Claudio G. Froehlich

Macroinvertebrates in neotropical streams: richness patterns along a catchment and assemblage structure between 2 seasons

We investigated macroinvertebrate richness in 10 streams of different sizes within the Carmo River catchment in Brazil. Specifically, we tested 2 predictions of the river continuum concept (RCC): 1) within the catchment, mid-sized streams (orders 3–4) have the richest biota, and 2) macroinvertebrate assemblage structure is more stable during the dry season than during the rainy season when natural spates are frequent. We sampled the streams using individual stones as sampling units. Observed and estimated values of richness did not follow the hump-shaped pattern of richness along a gradient of stream size as predicted by the RCC; the richest streams were smaller than those predicted. No difference in assemblage structure between seasons was found on the basis of observed and estimated richness or abundance. The similarity in assemblage structure between the rainy and dry seasons was also supported by multivariate analysis. Observed richness and species composition (reflected in multivariate analysis) were strongly correlated to stream size and the presence of fine sediments over rocks. Assemblage structure in these streams seems to be deterministic, in that richness and species composition are related to physical habitat characteristics.

Choice of macroinvertebrate metrics to evaluate stream conditions in Atlantic Forest, Brazil

The development of biomonitoring programs based on the macroinvertebrate community requires the understanding of species distribution patterns, as well as of the responses of the community to anthropogenic stressors. In this study, 49 metrics were tested as potential means of assessing the condition of 29 first- and second-order streams located in areas of differing types of land use in São Paulo State, Brazil. Of the sampled streams, 15 were in well-preserved regions in the Atlantic Forest, 5 were among sugarcane cultivations, 5 were in areas of pasture, and 4 were among eucalyptus plantations. The metrics were assessed against the following criteria: (1) predictable response to the impact of human activity; (2) highest taxonomic resolution, and (3) operational and theoretical simplicity. We found that 18 metrics were correlated with the environmental and spatial predictors used, and seven of these satisfied the selection criteria and are thus candidates for inclusion in a multimetric system to assess low-order streams in São Paulo State. These metrics are family richness; Ephemeroptera, Plecoptera and Trichoptera (EPT) richness; proportion of Megaloptera and Hirudinea; proportion of EPT; Shannon diversity index for genus; and adapted Biological Monitoring Work Party biotic index.

Ephemeroptera, Plecoptera and Trichoptera assemblages in two Atlantic Rainforest streams, Southeastern Brazil

Comunidades de Ephemeroptera, Plecoptera e Trichoptera (EPT) em substrato rochoso foram estudadas em dois riachos do Parque Estadual Intervales. Coletas com um amostrador de Surber (10 subamostras aleatorias, 1 m 2 ) foram feitas mensalmente de setembro de 1999 a setembro de 2000 e trimestralmente de dezembro de 2000 a setembro de 2001 nos Ribeiroes Bocaina e Agua Comprida. A fauna de EPT do Ribeirao Bocaina foi mais diversificada e mais abundante do que a do Ribeirao Agua Comprida. A fauna de EPT foi bastante diferente entre os dois riachos, tanto do ponto de vista da composicao faunistica quanto do ponto de vista funcional. Os resultados indicaram que nao houve um padrao sazonal claro da variacao temporal da densidade.

Studies on Brazilian Plecoptera 1. Some Gripopterygidae from the biological station at Paranapiacaba, state of Sao Paulo

Zusammenfassung Auf Seite(n) 18–19 befindet sich eine Liste der vom Verfasser als gultig angesehenen, von Brasilien bekannten Gripopterygiden. Die wichtigsten Anderungen gegenuber Illies’ Revision der sudamerikanischen Gripopterygiden betreffen die Gattungen Paragripopteryx und Jewettoperla. Es zeigt sich, das P. klapaleki weder artlich noch gattungsmasig zu P. gracilis (Burm.) Ill., 1963, gehort. Tatsachlich ist Jewettoperla ein Synonym von Paragripopteryx, und fur gracilis wird der Gattungsname Tupiperla eingefuhrt. Von der Biologischen Station in Paranapiacaba werden 4 Arten behandelt, 2 schon bekannte, P. klapaleki Enderl. und T. gracilis (Burm.) und zwei neue P. anga sp. n. und P. blanda sp. n. Die Beschreibungen grunden sich auf Erwachsene und Nymphen. Die Eier von P. klapaleki und P. anga sind abgeflacht und von einer dicken, von Follikelzellen gebildeten Hulle umschlossen; die von T. gracilis, die aus dem Abdomen eines in Alkohol aufbewahrten ? entnommen wurden, haben ein nacktes Chorion. Die Nymp...

Ephemeroptera, Plecoptera and Trichoptera assemblages in litter in a mountain stream of the Atlantic Rainforest from Southeastern Brazil

The study of Ephemeroptera, Plecoptera and Trichoptera associated with litter in southeastern Brazil streams aimed to answer the following questions: 1) Does richness and composition of EPT fauna differ between riffle and pool mesohabitats despite being associated to the same substratum, litter? 2) Does the similarity of the EPT fauna between both mesohabitats change with time? 3) Does the EPT functional feeding structure differ between both mesohabitats (riffles-pools)? In order to answer these questions, monthly collections, from November 1999 to June 2000, were done in Ribeirao (Stream) Bocaina with a D-net (10 litter patches in riffles and 10 in pools). The EPT fauna at Ribeirao Bocaina was more diversified and more abundant in the litter in riffles than in the litter in pools, although, when richness was standardized for the same number of individuals it became similar in both conditions. EPT fauna was very different between both mesohabitats in terms of faunal composition as well as in terms of function. Probably it was due to differences in water speed, in the time of litter residence and in the concentration of dissolved oxygen between both mesohabitats.

Bioaccumulation of metals in aquatic insects of streams located in areas with sugar cane cultivation

Streams located in areas of sugar cane cultivation receive elevated concentrations of metal ions from soils of adjacent areas. The accumulation of metals in the sediments results in environmental problems and leads to bioaccumulation of metal ions by the aquatic organisms. In the present study, bioaccumulation of the metals ions Al, Cd, Cr, Cu, Fe, Mg, Mn and Zn in aquatic insects in streams impacted by the sugar cane was evaluated. The results pointed out that the insects were contaminated by the sediment and that the collector organisms as Chironomus species accumulated higher concentration of metals than the predator organisms.

Brazilian Plecoptera 5. Old and new species of Kempnyia (Perlidae)

Male genitalia of K. flava and female genitalia of K. obtusa are figured; both are distinct species. Laeissa Navâs is a synonym of Kempnyia. K. colossica is redescribed. New species described are: K. guassu, K. alterosarum, K. vanini, K. sazimai, K. umbrina and K. jatim.

Brazilian Plecoptera 2. Species of the serrana‐group of Kempnyia (Plecoptera)

The serrana‐group of Kempnyia is reviewed. K. serrana (Navas) is redescribed from the type specimen and distinguished from K. gracilenta (Enderlein) with which it had recently been confused. The female of K. gracilenta is described and new material of the species is recorded. New species described are K. mirim, K. reichardti, and K. tamoya, all from Brazil.

On some Brazilian Onychophores

Resumo Peripatus evelinae Marcus e redescrito. Distribuicao das papilas da pele caracteri‐stica do subgenero Peripatus. Orgaos frontais presentes. ? (Iectotipo) com 33 pares de patas; tuberculos crurais em muitas patas pre‐genitais. ? (alotipo) com 35 pares de patas. Dois exemplares de Belem, Para, sao classificados, com reserva, como Peripatus (Epiperipatus) edwardsii (Blanch.). Padrao de colorido, distribuicao das papilas da pele e das pregas semelhantes a desta especie. Tuberculo nefridial dos 4° e 5° pares de patas independente to 3° arco da sola, o ? com 26 pares de patas e um tuberculo crural em cada pata dos dois pares pre‐genitais. A ? com 29 pares de patas. Peripatus (Epiperipatus) tucupi sp. n. baseia‐se em 2 ?? provenientes do Para. Holo‐tipo com 60 mm de comprimento e 34 pares de patas; paratipo com 48 mm e 35 pares de patas. Semelhante a P. brasiliensis Bouv., distinguindo‐se pelo maior numero de patas e de papilas accessorias pequenas e pelos tuberculos nefridiais dos 4° e 5° pares de patas ...

Natural history of three Hydropsychidae (Trichoptera, Insecta) in a "cerrado" stream from northeastern São Paulo, Brazil

The faunal composition of the Hydropsychidae (Trichoptcra) of Pedregulho Stream is presented. Feeding habits of larvae and behavioural aspects of both larvae and adults are described.