Wounding response in Porifera (sponges) activates ancestral signaling cascades involved in animal healing, regeneration, and cancer.

Upon injury, the homeostatic balance that ensures tissue function is disrupted. Wound-induced signaling triggers the recovery of tissue integrity and offers a context to understand the molecular mechanisms for restoring tissue homeostasis upon disturbances. Marine sessile animals are particularly vulnerable to chronic wounds caused by grazers that can compromise prey's health. Yet, in comparison to other stressors like warming or acidification, we know little on how marine animals respond to grazing. Marine sponges (Phylum Porifera) are among the earliest-diverging animals and play key roles in the ecosystem; but they remain largely understudied. Here, we investigated the transcriptomic responses to injury caused by a specialist spongivorous opisthobranch (i.e., grazing treatment) or by clipping with a scalpel (i.e., mechanical damage treatment), in comparison to control sponges. We collected samples 3 h, 1 d, and 6 d post-treatment for differential gene expression analysis on RNA-seq data. Both grazing and mechanical damage activated a similar transcriptomic response, including a clotting-like cascade (e.g., with genes annotated as transglutaminases, metalloproteases, and integrins), calcium signaling, and Wnt and mitogen-activated protein kinase signaling pathways. Wound-induced gene expression signature in sponges resembles the initial steps of whole-body regeneration in other animals. Also, the set of genes responding to wounding in sponges included putative orthologs of cancer-related human genes. Further insights can be gained from taking sponge wound healing as an experimental system to understand how ancient genes and regulatory networks determine healthy animal tissues.

A Soft Spot for Chemistry-Current Taxonomic and Evolutionary Implications of Sponge Secondary Metabolite Distribution.

Marine sponges are the most prolific marine sources for discovery of novel bioactive compounds. Sponge secondary metabolites are sought-after for their potential in pharmaceutical applications, and in the past, they were also used as taxonomic markers alongside the difficult and homoplasy-prone sponge morphology for species delineation (chemotaxonomy). The understanding of phylogenetic distribution and distinctiveness of metabolites to sponge lineages is pivotal to reveal pathways and evolution of compound production in sponges. This benefits the discovery rate and yield of bioprospecting for novel marine natural products by identifying lineages with high potential of being new sources of valuable sponge compounds. In this review, we summarize the current biochemical data on sponges and compare the metabolite distribution against a sponge phylogeny. We assess compound specificity to lineages, potential convergences, and suitability as diagnostic phylogenetic markers. Our study finds compound distribution corroborating current (molecular) phylogenetic hypotheses, which include yet unaccepted polyphyly of several demosponge orders and families. Likewise, several compounds and compound groups display a high degree of lineage specificity, which suggests homologous biosynthetic pathways among their taxa, which identifies yet unstudied species of this lineage as promising bioprospecting targets.

Chemistry, Chemotaxonomy and Biological Activity of the Latrunculid Sponges (Order Poecilosclerida, Family Latrunculiidae).

Marine sponges are exceptionally prolific sources of natural products for the discovery and development of new drugs. Until now, sponges have contributed around 30% of all natural metabolites isolated from the marine environment. Family Latrunculiidae Topsent, 1922 (class Demospongiae Sollas, 1885, order Poecilosclerida Topsent, 1928) is a small sponge family comprising seven genera. Latrunculid sponges are recognized as the major reservoirs of diverse types of pyrroloiminoquinone-type alkaloids, with a myriad of biological activities, in particular, cytotoxicity, fuelling their exploration for anticancer drug discovery. Almost 100 pyrroloiminoquinone alkaloids and their structurally related compounds have been reported from the family Latrunculiidae. The systematics of latrunculid sponges has had a complex history, however it is now well understood. The pyrroloiminoquinone alkaloids have provided important chemotaxonomic characters for this sponge family. Latrunculid sponges have been reported to contain other types of metabolites, such as peptides (callipeltins), norditerpenes and norsesterpenes (trunculins) and macrolides (latrunculins), however, the sponges containing latrunculins and trunculins have been transferred to other sponge families. This review highlights a comprehensive literature survey spanning from the first chemical investigation of a New Zealand Latrunculia sp. in 1986 until August 2020, focusing on the chemical diversity and biological activities of secondary metabolites reported from the family Latrunculiidae. The biosynthetic (microbial) origin and the taxonomic significance of pyrroloiminoquinone related alkaloids are also discussed.

A Virtual Screening Platform Identifies Chloroethylagelastatin A as a Potential Ribosomal Inhibitor.

Chloroethylagelastatin A (CEAA) is an analogue of agelastatin A (AA), a natural alkaloid derived from a marine sponge. It is under development for therapeutic use against brain tumors as it has excellent central nervous system (CNS) penetration and pre-clinical therapeutic activity against brain tumors. Recently, AA was shown to inhibit protein synthesis by binding to the ribosomal A-site. In this study, we developed a novel virtual screening platform to perform a comprehensive screening of various AA analogues showing that AA analogues with proven therapeutic activity including CEAA have significant ribosomal binding capacity whereas therapeutically inactive analogues show poor ribosomal binding and revealing structural fingerprint features essential for drug-ribosome interactions. In particular, CEAA was found to have greater ribosomal binding capacity than AA. Biological tests showed that CEAA binds the ribosome and contributes to protein synthesis inhibition. Our findings suggest that CEAA may possess ribosomal inhibitor activity and that our virtual screening platform may be a useful tool in discovery and development of novel ribosomal inhibitors.

Sponges-Cyanobacteria associations: Global diversity overview and new data from the Eastern Mediterranean.

Sponge-cyanobacteria associations have attracted research interest from an ecological, evolutionary and biotechnological perspective. Current knowledge is, in its majority, "hidden" in metagenomics research studying the entire microbial communities of sponges, while knowledge on these associations is totally missing for certain geographic areas. In this study, we (a) investigated the occurrence of cyanobacteria in 18 sponge species, several of which are studied for the first time for their cyanobionts, from a previously unexplored eastern Mediterranean ecoregion, the Aegean Sea, (b) isolated sponge-associated cyanobacteria, and characterized them based on a polyphasic (morphological-morphometric and molecular phylogenetic analysis) approach, and (c) conducted a meta-analysis on the global diversity of sponge species hosting cyanobacteria, as well as the diversity of cyanobacterial symbionts. Our research provided new records for nine sponge species, previously unknown for this association, while the isolated cyanobacteria were found to form novel clades within Synechococcus, Leptolyngbyaceae, Pseudanabaenaceae, and Schizotrichaceae, whose taxonomic status requires further investigation; this is the first report of a Schizotrichaceae cyanobacterium associated with sponges. The extensive evaluation of the literature along with the new data from the Aegean Sea raised the number of sponge species known for hosting cyanobacteria to 320 and showed that the cyanobacterial diversity reported from sponges is yet underestimated.

Batzella, Crambe and Monanchora: Highly Prolific Marine Sponge Genera Yielding Compounds with Potential Applications for Cancer and Other Therapeutic Areas.

Pyrroloquinoline and guanidine-derived alkaloids present distinct groups of marine secondary metabolites with structural diversity that displayed potentialities in biological research. A considerable number of these molecular architectures had been recorded from marine sponges belonging to different marine genera, including Batzella, Crambe, Monanchora, Clathria, Ptilocaulis and New Caledonian starfishes Fromia monilis and Celerina heffernani. In this review, we aim to comprehensively cover the chemodiversity and the bioactivities landmarks centered around the chemical constituents exclusively isolated from these three marine genera including Batzella, Crambe and Monanchora over the period 1981-2017, paying a special attention to the polycyclic guanidinic compounds and their proposed biomimetic landmarks. It is concluded that these marine sponge genera represent a rich source of novel compounds with potential applications for cancer and other therapeutic areas.

Cytotoxic Compounds Derived from Marine Sponges. A Review (2010-2012).

Abstract: This extensive review covers research published between 2010 and 2012 regarding new compounds derived from marine sponges, including 62 species from 60 genera belonging to 33 families and 13 orders of the Demospongia class (Porifera). The emphasis is on the cytotoxic activity that bioactive metabolites from sponges may have on cancer cell lines. At least 197 novel chemical structures from 337 compounds isolated have been found to support this work. Details on the source and taxonomy of the sponges, their geographical occurrence, and a range of chemical structures are presented. The compounds discovered from the reviewed marine sponges fall into mainly four chemical classes: terpenoids (41.9%), alkaloids (26.2%), macrolides (8.9%) and peptides (6.3%) which, along with polyketides, sterols, and others show a range of biological activities. The key sponge orders studied in the reviewed research were Dictyoceratida, Haplosclerida, Tetractinellida, Poecilosclerida, and Agelasida. Petrosia, Haliclona (Haplosclerida), Rhabdastrella (Tetractinellida), Coscinoderma and Hyppospongia (Dictyioceratida), were found to be the most promising genera because of their capacity for producing new bioactive compounds. Several of the new compounds and their synthetic analogues have shown in vitro cytotoxic and pro-apoptotic activities against various tumor/cancer cell lines, and some of them will undergo further in vivo evaluation.

Who Produces Ianthelline? The Arctic Sponge Stryphnus fortis or its Sponge Epibiont Hexadella dedritifera: a Probable Case of Sponge-Sponge Contamination.

The bromotyrosine derivative ianthelline was isolated recently from the Atlantic boreo-arctic deep-sea sponge Stryphnus fortis, and shown to have clear antitumor and antifouling effects. However, chemosystematics, field observations, and targeted metabolic analyses (using UPLC-MS) suggest that ianthelline is not produced by S. fortis but by Hexadella dedritifera, a sponge that commonly grows on S. fortis. This case highlights the importance of combining taxonomic and ecological knowledge to the field of sponge natural products research.

Investigation of freshwater sponges spicules deposits in a karstic lake in Brazil / Investigação de depósito de espículas de esponjas de água doce em um lago cárstico no Brasil

Abstract The environmental conditions which contributed to the formation of the notorious quaternary deposits of freshwater sponge spicules in karstic lentic environments in Brazil have been subject of some speculation. No investigation has yet been conducted to test whether these deposits currently originate in karstic lakes. To provide for such an investigation, Serra Negra Lake, which is formed on an ultramafic-alkaline-carbonatite dome at central western Brazil, close to the area of occurrence of the paleo-deposits was selected for the study. Bottom sediments were sampled at 10 stations across the lake, and water was sampled at five of the stations, in June/2011 (rainy season) and October/2011 (dry season). Analysis of granulometry, organic matter and presence of spicules were carried out in the sediments. Lake water was analysed for the main physical and chemical characteristics. Deposit of spicules was restricted to the northern area of the lake, which is rich in macrophyte. The taxonomic analysis of the spicules indicated the contribution of five sponge species, Dosilia pydanieli, Metania spinata, Radiospongilla amazonensis, Trochospongilla variabilis and Heterorotula fistula, which formed large deposits in neighbouring areas. The high silica concentration, derived from the dome volcanic rocks, constant water level and available substrate are credited for the continuous production of sponges and spicules, confirmed by the rare presence of gemmoscleres. The lake is classed as a minerotrophic fen type of bog with a heavy contribution from the surrounding creeks. Lake sediments are fine with high levels of organic matter and peat, which contributed to the trapping of spicules in the sediments.

Resumo As condições ambientais que contribuíram para a formação de notórios depósitos quaternários de espículas de esponjas de água doce em ambientes cársticos no Brasil têm sido objeto de algumas especulações. Nenhuma investigação foi ainda realizada para testar se esses depósitos originam-se atualmente em lagos cársticos. Para prover tal investigação, a Lagoa Serra Negra, formada em um domo ultramáfico-alcalino-carbonatítico, no centro oeste do Brasil, próximo à área de ocorrência dos referidos paleo-depósitos, foi selecionada para o estudo. Sedimentos de fundo foram amostrados em 10 estações ao longo do lago, e a água foi coletada em cinco das estações, em junho/2011 (estação chuvosa) e outubro/2011 (estação seca). Análises de granulometria, matéria orgânica e presença de espículas foram realizadas nos sedimentos. A água do lago foi analisada para as principais características físicas e químicas. O depósito de espículas foi restrito à área norte do lago, que é rico em macrófitas. A análise taxonômica das espículas indicou a contribuição de cinco espécies de esponjas, Dosilia pydanieli, Metania spinata, Radiospongilla amazonensis, Trochospongilla variabilis e Heterorotula fistula, que formaram grandes depósitos em áreas vizinhas. A alta concentração de sílica, derivada das rochas vulcânicas do domo, o nível constante da água e a disponibilidade de substrato são creditadas à produção contínua de esponjas e espículas, confirmada pela presença rara de gemoscleras. O lago é classificado como uma turfeira do tipo fen, minerotrófica, com forte contribuição dos arroios circundantes. Os sedimentos da lagoa são finos, com altos níveis de matéria orgânica e formação de turfa, o que contribuiu para a captura das espículas nos sedimentos.

The systematics of carnivorous sponges.

Carnivorous sponges are characterized by their unique method of capturing mesoplanktonic prey coupled with the complete or partial reduction of the aquiferous system characteristic of the phylum Porifera. Current systematics place the vast majority of carnivorous sponges within Cladorhizidae, with certain species assigned to Guitarridae and Esperiopsidae. Morphological characters have not been able to show whether this classification is evolutionary accurate, and whether carnivory has evolved once or in several lineages. In the present paper we present the first comprehensive molecular phylogeny of the carnivorous sponges, interpret these results in conjunction with morphological characters, and propose a revised classification of the group. Molecular phylogenies were inferred using 18S rDNA and a combined dataset of partial 28S rDNA, COI and ALG11 sequences. The results recovered carnivorous sponges as a clade closely related to the families Mycalidae and Guitarridae, showing family Cladorhizidae to be monophyletic and also including carnivorous species currently placed in other families. The genus Lycopodina is resurrected for species currently placed in the paraphyletic subgenus Asbestopluma (Asbestopluma) featuring forceps spicules and lacking sigmas or sigmancistras. The genera Chondrocladia and Cladorhiza are found to be monophyletic. However, results indicate that the subgenus Chondrocladia is polyphyletic with respect to the subgenera Meliiderma and Symmetrocladia. Euchelipluma, formerly Guitarridae, is retained, but transferred to Cladorhizidae. The four known carnivorous species currently in Esperiopsis are transferred to Abyssocladia. Neocladia is a junior homonym and is here renamed Koltunicladia. Our results provide strong evidence in support of the hypothesis that carnivory in sponges has evolved only once. While spicule characters mostly reflect monophyletic groups at the generic level, differences between genera represent evolution within family Cladorhizidae rather than evolution of carnivory in separate lineages. Conflicting spicule characters can be reinterpreted to support the inclusion of all carnivorous sponges within Cladorhizidae, and a carnivorous habit should thus be considered the main diagnostic character in systematic classification.

Mitochondrial group I and group II introns in the sponge orders Agelasida and Axinellida.

BACKGROUND: Self-splicing introns are present in the mitochondria of members of most eukaryotic lineages. They are divided into Group I and Group II introns, according to their secondary structure and splicing mechanism. Being rare in animals, self-splicing introns were only described in a few sponges, cnidarians, placozoans and one annelid species. In sponges, three types of mitochondrial Group I introns were previously described in two demosponge families (Tetillidae, and Aplysinellidae) and in the homoscleromorph family Plakinidae. These three introns differ in their insertion site, secondary structure and in the sequence of the LAGLIDADG gene they encode. Notably, no group II introns have been previously described in sponges. RESULTS: We report here the presence of mitochondrial introns in the cytochrome oxidase subunit 1 (COI) gene of three additional sponge species from three different families: Agelas oroides (Agelasidae, Agelasida), Cymbaxinella (p) verrucosa (Hymerhabdiidae, Agelasida) and Axinella polypoides (Axinellidae, Axinellida). We show, for the first time, that sponges can also harbour Group II introns in their COI gene, whose presence in animals' mitochondria has so far been described in only two phyla, Placozoa and Annelida. Surprisingly, two different Group II introns were discovered in the COI gene of C. verrucosa. Phylogenetic analysis indicates that the Group II introns present in C. verrucosa are related to red algae (Rhodophyta) introns. CONCLUSIONS: The differences found among intron secondary structures and the phylogenetic inferences support the hypothesis that the introns originated from independent horizontal gene transfer events. Our results thus suggest that self-splicing introns are more diverse in the mitochondrial genome of sponges than previously anticipated.

A Proposal for the Evolution of Cathepsin and Silicatein in Sponges.

Cathepsins are enzymes capable of degrading proteins intracellularly. They occur ubiquitously in opisthokonts, but their potential to provide insight across the evolutionary transition from protists to metazoans remains poorly investigated. Here, we explore the evolution of cathepsins using comparative analyses of transcriptomic datasets, focusing on both, protists (closely related to metazoans), and early divergent animals (i.e., sponges). We retrieved DNA sequences of nine cathepsin types (B, C, D, F, H, L, O, Z, and silicatein) in the surveyed taxa. In choanoflagellates, only five types (B, C, L, O, Z) were identified, all of them being also found in sponges, indicating that while all cathepsins present in protists were conserved across metazoan lineages, cathepsins F and H (and probably D) are metazoan acquisitions. The phylogeny of cysteine protease cathepsins (excluding cathepsin D) revealed two major lineages: lineage B (cathepsins B and C) and lineage L (cathepsins F, H, L, O, Z). In the latter lineage, a mutation at the active site of cathepsin L gave rise to silicatein, an enzyme exclusively known to date from siliceous sponges and involved in the production of their silica spicules. However, we found that several sponges with siliceous spicules did not express silicatein genes and that, in contrast, several aspiculate sponges did contain silicatein genes. Our results suggest that the ability to silicify may have evolved independently within sponges, some of them losing this capacity secondarily. We also show that most phylogenies based on cathepsin and silicatein genes (except for that of cathepsin O) failed to recover the major lineages of sponges.

Unexpected diversity and new species in the sponge-Parazoanthidae association in southern Japan.

Currently the genera Parazoanthus (family Parazoanthidae) and Epizoanthus (family Epizoanthidae) are the only sponge-associated zoantharians (Cnidaria, Anthozoa). The Parazoanthidae-sponge associations are widely distributed in tropical and subtropical waters from the intertidal to the deep sea in the Atlantic and Indo-Pacific Oceans. However, the taxonomic identification of both parties is often confused due to variable morphology and wide ecological ranges. In particular, Parazoanthidae species diversity remains poorly understood in the Indo-Pacific. In the present study, the diversity of the sponge-zoanthid association in the Indo-Pacific was investigated with 71 Parazoanthidae specimens collected from 29 different locations in Japan (n=22), Australia (n=6) and Florida, USA (n=1). For all specimens morphological analyses were performed and total DNA was extracted and amplified for four DNA markers (COI-mtDNA, mt 16S-rDNA, ITS-rDNA and ALG11-nuDNA). The combined data demonstrate that the specimens of this study are clearly different from those of all described Parazoanthus species, and lead us to erect Umimayanthus gen. n., within family Parazoanthidae, containing the three newly described species U. chanpuru sp. n., U. miyabi sp. n., U. nakama sp. n. The new genus also includes the previously described species U. parasiticus (Duchassaing and Michelotti, 1860; comb. nov.), previously belonging to the genus Parazoanthus. Neighbor joining, maximum likelihood and Bayesian posterior probability phylogenetic trees clearly demonstrate the monophyly of Umimayanthus gen. n. to the exclusion of all outgroup sequences. The phylogenetic results were also compared to morphological features, and polyp sizes, amount of sand content in tissues, types of connections between polyps, and cnidae data, in particular holotrichs-1, were useful in distinguishing the different species within this new genus. This new genus can be distinguished from all other Zoantharia by a unique and conserved 9 bp insertion and a 14 bp deletion in the mt 16S-rDNA region. Additionally, compared to Parazoanthus sensu stricto (i.e. P. axinellae [Schmidt, 1862]), Umimayanthus spp. are only found associated to sponges, and have a coenenchyme much less developed than Parazoanthus sensu stricto. Each new species can be distinguished from other congeners by a unique DNA sequence, numbers of tentacle, maximum sizes of holotrichs, associated sponge morphology, and colony morphology. The identification of the host sponge species is the next logical step in this research as this may also aid in the distinction of Umimayanthus species.

Deceptive desmas: molecular phylogenetics suggests a new classification and uncovers convergent evolution of lithistid demosponges.

Reconciling the fossil record with molecular phylogenies to enhance the understanding of animal evolution is a challenging task, especially for taxa with a mostly poor fossil record, such as sponges (Porifera). 'Lithistida', a polyphyletic group of recent and fossil sponges, are an exception as they provide the richest fossil record among demosponges. Lithistids, currently encompassing 13 families, 41 genera and >300 recent species, are defined by the common possession of peculiar siliceous spicules (desmas) that characteristically form rigid articulated skeletons. Their phylogenetic relationships are to a large extent unresolved and there has been no (taxonomically) comprehensive analysis to formally reallocate lithistid taxa to their closest relatives. This study, based on the most comprehensive molecular and morphological investigation of 'lithistid' demosponges to date, corroborates some previous weakly-supported hypotheses, and provides novel insights into the evolutionary relationships of the previous 'order Lithistida'. Based on molecular data (partial mtDNA CO1 and 28S rDNA sequences), we show that 8 out of 13 'Lithistida' families belong to the order Astrophorida, whereas Scleritodermidae and Siphonidiidae form a separate monophyletic clade within Tetractinellida. Most lithistid astrophorids are dispersed between different clades of the Astrophorida and we propose to formally reallocate them, respectively. Corallistidae, Theonellidae and Phymatellidae are monophyletic, whereas the families Pleromidae and Scleritodermidae are polyphyletic. Family Desmanthidae is polyphyletic and groups within Halichondriidae--we formally propose a reallocation. The sister group relationship of the family Vetulinidae to Spongillida is confirmed and we propose here for the first time to include Vetulina into a new Order Sphaerocladina. Megascleres and microscleres possibly evolved and/or were lost several times independently in different 'lithistid' taxa, and microscleres might at least be four times more likely lost than megascleres. Desma spicules occasionally may have undergone secondary losses too. Our study provides a framework for further detailed investigations of this important demosponge group.

Acidobacteria appear to dominate the microbiome of two sympatric Caribbean Sponges and one Zoanthid

BACKGROUND: Marine invertebrate-associated microbial communities are interesting examples of complex symbiotic systems and are a potential source of biotechnological products. RESULTS: In this work, pyrosequencing-based assessment from bacterial community structures of sediments, two sponges, and one zoanthid collected in the Mexican Caribbean was performed. The results suggest that the bacterial diversity at the species level is higher in the sediments than in the animal samples. Analysis of bacterial communities' structure showed that about two thirds of the bacterial diversity in all the samples belongs to the phyla Acidobacteria and Proteobacteria. The genus Acidobacteriumappears to dominate the bacterial community in all the samples, reaching almost 80% in the sponge Hyrtios. CONCLUSIONS: Our evidence suggests that the sympatric location of these benthonic species may lead to common bacterial structure features among their bacterial communities. The results may serve as a first insight to formulate hypotheses that lead to more extensive studies of sessile marine organisms' microbiomes from the Mexican Caribbean.

[Evolutionary history of Metazoa, ancestral status of the bilateria clonal reproduction, and semicolonial origin of the mollusca].

Evolutionary history of any metazoan group is a history of the entire ontogenetic cycles instead of separate stages and genes only. Ontogeny in the most objective way links two key components of the biological systematics: historically-independent characters attribution and phylogeny itself. A general theory encompassing "static" traditional taxonomy and dynamic evolutionary process, based on the ontogenetic transformation of the organisms' shape is suggested here to term as ontogenetic systematics. As an important practical implication of the ontogenetic systematics, a new model of the bilaterian metazoans evolution is suggested. The new model considers asexual clonal reproduction as a central feature of the ancestral ontogenetic cycles of basal Bilateria. The new scenario resolves several notable contradictions, e.g. morphological, ontogenetic and molecular similarities of Pogonophora, Vestimentifera, Phoronida simultaneously to protostomian Spiralia (Lophotrochozoa) and Deuterostomia. The suggested model implies individuation (possibly multiple) of ancestral semicolonial sedentary group as a major factor of the basal Bilateria diversification. In the late Ediacaran and early Cambrian thus existed ancestral bilaterian group that shared characters of both Spiralia and Deuterostomia and possessed polyp-shape body and cephalic secretory shield (like in modern Pterobranchia and Vestimentifera), that later on reduced in various lines. This ancestral taxon in rank of supraphylum is suggested to term as Carmaphora (shield-bearers). Presence of the enigmatic sedentary fossil of the genus Cloudina with vestimentiferan-like tubes and evident clonal reproduction already in the late Ediacaran, and most recent found of an unquestionable pterobranch already in the early Cambrian support the new model of Bilateria evolution.

Estructura de la comunidad de esponjas (Porifera) en tres arrecifes del Parque Nacional Morrocoy, Venezuela y su relación con algunas variables ambientales / Community structure of sponges (Porifera) in three reefs at Morrocoy National Park, Venezuela and its correspondence with some environmental variables

Sponges have an important ecological role in coral reef ecosystems. However, when compared to other benthic Phyla, it has been little researched. This research was focused in the variability of the community structure of sponges in three locations at Morrocoy National Park (Cayo Sombrero, Playa Mero and Punta Brava) exposed to different environmental conditions (transparency and currents intensity) and affected in different degree of severity by a mass mortality event in 1996. A total of 15 transects (10m long and 1m wide) were evaluated in three strata (between 3 and 15m depth) in each site, where all the individuals were counted by species. Relative abundance by species, diversity and evenness were calculated. Locations showed differences respect turbidity, wave and current intensity. 27 species were found in Morrocoy; Cayo Sombrero (23), Playa Mero (18) and Punta Brava (15). Agelas sceptrum, Amphimedon erina and Niphates erecta were the most common in first location; Niphates erecta and Dysidea etheria in Playa Mero and Dysidea etheria, Niphates erecta and Amphimedon erina in Punta Brava. The species composition showed statistical differences between all three locations; Cayo Sombrero resulted the most diverse and even, followed by Playa Mero and Punta Brava. According to Sorensen Similarity Index results, Cayo Sombrero and Playa Mero were more similar, while Punta Brava resulted the most different. The variability in environmental conditions and the differential mass mortality effects of 1996 in all three reefs, were probably the main causes of the differences between their sponge communities. Nevertheless, we cannot conclude about the weight of these factors.

El presente estudio pone en evidencia la variación en la estructura de la comunidad de esponjas en tres localidades del Parque Nacional Morrocoy (Cayo Sombrero, Playa Mero y Punta Brava) con distintas condiciones ambientales y afectadas diferencialmente por una mortalidad masiva ocurrida en 1996. En un total de 15 transectos de 10m de largo y 1m de ancho en cuatro estratos comprendidos entre 3 y 15m de profundidad en cada localidad; se contabilizaron los individuos por especie para calcular la abundancia relativa, diversidad y equidad. Se analizaron las variables ambientales por localidad y se aprecian diferencias entre ellas con respecto a la corriente, turbidez, y exposición al oleaje. Fueron totalizadas 27 especies; Cayo Sombrero (23), Playa Mero (18) y Punta Brava (15), en la primera localidad domina: Agelas sceptrum, Amphimedon erina y Niphates erecta, en Playa Mero: Niphates erecta y Dysidea etherea y en Punta Brava: Dysidea etherea, Niphates erecta y Amphimedon erina. La composición de especies mostró diferencias estadísticamente significativas entre localidades. La mayor diversidad y equidad correspondió a Cayo Sombrero; donde las condiciones fueron más favorables para el crecimiento de estos organismos, seguido de Playa Mero y Punta Brava, guardando las dos primeras mayor similitud entre sí, según Índice de Sorensen.

Antifouling activity of twelve demosponges from Brazil / Atividade anti-incrustante de doze demosponjas do Brasil

Benthic marine organisms are constantly exposed to fouling, which is harmful to most host species. Thus, the production of secondary metabolites containing antifouling properties is an important ecological advantage for sessile organisms and may also provide leading compounds for the development of antifouling paints. High antifouling potential of sponges has been demonstrated in the Indian and Pacific oceans and in the Caribbean and Mediterranean seas. Brazilian sponges remain understudied concerning antifouling activities. Only two scientific articles reported this activity in sponges of Brazil. The objective of this study was to test crude extracts of twelve species of sponges from Brazil against the attachment of the mussel Perna perna through laboratorial assays, and highlight promising species for future studies. The species Petromica citrina, Amphimedon viridis, Desmapsamma anchorata, Chondrosia sp., Polymastia janeirensis, Tedania ignis, Aplysina fulva, Mycale angulosa, Hymeniacidon heliophila, Dysidea etheria, Tethya rubra, and Tethya maza were frozen and freeze-dried before extraction with acetone or dichloromethane. The crude extract of four species significantly inhibited the attachment of byssus: Tethya rubra (p = 0.0009), Tethya maza (p = 0.0039), Petromica citrina (p = 0.0277), and Hymeniacidon heliophila (p = 0.00003). These species, specially, should be the target of future studies to detail the substances involved in the ability antifouling well as to define its amplitude of action.

Organismos bentônicos marinhos estão expostos constantemente à incrustação, que pode ser danosa para a maioria das espécies. Assim, a produção de metabólitos secundários com propriedades anti-incrustantes é uma vantagem ecológica importante para organismos sésseis e pode também orientar o estudo de substâncias para o desenvolvimento de tintas anti-incrustantes. O alto potencial anti-incrustante de esponjas tem sido demonstrado nos oceanos Índico e Pacífico, nos mares Mediterrâneo e Caribenho. Esponjas brasileiras permanecem pouco estudadas em relação à atividade anti-incrustante. Apenas dois artigos científicos registraram essa atividade em esponjas do Brasil. O objetivo desse estudo foi testar os extratos brutos de doze espécies de esponjas do Brasil contra a fixação do molusco Perna perna através de ensaios laboratoriais e também destacar espécies promissoras para estudos futuros. As espécies Petromica citrina, Amphimedon viridis, Desmapsamma anchorata, Chondrosia sp., Polymastia janeirensis, Tedania ignis, Aplysina fulva, Mycale angulosa, Hymeniacidon heliophila, Dysidea etheria, Tethya rubra e Tethya maza foram congeladas e liofilizadas logo após a coleta e posteriormente procedeu-se a extração com acetona ou diclorometano. O extrato bruto de quatro espécies inibiu significativamente a fixação de bissos: Tethya rubra (p = 0.0009), Tethya maza (p = 0.0039), Petromica citrina (p = 0.0277), e Hymeniacidon heliophila (p = 0.00003). Essas espécies, especialmente, devem ser priorizadas em estudos futuros para detalhamento das substâncias envolvidas na capacidade anti-incrustante, bem como para definir sua amplitude de ação.

Phylogeny and systematics of demospongiae in light of new small-subunit ribosomal DNA (18S) sequences.

The most diverse and species-rich class of the phylum Porifera is Demospongiae. In recent years, the systematics of this clade, which contains more than 7000 species, has developed rapidly in light of new studies combining molecular and morphological observations. We add more than 500 new, nearly complete 18S sequences (an increase of more than 200%) in an attempt to further enhance understanding of the phylogeny of Demospongiae. Our study specifically targets representation of type species and genera that have never been sampled for any molecular data in an effort to accelerate progress in classifying this diverse lineage. Our analyses recover four highly supported subclasses of Demospongiae: Keratosa, Myxospongiae, Haploscleromorpha, and Heteroscleromorpha. Within Keratosa, neither Dendroceratida, nor its two families, Darwinellidae and Dictyodendrillidae, are monophyletic and Dictyoceratida is divided into two lineages, one predominantly composed of Dysideidae and the second containing the remaining families (Irciniidae, Spongiidae, Thorectidae, and Verticillitidae). Within Myxospongiae, we find Chondrosida to be paraphyletic with respect to the Verongida. We amend the latter to include species of the genus Chondrosia and erect a new order Chondrillida to contain remaining taxa from Chondrosida, which we now discard. Even with increased taxon sampling of Haploscleromorpha, our analyses are consistent with previous studies; however, Haliclona species are interspersed in even more clades. Haploscleromorpha contains five highly supported clades, each more diverse than previously recognized, and current families are mostly polyphyletic. In addition, we reassign Janulum spinispiculum to Haploscleromorpha and resurrect Reniera filholi as Janulum filholi comb. nov. Within the large clade Heteroscleromorpha, we confirmed 12 recently identified clades based on alternative data, as well as a sister-group relationship between the freshwater Spongillida and the family Vetulinidae. We transfer Stylissa flabelliformis to the genus Scopalina within the family Scopalinidae, which is of uncertain position. Our analyses uncover a large, strongly supported clade containing all heteroscleromorphs other than Spongillida, Vetulinidae, and Scopalinidae. Within this clade, there is a major division separating Axinellidae, Biemnida, Tetractinellida, Bubaridae, Stelligeridae, Raspailiidae, and some species of Petromica, Topsentia, and Axinyssa from Agelasida, Polymastiidae, Placospongiidae, Clionaidae, Spirastrellidae, Tethyidae, Poecilosclerida, Halichondriidae, Suberitidae, and Trachycladus. Among numerous results: (1) Spirophorina and its family Tetillidae are paraphyletic with respect to a strongly supported Astrophorina within Tetractinellida; (2) Agelasida is the earliest diverging lineage within the second clade listed above; and (3) Merlia and Desmacella appear to be the earliest diverging lineages of Poecilosclerida.

Reconstruction of family-level phylogenetic relationships within Demospongiae (Porifera) using nuclear encoded housekeeping genes.

BACKGROUND: Demosponges are challenging for phylogenetic systematics because of their plastic and relatively simple morphologies and many deep divergences between major clades. To improve understanding of the phylogenetic relationships within Demospongiae, we sequenced and analyzed seven nuclear housekeeping genes involved in a variety of cellular functions from a diverse group of sponges. METHODOLOGY/PRINCIPAL FINDINGS: We generated data from each of the four sponge classes (i.e., Calcarea, Demospongiae, Hexactinellida, and Homoscleromorpha), but focused on family-level relationships within demosponges. With data for 21 newly sampled families, our Maximum Likelihood and Bayesian-based approaches recovered previously phylogenetically defined taxa: Keratosa(p), Myxospongiae(p), Spongillida(p), Haploscleromorpha(p) (the marine haplosclerids) and Democlavia(p). We found conflicting results concerning the relationships of Keratosa(p) and Myxospongiae(p) to the remaining demosponges, but our results strongly supported a clade of Haploscleromorpha(p)+Spongillida(p)+Democlavia(p). In contrast to hypotheses based on mitochondrial genome and ribosomal data, nuclear housekeeping gene data suggested that freshwater sponges (Spongillida(p)) are sister to Haploscleromorpha(p) rather than part of Democlavia(p). Within Keratosa(p), we found equivocal results as to the monophyly of Dictyoceratida. Within Myxospongiae(p), Chondrosida and Verongida were monophyletic. A well-supported clade within Democlavia(p), Tetractinellida(p), composed of all sampled members of Astrophorina and Spirophorina (including the only lithistid in our analysis), was consistently revealed as the sister group to all other members of Democlavia(p). Within Tetractinellida(p), we did not recover monophyletic Astrophorina or Spirophorina. Our results also reaffirmed the monophyly of order Poecilosclerida (excluding Desmacellidae and Raspailiidae), and polyphyly of Hadromerida and Halichondrida. CONCLUSIONS/SIGNIFICANCE: These results, using an independent nuclear gene set, confirmed many hypotheses based on ribosomal and/or mitochondrial genes, and they also identified clades with low statistical support or clades that conflicted with traditional morphological classification. Our results will serve as a basis for future exploration of these outstanding questions using more taxon- and gene-rich datasets.