Search

The aim of this study was to evaluate enzymatic (glutathione-S-transferase and catalase) and histological (branchial lesions) biomarkers in Ucides cordatus (Crustacea, Decapoda) from an industrial port region on the north coast of Brazil. The crabs were collected in two distinct locations of the Brazilian coast: A1 = region under influence of port activities; and A2 = low-impacted area. We performed histological examination in the gills and glutathione-S-transferase (GST) and catalase activity in the hepatopancreas. The most frequent and severe histological lesions were found in A1, especially rupture of pilaster cells and lamellar collapse. Catalase activity did not show a pattern capable of differentiating the two analyzed areas. On the other hand, GST activity presented a more pronounced response in the crabs of the port area (p

Made available in DSpace on 2022-04-29T08:36:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-01-01 Brachyuran crabs are considered one of the most representative groups in mangroves, being recognised as mangrove engineers. However, species that present commercial interest may have their population structure and spatial distribution affected by human activities, such as crab capture. Therefore, monitoring populations over time is essential. We investigated the population biology, size-weight relationship, condition factor and spatial distribution of Ucides cordatus in a mangrove ecosystem from southern Brazil, providing information for population status assessment. Males and females differed in abundance and frequency, body size, size-weight relationship and condition factor. Nonetheless, they presented the same spatial distribution pattern. Abundance, sex ratio and body size also revealed a possible influence of anthropised areas in the configuration and distribution of the species. Our results indicate a possible increase in the exploitation of the species, mainly due to the decrease of the largest male size classes’ frequency. Interspecific competition seems to be a possible biotic factor influencing its condition factor. The spatial species distribution highlighted the importance of sites with less anthropogenic influence for the maintenance of the species that can be considered as key areas for the conservation of the U. cordatus in Babitonga Bay. Laboratory of Biology of Marine and Freshwater Shrimp (LABCAM) Faculty of Sciences Department of Biological Sciences São Paulo State University (UNESP) Laboratory of Biology University of Vale do Itajaí (UNIVALI) Laboratory of Biology of Marine and Freshwater Shrimp (LABCAM) Faculty of Sciences Department of Biological Sciences São Paulo State University (UNESP)

Lead is a priority pollutant introduced in the aquatic environment by different sources commonly located in estuarine regions, such as ports, marinas and industries. Environmental agencies around the world set the maximum allowable concentration of lead in effluents, surface water and sediment, but few studies reported its accumulation and chronic toxicity in mangrove benthic invertebrates using concentrations believed to be safe. In the case of Brazilian mangrove environments, Ucides cordatus is a crab species of choice to be used in bioaccumulation studies. We have assessed biomarkers’ responses (DNA strand breaks, micronucleated cells, metallothioneins, enzymatic activity of aminolevulinic acid dehydratase and neutral red retention time) and the total bioaccumulation in six tissues of U. cordatus crabs resident to mangrove areas under different conservation status during a 28-day period bioassay. We also investigated Pb subcellular partition and biomarkers’ responses using a supposedly safe concentration (10 μg L−1). During the Pb exposure, the highest concentration of Pb was observed in crab gills. Crabs also showed a high ability to allocate Pb in detoxified forms. Multivariate analysis pointed out that bioaccumulation (total, active and detoxified) is linked to biomarkers. Even in supposedly safe dosage, U. cordatus triggered its defense mechanisms expressing more metallothioneins and presented relevant cyto-genotoxic damage. Our data suggest the development of biological tolerance to Pb in crabs from polluted areas. Our results provided a new insight about lead toxicity even at concentrations considered environmentally safe, which could support new strategies to manage estuarine areas considering their respective conservation status., Authors acknowledge the São Paulo State Research Foundation (FAPESP) for financial support to LFAM (Grants # 2010/01552-9, 2014/13448-2 and 2016/05414-6) and The Brazilian National Council for Scientific and Technological Development (CNPq) for a productivity fellowship to CDSP.

Metals are persistent pollutants, able to accumulate in the biota and magnify in trophic web. In the specific case of cadmium contamination, it has been the subject of considerable interest in recent years because of its biological effects and it is one of major pollutant in estuarine areas. Ucides cordatus is considered a mangrove local sentinel crab species in Brazil and there are previous studies reporting crab subpopulations living from pristine to heavily metal impacted areas in São Paulo coast (Southeastern Brazil). Taking into account the background knowledge about these subpopulations, we proposed the hypothesis that crabs from a highly polluted mangrove (Cubatão - CUB) have developed biological tolerance to cadmium compared to animals from an Environmental Protected Area (Jureia - JUR). Aiming to verify this hypothesis, we have investigated total bioaccumulation and subcellular partition of Cd, besides biomarkers' responses during a long-term exposure bioassay (28 days, with weekly sampling) using a supposedly safe Cd concentration (0.0022 mg L). Specimens from the pristine area (JUR) accumulated higher total Cd, as such as in its biologically active form in gills. Animals living in the polluted site (CUB) presented higher amounts of Cd in the mainly detoxifying tissue (hepatopancreas), which could be considered a pathway leading to tolerance for this metal. Multivariate analysis indicated that bioaccumulation (active, detoxified and total Cd) is linked to geno-cytotoxic damages. CUB subpopulation was considered more tolerant since it presented proportionally less damage and more capacity to allocate Cd in the main detoxifying forms and tissues., Authors thank the São Paulo Research Foundation (FAPESP) for financial support to LFAM (Cases # 2010/01552-9, 2014/13448-2 and 2016/05414-6) and Caio Nobre, Marcos Vinicius Evangelista, Pedro Augusto Gonçalves Ostanik, André Luiz Alves Mendes, Marina de Souza Paço and Bruna Delfin Ferreira for laboratory activity support. CDSP thanks CNPq for a productivity fellowship.

The aims of this study were to analyze biochemical and morphological responses (glutathione S-transferase activity and branchial lesions) in Ucides cordatus (crabs) and to verify how the species is responding to environmental contamination in a port (potentially contaminated area) and mangrove (reference area; Amazon Coast, Maranhao, Brazil). Adult males were captured bimonthly for a period of 1 year. Higher GST activity (1.03 ± 0.07 μmol min−1 mg protein−1) was observed in crabs in the port when compared with those in the reference area (p

Made available in DSpace on 2018-12-11T17:13:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2017-11-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Globally, there is a lack of knowledge about tropical ecotoxicology dealing with the potential impact of metal contamination in mangrove ecosystem. This habitat is considered a nursery for several animal species, among them the “uçá”-crab (Ucides cordatus), known as a key species due to its biological and economical importance. This study evaluated the association involving metal contamination (Cd, Cu, Pb, Cr, Mn and Hg) in water, sediment, red-mangrove vegetation (Rhizophora mangle) and tissues of uçá crab, together with its geno-cytotoxic responses, based on micronucleated hemocytes frequency and the retention time of neutral red in lysosomes. We assessed six mangrove areas with distinct pollution levels in São Paulo State, Brazil, where the water and sediment contamination by metals were associated with accumulation of these pollutants in biotic compartments (mangrove leaves and crab). In U. cordatus, metal accumulation was best explained by metal concentration found in leaves of R. mangle than in the water or sediment, indicating that feeding drives metal exposure in this organism. Mercury (Hg) concentration in sediment, copper (Cu) concentration in hepatopancreas of U. cordatus and lead (Pb) in water and green leaves of R. mangle showed a significant correlation with genotoxic impact in U. cordatus. However, copper concentration (in green/senescent leaves and hepatopancreas) and lead (in sediment), were the major metals affecting lysosomal membrane integrity. Therefore, representatives of all compartments were associated with cyto and genotoxicity in this species, thus requiring a holistic approach to issues related to sublethal damage. Probability estimates of cytogenetic impacts related to metal concentration in abiotic compartments (significantly correlated with known biomarkers: Hg in sediment; and Pb in water and sediment) are also presented. Our results highlight the need for environmental restoration of mangroves areas contaminated with metals, responsible for cytogenetic injuries and revealing a pre-pathological condition in this sentinel species, in addition to ecological disturbances. UNESP - Univ Estadual Paulista Instituto de Biociências (IB) Campus do Litoral Paulista (CLP) Laboratório de Biologia de Crustáceos / Grupo de Pesquisa em Biologia de Crustáceos (CRUSTA), Praça Infante Dom Henrique, s/n, Parque Bitaru UNIFESP - Univ Federal de São Paulo Departamento de Ciências do Mar Campus Baixada Santista, Avenida Almirante Saldanha da Gama 89, Ponta da Praia UNISANTA Universidade Santa Cecília Laboratório de Ecotoxicologia, Rua Oswado Cruz 266 UNESP - Univ Estadual Paulista Instituto de Biociências (IB) Campus do Litoral Paulista (CLP) Laboratório de Biologia de Crustáceos / Grupo de Pesquisa em Biologia de Crustáceos (CRUSTA), Praça Infante Dom Henrique, s/n, Parque Bitaru CNPq: 302813/2010-1

Made available in DSpace on 2018-12-11T17:06:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-11-01 Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) There is a global lack of knowledge on tropical ecotoxicology, particularly in terms of mangrove areas. These areas often serve as nurseries or homes for several animal species, including Ucides cordatus (the uçá crab). This species is widely distributed, is part of the diet of human coastal communities, and is considered to be a sentinel species due to its sensitivity to toxic xenobiotics in natural environments. Sublethal damages to benthic populations reveal pre-pathological conditions, but discussions of the implications are scarce in the literature. In Brazil, the state of São Paulo offers an interesting scenario for ecotoxicology and population studies: it is easy to distinguish between mangroves that are well preserved and those which are significantly impacted by human activity. The objectives of this study were to provide the normal baseline values for the frequency of Micronucleated cells (MN‰) and for neutral red retention time (NRRT) in U. cordatus at pristine locations, as well to indicate the conservation status of different mangrove areas using a multi-level biological response approach in which these biomarkers and population indicators (condition factor and crab density) are applied in relation to environmental quality indicators (determined via information in the literature and solid waste volume). A mangrove area with no effects of impact (areas of reference or pristine areas) presented a mean value of MN‰120 min, values which were assumed as baseline values representing genetic and physiological normality. A significant correlation was found between NRRT and MN, with both showing similar and effective results for distinguishing between different mangrove areas according to conservation status. Furthermore, crab density was lower in more impacted mangrove areas, a finding which also reflects the effects of sublethal damage; this finding was not determined by condition factor measurements. Multi-level biological responses were able to reflect the conservation status of the mangrove areas studied using information on guideline values of MN‰, NRRT, and density of the uçá crab in order to categorize three levels of human impacts in mangrove areas: PNI (probable null impact); PLI (probable low impact); and PHI (probable high impact). Results confirm the success of U. cordatus species’ multi-level biological responses in diagnosing threats to mangrove areas. Therefore, this species represents an effective tool in studies on mangrove conservation statuses in the Western Atlantic. UNESP - Univ Estadual Paulista Instituto de Biociências (IB) Campus do Litoral Paulista (CLP) Laboratório de Biologia de Crustáceos/CRUSTA Praça Infante Dom Henrique s/n Par - Grupo de Pesquisa em Biologia Laboratório de Biologia de Crustáceos-Praça Infante D. Henrique Campus Experimental do Litoral Paulista (CLP), s/n, Parque Bitaru UNISANTA - Univ Santa Cecília Laboratório de Ecotoxicologia, Oswaldo Cruz 266 UNIFESP - Univ Federal de São Paulo Departamento de Ciências do Mar Campus Baixada Santista, Avenida Almirante Saldanha da Gama 89, Ponta da Praia UNESP - Univ Estadual Paulista Instituto de Biociências (IB) Campus do Litoral Paulista (CLP) Laboratório de Biologia de Crustáceos/CRUSTA Praça Infante Dom Henrique s/n Par - Grupo de Pesquisa em Biologia Laboratório de Biologia de Crustáceos-Praça Infante D. Henrique Campus Experimental do Litoral Paulista (CLP), s/n, Parque Bitaru FAPESP: # 2010/01552-9

The present study was undertaken in two traditional communities that are located on the margins of the estuary and mangrove complex of the Mamanguape River, Paraíba state (PB), Brazil. This work describes the crabs capture techniques tapamento and redinha, and identifies the negative socio-environmental impacts of redinha, using qualitative methods (open and semi-structured interviews, guided tours, direct observation and the administration of questionnaires). Results indicate that currently only two principle techniques are used to capture Ucides cordatus: redinha and tapamento. Tapamento has a low impact in relation to redinha. Redinha was pointed out by interviewees as a system that has social impact (social conflicts, breaking of traditions, substitution and extinction of techniques) and environmental impact (less selective captures and high productivity, mangrove pollution, death of crabs caught in traps, cutting of the roots of Rhizophora mangle, micro-habitat loss resulting from galleries destroyed and polluted). Knowledge of crab harvesting carried out using these two techniques and the possible social and environmental impacts caused by redinha, can lead to more effective planning and actions towards the conservation of the species.O estudo foi realizado em duas comunidades tradicionais localizadas às margens do complexo estuário-manguezal do rio Mamanguape, Paraíba (PB), Brasil. Foram descritas as técnicas de captura (tapamento e redinha), identificando os impactos socioambientais negativos provocados pela redinha na captura de caranguejos, utilizando métodos qualitativos (entrevistas abertas e semiestruturadas, turnês guiadas, observação direta e questionários). Os resultados indicaram que atualmente apenas estas técnicas são usadas na captura de Ucides cordatus. O tapamento apresenta baixo impacto em relação à redinha, que é apontada pelos entrevistados como causadora de impactos sociais (conflitos sociais, rompimento de tradições, substituição e extinção de técnicas) e ambientais (captura menos seletiva e grande produtividade, poluição do manguezal, morte dos caranguejos presos às armadilhas, corte das raízes de Rhizophora mangle, perda de micro-habitat resultante das galerias destruídas e poluídas). O melhor conhecimento sobre a captura de caranguejos por tais técnicas, bem como seus possíveis impactos socioambientais, podem aumentar a eficiência de planejamento e ações voltados à conservação da espécie.

The sodium metabisulphite salt is usually used in shrimp culture to prevent black spot. Unfortunately the toxicological effect of this xenobiotic in decapod crabs is unknown. Thus, the present study aims to investigate the sodium metabisulphite LC50 - 96 h in the mangrove species Ucides cordatus. Crabs were collected in the tidal creek margins in Bragança estuarine and were submitted to preliminary test (screening) and posterior definitive test. Crabs were exposed in five different concentrations and a control group in five replicates, two crabs per recipient (5 L) during 96 hours. A negative correlation was observed to sodium metabisulphite concentration in relation to dissolved oxygen and pH. At the end of the experiment were obtained the following mortality index in relation to sodium metabisulphite concentrations: 100% in 86.0 mg.L-1, 74% in 62.0 mg.L-1, 52% in 52.0 mg.L-1, 44% in 38.0 mg.L-1. The value of LC50 - 96 h for U. cordatus was determinate at 42.58 mg.L-1/Na2S2O5. The results strongly indicate that sodium metabisulphite is toxic for U. cordatus, and this crab could be used for biomonitoring the environmental impact.O metabissulfito de sódio é um sal habitualmente usado no cultivo de camarão a fim de se evitar a melanose. Infelizmente o efeito toxicológico deste xenobiótico em caranguejos decápodes é desconhecido. O presente estudo objetiva investigar o LC50 - 96 h do metabissulfito de sódio na espécie Ucides cordatus em manguezal. A coleta dos caranguejos foi realizada nas margens do canal de maré estuarino em Bragança/PA. Os caranguejos foram submetidos a um teste preliminar (screening) e posteriormente ao teste definitivo, e foram expostos a cinco concentrações diferentes e um grupo controle com cinco repetições, com dois caranguejos por recipiente (5 L) durante 96 horas. Houve correlação negativa no aumento da concentração de metabissulfito de sódio com o oxigênio dissolvido e pH. No final do experimento foram obtidos os seguintes níveis de índice de mortalidade em relação s concentrações de metabissulfito de sódio: 100% em 86,0 mg.L-1, 74% em 62,0 mg.L-1, 52% em 52,0 mg.L-1, 44% em 38,0 mg.L-1. O valor da LC50 96h para U. cordatus foi determinado em 42,58 mg.L-1/Na2S2O5. Os resultados indicam que o metabissulfito de sódio é tóxico para U. cordatus e este caranguejo pode ser usado para biomonitoramento do impacto ambiental.

Although lethargic crab disease (LCD) is causing massive mortalities in populations of the mangrove crab Ucides cordatus of Northeastern Brazil, the identity of its etiological agent was hitherto unknown. In this study we provide robust evidence suggesting that LCD is caused by an anamorph Ascomycota (Fungi). We examined specimens of U. cordatus collected from stocks affected by LCD. Histological and TEM methods detected the presence of hyphae, conidia, and condiophores in several host tissues. Moreover, the abundance of fungal stages is negatively associated with crab health. Finally, DNA was isolated from the fungus and a region of its 18S ribosomal gene was sequenced. Phylogenetic analyses not only confirm the diagnosis of the LCD fungus in crab tissues as an ascomycete, but also suggest a close relationship with members of the subphylum Pezizomycotina.

Made available in DSpace on 2015-11-03T15:28:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-09-01. Added 1 bitstream(s) on 2015-11-04T10:14:50Z : No. of bitstreams: 1 S0001-37652014000301411.pdf: 616946 bytes, checksum: a9de946ce7be2af37fca2ef06420587b (MD5) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) O caranguejo de manguezal Ucides cordatus é um dos crustáceos mais explorados do Brasil. O presente estudo investigou a época reprodutiva desta espécie e o período do fenômeno da “andada”, quando os caranguejos estão ativos fora das tocas e ocorrem comportamentos agonísticos. Além disso, estes fatores foram relacionados com fatores ambientais em um manguezal da costa brasileira, com inferência sobre o manejo deste caranguejo. Os caranguejos reproduziram de outubro a fevereiro. A “andada” ocorreu de novembro a fevereiro, com características típicas nos primeiros dois meses, durante os períodos de lua cheia e lua nova, e foi influenciada positivamente pela temperatura do ar e do solo, luminosidade e amplitude de maré e negativamente pela salinidade. Baseado nos resultados do presente estudo, o período quando a “andada”ocorre poderia ser definido em outras partes do Brasil, o que auxiliaria no manejo deste recurso pesqueiro. Para Iguape, Estado de São Paulo, Brasil, sugerimos a proibição da pesca para ambos os sexos durante o mês de dezembro ou durante as luas cheia e nova, incluindo o mês de janeiro. The mangrove crab Ucides cordatus is one of the most exploited crustaceans in Brazil. The present study investigated the breeding season of this species and the period of the "andada" phenomenon, when the crabs are active outside their burrows and perform agonistic behaviors. Furthermore related them to environmental factors, in a mangrove on the coast of Brazil, with inferences about management of this crab. The crabs reproduced from October through February. The "andada" occurred from November through February, with typical characteristics in the first two months, during the full and new moon periods, and was influenced positively by the air and soil temperature, luminosity, and tidal amplitude, and negatively by salinity. Based on the results of the present study, the period when the "andada" occurs in other parts of Brazil could be defined, which will aid in managing this fishery. For Iguape, state of Sao Paulo, Brazil, we suggest a legal off-season for both sexes in December or during the full and new moon, including January. Inst Pesca Estado Sao Paulo, Programa Posgrad Aquicultura &Pesca, BR-05001970 Sao Paulo, Brazil Univ Fed Amazonas UFAM, ICET, BR-69103128 Itacoatiara, Amazonas, Brazil Univ Santa Cecilia UNISANTA, BR-11045100 Santos, SP, Brazil Univ Estadual Paulista UNESP, BR-11330900 Sao Vicente, SP, Brazil Univ Estadual Paulista UNESP, BR-11330900 Sao Vicente, SP, Brazil FAPESP: 2002/05614-2

Ucides cordatus is an abundant mangrove crab in Brazil constructing burrows of up to 2 m depth. Sediment around burrows may oxidize during low tides. This increase in sediment-air contact area may enhance carbon degradation processes. We hypothesized that 1) the sediment CO2 efflux rate is greater with burrows than without and 2) the reduction potential in radial profiles in the sediment surrounding the burrows decreases gradually, until approximating non-bioturbated conditions. Sampling was conducted during the North Brazilian wet season at neap tides. CO2 efflux rates of inhabited burrows and plain sediment were measured with a CO2/H2O gas analyzer connected to a respiration chamber. Sediment redox potential, pH and temperature were measured in the sediment surrounding the burrows at horizontal distances of 2, 5, 8 and 15 cm at four sediment depths (1, 10, 30 and 50 cm) and rH values were calculated. Sediment cores (50 cm length) were taken to measure the same parameters for plain sediment. CO2 efflux rates of plain sediment and individual crab burrows with entrance diameters of 7 cm were 0.7–1.3 µmol m−2s−1 and 0.2–0.4 µmol burrows−1s−1, respectively. CO2 released from a Rhizophora mangle dominated forest with an average of 1.7 U. cordatus burrows−1m−2 yielded 1.0–1.7 µmol m−2s−1, depending on the month and burrow entrance diameter. Laboratory experiments revealed that 20–60% of the CO2 released by burrows originated from crab respiration. Temporal changes in the reduction potential in the sediment surrounding the burrows did not influence the CO2 release from burrows. More oxidized conditions of plain sediment over time may explain the increase in CO2 release until the end of the wet season. CO2 released by U. cordatus and their burrows may be a significant pathway of CO2 export from mangrove sediments and should be considered in mangrove carbon budget estimates.

CAPES Reunir informações sobre a diversidade e ecologia de uma determinada região é a base para compreender os processos que afetam o equilíbrio de comunidades ou ecossistemas. O objetivo da presente tese foi comparar a diversidade e fornecer alguns aspectos da ecologia dos crustáceos da Infraordem Brachyura de duas áreas estuarinas do litoral sul do Estado de Pernambuco: o manguezal do Rio Ariquindá, considerado não impactado, e o manguezal do Rio Mamucabas, considerado pouco impactado. As espécies foram amostradas mensalmente entre abril de 2008 e março de 2009 e devidamente identificadas utilizando-se bibliografia especializada. Foram coletados um total de 8.394 exemplares de Brachyura, sendo 4.501 no manguezal do Rio Ariquindá (25 espécies e 14 gêneros) e 3.893 no manguezal do Rio Mamucabas (21 espécies e 12 gêneros). A maior frequência de espécies em ambos os manguezais encontrou-se entre os representantes da Superfamília Ocypodoidea, em especial do gênero Uca. Comparando os dois estuários, notou-se que 5 espécies (Acantholobulus bermudensis, Austinixa leptodactyla, Callinectes exasperatus, Hexapanopeus caribbaeus e Uca maracoani) foram amostradas apenas no manguezal do Rio Ariquindá, enquanto 1 espécie (Armases rubripes) foi encontrada apenas no Rio Mamucabas. A diversidade foi considerada média de acordo com os índices ecológicos e se encontra dentro do esperado para os manguezais. Entretanto, notou-se que a diversidade foi menor no manguezal do Rio Mamucabas. Em relação à espécie A. angustipes, os espécimes da população do manguezal do Rio Ariquindá são mais compridos e mais largos do que os do manguezal do Rio Mamucabas, onde a abundância de caranguejos e a frequência de fêmeas ovígeras foi menor. Em relação ao gênero Uca, notase que a maioria das espécies apresentou tamanhos maiores no manguezal do Rio Ariquindá. Dimorfismo sexual foi observado em várias espécies do presente estudo: em U. thayeri, por exemplo, os machos atingiram a maturidade sexual com tamanhos superiores do que as fêmeas em ambas as áreas de manguezal, provavelmente devido ao seu maior investimento no crescimento somático, enquanto as fêmeas gastam sua energia no processo reprodutivo. Na espécie Ucides cordatus, o fator de condição foi significativamente menor no manguezal do Rio Mamucabas. Todos os resultados indicam que o manguezal do Rio Mamucabas apresenta diversidade menor e populações com padrões ecológicos alterados, o que provavelmente está relacionado aos impactos ambientais que esse manguezal vem recebendo nos últimos anos (represamento, deposição de resíduos sólidos, desmatamento e crescente ocupação imobiliária). Tais fatos ressaltam a importância da mitigação dos impactos bem como da criação de planos de manejo e sustentabilidade para as espécies, tendo em vista a importância ecológica e econômica das mesmas.

The lethargic crab disease (LCD) is an emergent infirmity that has decimated native populations of the mangrove land crab (Ucides cordatus, Decapoda: Ocypodidae) along the Brazilian coast. Several potential etiological agents have been linked with LCD, but only in 2005 was it proved that it is caused by an ascomycete fungus. This is the first attempt to develop a mathematical model to describe the epidemiological dynamics of LCD. The model presents four possible scenarios, namely, the trivial equilibrium, the disease-free equilibrium, endemic equilibrium, and limit cycles arising from a Hopf bifurcation. The threshold values depend on the basic reproductive number of crabs and fungi, and on the infection rate. These scenarios depend on both the biological assumptions and the temporal evolution of the disease. Numerical simulations corroborate the analytical results and illustrate the different temporal dynamics of the crab and fungus populations.

Lethargic Crab Disease (LCD) caused extensive epizootic mortality of the mangrove land crab Ucides cordatus (Brachyura: Ocypodidae) along the Brazilian coast, mainly in the Northeastern region. The disease was named after the symptoms of slow movement of infected crabs. Causative agents were suspected to be two black yeast-like fungi of the family Herpotrichiellaceae (ascomycete order Chaetothyriales), judged by infected tissue biopsies from moribund U. cordatus. The aim of the present study is to prove that two species are involved in the disease: the recently described black yeast Exophiala cancerae, but also a less virulent, hitherto undescribed fonsecaea-like species, introduced here as the novel species Fonsecaea brasiliensis. Strains were identified by ITS rDNA sequencing, and species borderlines were established by multilocus sequencing and AFLP analysis. Fonsecaea brasiliensis proved to be closely related to the pathogenic species Cladophialophora devriesii which originally was isolated from a systemic infection in a human patient. The virulence of F. brasiliensis is lower than that of E. cancerae, as established by artificial inoculation of mangrove crabs. Keywords: Ucides cordatus; Mangrove crab; Lethargic Crab Disease (LCD); Exophiala cancerae; onsecaea brasiliensis; Virulence

A total of 2,130 individuals of Ucides cordatus (1,255 males and 875 females) were captured in a mangrove forest at Iguape, São Paulo, Brazil. For each crab, the following body structures were measured: carapace (width = CW; length = CL; depth = CD), 5th abdominal somite (AW), major chelar propodus (length = PL; width = PW; depth = PD), and 1st and 2nd gonopod pairs (length = GL1 and GL2). The Student "t" and Snedecor "F" tests were used to verify any changes in growth allometric rates during ontogeny. The relationships CLxCW, PLxCW (for both sexes), GL1xCW and GL2xCW (males) and AWxCW (females), showed a better fit by two equations for the juvenile and adult phases (p 59 mm). Females showed a similar size interval: (juvenile CW < 39 mm, pre-puberty 39 < CW < 53 mm, sub-adult 53 < CW < 58 mm, adult CW > 58 mm).Um total de 2,130 indivíduos de U. cordatus (1,255 machos e 875 fêmeas) foi coletado em Iguape (SP), Brasil. Cada exemplar foi submetido à biometria das seguintes estruturas: cefalotórax (largura = CW; comprimento = CL; altura = CD), quinto somito abdominal (AW), própodo quelar (comprimento = PL; espessura = PW; altura = PD), e 1º e 2º par de gonopódios (comprimento = GL1 e GL2). O teste "t" Student e "F" de Snedecor foram utilizados para identificar diferenças no grau de alometria e alterações ontogenéticas na taxa de crescimento, respectivamente. As relações CLxCW, PLxCW (ambos os sexos), GL1xCW e GL2xCW (machos) e AWxCW (fêmeas), apresentaram ajuste por duas equações representando a fase jovem e adulta (p59mm), com tamanho similar ao dos morfotipos das fêmeas (jovens CW58mm).

The visual system as an interface between the environment and the living organism can serve as a sensitive indicator especially in studies that deal with effects of radiation. The crab retina as the seat of the photoreceptors and the lamina ganglionaris as the place of second order neurons were the targets of our study. Conventional specimen preparation techniques for transmission electron microscopy (TEM) are adequate to preserve any modifications that may occur as a consequence of the experimental treatment. In this study we analyzed by TEM how retinal and lamina ganglionaris cells of the crab Ucides cordatus responded to a 30 min exposure to ultraviolet C (UV-C) and ultraviolet B (UV-B) radiation with doses of 7200 and 590J/cm(2), respectively. The results show that damaged cells occurred in both retina and lamina ganglionaris, but that the retinal cells were affected to a greater extent. Morphological alterations of the pigment granules and an increase in the quantity of lipid droplets of the retinal cells were also observed. Additional changes include an increase in heterochromatin, nuclear karyolyses and karyorrhexes, distention of rough endoplasmic reticulum and mitochondrial disruptions. The observed morphological changes are indicative of apoptotic processes and show that an exposure to light of wavelengths of 254 and 312 nm may be injurious to the visual system of invertebrates.

Invertebrate glial cells show a variety of morphologies depending on species and location. They have been classified according to relatively general morphological or functional criteria and also to their location. The present study was carried out to characterize the organization of glial cells and their processes in the zona fasciculata and in the protocerebral tract of the crab Ucides cordatus. We performed routine and cytochemical procedures for electron microscopy analysis. Semithin sections were observed at the light microscope. The Thiéry procedure indicated the presence of carbohydrates, particularly glycogen, in tissue and in cells. To better visualize the axonal ensheathment at the ultrastructural level, we employed a method to enhance the unsaturated fatty acids present in membranes. Our results showed that there are at least two types of glial cells in these nervous structures, a light one and a dark one. Most of the dark cell processes have been mentioned in the literature as extracellular matrix, but since they presented an enveloping membrane, glycogen and mitochondria - intact and with different degrees of disruption - they were considered to be glial cells in the present study. We assume that they correspond to the perineurial cells on the basis of their location. The light cells must correspond to the periaxonal cells. Some characteristics of the axons such as their organization, ensheathment and subcellular structures are also described.