Skip to main content

Phylogeny and evolution of calcareous sponges

Buy Article:

$50.00 plus tax (Refund Policy)

Abstract:

The most recent advances concerning the phylogeny and evolution of calcareous sponges (Calcarea or Calcispongia) are reviewed here, in the light of the history of taxonomy of the group and conceptions about its evolution, starting from Haeckel's works at the end of the 19th century. Calcisponge phylogeny has recently started to be addressed using modern tools of phylogenetic reconstruction: cladistic analysis of morphological characters and molecular phylogeny (so far using 18S and 28S rDNA sequences). The monophyly of calcareous sponges is strongly supported in these works, as is their subdivision into two clades, Calcinea (whose proposed synapomorphy is the basal position of nuclei in choanocytes, with no relation to the flagella) and Calcaronea (whose possible synapomorphy is the formation of the amphiblastula larva through the original process of eversion of the stomoblastula). While the molecular phylogeny of Calcinea is still in its infancy because of insufficient taxonomic sampling, several lines are emerging for the phylogeny of Calcaronea, and these are in strong disagreement with the classification issued from the "traditional" morphological approach. Phylogenetic hypotheses also permit the reconstruction of morphological character evolution, which appears complex and subject to a high level of homoplasy.

Cette revue propose de faire le point sur les avancées récentes concernant la phylogénie et l'évolution des éponges calcaires (Calcarea ou Calcispongia), à la lumière de l'histoire de la taxonomie et des conceptions évolutives sur ce groupe depuis les travaux de Haeckel à la fin du XIXème siècle. La phylogénie des calcisponges a commencé depuis peu à être étudiée à travers les outils modernes de la reconstruction phylogénétique : analyse cladistique de caractères morphologiques et phylogénie moléculaire (pour le moment, à partir des séquences d'ADNr 18S et 28S). Ces travaux apportent un soutien ferme à la monophylie des éponges calcaires et confirment leur subdivision en deux clades : Calcinea (dont une synapomorphie proposée est la position basale des noyaux dans les choanocytes, sans liaison avec les flagelles), et Calcaronea (dont une possible synapomorphie est la formation de la larve amphiblastula par un phénomène original d'éversion de la stomoblastula). Alors que la phylogénie moléculaire des Calcinea reste balbutiante, par insuffisance de l'échantillonnage taxonomique, quelques grandes lignes se dégagent pour la phylogénie des Calcaronea, en décalage important avec la classification du groupe issue de l'approche morphologique « traditionnelle ». Ces hypothèses phylogénétiques servent également de base à la reconstruction de l'histoire des caractères morphologiques, qui s'avère particulièrement complexe et sujette à un fort degré d'homoplasie.

Document Type: Research Article

Publication date: February 1, 2006

More about this publication?
  • Published since 1929, this monthly journal reports on primary research contributed by respected international scientists in the broad field of zoology, including behaviour, biochemistry and physiology, developmental biology, ecology, genetics, morphology and ultrastructure, parasitology and pathology, and systematics and evolution. It also invites experts to submit review articles on topics of current interest.
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Terms & Conditions
  • Sample Issue
  • Reprints & Permissions
  • Ingenta Connect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Partial Open Access Content
Partial Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
X
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more