Shallow Suberitida (Porifera, Demospongiae) from Peru.

This study describes 81 specimens belonging to Suberitida, collected during the projects Esponjas del Perú (ESPER), Esponjas da América do Sul (EsponjAS) and Semilla UCSUR 2019 (Demospongiae) along the coast of Peru, down to 30 m depth. Using morphological analyses, eight species were identified, one of which is new to science: Halichondria (H.) cristata, H. (H.) prostrata, Hymeniacidon perlevis, Johannesia reticulosa, Plicatellopsis expansa, Suberites aff. latus, Terpios cf. granulosus and Suberites inti sp. nov. Halichondria (H.) cristata, originally from Tierra del Fuego (SW Atlantic), was found widely distributed along the coast of Peru (06° S-14° S). The Magellanican H. (H.) prostrata and the formerly Chilean endemic P. expansa are extended up to Central Peru (12° S). Hymeniacidon perlevis, which presents a highly variable morphology (colour, shape, and spicule size), is firstly reported from the SE Pacific and its continuous occurrence in Peru (04° S-17° S) should be monitored given its supposed invasive potential. Johannesia reticulosa, previously known from Chile (20° S) and southern Peru (13° S), was found further north (11° S). Suberites latus and T. granulosus were originally recorded far-off from the Peruvian coast, in British Columbia and Hawaii, respectively. Thus, the occurrences of Suberites aff. latus and Terpios cf. granulosus are unexpected and should receive special attention in future molecular studies assessing their taxonomical status. Suberites inti sp. nov. characterised by its skeleton with ectosomal bouquets and multispicular choanosomal tracts, and two categories of straight tylostyles, is provisionally endemic to Paracas (13° S). With these results, the number of shallow Suberitida from Peru increases from 2 to 9. However, this number might rise as sampling in deeper environments could bring descriptions of new records.

Three new Hymedesmia Bowerbank, 1864 (Demospongiae, Poecilosclerida, Hymedesmiidae) from the Southeast Pacific (Peru and Chile).

Despite its 2000 km long shoreline, to date less than 50 sponge species have been reported from the entire Peruvian coast. A large collecting effort targeting marine sponges was undertaken between 2007 and 2009, yielding a comprehensive collection of nearly 900 samples, whose taxonomic study is underway. Three new species of Hymedesmiidae are presently described from the Peruvian coast, all belonging in Hymedesmia (Hymedesmia), one of which also found in Chile. Hymedesmia (H.) santarositae sp. nov., from Isla Santa Rosa (Paracas), is characterized by the presence of microstrongyles next to sigmas. Hymedesmia (H.) peruana sp. nov., from Isla Foca (Piura), is diagnosed by its three categories of acanthostyles, and single categories of tornotes and arcuate isochelae. Hymedesmia (H.) humboldti sp. nov., from Moquega and Arequipa regions in Peru, and Antofagasta and Atacama regions in Chile, is diagnosed by its two categories of acanthostyles, and single categories of (aniso)strongyles and arcuate isochelae, the latter abundant at the surface. An identification key for Hymedesmia spp. from the South-eastern Pacific, South-western Atlantic, the Sub-Antarctic and the Antarctic is provided.

Diving into the unknown: fourteen new species of haplosclerid sponges (Demospongiae: Haplosclerida) revealed along the Peruvian coast (Southeastern Pacific).

The Peruvian coast is certainly one of the poorest studied areas in the world for marine sponges biodiversity, with only 20 species registered so far from over 2,400 km coastline. In spite of its great species richness worldwide, there is not a single record of Haplosclerida in Peru. Accordingly, in this study we aimed to describe the species belonging to this order present in the relatively recent collections undertaken along the Peruvian coast by two of us (PhW, EH). Here, we describe fourteen new species, provisionally endemic to the Peruvian coast. This finding represents a major addition to the knowledge of the biodiversity of sponges along the Peruvian coast, increasing the list of species known to occur in this area by about 68%. This is also the largest single proposal of new Haplosclerida in over 37 years of sponge taxonomy worldwide. Niphates is for the first time recorded in the Southeastern Pacific, and an identification key to the Haplosclerida from the Peruvian coast is provided. Regarding the distribution of the described species, most of themexcept for Chalinula chelysa sp. nov.have a narrow geographic range, which might indicate their rarity or that the haplosclerid fauna in Peru is still poorly known.

Three new Raspailiidae Hentschel, 1923 (Axinellida, Demospongiae) from Peru.

Currently 26 sponge species are known for the Peruvian coast, but so far no raspailiids had been recorded from this region. Raspailiidae are distributed worldwide and its species are characterized by encrusting, massive, lobate, fan-shaped or branching growth forms, usually with a very hispid surface. In the present study, three new species of Raspailiidae are described from the Peruvian coast. Two new Eurypon spp. were collected at Islas Lobos de Afuera (Lambayeque). Eurypon lacertus sp. nov. is a thinly encrusting orange sponge with choanosomal skeleton composed of large tylostyles and small acanthostyles, and ectosomal skeleton with anisoxeas. Eurypon hookeri sp. nov. is a crustose, ruby red sponge, with choanosomal skeleton composed of large (subtylo)styles and acanthostyles, and ectosomal skeleton pierced by acanthostyles and (subtylo)styles, often surrounded by bouquets of smaller styles. The third new species, Plocamione matarani sp. nov., was collected at Matarani (Arequipa). It is a thinly encrusting orange sponge, the only Plocamione with two categories of choanosomal styles, and a single category of ectosomal styles, acanthostyles and anisoacanthostrongyles. These are the first records of Eurypon and Plocamione for the Peruvian coast, and the entire Southeastern Pacific, in the case of the latter.

First record of Ciocalypta Bowerbank, 1862 (Demospongiae, Suberitida, Halichondriidae) in the Eastern Pacific, with description of a new species from Peru.

Ciocalypta includes species with finger-shaped fistules emerging from a basal mass and skeleton composed by a central axis and secondary tracts supporting the ectosome. Although worldwide distributed, no species of this genus has been reported from the Eastern Pacific. In this study, a new Ciocalypta is described from shallow waters of the southern coast of Peru. Ciocalypta magnastyla sp. nov. is greenish white, possesses the typical fistules with oscula located at their tips, and it is characterized by the presence of large styles (370-1000/5.0-32.5 µm) in combination with oxeas of intermediate size (160-500/5.0-12.5 µm). This new species constitutes the first record of the genus for the Peruvian coast as well as for the entire Eastern Pacific.

Culturable bacterial communities associated to Brazilian Oscarella species (Porifera: Homoscleromorpha) and their antagonistic interactions.

Sponges offer an excellent model to investigate invertebrate-microorganism interactions. Furthermore, bacteria associated with marine sponges represent a rich source of bioactive metabolites. The aim of this study was to characterize the bacteria inhabiting a genus of sponges, Oscarella, and their potentiality for antimicrobial production. Bacterial isolates were recovered from different Oscarella specimens, among which 337 were phylogenetically identified. The culturable community was dominated by Proteobacteria and Firmicutes, and Vibrio was the most frequently isolated genus, followed by Shewanella. When tested for antimicrobial production, bacteria of the 12 genera isolated were capable of producing antimicrobial substances. The majority of strains were involved in antagonistic interactions and inhibitory activities were also observed against bacteria of medical importance. It was more pronounced in some isolated genera (Acinetobacter, Bacillus, Photobacterium, Shewanella and Vibrio). These findings suggest that chemical antagonism could play a significant role in shaping bacterial communities within Oscarella, a genus classified as low-microbial abundance sponge. Moreover, the identified strains may contribute to the search for new sources of antimicrobial substances, an important strategy for developing therapies to treat infections caused by multidrug-resistant bacteria. This study was the first to investigate the diversity and antagonistic activity of bacteria isolated from Oscarella spp. It highlights the biotechnological potential of sponge-associated bacteria.

Integrative taxonomic re-description of Halisarca magellanica and description of a new species of Halisarca (Porifera, Demospongiae) from Chilean Patagonia.

A series of recent expeditions in fjords and canals of Southern Chilean Patagonia allowed the re-collection of Halisarca magellanica Topsent, 1901 and the discovery of a new species, Halisarca desqueyrouxae sp. nov. The material studied was collected at depths ranging from 3 to 30 m at latitudes comprised between 42° and 49°S. Both species share the same habitat and show a morphological plasticity, but differ in their colour. Halisarca magellanica is bright pink to whitish with three morphs whereas H. desqueyrouxae sp. nov. is light brown to beige with two morphs. An extensive investigation in TEM and SEM reveals several differences among cell types with inclusions between both species. Three distinct spherulous cells occur. Type 1 is shared by both species, Type 2 is occasional in H. magellanica but absent from H. desqueyrouxae sp. nov. Type 3 is rare in H. magellanica and occurs abundantly in half of the specimens of H. desqueyrouxae sp. nov. Granular cells are shared by both species but do not occur in all specimens. Microgranular cells are characteristic of H. magellanica. Both species also clearly differ by their endobiotic bacteria. Phylogenetic analysis of cox1 sequences places H. magellanica as a sister group to all other previously published Halisarca species sequences (9.1-9.7% difference) except H. harmelini, while H. desqueyrouxae sp. nov. is placed as a sister group to H. dujardini (2.3% difference).

Lissodendoryx (Ectyodoryx) Lundbeck, 1909 (Coelosphaeridae, Poecilosclerida, Demospongiae) from Southern Chile: new species and a discussion of morphologic characters in the subgenus.

Our ongoing studies of the Chilean sponge fauna revealed four new species of Lissodendoryx (Ectyodoryx) that are described here, including three from the fjord's region (< 30 m depth, L.(E.) ballena sp. nov., L. (E.) corrugata sp. nov.,      L. (E.) coloanensis sp. nov.), and one from the deep waters off Diego Ramírez Archipelago (ca. 2000 m, L. (E.) diegoramirezensis sp. nov.). In addition, the type of L. (E.) anacantha was revised and found to bear much larger acanthostyles than originally reported. Our results revealed skeletal architectures quite distinct from that reported from the type species of L. (Ectyodoryx), and not predicted in the current diagnosis of Lissodendoryx, requiring an amended diagnosis. Ectosomal megascleres also set the majority of the new species apart from the type species of L. (Ectyodoryx), which does not have terminally microspined (sub)tylotes. This character is widespread in Lissodendoryx and might be pointing to phylogenetic affinities across the current subgeneric arrangement. Further morphologic characters and alternative phylogenetic scenarios are discussed, including hymedesmiid and myxillid affinities of the species described here.

New Hamacantha from Peru and resurrection of Zygherpe as subgenus (Demospongiae, Poecilosclerida, Hamacanthidae).

Two species of Hamacantha with tylostyles are reported here for the Peruvian coast, namely H. desmacelloides sp.nov. and H. hyaloderma. The former is the first species in the genus with apically microspined sigmas, similar to those known to occur in Neofibularia, and recently reported from genera Biemna, Desmacella, Rhabderemia and Sigmaxinella. Hamacantha hyaloderma was previously known from Mexico to Canada, and is here reported for the first time from the south east Pacific. The finding of a second species with tylostyles led us to reinstate subgenus Hamacantha (Zygherpe). The possible phylogenetic significance of apically microspined sigmas is discussed in view of recent findings on the basis of molecular data.

Biomineralization in living hypercalcified demosponges: toward a shared mechanism?

Massive skeletons of living hypercalcified sponges, representative organisms of basal Metazoa, are uncommon models to improve our knowledge on biomineralization mechanisms and their possible evolution through time. Eight living species belonging to various orders of Demospongiae were selected for a comparative mineralogical characterization of their aragonitic or calcitic massive basal skeleton. The latter was prepared for scanning and transmission electron microscopy (SEM and TEM), selected-area electron diffraction (SAED) and X-ray diffraction (XRD) analyses. SEM results indicated distinctive macro- and micro-structural organizations of the skeleton for each species, likely resulting from a genetically dictated variation in the control exerted on their formation. However, most skeletons investigated shared submicron to nano-scale morphological and crystallographical patterns: (1) single-crystal fibers and bundles were composed of 20 to 100nm large submicronic grains, the smallest structural units, (2) nano-scale likely organic material occurred both within and between these structural units, (3) {110} micro-twin planes were observed along aragonitic fibers, and (4) individual fibers or small bundles protruded from the external growing surface of skeletons. This comparative mineralogical study of phylogenetically distant species brings further evidence to recent biomineralization models already proposed for sponges, corals, mollusks, brachiopods and echinoderms and to the hypothesis of the universal and ancestral character of such mechanisms in Metazoa.

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. 

Biologically controlled mineralization in the hypercalcified sponge Petrobiona massiliana (Calcarea, Calcaronea).

Hypercalcified sponges, endowed with a calcium carbonate basal skeleton in addition to their spicules, form one of the most basal metazoan group engaged in extensive biomineralization. The Mediterranean species Petrobiona massiliana was used to investigate biological controls exerted on the biomineralization of its basal skeleton. Scanning and transmission electron microscopy (SEM, TEM) confirmed that basopinacocytes form a discontinuous layer of flattened cells covering the skeleton and display ultrastructural features attesting intense secretory activity. The production of a highly structured fibrillar organic matrix framework by basopinacocytes toward the growing skeleton was highlighted both by potassium pyroantimonate and ruthenium red protocols, the latter further suggesting the presence of sulfated glycosaminoglycans in the matrix. Furthermore organic material incorporated into the basal skeleton was shown by SEM and TEM at different structural levels while its response to alcian blue and acridine orange staining might suggest a similar acidic and sulfated chemical composition in light microscopy. Potassium pyroantimonate revealed in TEM and energy electron loss spectroscopy (EELS) analysis, heavy linear precipitates 100-300 nm wide containing Ca(2+) and Mg(2+) ions, either along the basal cell membrane of basopinacocytes located toward the decalcified basal skeleton or around decalcified spicules in the mesohyl. Based on the results of the previous mineralogical characterization and the present work, an hypothetical model of biomineralization is proposed for P. massiliana: basopinacocytes would produce an extracellular organic framework that might guide the assemblage of submicronic amorphous Ca- and Mg-bearing grains into higher structural units.

Multi-scale mineralogical characterization of the hypercalcified sponge Petrobiona massiliana (Calcarea, Calcaronea).

The massive basal skeleton of a few remnant living hypercalcified sponges rediscovered since the 1960s are valuable representatives of ancient calcium carbonate biomineralization mechanisms in basal Metazoa. A multi-scale mineralogical characterization of the easily accessible Mediterranean living hypercalcified sponge belonging to Calcarea, Petrobiona massiliana (Vacelet and Lévi, 1958), was conducted. Oriented observations in light and electron microscopy of mature and growing areas of the Mg-calcite basal skeleton were combined in order to describe all structural levels from the submicronic to the macroscopic scale. The smallest units produced are ca. 50-100nm grains that are in a mushy amorphous state before their crystallization. Selected area electron diffraction (SAED) further demonstrated that submicronic grains are assembled into crystallographically coherent clusters or fibers, the latter are even laterally associated into single-crystal bundles. A model of crystallization propagation through amorphous submicronic granular units is proposed to explain the formation of coherent micron-scale structural units. Finally, XRD and EELS analyses highlighted, respectively, inter-individual variation of skeletal Mg contents and heterogeneous spatial distribution of Ca ions in skeletal fibers. All mineralogical features presented here cannot be explained by classical inorganic crystallization principles in super-saturated solutions, but rather underlined a highly biologically regulated formation of the basal skeleton. This study extending recent observations on corals, mollusk and echinoderms confirms that occurrence of submicronic granular units and a possible transient amorphous precursor phase in calcium carbonate skeletons is a common biomineralization strategy already selected by basal metazoans.

Identification of the bacterial symbiont Entotheonella sp. in the mesohyl of the marine sponge Discodermia sp.

The lithistid sponge Discodermia dissoluta (family Theonellidae), is found in deep-waters throughout the Caribbean sea and is the source of discodermolide, a natural product with potential anticancer properties, and other secondary metabolites. As with other sponges, large numbers of microbes are harbored in the sponge mesohyl. The microbial population of the sponge mesohyl shows an abundance of large filamentous microbes. Fractionation of the dissociated sponge allowed enrichment of this microbe, which was then identified by analysis of the 16S rRNA genes. Its identity was confirmed through the use of fluorescent in situ hybridization. These studies have allowed the identification of this eubacterial microbe as belonging to the genus Entotheonella.

Experimental metamorphosis of Halisarca dujardini larvae (Demospongiae, Halisarcida): evidence of flagellated cell totipotentiality.

The potency of flagellated cells of Halisarca dujardini (Halisarcida, Demospongiae) larvae from the White Sea (Arctic) was investigated experimentally during metamorphosis. Two types of experiments were conducted. First, larvae were maintained in Ca2+ free seawater (CFSW) until the internal cells were released outside through the opening of the posterior pole. These larvae that only composed of flagellated cells (epithelial larvae) were then returned to sea water (SW) to observe their metamorphosis. The posterior aperture closed before they settled on a substratum and started a metamorphosis similar to intact larvae. Secondly, epithelial larvae were, first, further treated in CFSW and then mechanically dissociated. Separated cells or groups of cells were returned to SW, where they constituted large friable conglomerates. After 12-17 h in SW, flagellated cells showed the first steps of dedifferentiation, and regional differentiation was noticeable within conglomerates after approximately 24-36 h. External cells differentiated into pinacocytes while internal cells kept their flagella and became united in a layer. Within 48-72 h, internal cells of the conglomerates formed spherical or ovoid clusters with an internal cavity bearing flagella. These clusters further fused together in a rhagon containing one or two large choanocyte chambers. The sequence of cellular processes in epithelial larvae and in flagellated cell conglomerates was similar. Previous observations indicating the totipotentiality of larval flagellated cells during normal metamorphosis of H. dujardini are thus confirmed.

Ultrastructural evidence of extruding exocytosis of residual bodies in the freshwater sponge Ephydatia fluviatilis.

Exocytosis of residual bodies by choanocytes, archeocytes and endopinacocytes lining the aquiferous system of Ephydatia fluviatilis has been demonstrated using calibrated latex beads and Escherichia coli as tracers. In passing into the mesohyl or the lumen of the exhalant aquiferous canals, beads, and altered bacteria were enveloped by the plasma membrane of the cell containing them. The membrane constricted at a neck region to form extruding vacuoles. This process appeared first in choanocytes and later in other cell types. The occurrence of these buds increased with the length of incubation time, as did the number of particles they contained. Acid phosphatase activity was frequently associated with the particles budding from the cell membrane, confirming that this process followed digestive activity. Membranous vacuoles were recovered from the external medium and observed by TEM and those adhering to the substratum were seen by SEM. These observations proved that vacuoles were released from the sponges. This membrane-consuming mechanism of exoctyosis implies intense membrane replacement in the digestive cells of the sponge.