Leonardo Cruz da Rosa

Spatial distribution of the Ocypode quadrata (Crustacea: Ocypodidae) along estuarine environments in the Paranaguá Bay Complex, southern Brazil

O presente estudo avalia a distribuicao espacial de Ocypode quadrata Fabricius, 1787 em treze praias estuarinas distribuidas ao longo dos dois principais eixos do complexo estuarino da Baia de Paranagua, sul do Brasil. Em cada praia, a densidade de tocas do caranguejo em tres niveis distribuidos em torno da marca da preamar foi estimada durante os periodos de verao e de inverno. Todas as praias apresentaram uma declividade bem acentuada (2,6 a 8,3o de inclinacao) e a composicao do sedimento variando, em direcao ao interior do estuario, de areia fina bem selecionada a areia grossa muito pobremente selecionada. A salinidade da agua variou entre 31 (proximo a desembocadura da baia) e 14 nas praias estuarinas mais internas. As densidades de tocas de O. quadrata nas praias estuarinas foram similares as registradas para as praias oceânicas. Entretanto, a ausencia de tocas nas quatro praias estuarinas mais internas sugere que a salinidade junto com a penetrabilidade do sedimento possam ser fatores que inibam a ocorrencia desse caranguejo nas regioes superiores do estuario. Entre as outras praias, a densidade de tocas mostrou uma marcada sazonalidade; os baixos valores observados durante o inverno estao provavelmente relacionados a um atraso na atividade dos caranguejos devido as baixas temperaturas durante o comeco das manhas de inverno. A ausencia de um claro padrao de zonacao foi relacionada a particular morfologia das praias estuarinas.

Influência de um cultivo de camarão sobre o metabolismo bêntico e a qualidade da água

Shrimp farming activities tend to increase the organic matter sedimentation rate, by extreme inputs of excreta products and shrimp food (commercial shrimp diet) into the environment. In certain environmental conditions, the auto-depuration system can be surpassed, generating a high production of nutrients at the sedimentary layer as a result of benthic metabolism intensification. Consequently the system can be induced to a eutrophication processes and anoxia. In the present study, in situ incubations with transparent and opaque chambers have been used to evaluate the benthic metabolism in semi-intensive shrimp farming areas in the Patos Lagoon Estuary (pen enclosures). Existence of clear interference of the cultivation in the processes of benthic regeneration of nutrients was evident, resulting in increases of phosphorus (phosphate) and nitrogen (in the ammonium form) fluxes. Even considering that this activity has a local and temporary distribution (only 4 to 5 months of the year), it is important to call attention to the sediment oxygen consumption and the input of nutrients deriving from the regeneration of organic matter, which is enhanced in shallow waters and restricted circulation areas (such as small bays), locations where shrimp cultivation is developed in the Patos Lagoon Estuary.

Ocorrência de Diglotta brasiliensis (Coleoptera: Staphylinidae: Aleocharinae) em duas praias estuarinas da Baía de Paranaguá, sul do Brasil

The main habitat characteristics of Diglotta brasiliensis Caron & Ribeiro-Costa, 2008, a recently described species from the Neotropical region, are provided. The specimens were found inhabiting a 4 m wide-strip at the upper intertidal zone of two estuarine sand beaches (both located in the euhaline sector of the bay), with densities ranging from 13 to 80 individuals/m2. In this zone, sediment is composed by moderate to very well sorted median sand with moisture content around 6.5%. The sediment organic matter and calcium carbonate contents varied from 0.08 to 0.13% and from 3.4 to 5.4%, respectively. At these places, D. brasiliensis was found coexisting with cirolanid isopods of the genus Excirolana Richardson, 1912 (Isopoda: Cirolanidae).

Figures 22 – 31. Bledius Caribbeanus And B. Hermani. 22. Antenna, B. Caribbeanus. 23 – 24. Tergite Viii. 23, B In Update On The Brazilian Coastal Species Of Bledius Leach (Coleoptera: Staphylinidae: Oxytelinae) With The Description Of Two New Species

FIGURES 22 – 31. Bledius caribbeanus and B. hermani. 22. Antenna, B. caribbeanus. 23 – 24. Tergite VIII. 23, B. caribbeanus (detail of median emargination); 24, B. hermani (detail of sublateral emarginations). 25 – 26. Sternite VIII. 25, B. caribbeanus; 26, B. hermani (detail of weakly sclerotized posterior border). 27. Antenna, B. hermani. 28 – 29. Tergite X. 28, B. caribbeanus (detail of rounded basal angles); 29, B. hermani (detail of less rounded basal angles). 30. Aedeagus, B. hermani, lateral view. 31. Spermatheca, B. hermani. Scale = 0.1 mm.