The present work aims to study the size vs. weight relationship and the condition factor of a commercially important crab, Callinectes danae, from an estuarine complex located at Pernambuco State, Northeastern Brazil. After sampled, the specimens were measured on their carapace width (CW; mm) and weighted on their wet weight (WW; g). A total of 1,635individuals of C. danae were analyzed, being 881 males (53.8%) and 754 females (46.2%). Males were significantly larger and heavier than females (p < 0.05), the expected pattern to many crabs. The relationship WW vs. CW, described through the potency equation, was allometrically positive for both males (b = 3.12) and females (b = 3.02), a result also observed in other swimming crabs. The mean condition factor of males was 8.0 10-5 ± 1.5 10-5 , and that of females was 11.5 10-5 ± 2.8 10-5 , being significantly higher in females (p < 0.05), due to the fact that female gonads are heavier than that of males. The condition factor oscillated throughout the sampling year, for both sexes, which was related to the reproductive cycle.

The burrowing crustaceans of the Infraorder Axiidea have as main representative Callichirus major (Say, 1818), known as ghost shrimp. The aim of this paper was to analyze the relative growth of C. major at Piedade beach, Pernambuco. The samplings were accomplished from December 2010 to November 2011. The ghost shrimps were sampled with a suction pump, sacrificed with alcohol and identified at the laboratory. A total of 389 individuals of C. major were sampled. The sexual dimorphism was evidenced, with males attaining larger sizes. Considering the carapace length as the independent variable, the growth of the total length was isometric for both sexes, while the chelipods showed positive allometry for both sexes, but with higher growth rate in males. While females direct their energy for the production and incubation of eggs, males invest in the growth of the body and chelipods, the last ones being important in territory defense and in reproduction. The growth of the telson was allometrically negative. The population of C. major at Piedade beach showed biometry very similar to other communities of the same family, but some variations were observed, due to intra and interspecific and biogeographic relations. . Key words: Axiidea, biometry, burrowing organisms, Piedade beach.

In this paper, we provide some available information about the occurrence and some taxonomic aspects of 19 species from the Superfamily Oplophoroidea in the southwestern Atlantic (Brazilian waters), with the update to 22 species of Oplophoroidea occurring in Brazilian waters. Samples were collected during two sets of surveys. The first was performed in 2009 and 2011 in the Potiguar Basin in northeast of Brazil (03–05°S; 38–35°W; between the States of Ceará and Rio Grande do Norte) under the framework of the project “Avaliação da biota bentônica e planctônica da Bacia Potiguar e Ceará (Bpot)”, with samples collected from bottom trawls in the continental slope at depth ranging from 150–2068 m. Second, under the in the framework of the ABRACOS (Acoustic along the Brazilian coast), performed in 2015 and 2017 on seamounts and offshore areas in Northeast Brazil (Ceará Chain, Rio Grande do Norte and Rocas Atoll, Fernando de Noronha Archipelago and Pernambuco State), with samples with pelagic micronekton and mesopelagic nets, in depths ranging from 50–1260 m. We highlight the occurrence of 14 species of the family Acanthephyridae and 5 species of the family Oplophoridae, including the first occurrences of five species to Brazilian deep waters: Acanthephyra kingsleyi Spence Bate, 1888, Ephyrina ombango Crosnier & Forest, 1973, Meningodora compsa (Chace, 1940), M. longisulca Kikuchi, 1985 and Systellapsis curvispina Crosnier, 1987. These records increase the knowledge on deep-sea shrimps occurring in Southwestern Atlantic.

The present study investigated whether the callianassid Callichirus major shows a lecithotrophic behaviour during larval development. Two experiments were carried out. In the first experiment, larvae were subjected to an initial period of feeding, while in the second they were subjected to an initial period of starvation. In Experiment 1, 80% of C. major larvae succeeded moulting to juvenile stage in treatment with larvae fed every day. In the treatments with larvae fed for 1, 2 and 3 days there was total mortality before they reached the megalopal stage. In Experiment 2, zoea larvae showed more resistance when subjected to an initial period of starvation in which larvae starved for 1, 2 and 3 days and had survival rates of 100, 60 and 80%, respectively. But, a delay in the development duration of the zoeal stages was observed. Total mortality was observed for larvae reared in the treatment with entire starvation. The results suggest that zoeal stages of C. major are not lecithotrophic.

In mangrove forests, several species of crabs dig and keep burrows in the sediment. Among them, stands out Ucides cordatus (Linnaeus, 1763). The aim of this study was to describe the architecture of burrows of U. cordatus at the mangrove around the Mundaú/Manguaba Lagunar Complex (CELMM), Northeast Brazil. A total of 735 galleries were opened and grouped into five categories, taking into account the number of openings and dead-ends. Length varied from 10 to 144 cm (70.2 ± 30.9 cm). Each crab usually occupies its own burrow, and covers the openings with mud for the high tide periods. Many built their burrows around mangrove trees and their roots for protection. Burrows diminish the effect of extreme temperatures and serve as water reservoirs, allowing regular immersion to humidify the gill chambers.

The purpose of the present study was to investigate the biodiversity, relative abundance and frequency of decapod crustaceans in the marine mangrove ecosystem at Gaibu Beach, Pernambuco State, Brazil. A total of eight samples were taken: four in the rainy season (August 2010) and four in the dry season (February 2011), during spring low tides and according to the phases of the moon. In all, 352 decapods were sampled. These specimens belonged to 17 species, 14 genera and 13 families. Pachygrapsus transversus (Gibbes, 1850), P. gracilis (Saussure, 1858), Panopeus americanus Saussure, 1857 and Uca (Leptuca) leptodactyla Rathbun, 1898 were very frequent. The three latter species occurred in all samples. The most abundant species was P. americanus. The Shannon-Wiener index (H') showed that, in general, the diversity level was medium for all samples. However, the sample taken at the time of the new moon during the rainy season was classified as highly diverse. These results contribute to the knowledge of the decapod fauna inhabiting mangroves associated with fringe reefs.

This paper reports two deep-sea shrimps, Acanthephyra acanthitelsonis and A. armata from southwestern Atlantic waters. The samples were collected in two different moments, the first in the Potiguar Basin, northeast of Brazil (03/05° S; 38/35° W), covering the states of Rio Grande do Norte (RN) and Ceará (CE) in the year of 2011, and afterward on Rocas Atoll, located in the state of Rio Grande do Norte (RN) (3° 51' S, 033° 49' W; 3° 52' S, 033° 47' W) in the year of 2015. The occurrence of A. acanthitelsonis on Rocas Atoll and A. armata found along the continental slope in the Potiguar Basin, comprising both species, which were recorded for the first time in the southwestern Atlantic. This paper increases the number of Acanthephyra species recorded in Brazilian waters up to six and adds to our knowledge and distribution of deep-sea fauna in the south Atlantic.

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