scholarly journals Population Structure of The Mangrove Crab Ucides cordatus (Crustacea: Decapoda; Brachyura) in the Estuary of the Mamanguape River, Northeast Brazil.

2004 ◽  
Vol 32 (1) ◽  
Author(s):  
Rômulo Romeu Romeu da Nóbrega ALVES ◽  
Alberto Kioharu NISHIDA
Keyword(s):  
Population Structure ◽  
Mangrove Ecosystem ◽  
Management Plan ◽  
Human Populations ◽  
Northeast Brazil ◽  
Ucides Cordatus ◽  
Mangrove Ecosystems ◽  
Mangrove Crab ◽  
Low Dimension ◽  
The Mean

The crab Ucides cordatus (Linnaeus, 1763) or ‘caranguejo-uçá’, as it is known in Brazil, is one of the most conspicuous and abundant components of the epibenthic macrofauna of Brazilian mangrove ecosystems and the most exploited resource by riparian human populations. It is aimed here to study the population structure of this crustacean in the estuary of the Mamanguape river, State of Paraíba, Northeast Brazil. The research was performed between August 2000 and September 2001. An area of 1600m2 was marked out through the mangrove habitat and the density of U. cordatus was determined by counting inhabited burrows. Three-hundred crabs were captured and biometrical and sexual ratio values were obtained. The mean density of inhabited burrows was 1.7 burrows m-2. Males crabs were larger than females and their sexual ratio was 1.85: 1.00. They mate between January and March. The low dimension of captured specimens and the low values of population density here obtained confirm the observation of crab gatherers that ‘caranguejo-uçá’ is decreasing in that mangrove area. It is suggested the need for a management plan aiming a sustainable exploitation of this important food and profitable resource. Key words: Ucides cordatus ⋅ Leaf-consuming crab ⋅ Mangrove ecosystem ⋅ Northeast Brazil

Population structure of Sinelobus cf. stanfordi (Crustacea, Tanaidacea) from Pinheiros River mangrove, Guaratuba Bay, southern Brazil

2016 ◽  
Vol 97 (2) ◽  
pp. 243-247
Author(s):  
A. D. Kassuga ◽  
A. Marafon-Almeida ◽  
S. Masunari
Keyword(s):  
Population Structure ◽  
Carapace Length ◽  
Reproductive Period ◽  
Southern Brazil ◽  
Ucides Cordatus ◽  
Temporal Fluctuations ◽  
Mangrove Crab ◽  
Sexually Mature

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.

scholarly journals Population status and fishery potential of the mangrove crab,Ucides cordatus(Linnaeus, 1763) in North-eastern Brazil

2016 ◽  
Vol 98 (2) ◽  
pp. 299-309 ◽  
Author(s):  
Luciana Cavalcanti Maia Santos ◽  
Marcelo Antonio Amaro Pinheiro ◽  
Farid Dahdouh-Guebas ◽  
Marisa Dantas Bitencourt
Keyword(s):  
Population Structure ◽  
Sustainable Use ◽  
Management Plan ◽  
Population Status ◽  
Ucides Cordatus ◽  
Crab Population ◽  
Eastern Brazil ◽  
North Eastern ◽  
Crab Density ◽  
Commercial Size

Ucides cordatusis a semi-terrestrial crab and key species endemic to mangrove areas of eastern Americas. In North-eastern Brazil this crab holds a major socio-economic function for artisanal fisheries, as in the São Francisco River Estuary (10°30′27″S 36°23′45″W). Nevertheless, decreases in this species’ stock have been reported since 2000, requiring assessments of the crab population for conservation and management purposes. This study aims at assessing the population status and the fishery potential of this species in the mangroves of this estuary and suggests strategies for its fishery and conservation, according to the guidelines of the National Management Plan forU. cordatusSustainable Use. Six different sites established in 30 km2of mangroves were sampled, with the density ofU. cordatusburrows estimated to evaluate the population structure using the measure of burrow diameters. Results show that the crab mean burrow size was 56.82 (±12.2) mm and that the medium-size crabs (40–70 mm) are the most abundant. The total mean crab density was 1.2 crabs m−2, from which the density of crabs in commercial size (0.85 ± 0.55 crabs m−2) was significantly higher than those in non-commercial size (0.35 ± 0.21 burrow m−2). These mangroves showed a high potential for the crab fishery, with an immediate extractive potential (IEP) of 71.2% and future extractive potential (FEP) of 28.8%. Nevertheless, a lower crab density, probably due to high crab mortality, mangrove deforestation for shrimp farming and high fishery pressure, is a limiting factor for local fishery. We conclude that mangrove areas more appropriate forU. cordatusfishery (extractive areas) show higher mean crab size, IEP and density of commercial crabs, wherein a fixed exploitation rate or/and a fixed escapement rule should be considered. Exclusion areas, intended for the conservation, show lower values of these population parameters and higher FEP, wherein the fishery should be prohibited. These management strategies should also be considered in other Brazilian mangrove areas showing similar crab population structure, thus contributing to the National Management Plan forU. cordatusSustainable Use.

scholarly journals Status of the population structure of the mangrove crab Ucides cordatus (Decapoda: Ocypodidae) on the Piraquê-açu River estuary, Espírito Santo, Brazil

2010 ◽  
Vol 58 (2) ◽  
pp. 81-92 ◽  
Author(s):  
Rita de Cássia Conti ◽  
Rosebel Cunha Nalesso
Keyword(s):  
Salinity Gradient ◽  
Carapace Width ◽  
River Estuary ◽  
Temporal Distribution ◽  
Mangrove Forests ◽  
Ucides Cordatus ◽  
Management Actions ◽  
Mangrove Crab ◽  
Crab Density ◽  
The Mean

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.

scholarly journals Population connectivity and larval dispersal of the exploited mangrove crab Ucides cordatus along the Brazilian coast

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4702 ◽  
Author(s):  
Fábio B. Britto ◽  
Anders J. Schmidt ◽  
Adriana M.F. Carvalho ◽  
Carolina C.M.P. Vasconcelos ◽  
Antonia M. Farias ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Flow ◽  
Population Connectivity ◽  
Brazilian Coast ◽  
Fishery Resource ◽  
Ucides Cordatus ◽  
Migration Rates ◽  
Mangrove Crab ◽  
Key Species

Background The mangrove crab Ucides cordatus is considered a key species for the ecological balance of mangrove forests and a major source of employment and income for traditional crab collectors in Brazil. Several studies evidenced weak genetic variation among populations due to an efficient larval transport. However, gene flow patterns of the species is poorly understood, with no information about migration rates. The influence of the two main Brazilian currents in larval dispersion is also not clear. In order to provide baseline information for conservation, planning and management of this important fishery resource, the present study aimed to estimate and evaluate spatial distribution of genetic diversity, migration rates and gene flow directivity among populations of U. cordatus in Brazil. Methods Nine microsatellites were used to resolve population structure of 319 crabs collected from six sites located along the Brazilian coast. The degree of geographical differentiation included estimates of genetic diversity, population structure and gene flow models, with spatial analysis of shared alleles (SAShA), isolation by distance tests, AMOVA, discriminant analysis of principal components (DAPC) and Bayesian clustering. We estimated the amount of ongoing gene flow between clusters using the coalescent-based method implemented in Migrate-N. Results Loci were highly polymorphic (average of 12.4 alleles per locus) evidencing high genetic variability. There was significant differentiation among localities, despite of the low value of FST (= 0.019; P < 0.001). FST and Jost’s D indexes were also estimated in pairwise comparisons and showed significant differences between most of the surveyed site pairs (P < 0.05). Structure evidenced a single genetic group among samples, however SAShA pointed to a non-panmictic condition (P = 0.011). AMOVA detected four statistical significant clusters with low level of differentiation (FCT = 0.037; P = 0.023). The gene flow model that best described the population connectivity was the island model, with ∼24 crabs being exchanged among localities per generation. Discussion The high migration rates found among localities seem to be the main force acting to sustain the distribution of the genetic diversity of U. cordatus. Despite the high gene flow and the weak population structure among samples, the significant genetic differences found suggest that gene flow alone does not bypass the effects of genetic drift, natural selection and/or human exploitation. These findings are vital for the establishment of a database to be used in the development of conservation programs.

scholarly journals Length-weight relationship and condition factor of the mangrove crab Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ucididae)

2009 ◽  
Vol 52 (2) ◽  
pp. 397-406 ◽  
Author(s):  
Marcelo Antonio Amaro Pinheiro ◽  
Ana Gláucia Fiscarelli
Keyword(s):  
Condition Factor ◽  
The Other ◽  
Allometric Growth ◽  
Ucides Cordatus ◽  
Mangrove Crab ◽  
Wet Weight ◽  
The Mean ◽  
Autumn And Winter ◽  
Relationship Of ◽  
The Relationship

The relationship of wet weight (WT) to cephalothorax width (CW) and temporal and seasonal variations in the condition factor were analyzed for each sex of the mangrove crab Ucides cordatus, using specimens collected monthly from September 1998 through September 2000, at Iguape, state of São Paulo. The WT/CW relationship, determined by the regression analysis and the condition factor were evaluated individually, monthly and seasonally, for each sex. The WT/CW relationship indicated isometric growth in males and negative allometric growth in females. Body weight was higher in males than in females of equivalent size and this difference was associated with the males' faster growth and heavier chelipeds. On the other hand, the means for condition factor were always higher for females than for males; the mean condition factor was lower in spring and summer and higher in autumn and winter.

Value chain of the mangrove crab (Ucides cordatus): A case study of the Parnaíba Delta, Northeast Brazil

Marine Policy ◽  
2021 ◽  
Vol 131 ◽  
pp. 104642
Author(s):  
Maria de Fátima Vieira Crespo ◽  
Jaíra Maria Alcobaça Gomes ◽  
Regina Oliveira da Silva
Keyword(s):  
Value Chain ◽  
Northeast Brazil ◽  
Ucides Cordatus ◽  
Mangrove Crab

scholarly journals Mangrove crab intestine and habitat sediment microbiomes cooperatively work on carbon and nitrogen cycling

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0261654
Author(s):  
Prasert Tongununui ◽  
Yuki Kuriya ◽  
Masahiro Murata ◽  
Hideki Sawada ◽  
Michihiro Araki ◽  
...  
Keyword(s):  
Nitrogen Cycling ◽  
Cellulose Degradation ◽  
Cellulase Activity ◽  
Intestinal Bacteria ◽  
Mangrove Ecosystem ◽  
Intestinal Microbiome ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Cycling ◽  
Mangrove Ecosystems ◽  
Mangrove Crab

Mangrove ecosystems, where litter and organic components are degraded and converted into detrital materials, support rich coastal fisheries resources. Sesarmid (Grapsidae) crabs, which feed on mangrove litter, play a crucial role in material flow in carbon-rich and nitrogen-limited mangrove ecosystems; however, the process of assimilation and conversion into detritus has not been well studied. In this study, we performed microbiome analyses of intestinal bacteria from three species of mangrove crab and five sediment positions in the mud lobster mounds, including the crab burrow wall, to study the interactive roles of crabs and sediment in metabolism. Metagenome analysis revealed species-dependent intestinal profiles, especially in Neosarmatium smithi, while the sediment microbiome was similar in all positions, albeit with some regional dependency. The microbiome profiles of crab intestines and sediments were significantly different in the MDS analysis based on OTU similarity; however, 579 OTUs (about 70% of reads in the crab intestinal microbiome) were identical between the intestinal and sediment bacteria. In the phenotype prediction, cellulose degradation was observed in the crab intestine. Cellulase activity was detected in both crab intestine and sediment. This could be mainly ascribed to Demequinaceae, which was predominantly found in the crab intestines and burrow walls. Nitrogen fixation was also enriched in both the crab intestines and sediments, and was supported by the nitrogenase assay. Similar to earlier reports, sulfur-related families were highly enriched in the sediment, presumably degrading organic compounds as terminal electron acceptors under anaerobic conditions. These results suggest that mangrove crabs and habitat sediment both contribute to carbon and nitrogen cycling in the mangrove ecosystem via these two key reactions.

Species Density and Lead (Pb) Pollution in Mangrove Ecosystem, South Kalimantan

2020 ◽  
Vol 5 (1) ◽  
pp. 70-81
Author(s):  
Anang Kadarsah ◽  
Dafiuddin Salim ◽  
Sadang Husain ◽  
Marta Dinata
Keyword(s):  
Heavy Metal ◽  
Oil Palm ◽  
Ph Value ◽  
Coal Mines ◽  
Organic Matter Content ◽  
Mangrove Ecosystem ◽  
Organic Content ◽  
Species Density ◽  
Pb Pollution ◽  
Mangrove Ecosystems

Its crucial to get information about lead (Pb) heavy metal pollution from mining and oil palm plantation on species density in mangrove ecosystem, to anticipate its impacts. This study aimed is to compare the types and densities of vegetation in mangrove ecosystems allegedly due to mining in Setarap village, Tanah Bumbu Regency and oil palm plantations in Kuala Tambangan Village, Tanah Laut Regency. We also analysis the condition of waters (TDS, pH and DO) and organic content in sediments to acquire data from the South Kalimantan mangrove ecosystems. The results showed there were four species of true mangroves (Avicennia alba, Acanthus ebracteatus, Nypa fruticans and Rhizophora apiculate) could live well in the environment affected by mining or oil palm plantations. The species density for trees was low (933 ind/ha) for mangroves affected by coal mines, while those affected by oil palm plantations had higher densities (1,067 ind/ha). pH value of waters in affected area by coal mining showed more acidic value (pH 5.76) especially at the back, while those by palm oil plantations are more acidic (pH 6) in the estuary. Organic matter content in sediments affected by coal mines was in the range of 0.61-6.59%, while those affected by oil palm plantations showed higher values (0.12-2.19%). Lead heavy metal content (Pb) in waters affected by coal mines was 0.031-0.056 mg/L, while the area affected by oil palm plantations was of higher value (0.110-0.128 mg/L). Lead (Pb) levels in sediments indicate higher values than waters, which reach 3.512-6.046 mg/Kg (affected by coal mines), and in areas affected by oil palm plantations reaching 6.658-6.66 mg/Kg. The general conclusion is that vegetation densities in areas affected by coal mines are lower than oil palm plantations. The level of lead  (Pb) pollution in the sediments is higher than in the waters.

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