RESUMO
Over the past several decades molecular tools have shown an enormous potential to aid in the clarification of species boundaries in the marine realm, particularly in morphologically simple groups. In this paper we report a case of cryptic speciation in an allegedly cosmopolitan and ecologically important species-the excavating sponge Cliona celata (Clionaidae, Hadromerida). In the Northeast Atlantic and Mediterranean C. celata displays a discontinuous distribution of its putative growth stages (boring, encrusting, and massive) leading us to investigate its specific status. Phylogenetic reconstructions of mitochondrial (COI, Atp8) and nuclear (28S) gene fragments revealed levels of genetic diversity and divergence compatible with interspecific relationships. We therefore demonstrate C. celata as constituting a species complex comprised of at least four morphologically indistinct species, each showing a far more restricted distribution: two species on the Atlantic European coasts and two on the Mediterranean and adjacent Atlantic coasts (Macaronesian islands). Our results provide further confirmation that the different morphotypes do indeed constitute either growth stages or ecologically adapted phenotypes as boring and massive forms were found in two of the four uncovered species. We additionally provide an overview of the cases of cryptic speciation which have been reported to date within the Porifera, and highlight how taxonomic crypsis may confound scientific interpretation and hamper biotechnological advancement. Our work together with previous studies suggests that overconservative systematic traditions but also morphological stasis have led to genetic complexity going undetected and that a DNA-assisted taxonomy may play a key role in uncovering the hidden diversity in this taxonomic group.
Assuntos
Evolução Molecular , Especiação Genética , Filogenia , Poríferos/genética , Animais , Oceano Atlântico , Núcleo Celular/genética , DNA Mitocondrial/genética , Variação Genética , Geografia , Mar Mediterrâneo , Poríferos/classificação , Análise de Sequência de DNARESUMO
A C16 norsesterterpenoid (euplectellodiol, 1) and a norditerpenoid (2) have been isolated from the marine sponges Mycale euplectelloides and Diacarnus megaspinorhabdosa, respectively. Their structures have been determined by spectroscopic methods. Compounds 1 and 2 are new natural products.
Assuntos
Poríferos/química , Terpenos/química , Animais , Indonésia , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Oceanos e Mares , Terpenos/isolamento & purificaçãoRESUMO
Demosponge higher-level systematics is currently a subject of major changes due to the simplicity and paucity of complex morphological characters. Still, sponge classification is primarily based on morphological features. The systematics of the demosponge order Agelasida has been exceptionally problematic in the past. Here, we present the first molecular phylogenetic analysis based on three partially independent genes in demosponges in combination with a comprehensive search for biochemical synapomorphies to indicate their phylogenetic relationships. We show how sponges with fundamentally different skeletons can be in fact closely related and discuss examples of the misleading nature of morphological systematics in sponges.
Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/genética , Fator 1 de Elongação de Peptídeos/genética , Poríferos/anatomia & histologia , Poríferos/classificação , RNA Ribossômico 28S/genética , Animais , Biomarcadores/análise , DNA Ribossômico/genética , Filogenia , Poríferos/genéticaRESUMO
The Indonesian marine sponge Callyspongia pseudoreticulata was found to contain (3S,18S,4E,16E)-eicosa-1,19-diyne-3,18-diol-4,16-diene (1), the structure of which was determined by detailed spectroscopic analysis. Its absolute configuration was established using the modified Mosher's method after esterification of the secondary alcohols with Mosher's reagent.
