Internal and external relationships of the Cnidaria : implications of primary and predicted secondary structure of the 5'–end of the 23S–like rDNA

Odorico, Dimitri M.; Miller, David J.

doi:10.1098/rspb.1997.0011

Cited by 82 publications

(57 citation statements)

References 32 publications

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“…One classical problem to animal phylogeny is the evolution of cnidarians and the groups therein (Hyman, 1940;Brusca and Brusca, 1990;Bridge et al, 1992Bridge et al, , 1995Schuchert, 1993;Schierwater, 1994;Odorico and Miller, 1997). Particularly the systematic relationships within the Hydrozoa represent one of the most difficult and long-standing problems to evolutionary biologists.…”

Section: Introductionmentioning

confidence: 99%

<i>Sarsia marii</i> n. sp. (Hydrozoa, Anthomedusae) and the use of 16S rDNA sequences for unpuzzling systematic relationships in Hydrozoa

Schierwater¹,

Ender²

2000

Sci. Mar.

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SUMMARY: A new hydrozoan species, Sarsia marii, is described by using morphological and molecular characters. Both morphological and 16S rDNA data place the new species together with other Sarsia species near the base of a clade that developed‚ "walking" tentacles in the medusa stage. The molecular data also suggest that the family Cladonematidae (Cladonema, Eleutheria, Staurocladia) is monophyletic. The taxonomic embedding of Sarsia marii n. sp. demonstrates the usefulness of 16S rDNA sequences for reconstructing phylogenetic relationships in Hydrozoa.

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Section: Introductionmentioning

confidence: 99%

<i>Sarsia marii</i> n. sp. (Hydrozoa, Anthomedusae) and the use of 16S rDNA sequences for unpuzzling systematic relationships in Hydrozoa

Schierwater¹,

Ender²

2000

Sci. Mar.

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“…O filo Cnidaria é considerado um grupo monofilético composto por dois grandes clados, Anthozoa e Medusozoa (Collins 2002;Collins et al 2006), sendo esta divisão bem suportada por caracteres morfológicos e moleculares (Schuchert 1993;Bridge et al 1995;Odorico and Miller 1997;Collins 2002;Daly et al 2007;Kayal et al 2013;Zapata et al 2015). Seus representantes formam um grupo diverso de animais relativamente simples caracterizados pela presença da cnida (Odorico and Miller 1997;Collins 2002;Daly et al 2007;Collins 2009;Reft and Daly 2012) e diversidade do ciclo de vida com a presença ou ausência da alternância de gerações (Bridge et al 1995).…”

Section: Introdução Geralunclassified

“…Seus representantes formam um grupo diverso de animais relativamente simples caracterizados pela presença da cnida (Odorico and Miller 1997;Collins 2002;Daly et al 2007;Collins 2009;Reft and Daly 2012) e diversidade do ciclo de vida com a presença ou ausência da alternância de gerações (Bridge et al 1995).…”

Section: Introdução Geralunclassified

“…Os problemas classificatórios em Cnidaria têm atraído o interesse de zoólogos (Werner 1973a) e são diversos os trabalhos que apresentam teorias e hipóteses filogenéticas tentativas para classificar o grupo. As principais divergências concernem na problemática sobre: a diversificação dos ciclos de vida e qual dos dois estágios ou formas corporais (pólipo ou medusa) seria o mais basal (Werner 1973a;Werner 1973b;Bridge et al 1992;Schuchert 1993;Bridge et al 1995;Odorico and Miller 1997); na relação entre as quatro das atuais classes de Medusozoa (Hydrozoa, Scyphozoa, Cubozoa e Staurozoa); e entre os subgrupos de Hydrozoa e ordens de Scyphozoa (Marques and Collins 2004;Dawson 2004;Collins et al 2006;Daly et al 2007;Kayal et al 2012;Kayal et al 2013;Zapata et al 2015). Kayal et al (2013) ampliaram a amostragem dos genomas mitocondriais já apresentados para Cnidaria a fim de reavaliar as relações filogenéticas dentro do filo.…”

Section: Introdução Geralunclassified

“…As cubomedusas Tamoya haplonema (Carybdeida) e Chiropsalmus quandrumanus (Chirodropida) possuem abundância menor, mas são relativamente comuns (Nogueira Júnior et al 2010). Na Austrália as espécies do gênero Cassiopea normalmente são encontrados com a umbrella apoiada no substrato e a superficie oral para cima (Bigelow 1900; Morandini et al 2016b) (Bridge et al 1995;Odorico and Miller 1997;Marques and Collins 2004;Morandini et al 2016a). De um modo geral o ovo fertilizado se desenvolve em uma larva plânula que ao assentar se diferencia em um pólipo.…”

Section: Introdução Geralunclassified

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Conformação gonadal, caracterização histoquímica e ultraestrutural da gônada masculina e espermatozoides em espécies de águas-vivas (Cubozoa e Scyphozoa, Medusozoa, Cnidaria)

Tiseo¹

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Colonial origin for Eumetazoa: major morphological transitions and the origin of bilaterian complexity

Dewel

2000

Journal of Morphology

103

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A new hypothesis for the evolution of Bilateria is presented. It is based on a reinterpretation of the morphological characters shared by protostomes and deuterostomes, which, when taken together with developmental processes shared by the two lineages, lead to the inescapable conclusion that the last common ancestor of Bilateria was complex. It possessed a head, a segmented trunk, and a tail. The segmented trunk was further divided into two sections. A dorsal brain innervated one or more sensory cells, which included photoreceptors. “Appendages” or outgrowths were present. The bilaterian ancestor also possessed serially repeated “segments” that were expressed ontogenetically as blocks of mesoderm or somites with adjoining fields of ectoderm or neuroectoderm. It displayed serially repeated gonads (gonocoels), each with a gonoduct and gonopore to the exterior, and serially repeated “coeloms” with connections to both the gut and the exterior (gill slits and pores). Podocytes, some of which were serially repeated in the trunk, formed sites of ultrafiltration. In addition, the bilaterian ancestor had unsegmented coeloms and a contractile blood vessel or “heart” formed by coelomic myoepithelial cells. These cells and their underlying basement membrane confine the hemocoelic fluid, or blood, in the connective tissue compartment. A possible scenario to account for this particular suite of characters is one in which a colony of organisms with a cnidarian grade of organization became individuated into a new entity with a bilaterian grade of organization. The transformation postulated encompassed three major transitions in the evolution of animals. These transitions included the origins of Metazoa, Eumetazoa, and Bilateria and involved the successive development of poriferan, cnidarian, and bilaterian grades of organization. Two models are presented for the sponge‐to‐cnidarian transition. In both models the loss of a flow‐through pattern of water circulation in poriferans and the establishment of a single opening and epithelia sensu stricto in cnidarians are considered crucial events. In the model offered for the cnidarian‐to‐bilaterian transition, the last common ancestor of Eumetazoa is considered to have had a colonial, cnidarian‐grade of organization. The ancestral cnidarian body plan would have been similar to that exhibited by pennatulacean anthozoans. It is postulated that a colonial organization could have provided a preadaptive framework for the evolution of the complex and modularized body plan of the triploblastic ancestor of Bilateria. Thus, one can explore the possibility that problematica such as ctenophores, the Ediacaran biota, archaeocyaths, and Yunnanozoon reflect the fact that complexity originated early and involved the evolution of a macroscopic compartmented ancestor. Bilaterian complexity can be understood in terms of Beklemishev “cycles” of duplication and colony individuation. Two such cycles appear to have transpired in the early evolution of Metazoa. The first gave rise to a mult...

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Internal and external relationships of the Cnidaria : implications of primary and predicted secondary structure of the 5'–end of the 23S–like rDNA

Cited by 82 publications

References 32 publications

<i>Sarsia marii</i> n. sp. (Hydrozoa, Anthomedusae) and the use of 16S rDNA sequences for unpuzzling systematic relationships in Hydrozoa

<i>Sarsia marii</i> n. sp. (Hydrozoa, Anthomedusae) and the use of 16S rDNA sequences for unpuzzling systematic relationships in Hydrozoa

Conformação gonadal, caracterização histoquímica e ultraestrutural da gônada masculina e espermatozoides em espécies de águas-vivas (Cubozoa e Scyphozoa, Medusozoa, Cnidaria)

Colonial origin for Eumetazoa: major morphological transitions and the origin of bilaterian complexity

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