559 research outputs found

    Dinâmica populacional do caranguejo Austinixa aidae (Brachyura, Pinnotheridae): simbionte de Callichirus major (Thalassinidea, Callianassidae) no Atlântico sudoeste

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    The Pinnotheridae family is one of the most diverse and complex groups of brachyuran crabs, many of them symbionts of a wide variety of invertebrates. The present study describes the population dynamics of the pea crab Austinixa aidae (Righi, 1967), a symbiont associated with the burrows of the ghost shrimp Callichirus major (Say, 1818). Individuals (n = 588) were collected bimonthly from May, 2005 to September, 2006 along a sandy beach in the southwestern Atlantic, state of São Paulo, Brazil. Our data indicated that the population demography of A. aidae was characterized by a bimodal size-frequency distribution (between 2.0 and 4.0 mm and between 8.0 and 9.0 mm CW) that remained similar throughout the study period. Sex ratio does not differ significantly from 1:1 (p > 0.05), which confirms the pattern observed in other symbiontic pinnotherids. Density values (1.72 ± 1.34 ind. • ap.-1) are in agreement with those found for other species of the genus. The mean symbiosis incidence (75.6%) was one of the highest among species of the Pinnotheridae family, but it was the lowest among the three studied species of the genus. Recruitment pattern was annual, beginning in May and peaking in July, in both years, after the peak of ovigerous females in the population (from March to May). Our findings describe ecological and biological aspects of A. aidae similar to those of other species of this genus, even from different geographic localities.Pinnotheridae constitui um dos mais diversos e complexos grupos de caranguejos, sendo muitos deles simbiontes de uma grande variedade de invertebrados. O presente estudo descreve a dinâmica populacional do caranguejo pinoterídeo Austinixa aidae (Righi, 1967), um simbionte que vive associado às galerias do "corrupto" Callichirus major (Say, 1818). Os exemplares (n = 588) foram coletados a cada dois meses entre maio de 2005 e setembro de 2006, em uma praia arenosa no litoral de São Paulo, Brasil. Nossos resultados indicaram que a população de A. aidae foi caracterizada por uma distribuição bimodal em classes de tamanho (entre 2,0 e 4,0 mm (CC: comprimento da carapaça) e entre 8,0 e 9,0 mm (CC)), padrão constante ao longo do período de estudo. A razão sexual não diferiu significativamente de 1:1 (p > 0,05), confirmando o padrão observado para outros pinoterídeos simbiontes. Os valores de densidade desta espécie (1,72 ± 1,34 indivíduos por toca) estão de acordo com os estabelecidos para o gênero. A incidência média (75,6%) está entre as mais altas das espécies de Pinnotheridae, entretanto é a menor dentre as três espécies do gênero já estudadas. O padrão de recrutamento foi anual (tendo início em maio e atingindo maior proporção em julho, nos dois anos de estudo), e foi registrado após os picos de ocorrência de fêmeas ovígeras na população (de março a maio). Nossos resultados confirmam que A. aidae possui padrões ecológicos e biológicos similares aos desenvolvidos pelas espécies do gênero, mesmo em diferentes localidades

    Global biogeography, cryptic species and systematic issues in the shrimp genus <i>Hippolyte</i> Leach, 1814 (Decapoda: Caridea: Hippolytidae) by multimarker analyses

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    Hippolyte is a genus of small bodied marine shrimps, with a global distribution. Here, we studied the phylogenetic and biogeographic relationships amongst the species of this genus with two mitochondrial and two nuclear markers, using Bayesian Inference, Maximum Likelihood, genetic divergence, molecular clock and S-DIVA. In addition, the Indo-West Pacific genus Alcyonohippolyte was included. Based on sequences from 57 specimens of 27 species, we recovered a robust biogeographic scenario that shows the Indo-West Pacific as the probable ancestral area of the genus Hippolyte, which emerged in the Paleocene, followed by dispersal in three general directions: (1) South Pacific, (2) eastern Atlantic and Mediterranean Sea and (3) Americas, the latter with a primary colonization in the eastern Pacific followed by a radiation into the western Atlantic. Our analysis reveals that the species of the H. ventricosa group do not constitute a monophyletic group and Alcyonohippolyte does not constitute a reciprocally monophyletic group to Hippolyte, with both genera herein synonimised. The relationships and systematic status of several transisthmian and Atlantic species are clarified

    The reproductive performance of the Red-Algae shrimp Leander paulensis (Ortmann, 1897) (Decapoda, Palaemonidae) and the effect of post-spawning female weight gain on weight-dependent parameters

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    Decapod species have evolved with a variety of reproductive strategies. In this study reproductive features of the palaemonid shrimp Leander paulensiswere investigated. Individuals were collected in the coastal region of Ubatuba, São Paulo, Brazil. In all, 46 ovigerous females were examined in terms of the following reproductive traits: fecundity, reproductive output, brood loss and egg volume. Leander paulensis produces a large number of small eggs with an average fecundity of 635 ± 246 eggs. Egg volume increased significantly from early (0.034 ± 0.008 mm3) to late development stage (0.05 ± 0.012 mm3). The reproductive output did not correlate with female size. The weight of females bearing stage 2 eggs was significantly higher than that of females carrying stage 1 eggs. We assume that the reason for this weight gain is the recovery of female reserves that have been depleted for egg production. Moreover, we emphasize that this weight gain must be considered when evaluating weight-dependent variables such as reproductive output or brood loss in relation to female weight. Otherwise, an overestimation of these variables might lead to inaccurate results.Decápodes desenvolveram uma ampla variedade de estratégias reprodutivas. Neste estudo foram investigadas características reprodutivas da espécie de PalaemonidaeLeander paulensis. Os indivíduos foram coletados na região costeira de Ubatuba, São Paulo, Brasil. Foram examinadas 46 fêmeas ovígeras quanto aos seguintes aspectos reprodutivos: fecundidade, investimento reprodutivo, perda de ovos e volume dos ovos. Leander paulensis produz uma grande quantidade de pequenos ovos, com fecundidade média de 635 ± 246 ovos. O volume dos ovos aumentou significativamente quando comparado o estágio inicial (0.034 ± 0.008 mm3) com o estágio final de desenvolvimento (0.05 ± correlação com o tamanho das fêmeas. Fêmeas com ovos no estágio 2 apresentaram massa corpórea seca significativamente maior que aquelas carregando ovos no estágio inicial. Esse aumento de massa parece ser decorrente da recuperação de reservas energéticas das fêmeas, que teriam sido utilizadas durante a produção de ovos. Além disso, deve-se considerar neste tipo de avaliação o aumento da massa corpórea em relação ao investimento reprodutivo, assim como da perda de ovos relacionada à massa das fêmeas ou qualquer outra variável dependente do peso

    Shell Utilization Pattern by the Hermit Crab Isocheles sawayai Forest and Saint Laurent, 1968 (Anomura, Diogenidae) from Margarita Island, Caribbean Sea, Venezuela

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    Isocheles sawayai is a hermit crab that is occasionally mentioned in the literature, and recently its distribution was extended to Venezuelan waters. Because no information on the biology and shell use patterns of this species inhabiting Caribbean waters is available, we provide the first information on shell occupation patterns of I. sawayai from Venezuela. Specimens were collected monthly from January to December 2000 along the sandy shore of Margarita Island, Venezuela. The 942 specimens collected showed different shell use patterns between the sexes and according to the reproductive condition of the females. The gastropods Leucozonia nassa (37.37%), Engoniophos unicinctus (25.37%), Nassarius vibex (4.88%), Melongena melongena (4.25%), and Stramonita haemastoma (3.82%) represent 76% of the total occupied shells. Of the total of 26 different shell species occupied by I. sawayai, males were found occupying 21, while females were found occupying all 26 shell species. In general, both sexes most frequently occupied L. nassa and E. unicinctus. However, the percentage of females occupying these shells was significantly higher than that of the males. Regression analyses showed the best correlation between crab size, shell aperture width, and shell internal volume. The current comparative investigation, in combination with other South Atlantic populations of I. sawayai, provided further evidence of shell use adaptation in hermit crabs from different areas, and increases our insight into shell use of shallow-water hermit crabs

    Spermatophore and Gonopore Morphology of the Southwestern-Atlantic Hermit Crab Pagurus exilis (Benedict, 1892) (Anomura, Paguridae)

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    Marcelo A. Scelzo, Marina Z. Fantucci, and Fernando L. Mantelatto (2010) Spermatophore and gonopore morphology of the southwestern-Atlantic hermit crab Pagurus exilis (Benedict, 1892) (Anomura, Paguridae). Zoological Studies 49(3): 421-433. The form and function of the spermatophore have been used as a complementary tool in studies of the reproductive biology and systematics of hermit crabs. In this context, we describe the spermatophore and gonopore morphology of Pagurus exilis. The spermatophores were extracted from the distal part of the vas deferens of specimens collected in Argentina and Brazil. The spermatophores were composed of 3 major regions: a main ampulla (with a sperm capsule inside and an accessory ampulla at the base), a stalk, and a pedestal. Each spermatophore had a distinct dorsolateral suture line around the ampulla, where the rupture occurs to release the sperm. The spermatophore total length was 1.5 times the main ampulla length. The main ampulla was oval and slightly flattened. A triangular accessory ampulla extended from the main ampulla base to the pedestal on 1 side, and contained no to several sperm. The stalk is short and flattened, and as wide as the main ampulla. One to 3 spermatophores were found attached to each pedestal, which was almost oblong in shape. The dimensions of the spermatophore and its component parts were directly influenced by the size of the hermit crab. Gonopores of males were covered by long pappose setae, while female gonopores bore a few short cuspidate setae. Specimens from Brazil and Argentina had the same spermatophore morphology, corroborating the previously observed absence of genetic differences between the both populations. The spermatophore morphology of this species has similarities with the broad general pattern of the Paguridae, being most similar to one of the (at least) 3 patterns of spermatophore morphology described for Pa gurus. http://zoolstud.sinica.edu.tw/Journals/49.3/421.pdfPIP CONICET[5135/06]Universidad Nacional de Mar del Plata[EXA 357/06]Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq, Brasilia, Brazil)[490340/2004-0]Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq, Brasilia, Brazil)[490122/2006-0]CAPES (Brasilia, Brazil)Universidade de São Paulo - FFCLRP/USPUniversidade de São Paulo - Centro de Biologie Marinha (CEBIMar/USP, Sao Sebastiao, Brazil

    Análise comparativa de mensagens publicitarias transmitidas pelas empresas O Boticário e Natura no processo de posicionamento de marcas

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    Orientador: Renato Zancan MarchettiMonografia (Especialização) - Universidade Federal do Paraná, Setor de Ciências Sociais Aplicadas, Curso de Especialização em Estrategia e Gestão EmpresarialResumo: Esse estudo apresenta uma análise comparativa de propagandas da Natura e O Boticário, com o intuito de verificar quais elementos presentes em suas mensagens, são relevantes para se estabelecer o posicionamento de suas marcas. Assim, foi feito um levantamento bibliográfico, que contribuiu para o esclarecimento da importância de uma estratégia de comunicação, na qual todas as experiências do consumidor com as marcas reforçam o posicionamento definido, como pode ser observado no capítulo lI. A análise das propagandas da Natura e O Boticário, apresentadas no capítulo III demonstram como uma comunicação de marca bem elaborada pode refletir em sucesso para a empresa. Para tanto, verificou-se a localização da peça publicitária no tempo e espaço, a impressão geral da mensagem, a denotação e a conotação verbal e visual. Empresas de destaque analisam as necessidades dos indivíduos e as trabalham em suas campanhas publicitárias, utilizando-se de toda uma gama de elementos visuais e lingüisticos que incitam a aquisição de produtos. Portanto, esse estudo pretende iniciar uma reflexão sobre como trabalhar esses elementos em prol do posicionamento desejado pela empresa. Na prática, o sucesso das empresas analisadas refletem uma estratégia de comunicação de marca, que em concordância com seus objetivos de marketing conseguiram se posicionar como líderes no mercado brasileir

    Does Petrolisthes armatus (Anomura, Porcellanidae) form a Species Complex or Are We Dealing with Just One Widely Distributed Species?

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    Fernando L. Mantelatto, Leonardo G. Pileggi, Ivana Miranda, and Ingo S. Wehrtmann (2011) Does Petrolisthes armatus (Anomura, Porcellanidae) form a species complex or are we dealing with just one widely distributed species? Zoological Studies 50(3): 372-384. Petrolisthes armatus has the widest distribution known among members of the family Porcellanidae and is one of the most ubiquitous and locally abundant intertidal decapods along the Atlantic coast of the Americas. Considering its geographical distribution and morphological plasticity, several authors postulated the existence of a P. armatus species complex. In the present study we used genetic data from the mitochondrial 16S ribosomal gene to determine the genetic variability of P. armatus from selected locations within its eastern tropical Pacific and western Atlantic distributions. Our phylogenic analysis included 49 specimens represented by 26 species of the genus Petrolisthes and 16 specimens from 10 species and 4 related genera. Genetic distances estimated among the analyzed Petrolisthes species ranged from 2.6%-22.0%; varied between 0%-5.7% for 16S. Additionally, the revision of P. armatus specimens from Pacific Costa Rica and Brazilian Waters showed no geographically significant morphological variations among the analyzed specimens. Therefore, our morphological and genetic data do not support the hypothesis of a P. armatus complex within the specimens studied herein from the Americas, but convincingly confirm the monophyly and non-separateness of the members assigned as P. armatus. http://zoolstud.sinica.edu.tw/Journals/50.3/372.pdfCNPq-Brazil[Proc. 491490/2004-6]CNPq-Brazil[490353/2007-0]CONICIT-Costa Rica[CII-001-08]Univ. de Costa Rica[808-A8-209]CNPq[PQ 301261/04-0]CNPq[301359/07-5]CNPq[140677/08-9]FAPESP[2010/15588-8]FAPESP[05/50651-1]CAPES-Sandwich[1467/09-3]CAPES[02630/09-5]Universidade de São Paulo - FFCLRP/USPUniversidade de São Paulo - Centro de Biologia Marinha (CEBIMar/USP

    A description of the first zoeal stage of Pilumnus vinaceus A. Milne-Edwards, 1880 (Decapoda, Pilumnidae), with a revision of the first zoea morphology of Pilumnus Leach, 1815

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    The morphology of the first zoeal stage of Pilumnus vinaceus is described and compared with the zoea I of Pilumnus all species in the literature. Two ovigerous females of P. vinaceus were maintained in the aquarium facilities until the larvae hatch. The larvae of each ovigerous female were dissected using a stereoscopic microscope. The zoea I of P. vinaceus has common characteristics among the Pilumnidae as: [1] antenna of type 2; [2] maxilliped 1 with 2+2+3+3 setae on the basis and with 3,2,1,2,5 setae in the endopod; [3] maxilliped 2 with 1+1+1+1 setae on the basis and 1,1,6 setae on the endopod; [4] telson with furcal rami armed with dorsal and lateral spines. Considering the species of Pilumnus that occur in the western Atlantic, it becomes possible to identify P. vinaceus zoea I by means of the verification of the following characteristics: [1] pleonites with mediolateral processes; [2] number of setae on the antennule. It is however, important to consider that there is still a great deficit in the knowledge about the morphology of the larval forms of the species assigned to Pilumnus and we argue in favor of new descriptions to build a more robust dataset on zoeal morphology characters and use it in a phylogenetic context on the genus

    A multigene and morphological analysis expands the diversity of the seabod shrimp Xiphopenaeus Smith, 1869 (Decapoda: Penaeidae), with descriptions of two new species

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    After being stable for nearly a century, the taxonomic history of the genus Xiphopenaeus has been marked by many changes in the last three decades. The taxonomic status of the Atlantic species has a low resolution, and many species are still undefned and grouped as cryptic species. Here we employed an integrative approach to defne the species of Xiphopenaeus and the morphological characters needed to diferentiate them. We combined the analyses of two molecular markers (COI and 16S rDNA), scanning electron microscopy and light microscopy. Based on specimens from 17 localities from the Atlantic and Pacifc oceans, we detected fve divergent genetic groups, three in the Atlantic (A1, A2, A3) and two in the Pacifc (P1, P2). Male secondary sexual characters were able to diferentiate four out of the fve genetic groups. Group A1 corresponds to X. kroyeri, and A2 and A3 correspond to new species. We redescribed the genus and two new species are described and illustrated: Xiphopenaeus dincao nov. sp. (A2) and Xiphopenaeus baueri nov. sp. (A3). Since the holotype of X. riveti was missing and the specimen analysed from group P2 was a female, the status of the species of Xiphopenaeus from the Pacifc remains unresolved
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