Diversity and abundance of photosynthetic sponges in temperate Western Australia

<p>Abstract</p> <p>Background</p> <p>Photosynthetic sponges are important components of reef ecosystems around the world, but are poorly understood. It is often assumed that temperate regions have low diversity and abundance of photosynthetic sponges, but to date no studies have investigated this question. The aim of this study was to compare the percentages of photosynthetic sponges in temperate Western Australia (WA) with previously published data on tropical regions, and to determine the abundance and diversity of these associations in a range of temperate environments.</p> <p>Results</p> <p>We sampled sponges on 5 m belt transects to determine the percentage of photosynthetic sponges and identified at least one representative of each group of symbionts using 16S rDNA sequencing together with microscopy techniques. Our results demonstrate that photosynthetic sponges are abundant in temperate WA, with an average of 63% of sponge individuals hosting high levels of photosynthetic symbionts and 11% with low to medium levels. These percentages of photosynthetic sponges are comparable to those found on tropical reefs and may have important implications for ecosystem function on temperate reefs in other areas of the world. A diverse range of symbionts sometimes occurred within a small geographic area, including the three "big" cyanobacterial clades, <it>Oscillatoria spongeliae</it>, "<it>Candidatus </it>Synechococcus spongiarum" and <it>Synechocystis </it>species, and it appears that these clades all occur in a wide range of sponges. Additionally, spongin-permeating red algae occurred in at least 7 sponge species. This study provides the first investigation of the molecular phylogeny of rhodophyte symbionts in sponges.</p> <p>Conclusion</p> <p>Photosynthetic sponges are abundant and diverse in temperate WA, with comparable percentages of photosynthetic to non-photosynthetic sponges to tropical zones. It appears that there are three common generalist clades of cyanobacterial symbionts of sponges which occur in a wide range of sponges in a wide range of environmental conditions.</p

Patterns of sponge biodiversity in the Pilbara, Northwestern Australia

This study assessed the biodiversity of sponges within the Integrated Marine and Coastal Regionalisation for Australia (IMCRA) bioregions of the Pilbara using datasets amalgamated from the Western Australian Museum and the Atlas of Living Australia. The Pilbara accounts for a total of 1164 Linnean and morphospecies. A high level of “apparent endemism” was recorded with 78% of species found in only one of six bioregions, with less than 10% confirmed as widely distributed. The Ningaloo, Pilbara Nearshore and Pilbara Offshore bioregions are biodiversity hotspots (>250 species) and are recognised as having the highest conservation value, followed by North West Shelf containing 232 species. Species compositions differed between bioregions, with those that are less spatially separated sharing more species. Notably, the North West Province bioregion (110 species) exhibited the most distinct species composition, highlighting it as a unique habitat within the Pilbara. While sponge biodiversity is apparently high, incomplete sampling effort for the region was identified, with only two sampling events recorded for the Central West Transition bioregion. Furthermore, only 15% of records in the dataset are presently described (Linnean) species, highlighting the continuing need for taxonomic expertise for the conservation and management of marine biodiversity resource

Naturally prefabricated marine biomaterials: Isolation and applications of flat chitinous 3D scaffolds from Ianthella labyrinthus (demospongiae: Verongiida)

Marine sponges remain representative of a unique source of renewable biological materials. The demosponges of the family Ianthellidae possess chitin-based skeletons with high biomimetic potential. These three-dimensional (3D) constructs can potentially be used in tissue engineering and regenerative medicine. In this study, we focus our attention, for the first time, on the marine sponge Ianthella labyrinthus Bergquist & Kelly-Borges, 1995 (Demospongiae: Verongida: Ianthellidae) as a novel potential source of naturally prestructured bandage-like 3D scaffolds which can be isolated simultaneously with biologically active bromotyrosines. Specifically, translucent and elastic flat chitinous scaffolds have been obtained after bromotyrosine extraction and chemical treatments of the sponge skeleton with alternate alkaline and acidic solutions. For the first time, cardiomyocytes differentiated from human induced pluripotent stem cells (iPSC-CMs) have been used to test the suitability of I. labyrinthus chitinous skeleton as ready-to-use scaffold for their cell culture. Results reveal a comparable attachment and growth on isolated chitin-skeleton, compared to scaffolds coated with extracellular matrix mimetic Geltrex®. Thus, the natural, unmodified I. labyrinthus cleaned sponge skeleton can be used to culture iPSC-CMs and 3D tissue engineering. In addition, I. labyrinthus chitin-based scaffolds demonstrate strong and efficient capability to absorb blood deep into the microtubes due to their excellent capillary effect. These findings are suggestive of the future development of new sponge chitin-based absorbable hemostats as alternatives to already well recognized cellulose-based fabrics. © 2019 by the authors. Licensee MDPI, Basel, Switzerland

Naturally drug-loaded chitin: Isolation and applications

Naturally occurring three-dimensional (3D) biopolymer-based matrices that can be used in different biomedical applications are sustainable alternatives to various artificial 3D materials. For this purpose, chitin-based structures from marine sponges are very promising substitutes. Marine sponges from the order Verongiida (class Demospongiae) are typical examples of demosponges with well-developed chitinous skeletons. In particular, species belonging to the family Ianthellidae possess chitinous, flat, fan-like fibrous skeletons with a unique, microporous 3D architecture that makes them particularly interesting for applications. In this work, we focus our attention on the demosponge Ianthella flabelliformis (Linnaeus, 1759) for simultaneous extraction of both naturally occurring (“ready-to-use”) chitin scaffolds, and biologically active bromotyrosines which are recognized as potential antibiotic, antitumor, and marine antifouling substances. We show that selected bromotyrosines are located within pigmental cells which, however, are localized within chitinous skeletal fibers of I. flabelliformis. A two-step reaction provides two products: treatment with methanol extracts the bromotyrosine compounds bastadin 25 and araplysillin-I N20 sulfamate, and a subsequent treatment with acetic acid and sodium hydroxide exposes the 3D chitinous scaffold. This scaffold is a mesh-like structure, which retains its capillary network, and its use as a potential drug delivery biomaterial was examined for the first time. The results demonstrate that sponge-derived chitin scaffolds, impregnated with decamethoxine, effectively inhibit growth of the human pathogen Staphylococcus aureus in an agar diffusion assa

Assessing the complex sponge microbiota: core, variable and species-specific bacterial communities in marine sponges

Marine sponges are well known for their associations with highly diverse, yet very specific and often highly similar microbiota. The aim of this study was to identify potential bacterial sub-populations in relation to sponge phylogeny and sampling sites and to define the core bacterial community. 16S ribosomal RNA gene amplicon pyrosequencing was applied to 32 sponge species from eight locations around the world's oceans, thereby generating 2567 operational taxonomic units (OTUs at the 97% sequence similarity level) in total and up to 364 different OTUs per sponge species. The taxonomic richness detected in this study comprised 25 bacterial phyla with Proteobacteria, Chloroflexi and Poribacteria being most diverse in sponges. Among these phyla were nine candidate phyla, six of them found for the first time in sponges. Similarity comparison of bacterial communities revealed no correlation with host phylogeny but a tropical sub-population in that tropical sponges have more similar bacterial communities to each other than to subtropical sponges. A minimal core bacterial community consisting of very few OTUs (97%, 95% and 90%) was found. These microbes have a global distribution and are probably acquired via environmental transmission. In contrast, a large species-specific bacterial community was detected, which is represented by OTUs present in only a single sponge species. The species-specific bacterial community is probably mainly vertically transmitted. It is proposed that different sponges contain different bacterial species, however, these bacteria are still closely related to each other explaining the observed similarity of bacterial communities in sponges in this and previous studies. This global analysis represents the most comprehensive study of bacterial symbionts in sponges to date and provides novel insights into the complex structure of these unique associations

Multidimensional signals and analytic flexibility: Estimating degrees of freedom in human speech analyses

Recent empirical studies have highlighted the large degree of analytic flexibility in data analysis which can lead to substantially different conclusions based on the same data set. Thus, researchers have expressed their concerns that these researcher degrees of freedom might facilitate bias and can lead to claims that do not stand the test of time. Even greater flexibility is to be expected in fields in which the primary data lend themselves to a variety of possible operationalizations. The multidimensional, temporally extended nature of speech constitutes an ideal testing ground for assessing the variability in analytic approaches, which derives not only from aspects of statistical modeling, but also from decisions regarding the quantification of the measured behavior. In the present study, we gave the same speech production data set to 46 teams of researchers and asked them to answer the same research question, resulting insubstantial variability in reported effect sizes and their interpretation. Using Bayesian meta-analytic tools, we further find little to no evidence that the observed variability can be explained by analysts’ prior beliefs, expertise or the perceived quality of their analyses. In light of this idiosyncratic variability, we recommend that researchers more transparently share details of their analysis, strengthen the link between theoretical construct and quantitative system and calibrate their (un)certainty in their conclusions

A taxonomic study of tropical marine sponges (Porifera: Demospongiae: Haplosclerida and Petrosida) using morphological, chemical and reproductive character sets

This study was undertaken to determine whether the separation of sponge species (Phylum: Porifera, Class: Demospongiae, Subclass: Ceractinomorpha) into two orders, the Haplosclerida and Petrosida, was valid. To this end selected species from each order were collected from the Great Barrier Reef, Queensland, Australia. Their taxonomic position was compared using a number of character sets: morphological, chemical and reproductive.\ud \ud The most useful morphological characters for taxonomic purposes were organisation of the internal sponge skeleton, its components and their quantities. These characters allowed separation of the sponge species examined into five families, and also distinguished sponges at the species level. Development of the ectosomal skeleton was found to differentiate genera, and microscleres were useful for distinguishing some species.\ud \ud As a result of the morphological study four new species of Haplosclerida and three new species of Petrosida were described.\ud \ud Analyses of sterol chemistry did not support clear separation of sponge species into two orders but were found to be useful at the species level. Sponge species were found to have both a qualitative and quantitative sterol fingerprint. Sterol complements of species remained remarkably constant with geographic locality and season. This character set provided evidence for a species complex within Xestospongia muta. Three specimens of this species contained significantly different sterol complements, and two of the specimens were more similar to other species in the data set (Xestospongia n.sp.1 and X. testudinaria) than they were to each other. Results of this chemotaxonomic study suggest that most species currently classified in the same genus are generic complexes, as few species of the same genus had similar sterol complements. No cyclopropene or cyclopropane ring structures, previously thought to characterise species of the Petrosida, were found in the side chains of the fifty four sterols found from all species examined.\ud \ud The reproductive biology of six species, three classified in the Haplosclerida and three in the Petrosida, was monitored for two to four years. The reproductive mode of these species clearly separated them into two orders. Species of the Haplosclerida were found to brood larvae which is the normal reproductive mode of the subclass Ceractinomorpha. Species of the Petrosida did not conform to the normal ceractinomorph pattern. The three species examined (Xestospongia exigua, X. testudinaria and Xestospongia n.sp.1) had separate sexes and broadcast eggs and sperm.\ud \ud Reproductive characters also distinguished sponges at the species level. One species complex, in the Petrosida, was differentiated into two species (X. testudinaria and Xestospongia n.sp.1) when temporal isolation of spawning events was discovered. The spawning events of the two species were consistently separated by at least 15 days and diel timing of these events in both species was from 0700 hours. The mechanism, and possible environmental cues, whereby these species consistently separate their spawning events was not determined although X. testudinaria may have a semi-lunar periodicity. No lunar pattern was observed for Xestospongia n.sp.1. Larva of Xestospongia n.sp.1 were seen in aquaria three days after the spawning event in 1989. This is the first reported observation of larva from a species of the Petrosida.\ud \ud Two haplosclerid species found to brood female reproductive products did so in brood chambers situated basally in sponge individuals. This location may be a protective mechanism to avoid damage from turbulence or dehydration. Females of a third haplosclerid species, Haliclona symbiotica, had reproductive products aligned along the central axis of branches of adults. This location of sexual products is most 4-Iy a spatial confinement related to the symbiotic association this sponge maintains with the macroalga, Ceratodictyon spongiosum.\ud \ud All species of both orders examined that were reproductively active released sexual products in spring and summer.\ud \ud As a result of this study, one character set (reproductive mode) clearly supported the division of species into two orders. Sterol chemistry and morphological characters did not, but were useful at lower taxonomic levels. The distrepancies between higher taxonomic groupings, such as genus and family, suggests the taxonomy of these sponges is not currently resolved

REVISION OF THE MARINE SPONGE GENUS CAULOSPONGIA SAVILLE KENT, 1871 (DEMOSPONGIAE HADROMERIDA). Part 1. MORPHOLOGICAL AND SKELITAL CHARACTERS

Volume: 19Start Page: 65End Page: 8