11 research outputs found

    Effect of stock density of cultured Amazon Apple Snail Pomacea dolioides (Gastropoda: Ampullariidae) in Brazil

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    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 performanc


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    Chitin is the second most abundant biopolymer worldwide and is found in a large variety of animals. Besides shrimps, other species possess significant chitin contents in their external non-edible fraction, thus allowing them to be also economically viable sources of this macromolecule. According to mass-loss evaluation of crab residues, 78.4% of the mass is comprised of CaCO3 and 21.6% associated to the organic phase. The chitin content found was 8.0% of the residue’s initial mass and after the deacetylation step, the average chitosan yield was 5.0% of the initial residue mass. The thermal decomposition profiles of obtained chitin and chitosan samples were characteristic of biopolymers, exhibiting non-oxidative (190–360°C) and oxidative (340–670°C) events of mass loss. Vibrational spectroscopic analysis showed that the degrees of deacetylation of the obtained chitosan samples were time-dependent and between 68.4 and 81.9%

    Meat yield of Callinectes bocourti A. Milne Edwards, 1879 (Crustacea, Portunidae) in Iguape, São Paulo, Brazil

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    The objective of the present study was to analyze the meat yield for both sexes of the crab Callinectes bocourti in the region of Iguape, Brazil. The carapace width for males was 78.1-114.0 mm (96.7 ± 9.5 mm) and for females 76.0-106.3 mm (93.0 ± 7.8 mm). In males, the total wet weight ranged from 65.53 to 224.36 g (134.04 ± 40.77 g) and for females from 56.66 to 164.74 g (105.93 ± 26.88 g). A comparison of morphological structures revealed that the greatest meat yield was in the carapace (55.1%), followed by the right chela (16.9%), the left chela (15.9%), and the legs (12.1%). The total yield from the males (28.5%) was slightly higher than that from the females (22.1%). In general, portunids yield more meat than other crab species. The results of this study will allow the optimization of meat production for this crab species. Manual meat removal makes the process more expensive. This activity could offer an alternative to the fishing communities that live exclusively from this fishery resource. © 2007 Escuela de Ciencias del Mar Pontificia Universidad Católica de Valparaíso

    Relative growth of the mangrove crab Ucides cordatus (Linnaeus, 1763) (Crustacea, Brachyura, Ocypodidae) at Iguape, São Paulo, Brazil

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    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 2 nd 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)

    Fertilidade do caranguejo de mangue Ucides cordatus (Linnaeus) (Crustacea, Brachyura, Ocypodidae), em Iguape (São Paulo, Brasil) Fertility of the mangrove crab Ucides cordatus (Linnaeus) (Crustacea, Brachyura, Ocypodidae), at Iguape (São Paulo), Brazil

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    <abstract language="eng">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

    Embriologia do siri Arenaeus cribrarius (Lamarck) (Crustacea, Brachyura, Portunidae)

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    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.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Orientation and external morphology of burrows of the mangrove crab Ucides cordatus (Crustacea: Brachyura: Ucididae)

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    The aim of the present study was to characterize the external morphology and the orientation of burrows constructed by the mangrove crab Ucides cordatus. Data were obtained from two mangrove forests of similar vegetation dominance (Laguncularia racemosa) but differing in flooding heights. These mangroves were located near Barra de Icapara, Iguape City (SP), Brazil, (24 degrees 50'36 '' S-47 degrees 59'53'W). A total of 221 burrows were examined (120 on the high mangrove and 101 on the low mangrove). External morphology of the burrows was recorded by photographs for categorization and description. The directions of the burrow openings were recorded using a geological compass and the declivities of the ducts were measured with a clinometer. Females constructed 70.8% at Site A and 69.4% at Site B of the occupied burrows with the opening facing the margin of the river (P 0.05) at either site. In females, the tendency for burrow orientation possibly has a reproductive connotation as larval dispersal may be favoured and enhanced by the tides. Four groups of distinct tracks related to the morphotypes and developmental stages of U. cordatus were observed, No sediment constructions associated with the burrows were recorded for this species. Declivity of the burrows from juveniles was lower than from adults (P < 0.05), probably caused by the differential growth of the chelipeds in this species.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP