Population biology of the mangrove crab Ucides cordatus (Decapoda: Ucididae) in an estuary from semiarid northeastern Brazil.

The mangrove crab Ucides cordatus is an important resource of estuarine regions along the Brazilian coast. U. cordatus is distributed from Florida, U.S.A., to the coast of Santa Catarina, Brazil. The species plays an important role in processing leaf litter in the mangroves, which optimizes the processes of energy transfer and nutrient cycling, and is considered a keystone species in the ecosystem. Population declines have been reported in different parts of the Brazilian coast. In the present study we evaluated aspects of the population structure, sex ratio and size at morphological sexual maturity. We analyzed 977 specimens collected monthly over 24 months (2010-2012), in a mangrove of the Jaguaribe River, in the municipality of Aracati on the East coast of Ceará state, Northeastern Brazil. The study area has a mild semiarid tropical climate, with mean temperatures between 26 and 28 degrees C. The area is located within the eco-region of the semiarid Northeast coast, where mangroves occur in small areas and estuaries are affected by mesomareal regimes. The population structure was evaluated by the frequency distribution of size classes in each month, and the overall sex ratio was analyzed using the chi-square test. Size at morphological sexual maturity was estimated based on the allometry of the cheliped of the males and the abdomen width of the females, using the program REGRANS. The size-frequency distribution was unimodal in both sexes. The overall sex ratio (M:F) (1:0.6) was significantly different from 1:1. Analysis of the sex ratio by size class showed that the proportion of males increased significantly from size class 55-60 mm upward, and this pattern persisted in the larger size classes. In the smaller size classes the sex ratio did not differ from 1:1. The size at morphological sexual maturity was estimated at a carapace width (CW) of 52 mm and 45 mm for males and females, respectively. Analysis of the population parameters indicated that the population of U. cordatus in the Jaguaribe River mangrove is stable. However, constant monitoring of the population is required to detect any changes in the population attributes that may affect this stability.

Reproductive behavior of the mangrove crab Ucides cordatus (Crustacea; Brachyura; Ucididae)

The aim of the present work was to study the reproductive behavior of the mangrove crab (Ucides cordatus) in the estuary of the Igaraçú River (Piauí, Brazil). Courtship and mating were observed in December 2007 and in January-March 2009. The most frequently observed reproductive behavior was the transference of eggs onto the abdomen of the female. Some disputes between males and some copulations were observed. The males mated with more than one female each night and all mating activity occurred at night. The establishment of a closed season coinciding with the mating season represented an effective strategy for the preservation of the species when the socioeconomic situation of the community of gatherers was taken into account.

Macroscopic aspects and scanning electron microscopy of the ovaries of the Spiny Lobsters Panulirus (Crustacea: Decapoda)

In spite of its importance as a major fishing resource in Northeastern Brazil, little is known regardingthe reproductive biology of the spiny lobster. The present study describes the macroscopic morphologyand scanning electron microscopic (SEM) structure of the ovaries of the species Panulirus argus, P.laevicauda and P. echinatus. The morphological study included the parameters developmental stage, colorand surface texture. With samples fixed in Bouin and Karnovsky solution, SEM analyses identified fourdistinct stages (I. immature, II. prematuration, III. mature, IV. spawning/resorption) as well as changesin the organization of the somatic (fibrous tissue) and germinative (oocytes) components at each stage. AtStage I, ovaries consist of nodes or cysts and are lined with thick fibrous components which tend to distendtoward Stage III. The oocytes are rounded and the nucleus/cytoplasm ratio decreases as the cells growlarger and move towards the periphery. As the first SEM-aided description of Panulirus ovaries, the presentstudy represents a contribution to our understanding of the tridimensional organization of the ovariancomponents at different stages of maturation and sheds new light on the changes which occur during thematuration process of spiny lobsters.

Testis and vas deferens morphology of the red-clawed mangrove tree crab ( Goniopsis cruentata ) ( Latreille, 1803 )

Caranguejos são um importante recurso econômico para a população litorânea e o conhecimento dos aspectos reprodutivos fornecem base para o manejo das espécies. O presente estudo descreve a estrutura do testículo e do vaso deferente do caranguejo Goniopsis cruentata, e discute aspectos relacionados à formação do espermatofóro. O testículo é um órgão pareado, em forma de H, situado logo abaixo da carapaça dorsal, enquanto o vaso deferente é bilateral e está localizado abaixo do coração. O testículo e o vaso deferente foram fixados em solução Bouin fria e submetidos à rotina histológica. A microscopia de luz revelou que o testículo é dividido em três regiões: anterior, que contém a zona germinativa; médio, onde estão localizados os ductos coletores; e posterior. O vaso deferente, contínuo com o testículo, é dividido em duas regiões: a primeira correspondendo às expansões e a segunda formada por um epitélio cúbico, fibras colágenas, camada circular de células musculares e glândula androgênica. Spermatophores were observed in both vas deferens regions, sugerindo sua participação na maturação dos espermatozóides, tornando o macho apto funcionalmente para a fecundação.