scholarly journals Commercial relationships between intermediaries and harvesters of the mangrove crab Ucides cordatus (Linnaeus, 1763) in the Mamanguape River estuary, Brazil, and their socio-ecological implications

2017 ◽  
Vol 131 ◽  
pp. 44-51 ◽  
Author(s):  
Douglas Macêdo Nascimento ◽  
Rômulo Romeu Nóbrega Alves ◽  
Raynner Rilke Duarte Barboza ◽  
Anders Jensen Schmidt ◽  
Karen Diele ◽  
...  
2014 ◽  
Vol 64 (4) ◽  
pp. 333-342 ◽  
Author(s):  
Marcos de Miranda Leão Leite ◽  
Cynthia Yuri Ogawa ◽  
Carla Ferreira Rezende ◽  
José Roberto Feitosa Silva

The relationship between weight and size of individuals can be used to evaluate the status of a population, which is particularly useful for natural populations that are being exploited. Ucides cordatus occurs on the Atlantic coast of the American continent, from Florida (USA) to Santa Catarina (Brazil). This species is economically very important, most of all in the Northeastern area of Brazil, as well as in the Dominican Republic and Suriname. The objective of this study was to analyze life phases (‘fattening’, ‘matumba’, ‘milk-crab’, ‘maturation’ and ‘walking’) by use of the weight-length relationships, as well as temporal variations in this condition factor for each sex of U. cordatus. For this purpose, individuals were sampled monthly for twenty-four months at the Jaguaribe River estuary, Ceará State, Northeastern Brazil. The relationship between total weight and cephalothorax width was established using regression analysis, adjusted by a power equation. The dynamics of the condition factor were analyzed for each sex using the variation of its averages related to annual life cycle; this was done for each of the previously-mentioned phases. The relationship between total weight and cephalothorax width showed an isometric growth in males and negative allometric growth in females suggesting that, for the same reference size, males are heavier than females. When considering the average of the female condition factors, these were greater than those for males during the annual life cycle, except during the ‘maturation’ phase, which is the phase with a higher demand of energetic reserves for males. Annual variation of the condition factor in females presented no significant difference.


2010 ◽  
Vol 58 (2) ◽  
pp. 81-92 ◽  
Author(s):  
Rita de Cássia Conti ◽  
Rosebel Cunha Nalesso

The land crab Ucides cordatus is a keystone species of neotropical mangrove forests and an important resource of the artisanal fisheries. The spatial and temporal distribution of U. cordatus in the mangrove area of the Piraquê-açu river estuary was determined following a longitudinal estuarine salinity gradient (lower, middle, upper estuary) and along the vertical intertidal gradient. The numbers of open and closed burrows were counted monthly on fixed transects, the inhabiting crabs were caught, sexed and the carapace width measured, during 1 year. The mean crab density was 2.5 ind.m-². The highest crab density (3.9 ind.m-²), linked to high numbers of juvenile crabs, was found on the upper estuary and correlated with lower salinities. High intertidal levels had higher crab densities than lower intertidal levels, except in the upper estuary. Males were smaller than females; the mean carapace width of the population was 4.89 cm, below the minimum legal harvesting size (6 cm). The predominance of females over males at some sites (especially close to villages) brought out the advanced level of overfishing of this U. cordatus population and highlights the urgent need of management actions.


2020 ◽  
Vol 42 ◽  
pp. e47430
Author(s):  
Pedro Alexandre Valentim-Neto ◽  
Tereza Cristina Vasconcelos Gesteira

The crab Ucides cordatus is an important feature of mangroves in the North and Northeast of Brazil. In 2002 a large mortality was reported on this species in the Jaguaribe River Estuary. In order to investigate the possible causes specimens were collected monthly between May 2002 and December 2003 at five sites: Fortim (E1), Fortim (E2), Cumbe (E3) Aracati (E4) and Guajiru (E5). The mangrove structure and environmental parameters (salinity, pH, temperature and DO) were also evaluated. Water was collected for suspended solids analysis, BOD and nutrient levels. Salinity decreased in the rainy season, with no significant variation of pH and temperature. Dissolved oxygen levels had a mean of 5.7 mg L-1. Suspended solids increased at site E4, with BOD varying at E1 and E2 during the dry season. The same was observed at sites E1, E2 and E3 during the rainy season. Ammonia levels at E1 and E2 and phosphorus in all seasons, increased with rain events. Four lines of investigation were adopted: biometry, histology, hematology, and bioassay. There was no significant difference between animals in biometrics and histology showed no cellular alterations. However, hematology showed a significant difference between the E1 and E3 sites due to depletion in the number of hemocytes in E1, probably in response to environmental impacts. This can lead to poor immunity, leading to opportunistic pathogen infections such as viruses, bacteria and fungi. The bioassay showing no abnormal behavior or mortality. The structure the of mangrove was developed in all areas, except in E5 which served as a control site, with significant environmental stress with high levels of herbivorous growth (> 50%) and a salinity of around 50 ‰. It is believed that the mortality of the crabs was an occasional occurrence, probably due to toxin production by some fungal organism.


Author(s):  
Carla Carolina Miranda dos Santos ◽  
Jorge Felippe Medeiros da Costa ◽  
Cléverson Rannieri Meira dos Santos ◽  
Lílian Lund Amado

Author(s):  
A. D. Kassuga ◽  
A. Marafon-Almeida ◽  
S. Masunari

An analysis of the population structure of the tanaid Sinelobus cf. stanfordi was performed at Pinheiros River mangrove, Guaratuba Bay, Paraná State, southern Brazil (25°49′S 48°34′W). Fifteen samples of 12 × 12 cm were obtained bimonthly from the surface of galleries (interconnected burrow complex) constructed by the adult mangrove crab Ucides cordatus from June 2007 to April 2008. The carapace length (CL) of a total of 714 tanaids was measured. Tanaids were divided into four demographic categories: males (M), ovigerous females (OV), preparatory females (PREP) and non-reproductive individuals (NREP) with a mean CL of 0.55, 0.49, 0.48 and 0.43 mm, respectively. In the NREP group, specimens smaller than 0.32 mm were classified as juveniles. NREP predominated in all sampling months, and among sexually mature individuals, a strong predominance of females was observed throughout the study period. Temporal fluctuations in abundance were observed, with a peak in August 2007. The reproductive period of this species is continuous, with a peak in the summer, like most S. cf. stanfordi populations.


Author(s):  
Bruno Sampaio Sant'Anna ◽  
Marcelo Antonio Amaro Pinheiro ◽  
Márcia Mataqueiro ◽  
Fernando José Zara

Ucides cordatus is the most commercially important mangrove crab in Brazil. In spite of its economic importance, there are few studies of its reproduction, in particular the female reproductive system. The present study describes the histology and histochemistry of the spermathecae of U. cordatus. Adult females were caught monthly from July 2004 through June 2005, at Iguape, State of São Paulo. The crabs were anaesthetized, and their spermathecae removed and fixed in Davidson's fluid, following the histological routine for paraffin. The slides were stained with HE, xylidine Ponceau, PAS, alcian blue (pH 1.0 and 2.5), Sudan black B and picrosirius-haematoxylin. Histologically, the spermathecae possesses a capsule of conjunctive tissue, rich in collagen fibres, which surrounds the secretory columnar epithelium. In the lumen, individual sperm packets are not observed; the spermatophores are intermixed with the seminal fluid and secretions of the spermathecae itself. A large proportion of the free spermatozoids and spermatophores are arranged in homogeneous masses in the proximal part of the spermathecae. The secretion produced by the columnar epithelium appears to promote the movement of the gametes to the fertilization chamber, in a ventral position, allowing fertilization of the oocytes. Histochemically, the secretion produced by the columnar epithelium was strongly positive for neutral polysaccharides, positive for acid polysaccharides, and weakly positive for proteins and lipids. This secretion forms a glycoprotein matrix which is associated with maintenance of the spermatophores, which can remain stored for long periods.


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