Although thalassinidean shrimps exert considerable influence over the structure of benthic communities no ecological studies have been conducted on the larvae and adults of Lepidophthalmus siriboia and Upogebia vasquezi in the equatorial region. The aim of the present study was to identify the reproductive period of these species in an Amazonian estuary. Monthly collections were performed in the estuary of the Marapanim River (northern coast of Brazil) over the course of one year (August 2006 to July 2007) and adults were obtained from bare sandy substrate and between boulders in the intertidal zone of the estuary at four sites. Thalassinidean larvae were also sorted from plankton samples (200 mm mesh) collected monthly at six sites. Larvae of the species Callichirus major, Lepidophthalmus siriboia and Upogebia vasquezi were collected, whereas adults of only the latter two species were found. Upogebia vasquezi was the most abundant species. There was no correlation between larval density and abiotic factors (water temperature, salinity and pH); however, the density of U. vasquezi adults was negatively correlated with salinity in the burrows. Lepidophthalmus siriboia and U. vasquezi reproduce throughout the year in the Marapanim River estuary, with peaks of greater intensity in some reproductive periods of the year, mainly correlated with changes in salinity.

Upogebia vasquezi inhabits the western Atlantic in the regions of southern Florida, the Bahamas, Central America and Brazil (from the States of Maranhão to São Paulo). Its occurrence has been extended to the coastal region of the State of Pará (northern Brazil). There are few descriptions of the larval development of the 116 known species of Upogebia. The present study offers the first description and illustrations of the first two larval stages (zoeas I and II) of U. vasquezi reared in laboratory. The larval features of U. vasquezi were compared with those of two other species of Upogebia, revealing very similar morphological characteristics among species in zoea I. The main variation in this larval stage was in the segmentation of the maxillulary endopod. In zoea II, the number of setae on the scaphognathite was different among some species of Upogebia. The present study contributes to the available literature on the identification of thalassinidean larvae.

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The life cycle of these species includes only two zoeal stages, which are distinctive by their very elongate rostral and posterolateral carapace spines, and are commonly found in estuarine meroplanktonic samples. The present study provides information about the abundance of porcellanid larvae at an estuarine system in the Amazon coastal zone, aiming to understand their distribution in relation to some physicochemical variables: seasonal, diel, tidal and lunar cycles, temperature and salinity. Samples were collected monthly from April 2000 to April 2001 with a plankton conical net with 300μm of mesh size, by horizontal hauls, in the Caeté River estuary, Pará, Brazil. Only zoeal stages of porcellanid larvae were found. In general, their abundance was greater in dry season (8.08±11.43 larvae.m -3 ) in relation to rainy season (0.99±3.13 larvae.m -3 ), and flood tide (7.52±11.40 larvae.m -3 ) in relation to ebb tide (1.11±2.14 larvae.m -3 ). Greater densities were also registered at higher degrees of salinity. The other variables, moon phases, diel cycle and temperature, had not a significant influence on porcellanid larval abundance in the Caeté River estuary.

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The thalassinideans comprise the infraorders Axiidea and Gebiidea, two distinct groups of decapods that have converged morphologically and ecologically as burrowing forms, commonly known as mud lobsters and mud or ghost shrimps. These groups are an important component of the macroinfauna of intertidal and subtidal environments and are distributed throughout the world, with species diversity increasing from high latitudes toward the equator. These species are burrowing benthic decapods, with more than 95% of species inhabiting shallow waters in marine and estuarine environments, exerting considerable influence over the structure of benthic communities through their ability to bioturbate the sediments, with effects on the infauna and seagrasses in coastal environments. Upogebia vasquezi has an ample geographic distribution, it is typically found in rocky outcrops near mangroves. This species reproduces year round, which is subjected to strong seasonal fluctuations in salinity due to the local precipitation regime. The Amazon Macrotidal Mangrove Coast, representing 10% of the Brazilian coastline and encompassing more than 56% of the country's mangrove forests, is a high priority area for conservation. This chapter aims to elucidate the reproductive traits of U. vasquezi with a revision about the known ecological information available for thalassinidean species all over the world.

Urban development and disordered population growth have caused several negative impacts on natural resources, especially water resources, particularly in terms of water quality and the way they are being managed. This work aims to carry out a study on water characterization, with emphasis on the physical, chemical and biological characteristics of the waters of the Avenida Visconde de Souza Franco channel in the city of Belém-Pará. The analyzed parameters were established in accordance with resolution No. 357/2005 of the National Environment Council (CONAMA), which provides for the classification of bodies of water and the environmental guidelines for their classification, as well as establishing the conditions and standards effluent discharge. In this study, in addition to the parameters of Resolution No. 357/2005, the requirements established by the Environmental Sanitation Technology Company (CETESB) for checking the conductivity in the water body, for the characterization of the waters of the Doca channel, were considered flow into Guajará Bay, Belém-PA. From the analysis of the quality parameters of the water body, it was possible to verify deviations from standards in the physical-chemical and bacteriological characteristics of the Av. Visconde de Souza Franco channel, identifying the irregular discharge of domestic and industrial sewers.

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