Ana Maria Leal-Zanchet

Terrestrial flatworm (Platyhelminthes: Tricladida: Terricola) diversity versus man-induced disturbance in an ombrophilous forest in southern Brazil

Terrestrial flatworms, or Terricola, are sensitive to environmentalchanges and therefore might be excellent indicators of the conservation statusof natural habitats. The present study aimed to answer two main questions: (1)is terrestrial planarian diversity affected by human disturbances, and (2) isthere any species or group of species that indicates such disturbance? The studysite, National Forest of São Francisco de Paula, Brazil, was originallycovered by a mixed ombrophilous forest, but successive reforestations andselective logging have modified the original landscape. We studied Terricoladiversity in the four main habitats in the study area: mixed ombrophilous forest(NA), ombrophilous forest with selective Araucariaangustifolia logging (N), A. angustifoliareforestation (A), and reforestation of Pinus elliottii(P). According to an increasing degree of disturbance, the habitats might beordered as follows: (NA)<(N)<(A)<(P). We conducted 24 surveys in eachhabitat over a period of 1 year. Our results indicate that: (1)Terricola diversity is inversely related to the degree of habitat disturbance;(2) there are species (Geoplana franciscana,Geoplana sp. 5, and possibly Geoplanidae 3 andNotogynaphallia guaiana) that prefer habitats located onthe extreme right along the main axis of a detrended correspondence analysisordination and therefore can be considered as indicators of well preserved,natural habitats. On the other hand there are species(Xerapoa sp. 1, Choeradoplanaiheringi, G. marginata sensu Marcus andGeoplana sp. 2) preferring more disturbed habitats, whichmay form biological indicators of such disturbances.

Two new genera of geoplaninid land planarians (Platyhelminthes : Tricladida : Terricola) of Brazil in the light of cephalic specialisations

Two new genera of geoplaninid land planarians are described. Cephalic specialisations, mainly external morphology and musculature development, partially define each genus. Cephaloflexa, gen. nov. shows some peculiar characteristics, such as a gradual narrowing of the anterior third of the body and an upwards roll of the anterior tip, the absence of eyes and sensory pits on the apex, and the existence of a retractor muscle derived from the ventral cutaneous longitudinal musculature. Geoplana bergi Graff, 1899 is allocated to Cephaloflexa and is designated as the type species. The ventral cutaneous longitudinal muscles of Supramontana, gen. nov. (monotypic), are partially sunk into the mesenchyme, thus constituting a cephalic retractor muscle. A new species of each genus is also described. The external morphology and anatomy of the cephalic region of the new genera and of Geoplana Stimpson, 1857, Choeradoplana Graff, 1896 and Issoca C. G. Froehlich, 1955 are analysed. Emendations to the diagnoses of Issoca and Choeradoplana are proposed based on cephalic differentiations. Spanish abstractSe decriben Cephaloflexa, gen. nov. y Supramontana, gen. nov., dos nuevos generos de planarias terrrestres de la subfamilia Geoplaninae, ambos caracterizados por especializaciones cefalicas, como la morfologia externa y el desarrollo muscular. Se describe una nueva especie de cada genero. Se transfiere Geoplana bergi Graff, 1899 para el genero Cephaloflexa y se la designa especie tipo. Cephaloflexa, gen. nov. presenta caracteristicas peculiares, como el tercio anterior del cuerpo muy fino, region anterior enrollada hacia el dorso, ausencia de ojos y fosetas sensoriales en el apice anterior del cuerpo, y un musculo retractor derivado de la musculatura subcutanea longitudinal ventral. Supramontana, gen. nov., genero monotipico, tiene parte de la musculatura subcutanea longitudinal ventral hundida en el mesenquima y transformada en la region anterior en un musculo retractor cefalico. Se analiza la morfologia externa y la anatomia de la region cefalica de Geoplana Stimpson, 1857, Choeradoplana Graff, 1896 e Issoca Froehlich, 1955 y se proponen enmiendas a las diagnosis de Choeradoplana e Issoca basadas en las diferenciaciones cefalicas.

Predatory behavior of the land flatworm Notogynaphallia abundans (Platyhelminthes: Tricladida)

Land flatworms are carnivorous, mainly predators. However, knowledge on their predatory behavior and prey preference is very scarce. This paucity of data is a limiting factor in the study of their biology and organismal ecology, resulting in a very difficult task to breed them in the laboratory for prolonged periods if prey preference and predation frequency are unknown. We investigated the predatory behavior of Notogynaphallia abundans (Graff, 1899), Geoplaninae, based on laboratory experiments. In order to determine its predatory choices, we offered mollusks, earthworms, arthropods, and other land flatworms. Only land isopods were accepted, with an average consumption of 3.4 individuals per week. Linear regression showed a positive relationship between the number of consumed isopods and the increase/decrease in body mass. Consumption resulting in an increase in body mass was ca. four isopods per week. Predatory behavior, with a mean time-span of 28 min 45 s ± 15 min 47 s, includes encounter and capture of prey, immobilization, handling and feeding. Variation in the duration of this activity in N. abundans is clearly due to variations in the time necessary for transferring the prey from either the anterior or posterior thirds of the body to the mouth, as well as for external digestion and ingestion. In order to capture very active and fast-moving animals such as land isopods, N. abundans employs various strategies, using either the anterior or the posterior body regions to press the prey against the ground or against its own body, thus allowing it to deal with various responses by the prey, and thereby maximizing predatory success. Similar to other flatworms, both physical holding and entrapment in a mucous secretion are of fundamental importance for prey-immobilization. The different strategies employed by land flatworms in their predatory behavior are discussed, and behavioral plasticity in the capture and immobilization of prey in different platyhelminth groups is emphasized.

Two new species of Geoplanidae (Platyhelminthes, Tricladida, Terricola) of south Brazil

Two new species of terrestrial planarians in the family Geoplanidae, Geoplana franciscana and Notogynaphallia guaiana, from the State of Rio Grande do Sul, Brazil, are described. Both species have a multilayered lining in the female atrium. The study of specimens of N. goetschi, aimed at comparing it to N. guaiana, reveals the need for a re-description and review of N. goetschi.

A new species of terrestrial planarian (Platyhelminthes: Tricladida: Terricola) from South Brazil

Geoplana josefi sp. nov. of South Brazil is described herein. The species shows etary polymorphism. Neither youngs nor adults show the characteristic colour pattern of the mature worms. The species has a multilayered lining in the female atrium. The allopatric G. trigueira, which does not have such a lining, is similar externally and internally with adults of G. josefi, its seminal vesicle, however, being unpaired.

A new species of terrestrial planarian of the genus Notogynaphallia Ogren & Kawakatsu (Platyhelminthes, Tricladida, Terricola) from south Brazil and some comments on the genus

A new species of Notogynaphallia Ogren & Kawakatsu, 1990, from Southern Brazil, is described. Notogynaphallia ceciliae sp. nov. has an elongated body with parallel margins and five dorsal dark longitudinal stripes on a yellowish ground. It possess branched efferent ducts, each branch opening separately into the anterior and median thirds of the long prostatic vesicle. Comparative commentaries on the most important characters of the external and internal morphology of the 23 species of the genus are also presented, so delimiting smaller inside groups.

Focus on the details: morphological evidence supports new cryptic land flatworm (Platyhelminthes) species revealed with molecules

We found numerous dull brown land planarians of the subfamily Geoplaninae within native rainforests and in nearby man-disturbed habitats in Southeastern and South Brazil. Their external and internal morphology are similar to those of Obama ladislavii (Von Graff, 1899), with the exception of the luminous green dorsum of this species, from which a brownish-green variation is also known. Since morphological features commonly used to delimit geoplaninid species failed to distinguish them, we used coalescent and Bayesian-based molecular methods (GMYC, BPP). These methods indicated that we were actually dealing with three species, the greenish O. ladislavii, and two brownish, cryptic species. A meticulous morphological study of the specimens, including type material of O. ladislavii, allowed us to ascertain diagnostic features for each of the species, for which we also propose a molecular diagnosis. This integrative taxonomic study demonstrates the utility of molecular tools to weigh minor morphological features and thus to reveal otherwise cryptic species.

Freshwater microturbellarians (Platyhelminthes) from Rio Grande do Sul, Brazil

Ten species of freshwater microturbellarians of three ordens, Catenulida, Macrostomida and Rhabdocoela, were collected in seven sites situated in the Northeast region of Rio Grande do Sul, Brazil. Two species, Macrostomum johni Young, 1972 and Mesostoma productum (Schmidt, 1848), are cited for the first time for Brazil, the citation of M. johni being also the first one for the Neotropical Region. All species are cited for the first time for the state of Rio Grande do Sul.

Composição das comunidades de planárias terrestres (Platyhelminthes, Tricladida, Terricola) do Parque Nacional dos Aparados da Serra, Brasil

O Parque Nacional dos Aparados da Serra (PNAS), localizado na borda oriental do Planalto das Araucarias, e uma das principais unidades de conservacao do sul do Brasil, caracterizando-se pela ocorrencia de fragmentos de floresta ombrofila mista, intermediada por campos secos e umidos, e por uma area continua de floresta ombrofila densa. Registraram-se, para o PNAS, 35 especies de planarias terrestres, distribuidas em cinco generos (Geoplana Stimpson, 1857, Choeradoplana Graff, 1896, Notogynaphallia Ogren & Kawakatsu, 1990, Pasipha Ogren & Kawakatsu, 1990 e Cephaloflexa Carbayo & Leal-Zanchet, 2003), pertencentes a familia Geoplanidae, subfamilia Geoplaninae. Observaram-se 23 e 21 especies, respectivamente, nas areas de floresta ombrofila mista e floresta ombrofila densa. O coeficiente de similaridade de Jaccard entre as duas formacoes foi de 0,42. Em areas de campo nativo foi observada apenas uma especie. Sete especies foram coletadas em areas abertas antropizadas, sendo quatro delas tambem observadas nas areas de floresta. Amplia-se a distribuicao de quatro especies, a saber, Cephaloflexa bergi (Graff, 1899), Notogynaphallia graffi Leal-Zanchet & Froehlich, 2006, Geoplana franciscana Leal-Zanchet & Carbayo, 2001, e Geoplana josefi Carbayo & Leal-Zanchet, 2001, as duas ultimas conhecidas somente da sua localidade-tipo.

Redescrição de Choeradoplana iheringi Graff (Platyhelminthes, Tricladida, Terricola)

Choeradoplana iheringi Graff, 1899 was described on specimens proceeding from Taquara, Rio Grande do Sul, Brazil. Afterwards, RIESTER (1938), MARCUS (1951) and FROEHLICH (1955) analyzed specimens from southeast Brazil, identifying them as C. iheringi. In this study samples of C. iheringi from Sao Francisco de Paula, a site next to the type-locality, and specimens from the Southeast (Salesopolis, state of Sao Paulo), are comparatively analyzed. It was observed that the external morphology of the specimens from Sao Francisco de Paula and from Salesopolis is concordant with the original description of C. iheringi, as well as that by RIESTER (1938) and MARCUS (1951). The pharynx is better designated as bell-form, and not collar-form as described by GRAFF (1899). The copulatory apparatus is characterized by the presence of an intra-bulbar prostatic vesicle, consisting of two regions, an ental tubular one and an ectal one of variable shape; absence of penis papilla; and a male atrium, elongated and highlypleated. The copulatory apparatus of C. iheringi described by GRAFF shows some anatomical characteristics that distinguish it from the material studied by other authors, and from the material analyzed here. Some anatomical and histological characters of the copulatory apparatus distinguish the specimens from Sao Francisco de Paula from those of Salesopolis which are assigned to populational and/or physiological differences. The specimens from Sao Francisco de Paula and Salesopolis, as well as those analyzed by RIESTER (1938) and MARCUS (1951), are confirmed as C. iheringi Graff, 1899.