (S=4) e Pasipha (S=3). Dezoito espécies foram registradas exclusivamente em uma das áreas de estudo, enquanto oito espécies ocorreram em ambas localidades. Amplia-se a distribuição conhecida de Luteostriata abundans (Graff, 1899), Choeradoplana iheringiGraff, 1899, Obama ficki (Amaral & Leal-Zanchet, 2012), Imbira guaiana (Leal-Zanchet & Carbayo, 2001) e Pasipha hauseri (Froehlich, 1959). Além disso, os resultados enfatizam a importância de ampliação dos estudos taxonômicos de planárias terrestres, bem como das áreas de estudo no sul do Brasil.

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Turbellarians occur in a variety of wetlands, being also abundant in temporary water bodies. Several turbellarians are top predators in their microhabitats, many of them feeding on zooplankton. However, they are seldom taken into account in biodiversity studies. Information on turbellarian diversity in Brazilian freshwater ecosystems mainly came from taxonomical studies. In southern Brazil, there are a high number of wetlands, most of them represented by rice fields. Despite their impact on natural areas, these managed ecosystems can play an important role in freshwater biodiversity conservation. The aim of the present work was to report on an inventory done in irrigated rice fields of three areas of the Coastal Plain of southern Brazil, viz. Cachoeirinha, Santo Antônio da Patrulha e Camaquã. We found 144 species of freshwater turbellarians, distributed in six taxonomic groups (Catenulida, Macrostomida, Lecithoepitheliata, Proseriata, Rhabdocoela, and Tricladida). Twenty-three species are recorded for the first time for Brazil. Catenulida showed the highest relative abundance in Cachoeirinha, followed by Rhabdocoela. In Santo Antônio and Camaquã, Tricladida had the highest relative abundance, followed by Catenulida. Results suggest that some turbellarian species show a high level of habitat specificity with only 38% of the registered turbellarians occurring in a single study area. Although there is a paucity of turbellarian inventories in Brazilian natural wetlands, hampering a comparison between natural and managed wetlands, results indicate high species richness in the areas studied.

Os turbelários são encontrados em uma grande variedade de hábitats aquáticos, sendo abundantes inclusive em áreas úmidas temporárias. Diversos turbelários são predadores de topo nos seus microhabitats, muitos deles alimentando-se de zooplâncton. No entanto, raramente os turbelários são considerados em inventários de diversidade. Informações sobre sua diversidade nos ecossistemas límnicos brasileiros provêm principalmente de estudos taxonômicos. No Rio Grande do Sul, há um grande número de áreas úmidas, sendo a maioria delas representadas por lavouras de arroz. Esses ecossistemas manejados, embora tenham alto impacto sobre áreas naturais, podem exercer um importante papel na conservação da biodiversidade aquática. Este estudo teve por objetivo inventariar os turbelários ocorrentes em áreas de cultivo de arroz irrigado de três localidades da Planície Costeira do sul do Brasil (Cachoeirinha, Santo Antônio da Patrulha e Camaquã). Foram registradas 144 espécies de turbelários, distribuídas em seis grupos taxonômicos (Catenulida, Macrostomida, Lecithoepitheliata, Proseriata, Rhabdocoela e Tricladida). Vinte e três espécies são registradas pela primeira vez para o Rio Grande do Sul. Catenulida apresentou a maior abundância relativa em Cachoeirinha, seguida por Rhabdocoela, enquanto nas outras duas localidades, a maior abundância relativa foi de Tricladida, seguida por Catenulida. Os resultados sugerem que algumas espécies demonstram alto grau de especificidade de hábitat, pois cerca de 38% dos turbelários ocorreram em apenas uma das áreas de estudo. Apesar da existência de poucos inventários de turbelários em áreas úmidas naturais do Brasil, impedindo uma comparação entre áreas úmidas naturais e manejadas, os resultados indicam uma elevada riqueza de espécies de turbelários nas áreas de estudo.

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Os tricladidos terrestres são predadores de topo de cadeia no seu microhábitat, alimentando-se de outros invertebrados de solo. A riqueza de espécies de tricladidos pode indicar a diversidade de outros grupos. A composição das comunidades de planárias terrestres da Floresta Estacional Decidual, que ocupa um quarto da cobertura vegetal do Estado do Rio Grande do Sul, é pouco conhecida. O presente trabalho teve como área de estudo o maior remanescente dessa formação florestal no Rio Grande do Sul, apresentando os seguintes objetivos: inventariar as espécies de planárias terrestres no Parque Estadual do Turvo (PE-Turvo) e comparar as comunidades desse Parque com as de outras áreas do estado com inventários desses tricladidos. Na área de estudo, foram inventariadas 26 espécies, sendo duas pertencentes às subfamílias Rhynchodeminae e Bipaliinae, e as demais, à subfamília Geoplaninae. Além dos gêneros Rhynchodemus Leidy 1851 e Bipalium Stimpson, 1857, foram registrados os seguintes gêneros de Geoplaninae: Geoplana Stimpson 1857, Choeradoplana Graff 1896, Pasipha Ogren & Kawakatsu 1990 e Notogynaphallia Ogren & Kawakatsu 1990, além do grupo coletivo Pseudogeoplana Ogren e Kawakatsu, 1990. O maior número de espécies foi registrado para o gênero Geoplana (10), seguido pelo gênero Pasipha (4). Geoplana rubidolineata Baptista & Leal-Zanchet, 2005 havia sido registrada anteriormente apenas para sua localidade-tipo, no nordeste do estado. Bipalium kewense Moseley, 1878, de distribuição cosmopolita, foi encontrada apenas em local submetido a alto impacto antrópico, não tendo sido registrada em áreas de floresta. Para comparar as comunidades de planárias terrestres do PE-Turvo com as de outros tipos de vegetação do estado, utilizou-se o método de ordenação NMDS. Essa análise indicou que as comunidades de planárias terrestres do PE-Turvo e de outras áreas de Floresta Decidual, Semidecidual e Floresta Ombrófila Densa diferenciam-se das comunidades de áreas de Floresta Ombrófila Mista. A alta riqueza de espécies observada no PE-Turvo reforça sua importante contribuição para a conservação da diversidade regional.

Land triclads are top-predators in their microhabitats, feeding on other soil invertebrates. The species richness of triclads may indicate the diversity of other faunal groups. The community composition of land flatworms of areas of Deciduous Forest, which occupies a quarter of the vegetal cover of the state, is poorly known. The present study inventoried land planarians of the largest remnant of this type of forest in the State of Rio Grande do Sul, the Turvo State Park (SP-Turvo) and compared their communities with those of other localities of the state with inventories of land flatworms. We inventoried 26 species, two of them belonging to the subfamilies Rhynchodeminae and Bipaliinae, and 24 to the subfamily Geoplaninae. Besides the genera Rhynchodemus Leidy 1851 and Bipalium Stimpson, 1857, the following Geoplaninae genera were recorded: Geoplana Stimpson 1857, Choeradoplana Graff 1896, Pasipha Ogren & Kawakatsu 1990 and Notogynaphallia Ogren & Kawakatsu 1990, as well as the collective group Pseudogeoplana Ogren & Kawakatsu, 1990. The highest species richness was registered for the genus Geoplana (10), followed by the genus Pasipha (4). Geoplana rubidolineata Baptista & Leal-Zanchet, 2005 was previously only known from its type-locality, located in the northeast of the state. Bipalium kewense Moseley, 1878 which shows a cosmopolitan distribution was observed in a man-disturbed area, not being registered in forest areas. We employed an NMDS ordination to compare land planarian communities of the Turvo State Park to those of other types of forest of the state. The analysis indicated that land planarian communities of the Turvo State Park and those of other areas with Deciduous, Semideciduous and Dense Ombrophilous Forests differ from those of Mixed Ombrophilous Forests of the region. The high observed species richness in the Turvo State Park reinforces its important contribution for the conservation of the regional diversity.