6 research outputs found

    Crescimento relativo em Uca leptodactyla Rathbun (Crustacea Decapoda Ocypodidae) Relative growth in the fiddler crab Uca leptodactyla Rathbun (Crustacea Decapoda Ocypodidae)

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    <abstract language="eng">Relative growth of the male major chela and female abdome was studied in a population of the fiddler crab Uca leptodactyla Rathbun, 1898 from Itapoá, Santa Catarina coast, southern Brazil. Major chela length (CMQ) was measured from 191 males, and abdomen width (LAB) from 128 females. Carapace width (LC) was the reference dimension for both sexes, which ranged from 3.9 to 11.5 mm for males, and from 3.15 to 10.65 mm for females. Males grew bigger than females. Relationship between CMQ and LC showed a transition point at 8.35 mm LC in males, and between LA and LC at 7.10 mm LC in females. Growth was allometrically positive in the early ontogenesis and isometric after the puberal molting for both sexes. Regressions between LC and CMQ in males read as: logCMQ = -0,854536 + 2,19. logLC for empirical points at left of critical point and logCMQ = 0,063047 + 1,24. logLC for those at right. In females, this relation was logLAB = -0,603590 + 1,30. logLC and logLAB = -0,361464 + 1,07. logLC, respectively. These body dimensions were connected with reproductive activity of this species

    Alometria no crescimento de Uca mordax (Smith) (Crustacea, Decapoda, Ocypodidae) na Baía de Guaratuba, Paraná, Brasil Allometric growth in the fiddler crab Uca mordax (Smith) (Crustacea, Decapoda, Ocypodidae) from Guaratuba Bay, Parana, Brazil

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    Um estudo do crescimento relativo da maior quela do macho e do abdome da fêmea foi realizado numa população do caranguejo chama-maré Uca mordax (Smith, 1870) ocorrente no extremo oeste da Baía de Guaratuba, Paraná, sul do Brasil. O comprimento da maior quela (CMQ) foi medido em 319 machos, e a largura do abdome (LAB) em 356 fêmeas. Adicionalmente, seis chama-marés sexualmente indiferenciados foram analisados. A largura da carapaça (LC) foi escolhida como dimensão de referência para ambos os sexos, a qual variou de 1,94 a 20,0 mm para machos, de 2,50 a 18,85 mm para fêmeas, e de 1,94 a 3,15 para os indivíduos sexualmente indiferenciados. A relação entre o LC e CMQ mostrou um ponto de inflexão em 11,70 mm LC nos machos, e entre LC e LAB, em 8,77 mm LC dentre as fêmeas. Os machos (média LC = 14,24 mm) atingiram tamanhos pouco maiores do que as fêmeas (média LC = 13,97 mm). O crescimento foi alométrico positivo durante toda a ontogênese de ambos os sexos, isto é, antes e depois da muda puberal. As equações das relações entre LC e CMQ nos machos foram: logCMQ = -0,542265 + 1,51.logLC para machos juvenis e logCMQ = -1,446281 + 2,37.logLC para machos adultos. Nas fêmeas, a relação entre LC e LAB foi: logLAB = -0,607282 + 1,22.logLC e logLAB = -0,912074 + 1,60.logLC, respectivamente, para juvenis e adultas. Estas dimensões estão relacionadas com as atividades reprodutivas da espécie. O nível de alometria do CMQ dos machos adultos de U. mordax foi o mais alto dentre as espécies do gênero, cujo crescimento relativo desta dimensão foi estudado. A proporção de machos destros foi estatisticamente a mesma daqueles sinistros (1:1).<br>Relative growth of the male major chela and female abdomen was studied in a population of the fiddler crab Uca mordax (Smith, 1870) from Guaratuba Bay, Parana, Southern Brazil. Major chela length (CMQ) was measured from 319 males, and abdomen width (LAB) from 356 females. Also six small sexually undifferentiated crabs were measured. Carapace width (LC) was the reference dimension for both sexes, which ranged from 1.94 to 20.0 mm for males, from 2.50 to 18.85 mm for females, and from 1.94 to 3.15 mm for sexually undifferentiated crabs. Relationship between LC and CMQ showed a transition point at 11.70 mm LC in males, and between LC and LAB, at 8.77 mm LC in females. Males (mean LC = 14.24 mm) showed a slightly greater size than females (mean LC = 13,97 mm). These dimensions had positive allometrical growth during all life for both sexes: before and after the puberal molting. Regressions between LC and CMQ in males read as: logCMQ = -0,542265 + 1,51.logLC for male juveniles and logCMQ = -1,446281 + 2,37.logLC for male adults. In females, the regressions between LC and LAB were: logLAB = -0,607282 + 1,22.logLC for juveniles and logLAB = -0,912074 + 1,60.logLC for adults. These body dimensions are related to reproductive activities of this species. The level of allometry in CMQ of adult males was the highest among Uca species which relative growth of this dimension is known. The handedness had a proportion of 1:1 between right-handed and left-handed males

    Crustacea decapoda da praia rochosa da Ilha do Farol, Matinhos, Paraná: II. Distribuição espacial de densidade das populações

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    <abstract language="eng">Decapod crustaceans from rocky shore at Farol Isle, Matinhos, Paraná, Brazil. II. Spatial distribution of population densities. A study of the spatial distribution of the decapod populations from a rocky shore at Farol Isle, Matinhos, State of Paraná, Brazil (25º51'S, 48º32'W) was canied out. In the supralittoral the rocky surface is covered partially by a layer of litter coming from the terrestrial habitats; in the midlittoral boulders and pebbles cover the rocky basin and in the infralittoral, there is a belt of seaweeds. A total of 8 samples were taken by hand, two from each of the following levels: supralittoral (emersion time 8-12 hours), upper midlittoral (4-8), lower midlittoral (0-4) and limit between midlittoral and infralittoral, monthly, from May/1990 to April/1991. The number of species increased from supralittoral (5) to infralittoral (22) and a clear vertical zonation on density was observed according to the emersion time gradient. The supralittoral is characterized by grapsids Armases angustipes (Dana, (1852), Cyclograpsus integer H. Milne Edwards, 1837 and Metasesarma rubripes (Rathbun, 1897) which have terrestrial habits and aerial respiration as a main way in obtaining the oxygen. In the midlittoral, the decapods show three basic types of adaptation against emersion desiccation and thermal stresses: (1) by digging into wet mud among the stones such as Panopeus americanus Saussure, 1857, Panopeus occidentalis Saussure, 1857 and Eurypanopeus abbreviatus Stimpson, 1860, (2) by resting in shady and wet space between the boulders and pebbles or underside of them, like Pachygrapsus transversus (Gibbes, 1850), Petrolisthes armatus (Gibbes, 1850) and adults of Menippe nodifrons Stimpson, 1859 and (3) by clinging over the soaked filamentous algae layer on the pebbles or bouders surfaces, a strategy observed in small species such as Pilumnus dasypodus Kingsley, 1879, Podochela sp., Petrolisthes galathinus (Bosc, 1801 ), Alpheus bouvieri A. Milne Edwards, 1878 and juveniles of Menippe nodifrons. In the infralittoral, small species which are vulnerable to desiccation stresses share space by diversification of their diet and adaptation strategies such as camouflage, body color change according to the substratum, flattened body for tight adhesion on hard surface and rapid movements. The main species of this zone are Petrolisthes armatus, Petrolisthes galathinus, juveniles of Menippe nodifrons, Epialtus brasiliensis Dana, 1852, P. dasypodus, Synalpheus fritzmuelleri Coutière, 1909, Megalobrachium roseum (Rathbun, 1900) and species of Palaemonidae. The rocky shore at Farol Isle is a complex architectural environment due to the conjunction of diversified habitats such as litter over a hard surface, spaces and crevices among boulders and pebbles, muddy substratum and phytal
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