The terminology of sponge spicules

A new sponge from the Marjum Formation of Utah documents the Cambrian origin of the hexactinellid body plan

Modern poriferans are classified into four classes-Calcarea, Demospongiae, Hexactinellida and Homoscleromorpha-the recognition of which in fossil specimens almost exclusively relies on spicule morphology and arrangement. Early fossil representatives of the phylum Porifera are morphologically diverse, and many of them problematically display characteristics that are incompatible with the classification scheme developed for modern taxa. Critically, hexactine spicules-a diagnostic feature of hexactinellids among modern taxa-are found in various Cambrian and Ordovician taxa that cannot be accommodated within the hexactinellid body plan. Here we describe a new poriferan from the Drumian Marjum Formation of Utah, Polygoniella turrelli gen. et sp. nov., which exhibits a unique combination of complex anatomical features for a Cambrian form, including a syconoid-like organization, a thick body wall, and a multi-layered hexactin-based skeleton. The hexactinellid-like body wall architecture of this new species supports a Cambrian origin of the hexactinellid body plan and provides valuable insights into character evolution in early glass sponges.

Preliminary study of marine sponges (Porifera) in the littoral of Spermonde Archipelago, Indonesia

Previous ecological studies show higher sponge diversity in the Spermonde Archipelago, SW Sulawesi, Indonesia, compared to the World Porifera Database. This study aims to provide an updated checklist of sponges of the Spermonde Archipelago, focusing particularly on the littoral area. Systematic sampling was executed through several observations, with roving techniques, e.g., snorkeling and SCUBA diving. In situ photographs of living sponges were taken using an underwater digital camera. Some specimens were collected and stored at the Naturalis Biodiversity Center, Leiden. Fragments of samples were analyzed using light and scanning electron microscopy. A total of 27 sponges (Calcarea and Demospongiae) were catalogued from the littoral area of the Spermonde Archipelago. Some of these are new records for the Sulawesi Sea/Makassar Strait marine ecoregion, including four potentially novel taxa. Preliminary morphological descriptions of all examined samples are presented. This study highlights the sponge assemblage flourishing in a shallow area characterized by a paucity of live corals and a predominant environment by macroalgae, rocks, and rubble.

Silactins and Structural Diversity of Biosilica in Sponges

Sponges (phylum Porifera) were among the first metazoans on Earth, and represent a unique global source of highly structured and diverse biosilica that has been formed and tested over more than 800 million years of evolution. Poriferans are recognized as a unique archive of siliceous multiscaled skeletal constructs with superficial micro-ornamentation patterned by biopolymers. In the present study, spicules and skeletal frameworks of selected representatives of sponges in such classes as Demospongiae, Homoscleromorpha, and Hexactinellida were desilicified using 10% HF with the aim of isolating axial filaments, which resemble the shape and size of the original structures. These filaments were unambiguously identified in all specimens under study as F-actin, using the highly specific indicators iFluor™ 594-Phalloidin, iFluor™ 488-Phalloidin, and iFluor™ 350-Phalloidin. The identification of this kind of F-actins, termed for the first time as silactins, as specific pattern drivers in skeletal constructs of sponges opens the way to the fundamental understanding of their skeletogenesis. Examples illustrating the biomimetic potential of sophisticated poriferan biosilica patterned by silactins are presented and discussed.

Correcting sponge names: nomenclatural update of lower taxa level Porifera

The online World Porifera Database (WPD), the Porifera part of the World Register of Marine Species (WoRMS), lists virtually all published scientific names of sponges. The names of the WPD (as indeed all names in WoRMS) are guided by the Code of the International Comnission on Zoological Nomenclature (ICZN). The WPD names include all currently accepted as well as original combinations, and a majority of non-accepted non-original combinations. Currently, among the accepted names about 200 original lower taxa combinations were found to be accepted by default, usually varieties or formae, which were given that status in the WPD because there was no sufficient published information to support arguments for or against the accepted status. After 1961, varieties and formae are considered infrasubspecific taxa whose names are not regulated by the Code and the names are unavailable, but prior to that date these trinominal taxa are potential available names. It is the purpose of the present study to evaluate these original default accepted combinations and arrive at an argumented judgement on whether they are to be truly accepted or non-accepted. Furthermore, additional lower taxa name violations of the Code are also included. Overall, there are three categories of names of lower taxa treated here, (1) with combinations, which are judged to be accepted with elevated status as (sub)specific taxa, (2) with combinations judged to be junior synonyms, and (3) with combinations, which are violating articles of the Code. Among the last category there are a small number of varietal taxa described after the 1960 cut-off date, which are unavailable but are proposed to have the original name combination retained, but as new names with authorship and year changed to those of the present article. Also, names found to be unavailable for various reasons (four-name combinations, junior homonyms, phylocode names) are in this category. The following 31 new names are proposed (three of which are junior synonyms of senior accepted names, and an additional three are unavailable names made available by employing the same name combination with the present authorship and year): Aaptos hoshinoi nom.nov., Ancorina nanosclera nom.nov., Axinella kurushima nom.nov., Callyspongia (Cladochalina) desqueyrouxfaundezae nom.nov., Cliona carpenteri subsp. hentscheli nom.nov., Callyspongia (Toxochalina) gustavoi nom.nov., Craniella microspira nom.nov., Dictyaulus romani nom.nov., Grantia breitfussi nom.nov., Haliclona alba subsp. albapontica nom.nov., Haliclona aquaeductus subsp. sebastopolensis nom.nov., Haliclona inflata subsp. vladimiri nom.nov., Haliclona informis subsp. voldomaroi nom.nov., Haliclona palmata subsp. pontuseuxiniensis nom.nov., Haliclona (Gellius) arthuri nom.nov., Haliclona (Gellius) godthaabae nom.nov., Haliclona merguiensis nom.nov., Haliclona senjitanitai nom.nov., Iophon hentscheli nom.nov., Leucandra wilsoni nom.nov., Paraleucilla bassensis nom.nov. (= P. saccharata), Pione carpenteri subsp. hentscheli nom.nov., Psammocinia samaaii nom.nov., Protoschmidtia czerniavskyi nom.nov. (= Metschnikowia tuberculata), Reiswiginella nom.nov., Scalarispongia lamarcki nom.nov., Spheciospongia hentscheli nom.nov., Spongia (Spongia) vonlendenfeldi nom.nov. (= S. (S.) lignosa), Suberites austral nom.nov., Suberites dendyi nom.nov., Suberites simae nom.nov., and Timea levii nom.nov.

Miocene sponge assemblages in the face of the Messinian Salinity Crisis-new data from the Atlanto-Mediterranean seaway

The Messinian Salinity Crisis is considered as one of the most influential Cenozoic events that impacted negatively on the benthic fauna of the Mediterranean area. Changing environmental conditions, including a sharp reduction of water exchange between the Mediterranean Sea and the Atlantic Ocean, altered the geographical ranges of many organisms, including sponges (Porifera). Here, we report a unique assemblage of isolated sponge spicules from the upper Miocene of southwestern Spain. The newly recognized sponge fauna was inhabiting the Guadalquivir Basin-the corridor between the Mediterranean and the Atlantic Ocean at that time. It represents a taxonomically rich sponge community that consisted of members of "soft" and "lithistid" demosponges and hexactinellids. Demosponges are represented by at least thirty-four taxa, while hexactinellids are significantly rarer; only six taxa have been identified. From among eighteen taxa recognized to the species level, at least eight seem to be inhabiting this area to these days; six are recorded from adjacent areas, such as the Western Mediterranean, South European Atlantic Shelf, and the Azores, and three are present in the Red Sea and/or the Northern Atlantic. Intriguingly, some taxa seem to have their closest relatives in distant areas, such as the Indo-Pacific and Japanese waters which suggests that the range of some once widely-distributed populations shrunk after the isolation of the Mediterranean and the Messinian Salinity Crisis, surviving to the present day only in refugia.

Microbiome species diversity and seasonal stability of two temperate marine sponges Hymeniacidon perlevis and Suberites massa

BACKGROUND

Marine sponges are diverse and functionally important members of marine benthic systems, well known to harbour complex and abundant symbiotic microorganisms as part of their species-specific microbiome. Changes in the sponge microbiome have previously been observed in relation to natural environmental changes, including nutrient availability, temperature and light. With global climate change altering seasonal temperatures, this study aims to better understand the potential effects of natural seasonal fluctuations on the composition and functions of the sponge microbiome.

RESULTS

Metataxonomic sequencing of two marine sponge species native to the U.K. (Hymeniacidon perlevis and Suberites massa) was performed at two different seasonal temperatures from the same estuary. A host-specific microbiome was observed in each species between both seasons. Detected diversity within S. massa was dominated by one family, Terasakiellaceae, with remaining dominant families also being detected in the associated seawater. H. perlevis demonstrated sponge specific bacterial families including aforementioned Terasakiellaceae as well as Sphingomonadaceae and Leptospiraceae with further sponge enriched families present.

CONCLUSIONS

To our knowledge, these results describe for the first time the microbial diversity of the temperate marine sponge species H. perlevis and S. massa using next generation sequencing. This analysis detected the presence of core sponge taxa identified in each sponge species was not changed by seasonal temperature alterations, however, there were shifts observed in overall community composition due to fluctuations in less abundant taxa, demonstrating that microbiome stability across seasons is likely to be host species specific.

Two centuries of sponges (phylum Porifera) taxonomic studies in Indonesia (1820-2021): checklist and bibliography

Sponges in Indonesia have been studied since the 19th century during several historical expeditions and international collaborations. Hundreds of new species were reported from various locations, e.g., Ambon, Ternate, Sulawesi, Aru, and Kei Islands. This study aimed to create a sponge (Porifera: Calcarea, Demospongiae, Hexactinellida, and Homoscleromorpha) species checklist from Indonesia based on World Porifera Database. With a total of 731 species, our checklist comprises approximately 45 species of Calcarea, 566 species of Demospongiae, 115 species of Hexactinellida, and five species of Homoscleromorpha. The number of species are recorded from 12 marine ecoregions across the Indonesian Archipelago and freshwater habitats (Spongillida) between 1820-2021. The species composition indicates higher regional endemism or poorly studied since no other report after the original description. However, several marine ecoregions of Indonesia remain highly overlooked (e.g., Northeast Sulawesi, Papua, Southern Java, Western Sumatra), including freshwater habitats. Therefore, a taxonomic biodiversity baseline study, particularly on Porifera, is necessary to better understand the aquatic and marine biodiversity in the Indonesia Archipelago.

The genome of the reef-building glass sponge Aphrocallistes vastus provides insights into silica biomineralization

Well-annotated and contiguous genomes are an indispensable resource for understanding the evolution, development, and metabolic capacities of organisms. Sponges, an ecologically important non-bilaterian group of primarily filter-feeding sessile aquatic organisms, are underrepresented with respect to available genomic resources. Here we provide a high-quality and well-annotated genome of Aphrocallistes vastus, a glass sponge (Porifera: Hexactinellida) that forms large reef structures off the coast of British Columbia (Canada). We show that its genome is approximately 80 Mb, small compared to most other metazoans, and contains nearly 2500 nested genes, more than other genomes. Hexactinellida is characterized by a unique skeletal architecture made of amorphous silicon dioxide (SiO2), and we identified 419 differentially expressed genes between the osculum, i.e. the vertical growth zone of the sponge, and the main body. Among the upregulated ones, mineralization-related genes such as glassin, as well as collagens and actins, dominate the expression profile during growth. Silicateins, suggested being involved in silica mineralization, especially in demosponges, were not found at all in the A. vastus genome and suggests that the underlying mechanisms of SiO2 deposition in the Silicea sensu stricto (Hexactinellida + Demospongiae) may not be homologous.

New lithistid sponge of the genus Sollasipelta (Porifera, Demospongiae,Tetractinellida, Neopeltidae) from submarine caves of the Ryukyu Islands,southwestern Japan, with redescription of S. sollasi

A new species of 'lithistid' (rock sponge) Sollasipelta subterranea sp. nov. is described from near-shore submarine caves of Okinawa and Shimoji Islands, the Ryukyu Islands, southwestern Japan. This new species is characterized by the smooth dentate ectosomal pseudophyllotriaenes, slender choanosomal oxea/style/subtylostyles and two types of amphiasters, one of which is in two size classes. Sollasipelta subterranea sp. nov. is morphologically closest to Sollasipelta sollasi (Lévi & Lévi, 1989), known from the Philippines deep sea, and our examination of the type specimen of S. sollasi revealed that the pseudophyllotriaenes and desmas are substantially different between the two species, and both species possess two types of amphiasters, one of which has two size classes. Sollasipelta cavernicola (Vacelet & Vasseur, 1965) and S. punctata (Lévi & Lévi, 1983) are transferred to the genus Daedalopelta Sollas, 1888, based on possession of one type of amphiastes as microscleres. Sollasipelta mixta (Vacelet, Vasseur and Lévi, 1976) is formally transferred to the genus Neopelta Schmidt, 1880, based on the morphological characters. A key to species of the genus Sollasipelta Van Soest & Hooper, 2020 is also provided. Sollasipelta subterranea sp. nov. represents the first 'lithistid' sponge from submarine caves of the Western Pacific and the first species of sponge inhabiting anchialine cave environments in the Indo-West Pacific. This is also a new record of the family Neopeltidae from Japanese waters.

A morphological guide of neotropical freshwater sponge spicules for paleolimnological studies

Freshwater sponges (Porifera: Spongillida) are sessile invertebrates with skeletons composed of siliceous elements termed spicules. Sponge spicules (megascleres, microscleres, and gemmuloscleres) are characterized by widely varying sizes and shapes. These spicules are well-preserved in lacustrine, wetland, and riverine sediments and hold significant ecological and limnological information that can be applied as diagnostic tools in reconstructions of Quaternary environments. However, problems with taxonomy and the absence of systematic guidelines and standards of identification represent major challenges to utilizing freshwater sponges as a paleo-proxy. Here, we present a well-illustrated extraction protocol and morphological guide to the Neotropical freshwater sponge fauna. This guide is intended to introduce researchers and students to the study of freshwater sponges and their use as a diagnostic tool in paleoecology and paleolimnology.