Taxonomic and Functional Microbial Signatures of the Endemic Marine Sponge Arenosclera brasiliensis

The endemic marine sponge Arenosclera brasiliensis (Porifera, Demospongiae, Haplosclerida) is a known source of secondary metabolites such as arenosclerins A-C. In the present study, we established the composition of the A. brasiliensis microbiome and the metabolic pathways associated with this community. We used 454 shotgun pyrosequencing to generate approximately 640,000 high-quality sponge-derived sequences (∼150 Mb). Clustering analysis including sponge, seawater and twenty-three other metagenomes derived from marine animal microbiomes shows that A. brasiliensis contains a specific microbiome. Fourteen bacterial phyla (including Proteobacteria, Cyanobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Cloroflexi) were consistently found in the A. brasiliensis metagenomes. The A. brasiliensis microbiome is enriched for Betaproteobacteria (e.g., Burkholderia) and Gammaproteobacteria (e.g., Pseudomonas and Alteromonas) compared with the surrounding planktonic microbial communities. Functional analysis based on Rapid Annotation using Subsystem Technology (RAST) indicated that the A. brasiliensis microbiome is enriched for sequences associated with membrane transport and one-carbon metabolism. In addition, there was an overrepresentation of sequences associated with aerobic and anaerobic metabolism as well as the synthesis and degradation of secondary metabolites. This study represents the first analysis of sponge-associated microbial communities via shotgun pyrosequencing, a strategy commonly applied in similar analyses in other marine invertebrate hosts, such as corals and algae. We demonstrate that A. brasiliensis has a unique microbiome that is distinct from that of the surrounding planktonic microbes and from other marine organisms, indicating a species-specific microbiome

Twelve new Demospongiae (Porifera) from Chilean fjords, with remarks upon sponge-derived biogeographic compartments in the SE Pacific

This article reports on 12 new species originating from the Chilean fjords region, namely Clathria (Microciona) mytilifila sp. nov., Haliclona (Reniera) caduca sp. nov., Latrunculia (L.) ciruela sp. nov., Latrunculia (L.) copihuensis sp. nov., Latrunculia (L.) verenae sp. nov., Latrunculia (L.) yepayek sp. nov., Myxilla (Burtonanchora) araucana sp. nov., Neopodospongia tupecomareni sp. nov., Oceanapia guaiteca sp. nov., Oceanapia spinisphaera sp. nov., Suberites cranium sp. nov. and Tethya melinka sp. nov. The material studied was collected between 5 and 30 m depth at latitudes comprised between 42º and 50ºS, and is part of a large collection of Chilean sponges gathered by an international team in a series of expeditions. Identification keys are provided for SE Pacific Suberites and Latrunculia, and the known species of Myxilla (Burtonanchora) and Neopodospongia. A trans-Pacific link to the New Zealand fauna was retrieved for the latter genus. Distribution ranges apparent from the materials studied here are judged too preliminary to allow any inference on biotic boundaries in the SE Pacific. A revision of earlier assertions about these biogeographic units and their boundaries concluded that very little support remains other than for existence of a Magellanic fauna. This is in part a consequence of revising the taxonomy of sponge species originally deemed to underpin these areas. Specifically, the former proposal of a Central to Southern Chile biogeographic unit (33-56ºS) has been markedly undone

Perplexing distribution of 3-alkylpyridines in haplosclerid sponges.

Abstract: In this study we reviewed the natural product literature for the distribution of 3-alkylpyridines among sponge taxa. In parallel, we traced selected 3-alkylpyridines, amphitoxins, in three haplosclerid genera (Amphimedon, Callyspongia, Haliclona) in order to establish the utility of such compounds as genuine chemotaxonomic markers. We confirmed that this group of compounds had been almost solely extracted from sponges of the order Haplosclerida. Three groups of compounds within the 3-alkylpyridine derivatives were noteworthy, as they appear to be concentrated in restricted taxonomic units within the order Haplosclerida: 1) polymers, 2) cyclic dimers, and 3) bicyclic dimers. There was a concentration of the polymer amphitoxin in the families Niphatidae and Callyspongiidae of the suborder Haplosclerina, and more particularly in the genera Amphimedon and Callyspongia. Our experimental results reconfirmed the presence of amphitoxin in Callyspongia (Euplacella) biru, but we were unable to trace any amphitoxins or 3-alkylpyridines of any kind in Callyspongia (Callyspongia) truncata, Haliclona sp., and Amphimedon aff. queenslandica. Assuming that these classifications are correct, our results diminish the value of both amphitoxins and 3-alkylpyridines as monophyletic markers