Sponges as sentinels: Metal accumulation using transplanted sponges across a metal gradient.

To be effective sentinels, organisms must be able to be readily translocated to contamination hotspots. The authors sought to assess metal accumulation in genetically identical explants of a relatively common estuarine sponge, Suberites cf. diversicolor. Explants were transplanted to 7 locations across a metal contamination gradient in a large coastal estuary in southeastern Australia to establish, first, that explants of this species could be successfully translocated; second, that explants accumulated metals (cadmium, copper, lead, selenium, and zinc) sufficiently rapidly to be effective sentinels; third, that rates of metal accumulation in explants were in agreement with metal concentrations within sediments (<63-µm fraction) at each of the transplant locations; and finally, that changes in explant biomass correlated with overall metal load. Suberites were readily transplanted, with no mortality observed for the 2 mo of transplantation. Metal accumulation for lead, cadmium, and zinc was in close agreement with sediment metal concentrations, and explants showed dramatic increases in these metals in the heavily contaminated northern sections of the estuarine lake. No striking patterns were apparent for copper and selenium. Finally, growth was negatively correlated with total metal load and standardized total metal load in our explants. Taken together, these outcomes confirm that explants of this sponge are amenable to translocation and show considerable promise as biomonitors.

Bioactive compounds from marine sponges and their symbiotic microbes: a potential source of nutraceuticals.

Sponges are considered as the chemical factory in marine environment because of its immense production of chemically diverse compounds. Other than the chemical diversity, these compounds possess remarkable bioactivities. This great potential has aroused applications of sponge-derived compounds as therapeutics and at present, a number of promising compounds are in clinical and preclinical trials. Recently, nutraceuticals have received considerable interest among the health conscious community because of its multiple therapeutic effects. Natural health-promoting substances gain continuous popularity as nutraceuticals due to its reduced risk of side effects. This overview discusses the potentials of marine sponge-derived bioactivities as natural health-promoting compounds.

Crustose coralline algae and a cnidarian neuropeptide trigger larval settlement in two coral reef sponges.

In sessile marine invertebrates, larval settlement is fundamental to population maintenance and persistence. Cues contributing to the settlement choices and metamorphosis of larvae have important implications for the success of individuals and populations, but cues mediating larval settlement for many marine invertebrates are largely unknown. This study assessed larval settlement in two common Great Barrier Reef sponges, Coscinoderma matthewsi and Rhopaloeides odorabile, to cues that enhance settlement and metamorphosis in various species of scleractinian coral larvae. Methanol extracts of the crustose coralline algae (CCA), Porolithon onkodes, corresponding to a range of concentrations, were used to determine the settlement responses of sponge larvae. Cnidarian neuropeptides (GLW-amide neuropeptides) were also tested as a settlement cue. Settlement in both sponge species was approximately two-fold higher in response to live chips of CCA and optimum concentrations of CCA extract compared to 0.2 µm filtered sea water controls. Metamorphosis also increased when larvae were exposed to GLW-amide neuropeptides; R. odorabile mean metamorphosis reached 42.0±5.8% compared to 16.0±2.4% in seawater controls and in C. matthewsi mean metamorphosis reached 68.3±5.4% compared to 36.7±3.3% in seawater controls. These results demonstrate the contributing role chemosensory communication plays in the ability of sponge larvae to identify suitable habitat for successful recruitment. It also raises the possibility that larvae from distinct phyla may share signal transduction pathways involved in metamorphosis.

Comparison of spiculogenesis in in vitro ADCP-primmorph and explants culture of marine sponge Hymeniacidon perleve with 3-TMOSPU supplementation.

This study aims to test the feasibility of introducing functional chemical groups into biogenic silica spicules by examining the effect of supplementing a silican coupler [3-(trimethoxysilyl)propyl]urea (3-TMOSPU) as silica source in the cultures of archaeocytes-dominant-cell-population (ADCP) primmorphs and explants of the marine sponge Hymeniacidon perleve. Analysis by Fourier Transform Infrared Spectroscopy (FT-IR) confirmed that the organic group in 3-TMOSPU was introduced into silica spicules. By comparing ADCP-primmorph cultures when supplemented with Na2SiO3, 3-TMOSPU supplementation showed no notable effect on the primmorphs development and cell locomotion behaviors. A decline in silicatein expression quantified by real-time RT-PCR was, however, observed during spiculogenesis. The decline was slower for the 3-TMOSPU group whereas significantly fewer spicules were formed. When sponge papillae explants were cultured, 3-TMOSPU supplementation had no negative effect on sponge growth but inhibited the growth biofouling of the diatom Nitzschia closterium. By monitoring the detectable Si concentration, it seemed that 3-TMOSPU was converted by the sponge and its conversion was related to spiculogenesis. Analysis of spicule dimensional changes indicated that the inhibition of spiculogenesis by 3-TMOSPU supplementation was less in ADCP-primmorphs culture due to lower 3-TMOSPU/detectable Si ratio in the media.