Poecilosclerid Sponge Research Articles

Taxonomic and geographic novelties of Acarnus (Porifera: Demospongiae) from the Brazilian coast, with description of two new species

Acarnus are poecilosclerid sponges characterized mainly by cladotylote megascleres. Five species are known on the Brazilian coast: Acarnus innominatus Gray 1867, Acarnus radovani (Boury-Esnault, 1973), Acarnus toxeata Boury-Esnault, 1973, Acarnus nicoleae van Soest, Hooper & Hiemstra, 1991 and Acarnus microxeatus Nascimento & Pinheiro, 2023. This study describes two new Brazilian species, Acarnus hooperi sp. nov. and Acarnus tupiniquim sp. nov., from Rio de Janeiro and Bahia States, respectively, whose diagnosis is the presence of tylostyles, a character formally recorded for the first time in the family Acarnidae and the genus Acarnus. We also describe two of the previously known species, A. innominatus and A. toxeata. Additionally, an identification key for the Acarnus species from the Tropical Western Atlantic is proposed.

Reproduction and early life stages of the poecilosclerid sponge Crella incrustans

AbstractDespite their important ecological roles in marine ecosystems, reproduction and early life stages of the majority of marine sponges remain undescribed. Here we characterize the mode of reproduction and the early life stages of an abundant sponge in temperate Pacific waters, Crella incrustans. Through histology, we characterized the production of gametes and the sequential steps of larval ontogeny. Using in vivo observations, we described larval release, settlement, and metamorphosis. Specimens of C. incrustans presented spermatocytes, oocytes, and several developmental stages in the sponge mesohyl during the Australasian summer (from January to March 2020), demonstrating this sponge to be a simultaneous hermaphrodite with internal fertilization, asynchronous development, and brooded embryos. As in other viviparous demosponges, mature embryos were released during the Australasian summer as free‐swimming non‐tufted parenchymella larvae. Under laboratory conditions, 94.3% of larvae settled within 2 days and metamorphosed into functional settlers within a week. Gametogenesis, embryonic development, larval characteristics, settlement, and metamorphosis of C. incrustans are consistent with the reproductive features common to the majority of poecilosclerid sponges. Overall, our study provides important information on the early life stages of this temperate model species for future ecophysiological experiments.

New Sulfur-Containing Polyarsenicals from the New Caledonian Sponge Echinochalina bargibanti.

Arsenicin A (C3H6As4O3) was isolated from the New Caledonian poecilosclerid sponge Echinochalina bargibanti, and described as the first natural organic polyarsenic compound. Further bioguided fractionation of the extracts of this sponge led us to isolate the first sulfur-containing organic polyarsenicals ever found in Nature. These metabolites, called arsenicin B and arsenicin C, are built on a noradamantane-type framework that is characterized by an unusual As–As bonding. Extensive NMR measurements, in combination with mass spectra, enabled the assignment of the structure for arsenicin B (C3H6As4S2) as 2. The scarcity of arsenicin C and its intrinsic chemical instability only allowed the collection of partial spectral data, which prevented the full structural definition. After the extensive computational testing of several putative structures, structure 3 was inferred for arsenicin C (C3H6As4OS) by comparing the experimental and density functional theory (DFT)-calculated 1H and 13C NMR spectra. Finally, the absolute configurations of 2 and 3 were determined with a combined use of experimental and time-dependent (TD)-DFT calculated electronic circular dichroism (ECD) spectra and observed specific rotations. These findings pose great challenges for the investigation of the biosynthesis of these metabolites and the cycle of arsenic in Nature. Arsenicins B and C showed strong antimicrobial activities, especially against S. aureus, which is comparable to the reference compound gentamycin.

Short-chain alkanes fuel mussel and sponge Cycloclasticus symbionts from deep-sea gas and oil seeps.

Cycloclasticus bacteria are ubiquitous in oil-rich regions of the ocean and are known for their ability to degrade polycyclic aromatic hydrocarbons (PAHs). In this study, we describe Cycloclasticus that have established a symbiosis with Bathymodiolus heckerae mussels and poecilosclerid sponges from asphalt-rich, deep-sea oil seeps at Campeche Knolls in the southern Gulf of Mexico. Genomic and transcriptomic analyses revealed that in contrast to all known Cycloclasticus, the symbiotic Cycloclasticus appeared to lack the genes needed for PAH degradation. Instead, these symbionts use propane and other short-chain alkanes such as ethane and butane as carbon and energy sources, thus expanding the limited range of substrates known to power chemosynthetic symbioses. Analyses of short-chain alkanes in the environment of the Campeche Knolls symbioses revealed that these are present at high concentrations (in the µM to mM range). Comparative genomic analyses revealed high similarities between the genes used by the symbiotic Cycloclasticus to degrade short-chain alkanes and those of free-living Cycloclasticus that bloomed during the Deepwater Horizon (DWH) oil spill. Our results indicate that the metabolic versatility of bacteria within the Cycloclasticus clade is higher than previously assumed, and highlight the expanded role of these keystone species in the degradation of marine hydrocarbons.

Happy relationships between marine sponges and sediments – a review and some observations from Australia

Being sessile filter feeders, sponges may be disadvantaged by sediments in many ways, e.g. through clogging and burial. However, in order to correctly recognize negative effects of sediments in the field, natural relationships of sponge taxa adapted to a life with sediments need to be understood. The present publication reviews available literature and provides observations on natural and beneficial interactions of sponges with sediments, distinguishing several strategies: (1) Saving energy through sediment incorporation, reducing or replacing spicule production commonly occurs in keratose, verongimorph, tethyid and poecilosclerid sponges, which often received scientific names referring to sediments. (2) Forming sediment crusts externally or embedded in surface tissues reinforces outer layers, provides shade, and for external crusts camouflage and shelter from spongivory and desiccation. External crusts often occur in the tethyids and axinellids, while surface armour is most common in keratose sponges. (3) Anchoring in soft sediments provides a selective advantage for space colonization. This is mainly achieved in the hexactinellid, polymastiid and spirophorine sponges by using spicules (predominantly in deeper water), commonly in endopsammic sponges by rootlets, basal agglutination and basal incorporation of particles, and in various groups by attachment to buried materials (shallow water). (4) Living at least partially embedded in sediments (psammobiosis) appears to be best developed inOceanapiaspp. and bioeroding sponges, generates shelter from various external conditions and reduces the risk of spongivory. Typical morphological characters of sediment-adapted sponges are thus sediment skeletons and surface crusts (reinforcement), stalks and fistules (elevation above sediments), spicule tufts and root-systems (anchoring).

Origins and Evolutionary Flexibility of Chemosynthetic Symbionts From Deep-Sea Animals

Bathymodiolin mussels dominate hydrothermal vent and cold seep communities worldwide. Symbiotic associations with chemosynthetic sulfur- and methane-oxidizing bacteria that provide for their nutrition are the key to their ecological and evolutionary success. The current paradigm is that these symbioses evolved from two free-living ancestors, one methane-oxidizing and one sulfur-oxidizing bacterium. In contrast to previous studies, our phylogenetic analyses of the bathymodiolin symbionts show that both the sulfur and the methane oxidizers fall into multiple clades interspersed with free-living bacteria, many of which were discovered recently in metagenomes from marine oxygen minimum zones. We therefore hypothesize that symbioses between bathymodiolin mussels and free-living sulfur- and methane-oxidizing bacteria evolved multiple times in convergent evolution. Furthermore, by 16S rRNA sequencing and fluorescence in situ hybridization, we show that close relatives of the bathymodiolin symbionts occur on hosts belonging to different animal phyla: Raricirrus beryli, a terebellid polychaete from a whale-fall, and a poecilosclerid sponge from a cold seep. The host range within the bathymodiolin symbionts is therefore greater than previously recognized, confirming the remarkable flexibility of these symbiotic associations.

Syntheses of (±)-Hamigeran B and (±)-4-Bromohamigeran B

Hamigeran B and 4-bromohami­geran B were isolated from the poecilosclerid sponge Hamigera tarangensis Bergquist and Fromont in 2000. They posses mild antitumor activity towards P-388 whilst hamigeran additionally displays antiviral activity.

Antitumour polyether macrolides: Four new halichondrins from the New Zealand deep-water marine sponge Lissodendoryx sp.

The isolation is reported of four new variants of the halichondrin B skeleton, very minor potently bioactive components from the Poecilosclerid sponge Lissodendoryx sp. These compounds were isolated in microgram quantities only from a collection of 1 tonne of sponge. The structural elucidations relied heavily on the use of capillary NMR spectroscopy and the application of an HSQC-DEPT overlay technique.

New species from the deep Pacific suggest that carnivorous sponges date back to the Early Jurassic

AbstractSome deep-sea poecilosclerid sponges (Porifera) have developed a carnivorous feeding habit that is very surprising in sponges^1^. As shown by the typical morphology of their spicules, they most probably evolved from "normal sponges" under the difficult conditions of a deep-sea environment. Such evolution, which implies the loss of the diagnostic character of the phylum Porifera, i.e. a filter feeding habit through a complex aquiferous system, should be of great interest in the understanding of the origin of metazoans. Some scenarios, based on the hypothesis of the paraphyly of Porifera, allege that metazoans could derive from a sponge filter-feeding body plan. A difficulty, however, is to imagine the transition from a sponge grade of organization to other organization plans^2^. Carnivorous sponges demonstrate that a functional, non filter-feeding animal may derive from a conventional sponge body plan, albeit nothing is known of the age of this evolution. Here we report that newly discovered species of Chondrocladia from the deep Pacific display special spicules that were previously recorded only as isolated spicules from sediment dating back to the Early Jurassic and Miocene periods. This suggests that the evolution of carnivorous sponges from filter-feeding poecilosclerid demosponges could date back at least from the Early Mesozoic.

Revision of the genus Pozziella (Porifera: Poecilosclerida) with description ofthree new species from the eastern Pacific

To date, the poecilosclerid sponge genus Pozziella Topsent, 1896 was represented by two species: Pozziella clavisepta Topsent, 1896 and Pozziella aperta (Topsent, 1920), which are presently redescribed. During the campaign SO 144-3a of the project PAGANINI in the Pacific Ocean between the Galapagos Archipelago and Central America, three new species were recovered and are described here: Pozziella cerilla sp. nov., Pozziella neuhausi sp. nov. and Pozziella lueteri sp. nov. The present study led to a revision of the genus and an attempt to resolve the relationships between the species, based on the likeness of spicule complements and biometric characters. A similarity analysis revealed that Atlantic and Pacific species clustered separately. In addition, a key to all species of the genus based on spicular characters is provided.

On the First Polyarsenic Organic Compound from Nature: Arsenicin A from the New Caledonian Marine Sponge Echinochalina bargibanti

Reported here is the first polyarsenic compound ever found in nature. Denominated arsenicin A, it was isolated along a bioassay-guided fractionation of the organic extract of the poecilosclerid sponge Echinochalina bargibanti collected from the north-eastern coast of New Caledonia. In defining an adamantine-type polyarsenic structure for this compound, deceptively simple NMR spectra were complemented by extensive mass spectral analysis. However, it was only the synthesis of a model compound that provided the basis to discriminate structure 4 from other spectrally compatible structures for arsenicin A; to this end, a comparative ab initio simulation of IR spectra for the natural and the synthetic compounds was decisive. Arsenicin A is endowed with potent bactericidal and fungicidal activities on human pathogenic strains. All this may revive pharmacological interest in arsenic compounds while prompting us to rethink the arsenic cycle in nature.

New species of Poecilosclerida (Demospongiae, Porifera) from the Aleutian Islands, Alaska, USA

Five new species of poecilosclerid sponges, Artemisina amlia sp. nov., Coelosphaera oglalai sp. nov., Melonanchora globogilva sp. nov., Tedania kagalaskai sp. nov., and Mycale carlilei sp. nov, are described from the Aleutian Islands, Alaska, from depths ranging between 100–190m and are compared with congeners of the North Pacific Ocean.Keywords: Taxonomy, Porifera, Demospongiae, Poecilosclerida, new species, N-Pacific, Aleutian Islands, Alaska

A New Species of Poecilosclerid Sponge (Porifera) from Bathyal Methane Seeps in the Gulf Of Mexico

A new species of poecilosclerid sponge from methane seeps on the Louisiana Slope, Gulf of Mexico, USA is described. This thickly encrusting sponge grows around vestimentiferan tubes and has a very patchy distribution. The skeletal structure and the spicule set match those characterizing the genusEctyomyxilla. The new species,Ectyomyxilla methanophilasp. nov., is distinguished from the remaining species in the genus by the structure of its ectosomal skeleton, where small acanthostyles are never present, and by its choanosomal skeleton, which is barely reticulate and has echinated main tracts. The small size of the choanocyte chambers suggests occurrence of nutritional benefits derived from association with chemoautotrophic symbiotic bacteria. However, the presence of oscules, ostioles, aquiferous canals and choanocyte chambers indicates that this sponge also relies partly on filtration for its nutrition. This is the first record of the genusEctyomyxillain the northern hemisphere, and the first non-carnivorous demosponge known to exploit methane-rich marine environments.

Three new species of Poecilosclerid sponge from Korea

Three species of Poecilosclerid sponge (class Demospongiae, subclass Cerac‐tinomorpha) are newly described from the waters around Cheju Island, Keomun Island and Keoje Island. They are Antho (Plocamia) bakusi, Clathria (Clathria) koreana and Oxymycale rhoi.

Small-scale association measures in epibenthic communities as a clue for allelochemical interactions.

The small-scale associations in a rocky subtidal community in the northwestern Mediterranean were studied by a development of the continuous line transect method. This method allowed the overall measurement of non-randomness in interspecific contacts and the assignment of an association index to each species-pair, whose, significance was tested by Monte Carlo procedures. At the same time, the continuous recording allowed the study of the weakening of the interactions with increasing distances. Our purpose was to uncover evidence for allelochemical mechanisms of space occupation and maintenance. A strong non-randomness was found in the interspecific associations. This was mostly due to the interactions of the poecilosclerid sponge Crambe crambe (Schmidt) with its neighbours, especially its negative associations with other sponge species. The strength of the relationships fell drastically over the first few centimeters from the contact borders of the different species. The results pointed strongly to an allelochemical mechanism. The extracts of this sponge featured high bioactivity in laboratory assays, and field experiments demonstrated that the sponge can inhibit the growth of species in the community studied. Standard sampling techniques would have overlooked the spatial structure present in the data. The study emphasizes the need for both contact data and distance data in order to identify the underlying processes reliably. The line transect method provides both types of information easily and allows testing of models and identification of organisms likely to use chemical defenses in space competition. Its use as a preliminary step in studies of chemical ecology might help to detect presumptive allelochemical processes prior to experimental work on the potentially active species.

Imidazolone and Imidazolidinone Artifacts of a Pivotal Imidazolthione, Zyzzin, from the poecilosclerid sponge Zyzza massalis from the coral sea. The first thermochromic systems of marine origin

AbstractDry acetone extracts of the freeze‐dried, deep‐red powder of the poecilosclerid sponge Zyzza massalis (DENDY) from the Coral Sea gave the orange alkaloid zyzzin (= 4‐(1H‐indol‐3‐yl)‐1,5‐dihydro‐5‐thioxo‐1H‐imidazol‐2‐one 14), which underwent exchange of the 5‐thioxo for the 5‐oxo group during aqueous chromatographic workup, giving yellow 13. Both 13 and 14 added hydroxylic solvents at C(4)=N giving colourless, racemic products, 3 and 8, respectively, by incorporation of MeOH and 10 and 11, respectively, by incorporation of H2O. On warming 3 or 10 in DMSO, 13 was recovered, thus furnishing a novel thermochromic system. Optically active (+)‐12, which may be viewed to derive from enzymatic reduction of 14 at C(4)=N followed by S→O exchange, was also isolated from this sponge, along with the linear amides 16 and 19. Compound 3 proved to have antibacterial and antifungal activities.