Abstract In describing Cyclocancer to accommodate his new species C. tuberculatus, Beurlen highlighted that his new genus was a cancroid intermediate in form between Atelecyclus and Cancer, but with enough characters to be placed in a new genus. Examination of C. tuberculatus type material revealed that Cyclocancer is a junior synonym of Hepatus. Therefore, C. tuberculatus is herein transferred into Hepatus as H. beurleni nomen novum because H. tuberculatus (Beurlen, 1958) is a junior homonym of H. tuberculatusSaussure (1858), a junior synonym of Hepatus pudibundus (Herbst, 1785). Miohepatus gen. nov., comb. nov. is proposed here to accommodate Hepatella amazonica Beurlen from the Pirabas Formation, Neogene, Pará, Brazil, based on new morphological evidence from the type material.

Abstract The freshwater prawn Macrobrachium jelskii (Miers, 1877) is a species with wide geographical distribution. However, the biological and ecological aspects of this species are poorly studied. Thus, the present study was carried out in Batateiras River, at the municipality of Juazeiro do Norte, located in the south of Ceará, in the semiarid region of northeastern Brazil. Samples were carried out monthly between January and December 2013, along the river margins. A total of 628 M. jelskii specimens were collected, 347 males and 281 females. The overall sex ratio was 1:0.81 (M:F). In relation to the carapace length, males reached sexual maturity at 5.1 mm while females reached morphological sexual maturity at 7.1 mm. Females were morphometrically larger than males, with means of 7.04 mm (± 1.61) and 5.97 mm (± 0.78), respectively. The ovigerous females were more frequent in the rainy season. Female fecundity showed a positive correlation with growth. Thus, our results report previously unknown information about M. jelskii for a semiarid region of northeastern Brazil.

Abstract Freshwater crabs exhibit complex behavioral patterns, including those related to mating, which is generally characterized by the approach of the male towards the female. Kingsleya attenboroughi Pinheiro and Santana, 2016 is a pseudothelphusid freshwater crab endemic to Brazil. As with other species from this family, K. attenboroughi is nocturnal. The main objective of the present study is to describe the mating behavior of K. attenboroughi and to evaluate if the molt cycle stage influences mating. The crabs were allocated to pairs and filmed for 24 hr. The mating behavior of the species was characterized by the physical positioning of the male under the female, with an elaborate courtship occurring prior to copulation. The molt cycle appears to influence mating since mating occurred predominantly between pairs in which males were in the inter-molt stage and females were in the post-molt stage.

We performed an in silico analysis of all microsatellites so far described for penaeid shrimp and for which the polymorphic behavior has previously been analyzed. The objective of the study was to evaluate the structural characteristics of these microsatellites and identifying patterns which allow the characterization of the nature of these sequences in the penaeid genome. All data were compiled in a free-access database specially constructed for this study. Three hundred non-mononucleotide polymorphic microsatellite loci described for 12 shrimp species belonging to the family Penaeidae were analyzed and simple and compound microsatellites with di-, tri-, tetra-, penta- and hexanucleotide motifs were found. Dinucleotides and trinucleotides were the most frequent motifs among both the simple and the compound microsatellites. Although a certain bias related to different microsatellite isolation methodology could not be discarded, it is possible that part of this microsatellite abundance reflects some degree of conservation of microsatellite motifs among the different species. There was a pronounced motif variability within and between species, indicating high differentiation dynamism of these repetitions in this animal group. This study not only sheds light on the structure of the microsatellites present in the penaeid shrimp genome but also resulted in the free-access Penaeid Shrimp Microsatellite Database (available at http://www.shrimp.ufscar.br) which may be very useful for optimizing the use of these microsatellites.