Is meiofauna community structure in Artificial Substrate Units a good tool to assess anthropogenic impact in estuaries?

The applicability of estuarine meiofauna and harpacticoid copepods' communities in an artificial substrate unit (ASU) was assessed and compared to natural substrates (sediment and pneumatophores) as a tool to discern estuaries under different types of anthropogenic impacts. The ASU's replicates demonstrated a low variation of density among replicates when considering the total meiofauna and copepod species, which was reflected by a great similarity within the samples. In relation to the most abundant groups found, the ASU samples properly represented the natural substrates, even though nematodes were poor colonizers. That the ASU only showed significant differences between areas suggested that standard substrates could more efficiently detect the differences between communities and pointed toward the applicability of ASUs meiobenthic communities as useful tools for impact studies.

Mucorales from the semiarid of Pernambuco, Brazil

Nineteen taxa of Mucorales, belonging to Absidi, Apophysomyces, Cunninghamella, Fennellomyces, Lichtheimi, Mucor, Mycotypha, Rhizopus and Syncephalastrum were isolated from 36 composite soil samples in three semiarid areas in the State of Pernambuco (Triunfo, Cabrobó and Belém de São Francisco), Northeast Brazil, which are characterized by Caatinga vegetation. Triunfo is preserved, whereas Cabroró and Belém de São Francisco are experiencing low and severe desertification processes, respectively. Mucorales were isolated in Petri dishes in triplicate from 5 mg samples of soil placed on the surface of wheat germ agar plus chloramphenicol and Cercobin [Dimethyl 4,49-(103 phenylene) bis (3-thioallophanate)] medium. The plates were left on a bench at room temperature (28 ± 2 ºC) for 72 h of alternating dark and light periods. Absidia cylindrospora presented the highest amount of CFU/g of soil, followed by L. hyalospor, C. phaeospora and C. echinulata var. echinulata. The latter, and R. microsporus var. microsporus, presented the highest frequencies of occurrence. Soils from Triunfo showed higher diversity of Mucorales than the samples from the other areas, although without differing statistically in relation to species richness. The communities of Mucorales from the degraded areas were more similar, while that from the preserved area was quite different. Most of the identified specimens have been commonly isolated from soil in other Brazilian regions, which indicates that they are not endemic of the semiarid. Eleven taxa are registered for the first time in this ecosystem, while F. heterothallicus is reported for the first time in Brazil.

New records confirming the occurrence of the ghost shrimps Biffarius biformis (Biffar, 1970) and B. fragilis (Biffar, 1971) (Decapoda, Callianassidae) in Brazil and the southwestern Atlantic / Novos registros confirmam a ocorrência dos camarões fantasma Biffarius biformis (Biffar, 1970) e B. fragilis (Biffar, 1971) (Decapoda, Callianassidae) no Brasil e sudoeste do Atlântico

Previous records of the callianassid ghost shrimps Biffarius biformis (Biffar, 1971) and Biffarius fragilis (Biffar, 1970) from Pernambuco, northeastern Brazil, were considered as doubtful, because their original record (Carvalho et al. 1997) in a conference abstract cannot be considered as a valid publication. The original material examined by Carvalho et al. (1997) combined with the more recently collected material of B. biformis and B. fragilis, confirm the presence of these two species in Brazil and the southwestern Atlantic. Taxonomic and ecological remarks, as well as illustrations, are provided for both species.

A ocorrência dos camarões fantasma Biffarius biformis (Biffar 1971) e Biffarius fragilis (Biffar 1970) no nordeste do Brasil têm sido considerada duvidosa, porque o registro original (Carvalho et al. 1997) realizado em resumo durante uma conferência regional não pode ser considerado válido. Neste trabalho, o estudo dos espécimens examinados por Carvalho et al. (1997), combinados com o material coletado mais recentemente, confirma a presença dessas duas espécies na costa brasileira e no sudoeste do Atlântico. São fornecidas novas informações taxonômicas, ecológicas e ilustrações.

Zygomycetes from herbivore dung in the ecological reserve of Dois Irmãos, Northeast Brazil

Thirty-eight taxa of Zygomycetes distributed in 15 genera were recorded from tapir (Tapirus terrestris), camel (Camelus bactrianus), horse (Equus caballus), deer (Cervus elaphus), agouti (Dasyprocta aguti), donkey (Equus asinus), llama (Llama glama) and waterbuck (Kobus ellipsiprymnus) dung collected at the Reserva Ecológica de Dois Irmãos located in Recife, State of Pernambuco, Northeast Brazil. The samples were collected on a monthly basis from June 2005 to May 2006, taken to the laboratory and incubated in moist chambers. Higher number of taxa was observed in the excrements of tapir, followed by deer and donkey. The highest number of species was detected for Mucor, followed by Pilobolus. Statistical analyses showed significant differences in richness of Zygomycetes taxa between the herbivore dung types. Differences of species composition, however, were weak. Seasonality influenced the Zygomycetes species composition but not its richness. Variations in taxa composition between ruminants and non-ruminants dung were non significant.