• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 22
  • 6
  • 3
  • 1
  • 1
  • Tagged with
  • 34
  • 8
  • 7
  • 6
  • 6
  • 6
  • 5
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • 4
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Sexual plasticity in a marine goby (Lythrypnus dalli) social, endocrine, and genetic influences on functional sex /

Rodgers, Edmund W. January 2007 (has links)
Thesis (Ph. D.)--Georgia State University, 2007. / Title from file title page. Mattew S Grober, committee chair; Kim Wallen, Charles Derby, Laura Carruth, Tim Bartness, committee members. Electronic text (107 p. : ill. (some col.)) : digital, PDF file. Description based on contents viewed Jan. 31, 2008. Includes bibliographical references. (p. 94-107)
12

Desenvolvimento ontogenético e ecologia das larvas de Microgobius meeki no Complexo Estuarino de Rio Formoso, Pernambuco

FARIAS, Wialla Karmen Teixeira de 30 May 2017 (has links)
FALCÃO, Elisabeth Cabral Silva, também é conhecida em citações bibliográficas por: SILVA-FALCÃO, Elisabeth Cabral / Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-08-22T22:51:25Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Wialla Karmen Teixeira de Farias.pdf: 8624434 bytes, checksum: ced883f26cd62abb795984ea6fed9dae (MD5) / Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-08-29T21:02:42Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Wialla Karmen Teixeira de Farias.pdf: 8624434 bytes, checksum: ced883f26cd62abb795984ea6fed9dae (MD5) / Made available in DSpace on 2018-08-29T21:02:42Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Wialla Karmen Teixeira de Farias.pdf: 8624434 bytes, checksum: ced883f26cd62abb795984ea6fed9dae (MD5) Previous issue date: 2017-05-30 / CNPq / O complexo estuarino de Rio Formoso está inserido em duas áreas de proteção ambiental (APA Guadalupe e Costa dos Corais) e forma um mosaico com diferentes ecossistemas costeiros onde vivem diversos organismos, incluindo as larvas de peixes da espécie Microgobius meeki. Recentemente, este gobiídeo foi identificado como um potencial bioindicador das consequências de interferência antrópica em estuários e suas larvas são descritas como abundantes em alguns estuários do Brasil. O presente estudo teve como objetivo descrever os estágios iniciais do desenvolvimento desse peixe e avaliar os fatores abióticos que mais influenciaram as fases iniciais e os habitats utilizados ao longo deste desenvolvimento. As coletas de ictioplâncton foram realizadas bimensalmente (2009-2012), durante a baixa-mar, através de arrastos horizontais subsuperficiais (malha de 500 μm), em marés de quadratura e sizígia, na coluna d’água associada a habitats de manguezal, prado de fanerógamas e recife de arenito. Em cada um dos habitats foram feitas tréplicas aleatórias por período (diurno e noturno) nas duas estações (estiagem e chuvosa). Apesar da lacuna de informações taxonômicas acerca da espécie abordada, os exemplares examinados apresentaram várias características morfológicas comuns ao gênero Microgobius, que permitiram descrever, ineditamente, os estágios larvais iniciais. Foram estudados 168 indivíduos da espécie, sendo 58, 106 e 4 nas fases de pré-flexão, flexão e pós-flexão, respectivamente. No exame comparativo desses estágios, verificou-se uma densa pigmentação ao longo de toda a porção inferior do corpo (acima e abaixo do intestino), que evidencia a bexiga natatória arredondada. Os exemplares de M. meeki estiveram representados nos três ecossistemas costeiros, sendo encontrados mais abundantemente nos estágios iniciais de desenvolvimento (pré-flexão e flexão) no período noturno, na estação chuvosa e no recife. Poucas larvas foram coletadas durante o dia, com exceção do registro de 5 larvas em pré-flexão. As larvas relacionaram-se positivamente apenas com o fator temperatura, não apresentando relação com a salinidade ou pH. As informações obtidas sugerem preferência dos estágios mais iniciais pelo recife, enquanto o estágio de pós- flexão foi encontrado nos habitats mais internos do estuário. A conectividade ecossistêmica da região assegura o desenvolvimento larval no estuário tropical, sendo este resultado um importante indicativo para a preservação de M. meeki. / The Rio Formoso´s estuarine complex is present in two areas of environmental protection (EPA Guadalupe and Costa dos Corais) and forms a mosaic with different coastal ecosystems, habitat for a big diversity of organisms, including Microgobius meeki specie. Recently, this gobie was identified as a potential bioindicator of anthropic interference in estuaries, where their larvae are described as abundant in some Brazilian estuaries. This study aimed to describe the early larval development of M. meeki and to evaluate the abiotic factors that most influenced the initial phases and habitats used throughout this development. The ichthyoplankton collections were carried out bi-monthly (2009-2012), during low tide, through subsurface horizontal trawls (mesh of 500 μm), in neap and spring tides, on a water column associated with mangrove habitats, of seagrass e beachrocks. In each habitat, random rejoinders were made in day and night periods and in dry and rainy seasons. In spite of the lack of taxonomic information about the species studied, the specimens examined presented several morphological caracteristics common to the genus Microgobius, which allowed for the description of the initial larval stages.168 individuals of the species were studied, being 58, 106 and 4 individuals in the pre-flexion, flexion and post-flexion phases, respectively. In the comparative examination of these stages, a dense pigmentation was observed throughout the lower portion of the body (above and below the gut), which shows a rounded bladder. The M. meeki specimens were represented in the three habitats, being found more abundantly in the early development stages (pre-flexion and flexion) at night, in the rainy season and at the reef. Few larvae were collected during the day, with the exception of the 5 larvae record in pre-flexion. The larvae were positively related only to the temperature factor, with no relation to salinity or pH. The information obtained suggests the preference of the earliest stages by the reef, while the post-flexion stage was found in the innermost habitats of the estuary. The ecosystem connectivity of the region ensure the larval development in the tropical estuary, being this result an important indicative for the M. meeki preservation.
13

Efeitos dos ciclos de iluminação e de marés na ritmicidade da atividade locomotora de Bathygobius soporator (Valenciennes,1837) (Teleostei: Perciformes: Gobiidae) / The effect of the light and tidal cycles on the rhythmicity of the locomotor activity of Bathygobius soporator (Valenciennes 1837) (Teleostei: Perciformes: Gobiidae)

Nomura, Mariene Mitie 04 June 2008 (has links)
Muitos trabalhos sobre comportamento consideram que os ritmos observados são simplesmente uma resposta aos estímulos ambientais. No entanto, desde o século XVIII, sabe-se que a temporização é real e muitos organismos exibem ritmos endógenos que são arrastados por zeitgebers ou \"doadores de tempo\". Para a grande maioria dos seres vivos, o principal zeitgeber é o ciclo claro/escuro (CE). No entanto, para os organismos das zonas entremarés, o ciclo das marés é tão importante quanto o ciclo de luz. A maré e seus componentes agindo como zeitgeber têm sido estudados com invertebrados e pouca atenção tem sido dada aos peixes que vivem nas zonas entremarés. Uma das espécies mais comuns destes ambientes é o Bathygobius soporator, conhecido como amborê, e o presente trabalho teve como objetivo verificar a presença de ritmicidade em sua atividade locomotora, avaliando as contribuições endógenas e exógenas dos ciclos de luminosidade, da variação da coluna d\'água e da turbulência da água sobre este ritmo. Para isso, os amborês foram mantidos em aquários individuais onde as condições abióticas puderam ser controladas de acordo com os experimentos em andamento. A atividade locomotora foi registrada com câmeras de segurança e fontes de luz infravermelha acopladas a um vídeo \"time-lapse\" que fez o registro de um quadro a cada trinta segundos. As distâncias percorridas a cada trinta segundos foram categorizadas em quatro classes discretas, e esses valores foram agrupados a cada trinta minutos, compondo 48 pontos a cada 24 horas. A análise das séries temporais foi feita através do programa \"El Temps\" que gerou actogramas e periodogramas de Lomb-Scargle, que permitem identificar ritmos com períodos significativos. Diante dos resultados obtidos, pôde-se concluir que o ciclo CE e de variação na coluna d\'água são zeitgebers, enquanto a turbulência é um agente mascarador para a ritmicidade locomotora dos amborês. Concluiu-se, também, que os relógios biológicos nos amborês não são rígidos e possuem acoplamento extremamente frágil, gerando uma alta plasticidade na expressão dos ritmos endógenos e exógenos, o que está de acordo com o modo de vida dos amborês observados no ambiente natural. / Many organisms\' rhythms are considered to be simple reactions to the cyclical changes in the environment. However, the endogenous rhythms entrained by zeitgebers are well known and have been described for many organisms since the 18th century. Although the light/dark cycle (LD) is the main zeitgeber for most living beings, the tidal cycles are as important for the intertidal organisms. It has been studied as a zeitgeber mainly for invertebrates, and little attention has been given to the intertidal fish. Bathygobius soporator, also known as frillfin goby, is one of the most abundant species in the tropical intertidal zone, and this project was designed to verify the rhythmicity in its locomotor activity, and measure how the LD cycle, the cyclical change in water level, and the turbulence cycle affect the endogenous and/or exogenous aspects of this rhythm. The gobies were kept in individual aquariums where all abiotic conditions were controlled according to the requirements of each experiment. The locomotor activity was recorded with security cameras and infrared light bulbs connected to a time-lapse video recorder that taped one frame every thirty seconds. The distance moved by each fish every thirty seconds was categorized into four discrete classes. The values assigned to these classes of movements were added into thirty minutes blocks, thus giving 48 numbers for every 24 hours. The collected data was analyzed by the \"El Temps\" software that provided actograms and Lomb-Scargle periodograms which allowed the detection of rhythms and significant periods. The results led us to conclude that LD cycle and the cyclical change in water level are zeitgebers to locomotor activity of B. soporator, and that the turbulence is a masking agent. We could also affirm that the frillfin gobies\' biological clocks are weak and have a very fragile coupling, giving the fish a malleable expression of their endogenous and exogenous rhythms. This concurs with the natural history of B. soporator.
14

The feeding ecology of the mudskipper : Boleophthalmus pectinirostris (Pisces: periophthalmidae) at the Mai Po Marshes nature reserve, Hong Kong /

Yang, Ka-yee, Josephine. January 1996 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 97-111).
15

Efeitos dos ciclos de iluminação e de marés na ritmicidade da atividade locomotora de Bathygobius soporator (Valenciennes,1837) (Teleostei: Perciformes: Gobiidae) / The effect of the light and tidal cycles on the rhythmicity of the locomotor activity of Bathygobius soporator (Valenciennes 1837) (Teleostei: Perciformes: Gobiidae)

Mariene Mitie Nomura 04 June 2008 (has links)
Muitos trabalhos sobre comportamento consideram que os ritmos observados são simplesmente uma resposta aos estímulos ambientais. No entanto, desde o século XVIII, sabe-se que a temporização é real e muitos organismos exibem ritmos endógenos que são arrastados por zeitgebers ou \"doadores de tempo\". Para a grande maioria dos seres vivos, o principal zeitgeber é o ciclo claro/escuro (CE). No entanto, para os organismos das zonas entremarés, o ciclo das marés é tão importante quanto o ciclo de luz. A maré e seus componentes agindo como zeitgeber têm sido estudados com invertebrados e pouca atenção tem sido dada aos peixes que vivem nas zonas entremarés. Uma das espécies mais comuns destes ambientes é o Bathygobius soporator, conhecido como amborê, e o presente trabalho teve como objetivo verificar a presença de ritmicidade em sua atividade locomotora, avaliando as contribuições endógenas e exógenas dos ciclos de luminosidade, da variação da coluna d\'água e da turbulência da água sobre este ritmo. Para isso, os amborês foram mantidos em aquários individuais onde as condições abióticas puderam ser controladas de acordo com os experimentos em andamento. A atividade locomotora foi registrada com câmeras de segurança e fontes de luz infravermelha acopladas a um vídeo \"time-lapse\" que fez o registro de um quadro a cada trinta segundos. As distâncias percorridas a cada trinta segundos foram categorizadas em quatro classes discretas, e esses valores foram agrupados a cada trinta minutos, compondo 48 pontos a cada 24 horas. A análise das séries temporais foi feita através do programa \"El Temps\" que gerou actogramas e periodogramas de Lomb-Scargle, que permitem identificar ritmos com períodos significativos. Diante dos resultados obtidos, pôde-se concluir que o ciclo CE e de variação na coluna d\'água são zeitgebers, enquanto a turbulência é um agente mascarador para a ritmicidade locomotora dos amborês. Concluiu-se, também, que os relógios biológicos nos amborês não são rígidos e possuem acoplamento extremamente frágil, gerando uma alta plasticidade na expressão dos ritmos endógenos e exógenos, o que está de acordo com o modo de vida dos amborês observados no ambiente natural. / Many organisms\' rhythms are considered to be simple reactions to the cyclical changes in the environment. However, the endogenous rhythms entrained by zeitgebers are well known and have been described for many organisms since the 18th century. Although the light/dark cycle (LD) is the main zeitgeber for most living beings, the tidal cycles are as important for the intertidal organisms. It has been studied as a zeitgeber mainly for invertebrates, and little attention has been given to the intertidal fish. Bathygobius soporator, also known as frillfin goby, is one of the most abundant species in the tropical intertidal zone, and this project was designed to verify the rhythmicity in its locomotor activity, and measure how the LD cycle, the cyclical change in water level, and the turbulence cycle affect the endogenous and/or exogenous aspects of this rhythm. The gobies were kept in individual aquariums where all abiotic conditions were controlled according to the requirements of each experiment. The locomotor activity was recorded with security cameras and infrared light bulbs connected to a time-lapse video recorder that taped one frame every thirty seconds. The distance moved by each fish every thirty seconds was categorized into four discrete classes. The values assigned to these classes of movements were added into thirty minutes blocks, thus giving 48 numbers for every 24 hours. The collected data was analyzed by the \"El Temps\" software that provided actograms and Lomb-Scargle periodograms which allowed the detection of rhythms and significant periods. The results led us to conclude that LD cycle and the cyclical change in water level are zeitgebers to locomotor activity of B. soporator, and that the turbulence is a masking agent. We could also affirm that the frillfin gobies\' biological clocks are weak and have a very fragile coupling, giving the fish a malleable expression of their endogenous and exogenous rhythms. This concurs with the natural history of B. soporator.
16

Microhabitat Association of Cryptobenthic Reef Fishes (Teleostei: Gobiidae) in the Central Red Sea

Troyer, Emily 05 1900 (has links)
Knowledge of biodiversity within an ecosystem is essential when trying to understand the function and importance of that ecosystem. A challenge when assessing biodiversity of reef habitats is cryptobenthic fishes, which encompass many groups that have close associations with the substrate. These fishes can be behaviorally cryptic, by seeking refuge within the reef matrix, or visually cryptic, using cryptic coloration to match the surrounding habitat. These factors make visual surveys inadequate for sampling these fishes. One such group of cryptobenthic fishes are the gobies, family Gobiidae, which currently represent over 1600 species, although new species are continually being discovered. Gobies are often small (less than 5 cm), and many species will be associated with a very specific microhabitat type. Due to the understudied nature of the Red Sea, little is known about habitat preferences of gobies within the region. In order to determine the differences in goby community structure within the central Red Sea, fishes were sampled at one reef using 1 m² enclosed rotenone stations from three distinct microhabitats: hard coral, rubble, and sand. Following collection, specimens were photographed and sequenced using COI, to aid in species identification. 232 individuals were collected representing 31 species of goby. Rubble microhabitats were found to host the majority of collected gobies (69%), followed by hard coral (20.6%), then sand (9.9%). Goby assemblages in the three microhabitats were significantly different from each other, and evidence of habitat-specialists was found. These results provide essential baseline information about the ecology of understudied cryptobenthic fishes that can be used in future large-scale studies in the Red Sea region.
17

Molecular systematics of the South African gobiid fishes of the genus glossogobius gill, 1862 (teleostei : gobiidae)

Maake, Pholoshi Abram January 2009 (has links)
Thesis (M.Sc. (Zoology)) --University of Limpopo, 2009 / The genus, Glossogobius Gill, 1862 belongs to the family Gobiidae, a large fish family represented by several thousand species. In southern African there are about 51 genera comprising about 107 species. It has been suggested that gobies underwent an extensive ecological radiation, with species diversifying into marine, brackish and freshwater habitats. The genus Glossogobius has about 22 species with an Indo-west Pacific distribution. The overall aim of the current study was to examine the systematics of Glossogobius in southern Africa using molecular markers in an attempt to clarify the geographic distribution and species status. A total of 131 individuals of G. callidus were collected from rivers and estuaries throughout the species’ distribution in two southern African biogeographic regions (subtropical and warmtemperate) using six-meter seine nets, while individuals of G. tenuiformis were only collected in KwaZulu-Natal region. Additional specimens and taxa were downloaded from Genbank and also loaned from the SAIAB DNA collection and the Art Gallery and Museum of the Northern Territory(NTM), Darwin Australia. This study employed mtDNA cytochrome b (cyt b) and the nuclear S7 ribosomal protein gene intron 1 (S7 intron 1) as genetic markers. In determining the phylogeographic structure of the river goby general methods such as AMOVA, demography analyses, network of haplotypes and phylogenetic tree reconstruction were employed. Evolutionary relationships within the genus were resolved by employing parsimony (MP), Bayesian Inference (BI) and Maximum likelihood (ML) tree reconstruction analyses. Both MP and ML were computed in PAUP* while BI was computed using Mr Bayes.Initially, a large-scale assessment of the genetic structure and diversity of G. callidus was undertaken. This species has a wide distribution in most estuaries and coastal river systems along the east coast of southern Africa, and in inland freshwater systems from the north-eastern parts. Overall,patterns of haplotype relatedness, high haplotypic diversity related to low nucleotide diversity, and mismatch distribution analysis supported a population expansion hypothesis with continued restricted dispersal and gene flow. Two major historically isolated lineages (5% divergence, cyt b)were identified within this species, one comprising subtropical samples (KwaZulu-Natal lineage),and the other including the majority of the warm temperate localities and a few subtropical localities(EC, Eastern Cape lineage). Glossogobius callidus individuals collected from riverine localities within the EC lineage were geographically structured and support the general hypothesis of structure among freshwater species while the estuarine individuals were less structured. Although, the individuals from these two lineages were morphologically inseparable, the high genetic separation between the two conforms to the reports that G. callidus is a species complex. The results further revealed some evolutionary significant units (Nkanini/Kosi bay lineage, and Mozambique) in the KZN lineage, KwaZulu-Natal. However, there were other identified localities with restricted gene flow and some degree of reproductive isolation that were not evolutionary significant. Thus, the results indicate that G. callidus is a species with relatively strong population and phylogeographic structure in southern Africa.The validity of the species of the genus Glossogobius in southern Africa (G. callidus and G. giurus with its synonymy G. tenuiformis) was investigated by estimating the relationships among the Glossogobius taxa in southern Africa, using the same molecular markers. Based on a model selected under AIC in Modeltest, ML analysis of the dataset also recovered a phylogram which was similar to MP and BI in recognising the major clades in many respects. All analyses recovered monophyly for all southern African species of the genus. Although the cyt b analyses included Glossogobius species from Australia, there was no evidence of a phylogeographic break between the two continents. However, it appears that each southern African Glossogobius species has a sister species occurring in Australia according to the cyt b dataset. Glossogobius aureus was revealed as the probable sister species to G. tenuiformis while the African G. giuris group was monophyletic with the Australian G. giuris. The two G. callidus groups that appear to represent two unique species (sp. 1 and sp. 2) were also sister taxa to the undescribed Glossogobius sp. from Australia. It could be postulated that this inter-continental species relationships were a result of either allopatric or sympatric speciation events, to the ancestral taxa of each of these three sister groups which in turn split up during the Gondwana breakup. The inclusion of G. celebius (a freshwater and brackish species with an Asian and Oceania distribution) in the S7 intron dataset did not affect the monophyly of southern African species. However, this species appears to be more basal in the genus than the southern African species. The results further indicated that G. tenuiformis (previously a synonym of G. giuris) forms a separate clade that is distinct from the G. giuris species group. Although G. tenuiformis and G. giuris formed a monophyletic group in all analyses involving the S7 intron 1, individuals from each species were monophyletic and strongly supported. The scanning electron micrographs of the cheek papillae of the two species further revealed morphological differences. The congruence between both morphology and molecular data indicated that G. tenuiformis is unequivocally distinct from G. giuris and it is therefore suggested that the taxonomic status of the G. giuris group be revised. / National Research Foundation, the Ernst and Ethel Eriksen Trust, the South African Institute for Aquitic Biodiversity (SAIAB), and the University of Limpopo
18

Delivering oxytetracycline to first-feeding zebrafish Danio rerio (Hamilton) and goby Asterropteryx semipunctata (Rüppell) larvae using lipid spray beads /

Temple, Ephraim E. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 35-40). Also available on the World Wide Web.
19

The ecology of mudskippers (Pisces: Periophthalmidae) at the Mai Po Marshes Nature Reserve, Hong Kong /

Chan, Ka-yi, Phoebe. January 1989 (has links)
Thesis (M. Phil.)--University of Hong Kong, 1990.
20

Diversifica??o evolutiva de gob?deos no litoral brasileiro: padr?es citogen?ticos e ecomorfol?gicos

Lima Filho, Paulo Augusto de 05 May 2011 (has links)
Made available in DSpace on 2014-12-17T14:33:05Z (GMT). No. of bitstreams: 1 PauloALF_DISSERT.pdf: 2064193 bytes, checksum: f7bd272b82440f00076ae87259d903f5 (MD5) Previous issue date: 2011-05-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The fishes of the order Perciformes are characterized as an important model for understanding the genetic structure of marine populations, because besides they present examples of conservation chromosomal, also they present the karyotype diversification for some groups. Gobiidae family is the most specious in the marine environment. Among its representatives, many species are part of a cryptic fauna little noticed and studied, a wide distribution with behavioral and reproductive characteristics, that make them conducive to the action of biogeographical barriers. Morphologically this family presents reduced body structures through simplification and regressions. Despite their importance in evolutionary inferences, cytogenetics data are incipient facing their species diversity, especially with western Atlantic species. In order to estimate the evolutionary diversity in Gobiidae, it were developed cytogenetic analysis and the standards body, through geometric morphometrics in five species on the Brazilian coast, Coryphopterus glaucofraenum, Bathygobius mystacium, B. soporator, Ctenogobius smaragdus e C. Boleosoma. The data show significant karyotype and morphological diversity among the species. The pericentric inversions and mergers play an important role in chromosomal evolution of this family, causing karyotypic structural and numerical differences in all species. Karyotypic and morphological comparisons among geographic samples of B. soporator from the coast of Maranh?o, Rio Grande do Norte and Bahia showed cytogenetics patterns commons, but different morphological patterns. A sample from the Atol das Rocas revealed conspicuous morphological and karyotypic differentiation of another continental populations, confirming the presence of a new island species. The approaches done reveal diversification consistent with characteristics of a group of low vagile and largely able to environmental selection due from peculiar ecological requirements / Os peixes da ordem Perciformes caracterizam-se como um modelo importante para o entendimento da estrutura gen?tica de popula??es marinhas, pois apresentam tanto exemplos de conserva??o cromoss?mica como de diversifica??o cariot?pica para alguns grupos. Gobiidae ? a fam?lia mais especiosa no ambiente marinho. Entre seus representantes, muitas esp?cies fazem parte de uma fauna cr?ptica pouco percebida e estudada, apresentando ampla distribui??o com caracter?sticas comportamentais e reprodutivas que as tornam prop?cias ? a??o de barreiras biogeogr?ficas. Morfologicamente esta fam?lia apresenta estruturas corporais reduzidas atrav?s de simplifica??es e regress?es. Dados citogen?ticos, apesar da import?ncia em infer?ncias evolutivas, s?o incipientes frente sua diversidade de esp?cies, sobretudo para esp?cies do Atl?ntico Ocidental. Visando estimar a diversidade evolutiva em Gobiidae foram desenvolvidas an?lises citogen?ticas e dos padr?es corporais, atrav?s de morfometria geom?trica, em cinco esp?cies presentes no litoral brasileiro, Coryphopterus glaucofraenum, Bathygobius mystacium, B. soporator, Ctenogobius smaragdus e C. Boleosoma. Os dados obtidos demonstram marcante diversidade cariot?pica e morfol?gica entre as esp?cies. As invers?es peric?ntricas e fus?es desempenham papel importante na evolu??o cromoss?mica desta fam?lia, ocasionando diferen?as cariot?picas estruturais e num?ricas em todas as esp?cies. Compara??es cariot?picas e morfol?gicas entre amostras geogr?ficas de B. soporator provenientes do litoral do Maranh?o, Rio Grande do Norte e Bahia evidenciaram padr?es citogen?ticos comuns, mas padr?es morfol?gicos diferentes. Uma amostra proveniente do Atol das Rocas revelou consp?cua diferencia??o cariot?pica e morfol?gica das demais popula??es continentais, confirmando a presen?a de uma nova esp?cie insular. As abordagens empregadas revelam diversifica??es compat?veis com um grupo com caracter?sticas de baixa vagilidade e amplamente sujeito a sele??o ambiental decorrente de exig?ncias ecol?gicas peculiares

Page generated in 0.0358 seconds