A short LSU rRNA fragment as a standard marker for integrative taxonomy in calcareous sponges (Porifera: Calcarea)

New carnivorous sponges (Porifera: Cladorhizidae) from Western Australia, collected by a Remotely Operated Vehicle (ROV)

The last two decades have reinvigorated systematic research on predatory sponges, mainly fuelled by advances in technology that have facilitated collection in deep-water habitats. This research presents six new species of carnivorous sponges from the family Cladorhizidae Dendy, 1922 from the western continental margin of Australia. The new species are Abyssocladia johnhooperi nov. sp., Abyssocladia aurora nov. sp., Abyssocladia janusi nov. sp., Axoniderma challengeri nov. sp., Cladorhiza vanessaekins nov. sp. and Nullarbora ningalooa nov. sp.. This material was collected by ROV during expeditions FK200308 to the Ningaloo Canyons expedition off the mid-west coast near Ningaloo, and FK200126 to the Southwest Australian canyons expedition, in Western Australia. These and other expeditions by the Schmidt Ocean Institute in 2020-21 formed a campaign around Australia's deep sea and mesophotic environments, which has vastly increased our understanding of biodiversity in these habitats.

Deep Water Polymastiidae (Porifera, Polymastiida) from the South West Pacific

This study reports on some deep water sponges in the family Polymastiidae collected during the 2017 Abyss Cruise off the East Coast of Australia and the 2003 NORFANZ Expedition to the Lord Howe and Norfolk Ridges in the Tasman Sea, Southwest Pacific Ocean. Species of Radiella, Spinularia, Ridleia, Tentorium and Polymastia were collected from abyssal and bathyal depths. From these collections, seven new species were discovered: Radiella nidula sp. nov., Radiella pumix sp. nov., Radiella sclera sp. nov., Spinularia flagellata sp. nov., Tentorium labium sp. nov., Ridleia echidna sp. nov. and Polymastia norfanzii sp. nov. In addition, two species previously known are redescribed based on the new collections: viz. Polymastia zitteli and Polymastia invaginata.

Integrative taxonomy of calcareous sponges (Porifera: Calcarea) from Réunion Island, Indian Ocean

The Western Indian Ocean Province is reckoned for its rich marine diversity; however, sponges of the Mascarene Islands ecoregion are still poorly known. In La Réunion, only three species of class Calcarea have been registered. Hence, calcareous sponges were searched in seven sites representing various habitats of the Western coast of La Réunion, but found in only three of them. A total of 23 sponge samples was identified using morphological and molecular taxonomy. This sampling represents 11 species, all new records for the region, and seven of them are new to science: Ascandra mascarenica sp. nov., A. oceanusvitae sp. nov., Janusya indica gen. et sp. nov., Leucascus tenuispinae sp. nov., Lelapiella tertia sp. nov., Soleneiscus intermedius sp. nov. and Leucandra ornata sp. nov.; and a new genus, Janusya gen. nov.. Based on results from this and from previous studies, we propose the synonymization of the order Murrayonida with Clathrinida. A very low sampling effort has thus increased the number of calcareous sponge species from the Mascarenes Islands ecoregion by 69 % and from La Réunion by 367%.

Community composition and functional prediction of prokaryotes associated with sympatric sponge species of southwestern Atlantic coast

Prokaryotes contribute to the health of marine sponges. However, there is lack of data on the assembly rules of sponge-associated prokaryotic communities, especially for those inhabiting biodiversity hotspots, such as ecoregions between tropical and warm temperate southwestern Atlantic waters. The sympatric species Aplysina caissara, Axinella corrugata, and Dragmacidon reticulatum were collected along with environmental samples from the north coast of São Paulo (Brazil). Overall, 64 prokaryotic phyla were detected; 51 were associated with sponge species, and the dominant were Proteobacteria, Bacteria (unclassified), Cyanobacteria, Crenarchaeota, and Chloroflexi. Around 64% and 89% of the unclassified operational taxonomical units (OTUs) associated with Brazilian sponge species showed a sequence similarity below 97%, with sequences in the Silva and NCBI Type Strain databases, respectively, indicating the presence of a large number of unidentified taxa. The prokaryotic communities were species-specific, ranging 56%-80% of the OTUs and distinct from the environmental samples. Fifty-four lineages were responsible for the differences detected among the categories. Functional prediction demonstrated that Ap. caissara was enriched for energy metabolism and biosynthesis of secondary metabolites, whereas D. reticulatum was enhanced for metabolism of terpenoids and polyketides, as well as xenobiotics' biodegradation and metabolism. This survey revealed a high level of novelty associated with Brazilian sponge species and that distinct members responsible from the differences among Brazilian sponge species could be correlated to the predicted functions.

Sponges as bioindicators for microparticulate pollutants?

Amongst other threats, the world's oceans are faced with man-made pollution, including an increasing number of microparticulate pollutants. Sponges, aquatic filter-feeding animals, are able to incorporate fine foreign particles, and thus may be a potential bioindicator for microparticulate pollutants. To address this question, 15 coral reef demosponges sampled around Bangka Island (North Sulawesi, Indonesia) were analyzed for the nature of their foreign particle content using traditional histological methods, advanced light microscopy, and Raman spectroscopy. Sampled sponges accumulated and embedded the very fine sediment fraction (<200 μm), absent in the surrounding sand, in the ectosome (outer epithelia) and spongin fibers (skeletal elements), which was confirmed by two-photon microscopy. A total of 34 different particle types were identified, of which degraded man-made products, i.e., polystyrene, particulate cotton, titanium dioxide and blue-pigmented particles, were incorporated by eight specimens at concentrations between 91 and 612 particle/g dry sponge tissue. As sponges can weigh several hundreds of grams, we conservatively extrapolate that sponges can incorporate on average 10,000 microparticulate pollutants in their tissue. The uptake of particles, however, appears independent of the material, which suggests that the fluctuation in material ratios is due to the spatial variation of surrounding microparticles. Therefore, particle-bearing sponges have a strong potential to biomonitor microparticulate pollutants, such as microplastics and other degraded industrial products.

Identification of an aquaculture poriferan "Pest with Potential" and its phylogenetic implications

Correct identification and classification of sponges is challenging due to ambiguous or misleading morphological features. A particular case is a blue keratose sponge occasionally referred to as the “Blue Photo Sponge” among aquarists, which appears frequently (and in several cases unintended) in private aquaria. This spicule-less species, occasionally specified as Collospongia auris Bergquist, Cambie & Kernan 1990, not only displays a high phenotypic plasticity in growth form and colour, it also proliferates in aquacultures under standard conditions unlike most other sponges. Therefore, this species is regarded as a pest for most aquarists. In turn, the ease of cultivation and propagation in aquacultures qualifies this species as a model organism for a wide array of scientific applications. For these purposes, correct identification and classification are indispensable. We reconstructed ribosomal gene trees and determined this species as Lendenfeldia chondrodes (De Laubenfels, 1954) (Phyllospongiinae), distant to Collospongia auris, and corroborated by skeletal features. Additionally, the resulting phylogeny corroborated major shortcomings of the current Phyllospongiinae classification—its consequences are discussed.

Integrative systematics of clathrinid sponges: morphological, reproductive and phylogenetic characterisation of a new species of Leucetta from Antarctica (Porifera, Calcarea, Calcinea) with notes on the occurrence of flagellated sperm

Our study reports on the occurrence of a new species of Leucetta (Calcinea, Calcarea) from the Southern Ocean, Leucetta giribeti, sp. nov., collected in the shallow waters (15m depth) of Deception Island, South Shetland Islands. This new taxon is described based on a combination of morphological and molecular data, including the description of oocytes, embryos, larvae and sperm found in the choanosome. While female reproductive elements showed great similarities with those of other calcineans, sperm is reported here for the first time in the whole Calcinea subclass. Sperm cells are flagellated and possess a typical spermatic mid-piece, which is usually observed in cnidarians. In our phylogenetic analyses, we recovered Leucetta giribeti, sp. nov. as sister species of a clade formed by species of the genera Leucetta, Pericharax and Leucettusa. Although the clade in which Leucetta giribeti, sp. nov. is placed is supported by molecular and morphological features, we cannot propose a new genus due to uncertainties regarding the type species of the genus, Leucetta primigenia Haeckel, 1872. Our study reinforces the relevance of integrative approaches in the description of new taxa and contributes to resolving the poorly known reproductive patterns of Antarctic sponge species.

Transcriptome sequencing and delimitation of sympatric Oscarella species (O. carmela and O. pearsei sp. nov) from California, USA

The homoscleromorph sponge Oscarella carmela, first described from central California, USA is shown to represent two superficially similar but both morphologically and phylogenetically distinct species that are co-distributed. We here describe a new species as Oscarella pearsei, sp. nov. and re-describe Oscarella carmela; the original description was based upon material from both species. Further, we correct the identification of published genomic/transcriptomic resources that were originally attributed to O. carmela, and present new Illumina-sequenced transcriptome assemblies for each of these species, and the mitochondrial genome sequence for O. pearsei sp. nov. Using SSU and LSU ribosomal DNA and the mitochondrial genome, we report the phylogenetic relationships of these species relative to other Oscarella species, and find strong support for the placement of O. pearsei sp. nov. in a distinct clade within genus Oscarella defined by the presence of spherulous cells that contain paracrystalline inclusions; O. carmela lacks this cell type. Oscarella pearsei sp. nov and O. carmela can be tentatively distinguished based upon gross morphological differences such as color, surface texture and extent of mucus production, but can be more reliably identified using mitochondrial and nuclear barcode sequencing, ultrastructural characteristics of cells in the mesohyl, and the morphology of the follicle epithelium which surrounds the developing embryo in reproductively active individuals.

Molecular biodiversity of Red Sea demosponges

Sponges are important constituents of coral reef ecosystems, including those around the Arabian Peninsula. Despite their importance, our knowledge on demosponge diversity in this area is insufficient to recognize, for example, faunal changes caused by anthropogenic disturbances. We here report the first assessment of demosponge molecular biodiversity from Arabia, with focus on the Saudi Arabian Red Sea, based on mitochondrial and nuclear ribosomal molecular markers gathered in the framework of the Sponge Barcoding Project. We use a rapid molecular screening approach on Arabian demosponge collections and analyze results in comparison against published material in terms of biodiversity. We use a variable region of 28S rDNA, applied for the first time in the assessment of demosponge molecular diversity. Our data constitutes a solid foundation for a future more comprehensive understanding of sponge biodiversity of the Red Sea and adjacent waters.