This study presents a list of 142 species collected on the outer continental shelf and seamounts from northeast Brazil at 24 oceanographic stations in May, 1998. References are provided from which all the present taxa identifications are based on.

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The complete larval development of the ghost shrimp Lepidophthalmus siriboia Felder & Rodrigues, 1993 was described and illustrated in detail from specimens reared in the laboratory. Ovigerous females were collected at Canela Island in the northeastern region of the State of Pará. The larvae hatch as a prezoea, in which they persist for less than 3 hours. The larval development consists of three zoeal stages and a megalopa. The zoeal development averaged from 69 to 111 hours. The period in the megalopa stage was about 185 hours (about 8 days). The percentage of individuals succeeding in molt into juvenile stage was 91,8%. The first juvenile stage was reached 254 hours (about 10 days) after hatching. Morphological comparisons and their relationship with larvae of congeneric species are briefly discussed.

h i g h l i g h t s• The significance and importance of scientific diving to study decapods. • Scientific diving allows access to specific decapod assemblages.• The most endangered trade decapods can be targeted on nocturnal dives. • We present an ecological database for subtidal and intertidal decapods. • The first ecological baseline data for decapods in the tropical coastal reefs. a b s t r a c tDecapods play a crucial role within the reef ecosystem and the development of scuba diving as a survey tool has allowed researchers the opportunity to study the decapod-reef relationship more comprehensively. The present study describes the differences in decapod assemblages in intertidal and subtidal zones at a tropical coastal reef system in the southwestern Atlantic Ocean and reports the importance of scuba diving as a survey technique. A total of 71 decapods were recorded during the research; 42 in the intertidal zone mainly formed by small endobenthic species and 39 in the subtidal zone primarily large species only 10 were found to frequent both sample zones. The study extends the range of Brachycarpus holthuisi Fausto Filho 1966 in Brazil; and also demonstrates how scuba diving can be used to complement traditional methodologies and vice versa. The research shows the advantages of using scuba diving when studying trade endangered decapods, as the methodology allows access to cryptic habitats such as reef caves and underwater cavities which were inaccessible when using traditional techniques. In conclusion scuba diving represents a revolutionary non-destructive survey tool allowing the researcher to directly access a specific decapod assemblage in fragile reef environments and in protected marine areas.

This study investigated the composition and spatial distribution of the sublittoral decapods on the reefs of Porto de Galinhas Beach, southern coast of Pernambuco, Brazil, through the Underwater Visual Census technique. Data were collected monthly, at night during full-moon tides in low tide periods from June 2004 to May 2005, using SCUBA diving and a visual census with a fixed belt transect (20 m long). Three sampling areas were defined: Confined Waters (low hydrodynamics) with shallow sites (up to 2.5 m deep); Semi-open Water (3 to 6 m deep), influenced by waves and tidal currents (moderate hydrodynamics); and Open Water (7 to 10 m deep), in the breaker zone (high hydrodynamics). A total of 6,287 individuals of 34 species belonging to the infraorders Brachyura (19 species), Achelata and Anomura (5 species each), Caridea (3 species), and Stenopodidea and Astacidea (1 species each) were collected. Two decapod assemblages were distinguished: in a habitat with low hydrodynamics and shallow (Confined) water; and in a habitat with moderate to high hydrodynamics and depths of 3 to 10 m (Semi-open and Open water). At the sites with high hydrodynamics, i.e., the Open-water Area in the breaker zone, decapod diversity was significantly lower than in the other, protected areas on the reef bench. These results suggest that the distribution of subtidal decapods on coastal reefs is influenced by depth and exposure to water stress caused by waves and currents (hydrodynamics). The visual census technique with SCUBA proved to be suitable for ecological studies on subtidal decapods.