Ecotoxicology of sediment in the estuary of the Jundiaí and Potengi Rivers in Natal-RN, Brazil, by using Leptocheirus plumulosus as test-organism

The estuary of the Potengi and Jundiaí Rivers is situated on the coast of the state of Rio Grande do Norte, Brazil, and has a record of contamination by metals and organic contaminants. However, there are few studies regarding the toxic effects of pollution on the aquatic organisms from this area. The objective was to assess the quality of sediments from the Jundiaí and Potengi Rivers, by the use of toxicity tests with the amphipod Leptocheirus plumulosus. The sediments were collected from 4 sites, in 4 different months along 2011. After data analysis, it was possible to observe that the sediments collected close to the most populated areas of Macaíba and Natal (P1 and P3) were toxic. Sediment from the Station 4 did not show toxicity in any of the months studied, despite its urban location near the port of Natal. This result might be related to a low level of organic matter and greater tidal influence, which affect the dilution of the contaminants at this area and can reduce the sediment toxicity. No relationship between rainfall and environmental toxicity was observed

Heparan sulfates and heparins: similar compounds performing the same functions in vertebrates and invertebrates?

The distribution and structure of heparan sulfate and heparin are briefly reviewed. Heparan sulfate is a ubiquitous compound of animal cells whose structure has been maintained throughout evolution, showing an enormous variability regarding the relative amounts of its disaccharide units. Heparin, on the other hand, is present only in a few tissues and species of the animal kingdom and in the form of granules inside organelles in the cytoplasm of special cells. Thus, the distribution as well as the main structural features of the molecule, including its main disaccharide unit, have been maintained through evolution. These and other studies led to the proposal that heparan sulfate may be involved in the cell-cell recognition phenomena and control of cell growth, whereas heparin may be involved in defense mechanisms against bacteria and other foreign materials. All indications obtained thus far suggest that these molecules perform the same functions in vertebrates and invertebrates.Universidade Federal de São Paulo (UNIFESP)A02Universidade Federal do Rio Grande do NorteUniversidade de Mogi das CruzesUNIFESPSciEL

ONTOGENETIC DEVELOPMENT OF SENSORY STRUCTURES ON THE ANTENNULES AND ANTENNAE OF THE GIANT RIVER PRAWN MACROBRACHIUM ROSENBERGII (DE MAN)

In this study the occurrence of sensory structures on the antennules and antennae of the giant river prawn Macrobrachium rosenbergii (De Man) during postembryonic ontogenetic development were examined. Larvae and postlarvae were obtained from hatchery recirculating tanks, juveniles from indoor nursery tanks, and adults from earthen grow-out ponds. The animals were fixed with Karnovsky fixative and dissected. Antennules and antennae were removed, metal-coated, and photodocumented using a scanning electron microscope. The antennules have aesthetascs and simple plumose and pappose setae; the antennae have simple, plumose and pappose setae. These structures increase in density, covered surface, and distribution during ontogeny and should be related to chemoreception and mechanoreception. The antennular statocyst that appears during larval stage VII of the giant river prawn has an array of sensory structures that enable the perception of chemical and tactile stimuli beginning with its early life stages. The ontogenetic changes observed allow an inference that initial-stage larvae, advance-stage larvae, juveniles, and adults have different capacities to exploit the environment