ABSTRACT The relationship between color and size supports the hypothesis that color is an important signal for some crab species during mating rituals or agonistic interactions. Thus, the objective of this study was to describe the color variation of D. pagei and its relationship with sex and sexual maturity. The crabs were placed on a surface for photographic recording of the body parts: cephalothorax, chelipeds, abdomen and pereiopods using a digital camera installed on a photographic table. Images were converted to the spectrum of red, green, blue and also of them combined (RGB). The values of each spectrum revealed that the color variation of the cephalothorax and chelipeds were different between adults and juveniles. The abdomen and pereiopods showed color variation in both sexes and at developmental stages. The pattern of color variation observed in juveniles ranged from light to dark brown and adults are from orange to intense red. The change in color of the cephalothorax and chelipeds could be used as a character to determine the onset of sexual maturity. The high color variation of the abdomen and pereiopods in both sexes and at developmental stages, though, indicates individual variation which probably is associated with other factors, such as molt stage or even the quality of food available.

RESUMO Poucos estudos avaliaram a diversidade de anuros em fragmentos florestais urbanos ou em áreas com diferentes graus de impacto antrópico na Amazônia. Neste estudo foi determinada a composição e abundância de anuros em áreas urbanas e rurais no município de Itacoatiara, na Amazônia central, Brasil. Anuros foram amostrados entre janeiro de 2012 e maio de 2013 em 10 locais na área urbana e cinco na área rural. Um total de 1.538 indivíduos (930 na área rural e 608 na área urbana) foram registrados, compreendendo 29 espécies e cinco famílias. A área rural apresentou maior riqueza de espécies, com 10 espécies exclusivas. Todas as espécies identificadas na área urbana também foram encontradas na área rural, mas a abundância das espécies entre ambas áreas variou consideravelmente. Curvas de rarefação por amostragem e por número de indivíduos tenderam à estabilização na riqueza de espécies somente na área urbana. Concluímos que a comunidade de anuros na área urbana está empobrecida devido à ausência de muitas espécies associadas à ambientes inalterados de florestas de terra firme, várzea e igapó. A degradação da qualidade e a perda de habitat nas paisagens urbanas são os principais fatores que ameaçam a diversidade de anfíbios. A comunidade de anuros registrada neste estudo foi similar às de outros habitats na Amazônia. Medidas de conservação envolvendo anuros nesta região devem considerar a preservação de um mosaico de habitats que inclua áreas naturais de floresta de terra firme, várzea e igapó.

ABSTRACT Few studies in the Amazon region have evaluated anuran diversity in urban forest fragments or in areas with differing degrees of anthropogenic impact. We determined the composition and abundance of the anurofauna in urban and rural sites within the municipality of Itacoatiara in central Amazonia, Brazil. Specimens were sampled from January 2012 to May 2013 in 10 urban sites and five rural sites. A total of 1,538 anurans (930 in rural sites and 608 in urban sites) were recorded, belonging to 29 species in five families. Species richness was higher in rural sites, with 10 exclusive species. All species found in urban sites were also found in rural sites, however, species abundance varied considerably between the habitats. Sampling- and individual-based rarefaction curves showed a tendency toward stabilization of species richness only in the urban sites. We concluded that the anuran assemblages in the urban sites are depauperate due to the absence of many species associated to pristine terra firme or várzea and igapó forests. Habitat loss and quality degradation in urban landscapes are the main factors threatening amphibian diversity. The anuran assemblages in our study areas were similar to those recorded in other Amazonian habitats. Conservation measures involving anurans in this region should consider the preservation of habitat mosaics, including both pristine terra firme, várzea and igapó forests.

ABSTRACT This study evaluated the biomass gain, specific growth rate, absolute weight gain, and survival rate of the gastropod Pomacea dolioides cultivated in different stocking densities. To perform the experiment, samples were collected in March and June 2015. A total of 40 adult specimens were collected in the Jauary neighborhood (03°08′19.9"S, 58°27′32.5"W), municipality of Itacoatiara, AM, Brazil. They were kept in the laboratory for breeding to obtain the young P. dolioides, which were distributed into tanks containing 4 L of water and an aeration system, in three densities: 2.5 animals/L, 5 animals/L, and 10 animals/L, and were fed fish ration (34% gross protein). The specimens were measured for shell length and weight every fifteen days. The survival rate did not differ between treatments 2.5 and 5 animals/L (100%) and 10 animals/L (95.83%). The density with the best cultivation results was 2.5 animals/L, being most effective for the parameters of growth, weight gain, specific growth rate, and percentage weight gain, when compared with the other treatments after 225 days of the experiment. For future cultivation of this species, a density of 2.5 animals/L should be used to improve handling performance.

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 (p<0.01). A determinação dos tamanhos indicados pelas relações morfométricas permitiu a divisão de cada sexo em quatro morfotipos. Os machos foram classificados como jovens (CW<32mm), pré-púberes (32<CW<51mm), sub-adultos (51<CW<59mm) e adultos (CW>59mm), com tamanho similar ao dos morfotipos das fêmeas (jovens CW<39mm; pré-púberes 39<CW<53mm; sub-adultas 53<CW<58mm; adultas CW>58mm).

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<0.01). The inflexion point size between regression lines, indicated by each morphometric relationship, allowed to propose four morphotypes for U. cordatus. Males were classified in juvenile (CW < 32 mm), pre-puberty (32 < CW < 51 mm), sub-adult (51 < CW < 59 mm) and adult (CW > 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).

A total of 58 Ucides cordatus (Linnaeus, 1763) ovigerous females in final embryonic stage were collected in mangrove forest at Iguape (São Paulo). Each female were kept in laboratory until the larvae hatching and had their carapace width (CW) measured with caliper (0.05 mm) and the larval number (LN) calculated by volumetric method. The hatching rates (HR) were calculated for each animal's size class (5 mm). The values of LN and CW obtained were subjected to regression analyses and the best fitting model was chosen by comparing the obtained determination coefficients (R²). The fertility varied from 71,200 to 220,800 larvae (147,169 ± 32,070 larvae), corresponding to 41.7 to 76.8 mm CW (63.7±7.9 mm), respectively. The relationship LNxCW was expressed by the equation LN = 284.1CW1.5º¹ (N = 58; R² = 0.74; p < 0.01), that showed a positive correlation between the variables. Most part of ovigerous females (89.7%) showed their hatching during the nightly period. A negative correlation between HR and CW was observed in these animals (p < 0.05), probably due to reduction of spermatophores in the seminal receptacle (multiparous females) or due to senility in the females with large size. The biological studies of U. cordatus are very important for practices adoption that preserve and make the rational use of this recourse in Brazilian's mangrove forests.

Ovigerous females of Arenaeus cribrarius were collected at Ubatuba, São Paulo, and maintaining in aquaria under controlled temperature (25±1ºC), salinity (35±1‰) and photoperiod (12:12). A small sample of eggs was collected for each 24h, for morphological description, chromatic changes and biometric analysis throughout the embryonic development. Eight egg stages were photographed and had their small and large diameters measured under a microscope provided with camera lucida. The egg's shape was low elliptical during all the embryogenesis and showed size increase (24.4%) and volume (91.1 %), when the last stage were compared with the first one. According to mean egg diameter and volume, the eggs should be pooled in three different groups (1-3; 4-6; 7-8) corresponding to initial, intermediate and final stages. The attained results were compared with the literature which emphasizing the species of Portunidae's family.