In the search of bioactive compounds from marine sponges from Mauritius Waters, a preliminary cytotoxic assessment of their extracts was conducted. Marine sponges are important sources of secondary metabolites with the potential of treating human diseases such as cancer, a range of viral diseases, Alzheimer, malaria, and inflammations. The ethyl acetate, hexane and methanol extracts obtained from 26 species were evaluated at 50 μg/mL by MTT assay on HeLa, KB and HL-60 cancer cells. Statistical analysis showed that the ethyl acetate extracts had an average of 56.7% cytotoxicity and were more potent than hexane (44.2%) and methanol (33.4%) extracts. Further studies by MTS assay of selected extracts on KB cells showed IC50 values of 0.48 μg/mL, 85 ng/mL and 0.5 ng/mL for Biemna tubulata (BTUE), Epipolasis suluensis (ESE) and Hyrtios sp (HYSE) respectively. The IC50 values of BTUE, ESE and HYSE on HL-60 cells were 1.44 μg/mL, 2.28 μg/ mL and 1.3 ng/mL respectively. HYSE was more active that BTUE and ESE as it displayed IC50 values at nano-level concentrations on KB and HL-60. HYSE induces early apoptosis at 2 ng/mL after 24 h treatment of HL-60 cells and the effect is dose-dependent without blockage of the cell cycle. Conversely BTUE and ESE elicited a moderate blockade of the cell cycle at the micromolar level associated with apoptosis. Further research is required to identify chemical components in HYSE, BTUE, and ESE. *Correspondence to: Avin Ramanjooloo, Mauritius Oceanography Institute, Avenue des Anchois, Morcellement de Chazal, Albion, Mauritius, E-mail: aramanjooloo@moi.intnet.mu

Phylogeography of animals provides clues to processes governing their evolution and diversification. The Indian Ocean has been hypothesized as a 'dispersal corridor' connecting hydrothermal vent fauna of Atlantic and Pacific oceans. Stalked barnacles of the family Eolepadidae are common associates of deep-sea vents in Southern, Pacific and Indian oceans, and the family is an ideal group for testing this hypothesis. Here, we describe Neolepas marisindica sp. nov. from the Indian Ocean, distinguished from N. zevinae and N. rapanuii by having a tridentoid mandible in which the second tooth lacks small elongated teeth. Morphological variations suggest that environmental differences result in phenotypic plasticity in the capitulum and scales on the peduncle in eolepadids. We suggest that diagnostic characters in Eolepadidae should be based mainly on more reliable arthropodal characters and DNA barcoding, while the plate arrangement should be used carefully with their intraspecific variation in mind. We show morphologically that Neolepas specimens collected from the South West Indian Ridge, the South East Indian Ridge and the Central Indian Ridge belong to the new species. Molecular phylogeny and fossil evidence indicated that Neolepas migrated from the southern Pacific to the Indian Ocean through the Southern Ocean, providing key evidence against the 'dispersal corridor' hypothesis. Exploration of the South East Indian Ridge is urgently required to understand vent biogeography in the Indian Ocean.

DNA sequence alignment data for phylogeographic analysis of the present study

Novel quaternary ammonium compounds (QUATS) derived from L-Tyrosine and L-3,4-dihydroxyphenylalanine (L-DOPA) with chain lengths varying from C-10 to C-16 were synthesised and their physicochemical properties were determined. The CMCs of the QUATS were higher than their corresponding ester hydrochloride derivatives due to the increase in bulkiness of the head group in the micellar structure as confirmed by H-1 NMR spectroscopic investigations of the QUATS in DMSO d(6)-D2O system. The antibacterial effectiveness of the QUATS was evaluated against gram positive and gram negative bacteria and was found to possess good to excellent antibacterial properties. The QUAT tyrosine derivatives showed an optimum activity at C-14 and C-12 with respect to gram positive and negative strains respectively, while the C-12 QUAT DOPA derivative displayed optimal activity against both strains. The elucidation of their mode of action was studied by their interaction with 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) vesicles and the QUATS were found to interact with DPPC via both electrostatic and hydrophobic interactions. The toxicity of these compounds was assessed by their hemolytic activities and in vitro cytotoxicity against epidermoid carcinoma (KB) and lung fibroplast cells (MRC-5). Correlation of the MIC and HC50 with the CMC showed that the monomeric form of the QUATS displayed better antibacterial and lower hemolytic activities over their micellar form, showing that these compounds can act as antibacterial agents at monomeric concentrations, yet being non-hemolytic at these concentrations. Cytotoxicity evaluation showed an increase in activity with chain length of the tyrosine QUATS, with an increasing selectivity towards the cancer cells over normal cells. (C) 2016 Elsevier B.V. All rights reserved.

Actinobacteria commonly known as actinomycetes are often constituents of the sponge-associated bacterial communities and are well known producers of bioactive compounds. In the present study, 7 actinomycete species representing 3 genera were successfully isolated from the sponge Spheciospongia vagabunda (Ridley, 1884) and Neopetrosia exigua (Kirkpatrick, 1900) from Mauritius. The sponge N. exigua hosted a higher actinomycete diversity resulting in 71% of the total number of actinomycete strains recorded. Streptomyces sp. and Micrococcus sp. were the most common actinomycete genera, both representing 43% of the total actinomycetes isolated from both host sponges. Actinomycete Isolation Agar was the most effective medium for the selection of actinobacteria, yielding in 57% of the total actinobacterial strains isolated. This study is the first to report on sponge-associated actinomycete communities from Mauritius and paves the way for future sponge-associated actinobacterial research in the Mascarene region.

Fluid chemistry and microbial community patterns in chimney habitats were investigated in two hydrothermal fields located at the Central Indian Ridge. Endmember hydrothermal fluid of the Solitaire field, located similar to 3 km away from the spreading center, was characterized by moderately high temperature (307 degrees C), Cl depletion (489 mM), mildly acidic pH (>= 4.40), and low metal concentrations (Fe <= 105 mu M and Mn = 78 mu M). Chloride depletion indicates that the subseafloor source fluid had undergone phase separation at temperatures higher than similar to 390 degrees C while the metal depletion was likely attributable to fluid alteration occurring at a venting temperature of around 307 degrees C. These different temperature conditions suggested from fluid chemistry might be associated with an off-spreading center location of the field that allows subseafloor fluid cooling prior to seafloor discharge. The microbial community in the chimney habitat seemed comparable to previously known patterns in typical basalt-hosted hydrothermal systems. Endmember hydrothermal fluid of the Dodo field, standing on center of the spreading axis, was characterized by high H-2 concentration of 2.7 mM. The H-2 enrichment was likely attributable to fresh basalt-fluid interaction, as suggested by the nondeformed sheet lava flow expansion around the vents. Thermodynamic calculation of the reducing pyrite-pyrrhotite-magnetite (PPM) redox buffer indeed reproduced the H2 enrichment. The quantitative cultivation test revealed that the microbial community associated with the hydrothermal fluid hosted abundant populations of (hyper) thermophilic hydrogenotrophic chemolithoautotrophs such as methanogens. The function of subseafloor hydrogenotrophic methanogenic populations dwelling around the H-2-enriched hydrothermal fluid flows was also inferred from the C-13-and D-depleted signature of CH4 in the collected fluids. It was observed that the hydrothermal activity of the Dodo field had ceased until 2013.

This report describes the use of α-glucosidase to evaluate the anti-diabetic potential of extracts from marine sponges collected in the Mauritius waters. Initial screening at 1.0 mg/mL of 141 extracts obtained from 47 sponge species revealed 10 extracts with inhibitory activity greater than 85%. Seven of the 10 extracts were further tested at 0.1 and 0.01 mg/mL and only the methanol extract of two sponges namely Acanthostylotella sp. (ASSM) and Echinodictyum pykei (EPM) showed inhibition activity greater than 60% at 0.1 mg/mL with an IC50 value of 0.16 ± 0.02 and 0.04 ± 0.01 mg/mL, respectively, while being inactive at 0.01 mg/mL.

The present study aimed at validating the phytomedicinal properties of selected species from the Asteraceae family, namely Psiadia arguta (Pa), Psiadia viscosa (Pv) Psiadia lithospermifolia (Pl) , and Distephanus populifolius (Dp). Hexane, ethyl acetate, and methanol leaf extracts were studied for their antioxidant properties and antibacterial activity. The phenolics levels varied from 24.05 to 231.6 mg gallic acid equivalent/g with the maximum level in methanol extracts of Pa and Dp. The highest flavonoids and proanthocyanidins content were noted in Pa methanolic extract with 65.7 mg quercetin/g and 25.05 mg catechin/g extract, respectively. Pa polar extracts had also the maximum free radical scavenging activity(DPPH) with IC50 11.31 and 11.6 μg/ml respectively. The maximum ferric reducing potential(FRAP) was noted in Pl methanol extracts 281.60 mmol Fe2+/g extract. The antioxidant capacity based on DPPH and FRAP values were positively correlated to total phenolics, flavonoid and proanthocyanidins. All four species exhibited antimicrobial activity against the tested bacteria (both Gram-negative and Gram-positive). Hexane and ethyl acetate extracts of Psiadia species were the most promising extracts, with the lowest minimum inhibitory concentrations (MIC) values ranging from 19.53 to78.125 μg/ml. Keywords— antibacterial, DPPH, flavonoids, FRAP, Psiadia spp.

Over the past 40years, there have been few reports describing marine natural product chemistry and related research from Mauritius. These came out from expeditions starting in the early 1970s by research groups of Dr. Petitt from the University of Arizona, followed by a latent phase to re-emerge as an area of potential scientific interest in early 2000s by investigation of the research group of Dr. Marie from the Mauritius Oceanography Institute. The natural product chemistry of Mauritius marine flora and fauna is relatively unknown and this review provides an overview of the contribution made by several groups towards the isolation, identification and bioactivity determination of these marine-derived natural products. The marine organisms reviewed include invertebrates, plants and microorganisms, emphasizing the biodiversity found in the vast Exclusive Economic Zone (EEZ) of Mauritius.

OBJECTIVES:Based on previous screening results, the cytotoxic effect of the hexane (JDH) and ethyl acetate extracts (JDE) of the marine sponge Jaspis diastra were evaluated on HeLa cells and the present study aimed at determining their possible mechanism of cell death.METHODS:Nuclear staining, membrane potential change, flow cytometry analysis of cell cycle distribution and annexin V staining were undertaken to investigate the effects of JDE and JDH. Electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance were used to characterize an isolated bioactive molecule.KEY FINDINGS:JDE displayed an IC50 25 times more significant than the JDH. Flow cytometry analysis revealed JDE induced apoptosis in HeLa cells accompanied by the collapse of mitochondrial membrane potential. Fractionation of JDE resulted in the isolation of the known cytotoxic cyclodepsipeptide, Jaspamide.CONCLUSIONS:Taking our results together suggest that JDE can be valuable for the development of anticancer drugs, especially for cervical cancer. Further investigations are currently in progress with the aim to determine and isolate other bioactive compounds from this extract.

The distribution and abundance of the sponge Spheciospongia vagabunda (Ridley, 1884) was investigated in a shallow lagoon (Albion) of Mauritius (Western Indian Ocean). Sponge abundance and environmental parameters were assessed. Sponges in Albion lagoon were mostly distributed in the central part of the lagoon some distance from wave action. Two distinctive sponge patches were found, the largest patch being 15350 m2 in area. Unlike most Porifera, S. vagabunda was mostly anchored in sand and not on hard substratum. A t-test revealed a significant difference in sponge size between sponge assemblages (t = 3.01; p < 0.05). One-way ANOVA indicated that environmental parameters did not influence sponge abundance within the lagoon (p <0.05). This study provides a baseline for future monitoring of these benthic animals in the Albion lagoon. Corresponding author: SSB Email: sann_1205@hotmail.com INTRODUCTION The Phylum Porifera is the oldest metazoan group found in our oceans (Müller, 1995). They have highly effective chemical defences to discourage predators, contributing to their evolutionary success (Finks, 1970; Randall & Hartman, 1968). Sponges are widely represented in freshwater (Cocchiglia et al., 2013) as well as in most marine ecosystems (Worheide et al., 2012). Spheciospongia vagabunda (Ridley, 1884) is an Indo-Pacific sponge (Family Clionaidae) found in coastal lagoons (Levi, 1998; Sutcliffe et al., 2010). Sponges of the genus Spheciospongia have been most documented in Singapore (Cheng et al., 2008; Lim et al., 2012). Spheciospongia vagabunda is very well adapted to shallow water environments Cheng et al., 2008) and has the ability to survive in the intertidal zone (Lim et al., 2012). Sponges are of ecological and biopharmaceutical importance. Polychaetes, molluscs and crustaceans have been found associated with Spheciospongia spp. (Pearse, 1950; Westinga & Hoetjes, 1981) and bioactive compounds such as glycolipids (Costantino et al., 2008) and sterols (Arreguin-Espinosa et al. 1999) have been extracted from Spheciospongia vesparium (Lamarck, 1815). Two new O-glycosylated angucyclines were recently isolated from S. vagabunda from the Red Sea (Abdelmohsen et al., 2014). The distribution of sponges usually depends on a number of physical and biological parameters (Knapp & Bell, 2010) such as depth (Nunez Flores et al., 2010), turbidity (Zea, 1994), salinity (Roberts et al., 2006), water flow (Bell & Barnes, 2003), nutrient concentration (Wilkinson & Cheshire, 1989), substratum type (Bell & Barnes, 2000a; Powell et al., 2010) and predation (Waddell & Pawlik, 2000). The abundance and diversity of most sponge species increase with depth (Sorokin & Currie, 2009). For example, Knapp & Bell (2010) have reported the influence of depth on sponge assemblages in lagoons in Palmyra Atoll. It is known that marine sponges avoid turbid waters since particulate matter in the water column often clogs their oscula, hindering respiration and feeding (Roberts et al., 2006). The influence of salinity and pH on sponges is less understood than depth and turbidity, and seems to be species-dependent. Hitherto, no studies have reported the effects of salinity or pH on Spheciospongia spp. but some studies have focused on the influence of the aforementioned parameters on Cliona celata Grant, 1826 (Family: Clionidae) (Emson, 1966; Miller et al., 2010; Duckworth & Peterson, 2012). Miller et al. (2010) reported that C. celata can withstand high salinity changes of up to 42 PSU but, in contrast, low pH values negatively affected it (Emson, 1966; Duckworth & Peterson, 2012). Compared to other tropical ecosystems, such as those in the Caribbean (Pawlik, 2011) and Indonesia (Bell & Smith, 2004), few studies (e.g. Barnes & Bell, 2002) have focused on the distribution and abundance of sponges in the Mascarene region. Recent studies on Mauritian sponges have focused mainly on their biological activity in terms of marine natural products (Marie et al., 2013). This study constitutes the first investigation of S. vagabunda (Ridley, 1884) in the lagoon of Albion. The distribution of S. vagabunda was thus mapped in Albion and their abundance, size and preferred substrata were investigated. The influence of environmental parameters (water depth, turbidity, salinity and pH) on its abundance was also taken into consideration. MATERIALS and METHODS

The macrofaunal community associated with the sponge Neopetrosia exigua (Kirkpatrick, 1900) were studied across a Mauritian lagoon (West Indian Ocean). A total of 191 individuals belonging to 18 macro-invertebrate species were found in association with the host sponge collected at depths of 1.4 – 2.7 m. Polychaetes and amphipods mostly inhabited the sponge canals whereas crabs and brittle stars were found at bases of the sponges. The most speciose taxon was Crustacea (61%, 11 spp.), followed by Polychaeta (33%, 6 spp.) and Echinodermata (6%, 1 sp.). However, the most dominant species was the polychaete Haplosyllis djibouitensis (Gravier, 1900) representing 71% of total number of specimens collected. The number of species and individuals and the diversity index values were positively, but the evenness index values were negatively correlated with the sponge volume and water depth. The sponge N. exigua provides shelter and food for a number of invertebrates and contributes to the maintenance of biodiversity in the lagoon.

Purpose: To investigate the antimicrobial activity of crude and fractionated extracts of Biemna tubulosa and Stylissa spp. thriving in Trou aux Biches lagoon, North East Mauritius.Methods: Crude extracts (methanol: dichloromethane 1: 1) and fractions of Biemna tubulosa and Stylissa spp (hexane, ethyl acetate and butanol) were tested against some bacterial organisms, namely, Escherichia coli, Staphylococcus aureus and Enterococcus faecalis, using broth microdilution assay. The extracts were screened for the presence of compounds that could be responsible for bioactivity.Results: Preliminary chemical screening revealed the presence of tannins, saponins, terpenes, alkaloids and phenols. The hexane fraction of Stylissa spp. and the ethyl actetate and butanol extracts of Biemna tubulosa were more active than the control antibiotic. Maximum antimicrobial activity was noted for the butanol fraction of Biemna tubulosa with minimum inhibitory concentration (MIC) of 0.091 mg/ml against E. coli. The hexane soluble fraction of Stylissa spp. was more active with MIC of 0.125 mg/ml against S. aureus and E. coli and 0.250 mg/ml against E. faecalis.Conclusion: The broad spectrum antibacterial activity of these sponges seemed to be due to the presence of sesterterpenes and triterpenes, alkaloids and tannins detected in the extract fractions. This is probably the first report on the antimicrobial activity of Biemna tubulosa and Stylissa spp. from Mauritius waters.

As part of our ongoing studies on bioactive natural products from marine sponges, we investigated the cytotoxic potential of extracts from the new sponge Petrosia tuberosa sampled from Mauritius waters. Bioguided fractionation of the ethyl acetate extract by vacuum liquid chromatography (VLC) revealed two fractions, namely VLC (6-9) and (13-17) showing cell deaths of 86 ± 1% and 88 ± 4%, respectively, at 50 μg/mL on HeLa cells. At 10 μg/mL, only VLC (13-17) displayed a significant cell death (56 ± 7%) compared with VLC (6-9) (8 ± 1 %). The cytotoxic activity of VLC (13-17) was also determined on nine other human cancer cell lines. Clonogenic assay, mitochondrial membrane potential change, DNA fragmentation and microscopic analysis of fraction VLC (13-17) revealed distinct features of apoptosis on HeLa cells. Further fractionation and purification of this fraction by chromatographic techniques resulted in isolation of one known secondary metabolite, petrosynol. Its structure was determined by 1 H and 13 C-NMR analyses.

Marine sponges are considered as a gold mine of new natural products possessing numerous biological activities. We examined the cytotoxic properties of the ethyl acetate extract (JDE) of the previously unrecorded sponge, Jaspis sp. collected from Mauritius Waters. JDE displayed an interesting IC50 of 0.057±0.04μg/mL on HL-60 cells evaluated by MTS assay. Mitochondrial membrane potential change, microscopic analysis and DNA fragmentation assays also confirmed JDE induced apoptosis on HL-60 cells. Annexin V staining demonstrated that JDE induced apoptosis at different concentrations. Treatment with 100ng/mL of JDE led to an accumulation of cells in G2/M phase after 24 h, causing a significant increase of cells (24h: 5.84%; 48h: 13.41%) in sub-G1 phase suggesting that JDE can induce cell cycle arrest in G2/M phase.

The distribution, abundance and physico-chemical parameters affecting the sponge Spheciospongia vagabunda were studied in a shallow lagoon (Albion) of Mauritius. Visual censuses were conducted along the 2 Km lagoon and GPS coordinates around sponge assemblages (patches) were noted. Sponge abundance and ecological parameters were assessed by random throws of quadrats and physico-chemical parameters, including water depth; salinity, pH, and turbidity were noted. A distribution map of Spheciospongia vagabunda was constructed on Google Earth. Two distinctive sponge patches with the largest patch averaging 15350 m 2 were identified. Spheciospongia vagabunda in Albion were mostly anchored in the sand which is an unlikely substratum for Poriferans. Some sponges were also observed next to the seagrass Syringodium filiforme . Statistical analysis (t-test) showed that there was a significant difference among sponge size between both sponge assemblages (t = 3.01; p < 0.05). One-way ANOVA analysis indicated that physico-chemical parameters of surrounding water did not influence the sponge abundance within the lagoon. Spheciospongia vagabunda were mostly distributed in shallow regions (3.3 sponge/m 2 at a depth of 1.18 m). This study adds to the lack of knowledge on Mauritian sponges and also acts as a baseline study for further monitoring of these benthic animals in the Albion lagoon.

Dispersal ability plays a key role in the maintenance of species in spatially and temporally discrete niches of deep-sea hydrothermal vent environments. On the basis of population genetic analyses in the eastern Pacific vent fields, dispersal of animals in the mid-oceanic ridge systems generally appears to be constrained by geographical barriers such as trenches, transform faults, and microplates. Four hydrothermal vent fields (the Kairei and Edmond fields near the Rodriguez Triple Junction, and the Dodo and Solitaire fields in the Central Indian Ridge) have been discovered in the mid-oceanic ridge system of the Indian Ocean. In the present study, we monitored the dispersal of four representative animals, Austinograea rodriguezensis, Rimicaris kairei, Alviniconcha and the scaly-foot gastropods, among these vent fields by using indirect methods, i.e., phylogenetic and population genetic analyses. For all four investigated species, we estimated potentially high connectivity, i.e., no genetic difference among the populations present in vent fields located several thousands of kilometers apart; however, the direction of migration appeared to differ among the species, probably because of different dispersal strategies. Comparison of the intermediate-spreading Central Indian Ridge with the fast-spreading East Pacific Rise and slow-spreading Mid-Atlantic Ridge revealed the presence of relatively high connectivity in the intermediate- and slow-spreading ridge systems. We propose that geological background, such as spreading rate which determines distance among vent fields, is related to the larval dispersal and population establishment of vent-endemic animal species, and may play an important role in controlling connectivity among populations within a biogeographical province.

Patients diagnosed with Alzheimer's disease (AD) show a characteristic neurochemical deficit of acetylcholine, especially in the basal forebrains. The use of acetylcholinesterase (AChE) inhibitors to retard the hydrolysis of acetylcholine has been suggested as a promising strategy for AD treatment. In this study, we evaluated the acetylcholinesterase inhibitory (AChEI) activities of 134 extracts obtained from 45 species of marine sponges. Thin-layer chromatography (TLC) and microplate assays reveal potent acetylcholinsterase inhibitory activities of two AcOEt extracts from the sponges Pericharax heteroraphis and Amphimedon navalis PULITZER-FINALI. We further investigated the inhibitory kinetics of the extracts and found them to display mixed competitive/noncompetitive inhibition and associated their inhibitory activity partly to terpenoids. Acetylcholinesterase inhibitors from marine organisms have been rarely studied, and this study demonstrated the potential of marine sponges as a source of pharmaceutical leads against neurodegenerative diseases.