RESUMO

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‰<3 and NRRT>120min, 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.

Assuntos

RESUMO

Specimens of Ucides cordatus were captured from September 1998 to September 2000 in mangrovesfrom Iguape, SP, Brazil (24º41’25''S - 47º27’48''W) and analyzed by sex, biological period(reproductive, October to March; and non-reproductive, from April to September) and size. Themeat yield of each corporal structure, and the residuals were quantified. Each crab was measured(carapace width) with a vernier caliper (0.05 mm) and their corporal structures weighed withan analytic scale (0.0001 g). Biometric variables were previously tested (normality andhomoscedasticity) with indication of a statistical parametric procedure (ANOVA) at 5% significancelevel. Males had higher wet weight than females, the same occurring when their corporal structureswere compared (p<0.05). The meat yield in males was of 25.4%, a little above than what wasregistered in females (21.1%); meat yield hierarchy among corporal structures was very similarbetween sexes and biological periods, but differing in relation to chelipeds, which were bigger inmales. During the reproductive period males had a bigger meat yield due to their size whencompared to males of non-reproductive period, as well as with females independently of theirbiological period. The expressive meat yield in males can be explained by the positive allometricgrowth of the chelipeds after puberty molt when this structure grows proportionally more than thebody itself, accounting for 40% of the total wet weight in this gender.

Espécimes de Ucides cordatus foram capturados de setembro de 1998 a setembro de 2000, nosmanguezais de Iguape, SP, Brasil (24º41’25''S – 47º27’48''O) e analisados por sexo, período biológico(reprodutivo: outubro a março; e não reprodutivo: abril a setembro) e tamanho. O rendimento decarne de cada estrutura corporal e os resíduos foram quantificados. Cada caranguejo foi medido(largura da carapaça) com um paquímetro (0,05 mm) e suas estruturas corporais pesadas com umabalança analítica (0,0001 g). As variáveis biométricas foram previamente testadas (normalidade ehomocedasticidade) com indicação de um procedimento estatístico paramétrico (ANOVA) ao nívelde 5% de significância. Os machos apresentaram maior peso úmido do que as fêmeas, o mesmoocorrendo quando suas estruturas corporais foram comparadas (p<0,05). O rendimento de carnenos machos foi de 25,4%, pouco acima daquele registrado nas fêmeas (21,1%), sendo a hierarquiade rendimento de carne entre as estruturas corporais muito similares entre os sexos e os períodosbiológicos, porém diferindo em relação ao peso dos quelípodos, que foram maiores nos machos.Durante o período reprodutivo, os machos apresentaram um maior rendimento de carne de acordocom seu tamanho em relação aos machos do período não reprodutivo, bem como com as fêmeas,independentemente do seu período biológico. O rendimento de carne, mais expressivo nos machos,pode ser explicado pelo crescimento alométrico positivo de seus quelípodos logo após a muda dapuberdade, quando esta estrutura cresce proporcionalmente mais do que o próprio corpo,representando 40% do peso úmido total neste gênero

Assuntos

RESUMO

Specimens of Ucides cordatus were captured from September 1998 to September 2000 in mangrovesfrom Iguape, SP, Brazil (24º4125''S - 47º2748''W) and analyzed by sex, biological period(reproductive, October to March; and non-reproductive, from April to September) and size. Themeat yield of each corporal structure, and the residuals were quantified. Each crab was measured(carapace width) with a vernier caliper (0.05 mm) and their corporal structures weighed withan analytic scale (0.0001 g). Biometric variables were previously tested (normality andhomoscedasticity) with indication of a statistical parametric procedure (ANOVA) at 5% significancelevel. Males had higher wet weight than females, the same occurring when their corporal structureswere compared (p<0.05). The meat yield in males was of 25.4%, a little above than what wasregistered in females (21.1%); meat yield hierarchy among corporal structures was very similarbetween sexes and biological periods, but differing in relation to chelipeds, which were bigger inmales. During the reproductive period males had a bigger meat yield due to their size whencompared to males of non-reproductive period, as well as with females independently of theirbiological period. The expressive meat yield in males can be explained by the positive allometricgrowth of the chelipeds after puberty molt when this structure grows proportionally more than thebody itself, accounting for 40% of the total wet weight in this gender.(AU)

Espécimes de Ucides cordatus foram capturados de setembro de 1998 a setembro de 2000, nosmanguezais de Iguape, SP, Brasil (24º4125''S 47º2748''O) e analisados por sexo, período biológico(reprodutivo: outubro a março; e não reprodutivo: abril a setembro) e tamanho. O rendimento decarne de cada estrutura corporal e os resíduos foram quantificados. Cada caranguejo foi medido(largura da carapaça) com um paquímetro (0,05 mm) e suas estruturas corporais pesadas com umabalança analítica (0,0001 g). As variáveis biométricas foram previamente testadas (normalidade ehomocedasticidade) com indicação de um procedimento estatístico paramétrico (ANOVA) ao nívelde 5% de significância. Os machos apresentaram maior peso úmido do que as fêmeas, o mesmoocorrendo quando suas estruturas corporais foram comparadas (p<0,05). O rendimento de carnenos machos foi de 25,4%, pouco acima daquele registrado nas fêmeas (21,1%), sendo a hierarquiade rendimento de carne entre as estruturas corporais muito similares entre os sexos e os períodosbiológicos, porém diferindo em relação ao peso dos quelípodos, que foram maiores nos machos.Durante o período reprodutivo, os machos apresentaram um maior rendimento de carne de acordocom seu tamanho em relação aos machos do período não reprodutivo, bem como com as fêmeas,independentemente do seu período biológico. O rendimento de carne, mais expressivo nos machos,pode ser explicado pelo crescimento alométrico positivo de seus quelípodos logo após a muda dapuberdade, quando esta estrutura cresce proporcionalmente mais do que o próprio corpo,representando 40% do peso úmido total neste gênero(AU)

Assuntos