Soft Coral Sarcophyton Glaucum Research Articles

LC-HRMS Profiling and Cytotoxic Potential of Actinomycetes Associated with the Red Sea Soft Coral Sarcophyton glaucum: In vitro and In silico Studies.

In the current study, the actinomycetes associated with the red sea-derived soft coral Sarcophyton glaucum were investigated in terms of biological and chemical diversity. Four different media, M1, ISP2, Marine Agar (MA), and Actinomycete isolation agar (AIA) were used for the isolation of three strains of actinomycetes that were identified as Streptomyces sp. UR 25, Micromonospora sp. UR32 and Saccharomonospora sp. UR 19. LC-HRMS analysis was used to investigate the chemical diversity of the isolated actinobacteria. The LC-HRMS data were statistically processed using MetaboAnalyst 5.0 viz to differentiate the extract groups and determine the optimal growth culturing conditions. Multivariate data statistical analysis revealed that the Micromonospora sp. extract cultured on (MA) medium is the most distinctive extract in terms of chemical composition. While, the Streptomyces sp. UR 25 extracts are differ significantly from Micromonospora sp. UR32 and Saccharomonospora sp. UR 19. Biological investigation using in vitro cytotoxic assay for actinobacteria extracts revealed the prominent potentiality of the Streptomyces sp. UR 25 cultured on oligotrophic medium against human hepatoma (HepG2), human breast adenocarcinoma (MCF-7) and human colon adenocarcinoma (CACO2) cell lines (IC50 =3.3, 4.2 and 6.8 μg/mL, respectively). SwissTarget Prediction speculated that among the identified compounds, 16-deethyl, indanomycin (8) could have reasonable affinity on HDM2 active site. In this respect, molecular docking study was performed for compound (8) to reveal a substantial affinity on HDM2 active site. In addition, molecular dynamics simulations were carried out at 200 ns for the most active compound (8) compared to the co-crystallized inhibitor DIZ giving deeper information regarding their thermodynamic and dynamic properties as well.

Unveiling the potential of marine-derived diterpenes from the order Alcyonacea as promising anti-obesity agents

Metabolic syndrome (MS) represents a global health challenge characterized by various metabolic disorders, including HOMA-IR (insulin resistance), obesity, dyslipidemia, and hypertension. In our pursuit of identifying natural alternatives for the development of effective and safe anti-obesity medications, we examined the potential of the methanolic extract of the Red Sea derived soft coral Sarcophyton glaucum, where serum levels of glucose, insulin, HOMA-IR, lipid profile, fetuin A and B, PTP1Β (Protein tyrosine phosphatase 1B), adropin and omentin were determined. Furthermore, the expression of the UCP1 (Uncoupling protein 1) and PPARGC1A (Peroxisome proliferator–activated receptor-g coactivator-1a) genes have been assessed, to evaluate the anti-obesity potential of S. glaucum organic extract. Our findings demonstrated a significant decrease in glucose, HOMA-IR, cholesterol, triglyceride, LDL-C, fetuin A and B, and PTP1Β levels, accompanied by a significant increase in insulin, HDL-C, adropin, omentin, UCP1, and PPARGC1A expression after treatment with the soft coral extract. These promising outcomes can be attributed to the remarkable ingredients present in the extract, which were further supported by histopathological findings. In addition, a virtual screening protocol including molecular docking (MDock) and Structure-Activity Relationships (SARs) of 27 marine diterpenes was also explored to identify potential PTP1Β inhibitors targeting simultaneously the catalytic site and allosteric site, as well as fetuin A modulators. Moreover, the six most promising predicted marine diterpenes (4, 8, 9, 10, 13 and 14) were investigated for their pharmacokinetic properties, druglike nature and medicinal chemistry friendliness using the SwissADME platform. Of these, four marine diterpenes (4, 8, 9, and 10) were predicted to exhibit the appropriate drug-like properties.

Cembranoids and their bioactivities in soft coral Sarcophyton glaucum

Chemical constituents in soft coral Sarcophyton glaucum were separated and purified by various chromatographic methods. Based on the spectral data, physicochemical properties, and comparison with the data reported in the literature, nine cembranoids, including a new cembranoid named sefsarcophinolide(1) together with eight known cembranoids, namely(+)-isosarcophine(2), sarcomilitatin D(3), sarcophytonolide J(4),(1S,3E,7E,13S)-11,12-epoxycembra-3,7,15-triene-13-ol(5), sarcophytonin B(6),(-)-eunicenone(7), lobophytin B(8), and arbolide C(9), were identified. As revealed by biological activity experiment results, compounds 2-6 had weak acetylcholinesterase inhibitory activity, and compound 5 displayed weak cytotoxicity against K562 tumor cell line.

Investigating the hepatoprotective potentiality of marine-derived steroids as promising inhibitors of liver fibrosis.

It has been reported that organic extracts derived from soft corals belonging to the genus Sarcophyton have exhibited a wide range of therapeutic characteristics. Based on biochemical and histological techniques, we aimed to assess the hepatoprotective role of the organic extract and its principal steroidal contents derived from the Red Sea soft coral Sarcophyton glaucum on acetaminophen-induced liver fibrosis in rats. Serum liver function parameters (ALT, AST, ALP and total bilirubin) were quantified using a spectrophotometer, and both alpha-fetoprotein (AFP) and carcinoembryonic antigen (CEA) levels were determined by using enzyme-linked immunosorbent assay (ELISA) kits while transformed growth factor beta (TGF-β) and tumor necrosis factor α (TNF-α) in liver tissue homogenate were determined using ELISA, and TGF-β and TNF-α gene expression in liver tissue was determined using real-time PCR following extraction and purification. Histopathological alterations in hepatic tissue were also examined under a microscope. In order to prioritize the isolation and characterization of the most promising marine steroids from the organic extract of the Red Sea soft coral Sarcophyton glaucum as hepatoprotective agents, a computational approach was employed. This approach involved molecular docking (MDock) and analysis of the structure-activity relationship (SAR) against glutathione-S-transferase (GST) and Cu-Zn human superoxide dismutase (Cu-ZnSOD) enzymes. Although the major role in the detoxification of foreign chemicals and toxic metabolites of GST and SOD enzymes is known, there is a lack of knowledge about the mode of action of the hepatoprotective process and those of the targets involved. The present study investigated the multiple interactions of a series of marine steroids with the GST and SOD enzymes, in order to reveal insights into the process of hepatoprotection.

Cembranoids from the Red Sea soft coral Sarcophyton glaucum protect against indomethacin-induced gastric injury.

Soft corals and their secondary metabolites represent an exceptional source of potential drugs. In this regard, Sarcophyton glaucum-derived secondary metabolites were examined for their preventive activities against indomethacin-induced gastric ulcer. Extraction and chromatographic processing of a specimen of S. glaucum collected from the Red Sea waters of Jeddah city resulted in the isolation of eight metabolites including two furanone-based cembranoids (1 and 2), two known pyran-based cembranoids (3 and 4), a known aromadendrene derivative (5), a δ-lactone fatty acid derivative (6), and two known gorgostane-type sterols (7 and 8). Compounds 1 and 6 are new chemical structures, named Δ12(20)-sarcophine and sarcoglaucanoate, respectively. In an initial pilot experiment, compounds 1 and 2 showed significant protective activities against indomethacin-induced peptic ulcer in rats. These datawere evidenced by their ability to ameliorate the elevated ulcer indices and prevent histopathological alterations observed in the untreated animals. Their effects were mediated by enhanced mucin as shown by Alcian blue and periodic acid-Schiff (PAS) staining of stomach sections. Compounds 1 and 2 exerted significant antioxidant properties as they prevent reduced glutathione (GSH) depletion, malondialdehyde (MDA) accumulation, and superoxide dismutase (SOD) exhaustion. Furthermore, immunohistochemical analyses indicated that both compounds inhibited the expression of interleukin-6 (IL-6) and tumor necrosis-α (TNF-α) as compared to indomethacin alone-treated animals. These actions were accompanied by significant enhancement of tumor growth factor-β (TGF-β) expression. In conclusion, two cembranoids exhibited protective activities against indomethacin-induced peptic ulcer. This is, at least partly, mediated by their pro-mucin, antioxidant, anti-inflammatory, and TGF-β stimulating properties.

Accumulation of commonly used agricultural herbicides in coral reef organisms from iSimangaliso Wetland Park, South Africa

Coral reefs are amongst the most biodiverse ecosystems on earth, but are significantly impacted by agricultural runoff. Despite herbicides being commonly detected in coastal waters, the possibility of herbicide accumulation in coral reef species has largely been overlooked. We investigate the accumulation of several herbicides in five species of coral reef invertebrates collected from ten sites along the Maputaland coast, South Africa. Multiple herbicide residues were detected in 95% of the samples, with total average concentrations across sites ranging between 25.2 ng g−1 to 51.3 ng g−1 dw. Acetochlor, alachlor and hexazinone were the predominant herbicides detected at all sites, with atrazine and simazine detected less frequently. Significant interactive effects were detected between sites nested in reef complex crossed with species, based on multiple and total herbicide concentrations. In general, multivariate herbicide concentrations varied significantly between species within and across most sites. Contrastingly, the concentrations of the different herbicides and that of total herbicide did not differ between conspecifics at most sites nested in their respective reef complexes. On average, highest total herbicide concentrations were measured in soft coral (Sarcophyton glaucum; 90.4 ± 60 ng g−1 and Sinularia gravis; 42.7 ± 25 ng g−1) and sponge (Theonela swinhoei; 39.0 ± 40 ng g−1) species, while significantly lower concentrations were detected in hard corals (Echinopora hirsutissima; 10.5 ± 5.9 ng g−1 and Acropora austera; 5.20 ± 4.5 ng g−1) at most sites. Agricultural runoff entering the ocean via the uMfolozi-St Lucia Estuary and Maputo Bay are likely sources of herbicide contamination to coral reefs in the region. There is an urgent need to assess the long-term effects of herbicide exposure on coral reef communities.

Xishaglaucumins A—J, New Cembranoids with Anti‐Inflammatory Activities from the South China Sea Soft Coral Sarcophyton glaucum

Comprehensive SummaryTen new cembrane‐type diterpenoids, namely xishaglaucumins A—J (1—10), along with ten known related ones (11—20), have been isolated from the soft coral Sarcophyton glaucum collected off the Xisha Island in the South China Sea. Their structures were elucidated by extensive spectroscopic analysis, quantum mechanical nuclear magnetic resonance (QM‐NMR) methods, X‐ray diffraction analysis, chemical methods and comparison with the reported data in the literature. The absolute configuration of new compounds 1, 5 and known compounds 11, 12, 16 and 20 were determined either by chemical methods or by X‐ray diffraction analysis using Cu Kα (λ = 1.5417 Å). In in vitro bioassay, compound 4 exhibited inhibitory effects on lipopolysaccharide (LPS)‐induced inflammatory responses in BV‐2 microglial cells.

Ximaoglaucumins A − F, new cembranoids with anti-inflammatory activities from the South China Sea soft coral Sarcophyton glaucum

Six new cembrane-type diterpenoids, namely ximaoglaucumins A−F (1–6), along with fifteen known related ones (7–10 and 14–24), have been isolated from the soft coral Sarcophyton glaucum collected off the Ximao Island in the South China Sea. Their structures, including absolute stereochemistry, were elucidated by extensive spectroscopic analysis, quantum mechanical nuclear magnetic resonance (QM-NMR) methods, X-ray diffraction analysis, chemical methods, as well as comparison with the reported data in the literature. Further, detailed analysis of spectroscopic data of 7 not only clarified the confusions regarding 7, 11 (sarcophytolol) and 12/13 (sarcotrocheliol) in the literature, but also led to revise the structure of 11, which was mis-assigned due to careless/erroneous interpretation of the 2D NMR spectra, and to correct the structures of 12/13, which were both wrongly depicted. In in vitro bioassay, compounds 8 and 20 exhibited potent inhibitory effects on lipopolysaccharide (LPS)-induced inflammatory responses in BV-2 microglial cells.

Cytotoxic and Antileishmanial Activities of the Red Sea Soft Coral Sarcophyton glaucum Extract and Some of Its Isolates

Cytotoxic and Antileishmanial Activities of the Red Sea Soft Coral Sarcophyton glaucum Extract and Some of Its Isolates

Culture systems influence the physiological performance of the soft coral Sarcophyton glaucum

There is an urgent need to develop means of ex situ biobanking and biopreserving corals and other marine organisms whose habitats have been compromised by climate change and other anthropogenic stressors. To optimize laboratory growth of soft corals in a way that could also benefit industry (e.g., aquarium trade), three culture systems were tested herein with Sarcophyton glaucum: (1) a recirculating aquaculture system (RAS) without exogenous biological input (RAS−B), (2) a RAS with “live” rocks and an exogenous food supply (RAS+B), and (3) a simple flow-through system (FTS) featuring partially filtered natural seawater. In each system, the effects of two levels of photosynthetically active radiation (100 or 200 μmol quanta m−2 s−1) and flow velocity (5 or 15 cm s−1) were assessed, and a number of soft coral response variables were measured. All cultured corals survived the multi-month incubation, yet those of the RAS−B grew slowly and even paled; however, once they were fed (RAS−B modified to RAS+B), their pigmentation increased, and their oral discs readily expanded. Light had a more pronounced effect in the RAS−B system, while flow affected certain coral response variables in the FTS tanks; there were few effects of light or flow in the RAS+B system, potentially highlighting the importance of heterotrophy. Unlike the ceramic pedestals of the FTS, those of the RAS+B did not regularly become biofouled by algae. In concert with the aforementioned physiological findings, we therefore recommend RAS+B systems as a superior means of biopreservating and biobanking soft corals.

Calamusins J-K: new anti-angiogenic sesquiterpenes from Sarcophyton glaucum

Chemical investigation of the organic extract of the marine soft coral Sarcophyton glaucum from Red Sea, Egypt, afforded two new hydroazulenes; calamusin J (1) and its hydroperoxide derivative calamusin K (2) in addition to eight known compounds. Structure of compounds 1-2 were confirmed by intensive NMR and mass spectrometry studies. The coral extract and the obtained compounds were examined against a set of diverse microorganisms. The in vitro anti-cancer properties were assessed against colon (Caco-2) and breast (MCF-7) cell lines together with their exerted cytotoxicity on the immortalized normal epithelium (hTERT-RPE1) cell type. The anti-angiogenic power was also highlighted through suppressing MCF-7 cell migration and the significant inactivation of VEGFR2 enzyme. Compounds 1,2 are the most potent angiogenic inhibitors (represented by 1.2- and 1.4-fold enzyme inactivation, respectively) relative to sorafenib. The polyhydroxy sterol; 5α-3β,6α,11-trihydroxy-24-methyl-9,11-seco-5a-cholest-7-en-9-one (S4) inhibited effectively the growth of Caco-2 and MCF-7 with GI50 of 0.62 and 2.3 µM, respectively.

Exploration of Chemical Diversity and Antitrypanosomal Activity of Some Red Sea-Derived Actinomycetes Using the OSMAC Approach Supported by LC-MS-Based Metabolomics and Molecular Modelling.

In the present study, we investigated the actinomycetes associated with the Red Sea-derived soft coral Sarcophyton glaucum in terms of biological and chemical diversity. Three strains were cultivated and identified to be members of genera Micromonospora, Streptomyces, and Nocardiopsis; out of them, Micromonospora sp. UR17 was putatively characterized as a new species. In order to explore the chemical diversity of these actinobacteria as far as possible, they were subjected to a series of fermentation experiments under altering conditions, that is, solid and liquid fermentation along with co-fermentation with a mycolic acid-containing strain, namely Nocardia sp. UR23. Each treatment was found to affect these actinomycetes differently in terms of biological activity (i.e., antitrypanosomal activity) and chemical profiles evidenced by LC-HRES-MS-based metabolomics and multivariate analysis. Thereafter, orthogonal projections to latent structures discriminant analysis (OPLS-DA) suggested a number of metabolites to be associated with the antitrypanosomal activity of the active extracts. The subsequent in silico screenings (neural networking-based and docking-based) further supported the OPLS-DA results and prioritized desferrioxamine B (3), bafilomycin D (10), and bafilomycin A1 (11) as possible antitrypanosomal agents. Our approach in this study can be applied as a primary step in the exploration of bioactive natural products, particularly those from actinomycetes.

Sarcophine and (7S, 8R)-dihydroxydeepoxysarcophine from the Red Sea soft coral Sarcophyton glaucum as in vitro and in vivo modulators of glycine receptors

The inhibitory glycine receptor (GlyR) is a key mediator of synaptic signalling in spinal cord, brain stem, and higher centres of the central nervous system. We examined the glycinergic activity of sarcophine (SN), a marine terpenoid known for its various biological activities, and its trans-diol derivative (7S, 8R)-dihydroxy-deepoxysarcophine (DSN). SN was isolated from the Red Sea soft coral Sacrophyton glaucum, DSN was semisynthesized by hydrolysis of the epoxide ring. In cytotoxicity tests against HEK293 cells, SN and DSN had LD50 values of 29.3 ± 3.0 mM and 123.5 ± 13.0 mM, respectively. Both compounds were tested against recombinant human α1 glycine receptors in HEK293 cells using whole-cell recording techniques. Both, SN and DSN were shown for the first time to be inhibitors of recombinant glycine receptors, with KIvalues of 2.1 ± 0.3 μM for SN, and 109 ± 9 μM for DSN. Receptor inhibition was also studied in vivo in a mouse model of strychnine toxicity. Surprisingly, in mouse experiments strychnine inhibition was not augmented by either terpenoid. While DSN had no significant effect on strychnine toxicity, SN even delayed strychnine effects. This could be accounted for by assuming that strychnine and sarcophine derivatives compete for the same binding site on the receptor, so the less toxic sarcophine can prevent strychnine from binding. The combination of modulatory activity and low level of toxicity makes sarcophines attractive structures for novel glycinergic drugs.

Purification and identification of novel cytotoxic oligopeptides from soft coral Sarcophyton glaucum.

Globally, peptide-based anticancer therapies have drawn much attention. Marine organisms are a reservoir of anticancer peptides that await discovery. In this study, we aimed to identify cytotoxic oligopeptides from Sarcophyton glaucum. Peptides were purified from among the S. glaucum hydrolysates produced by alcalase, chymotrypsin, papain, and trypsin, guided by a methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay on the human cervical cancer (HeLa) cell line for cytotoxicity evaluation. Purification techniques adopted were membrane ultrafiltration, gel filtration chromatography, solid phase extraction (SPE), and reversed-phase high-performance liquid chromatography (RP-HPLC). Purified peptides were identified by de novo peptide sequencing. From papain hydrolysate, three peptide sequences were identified: AGAPGG, AERQ, and RDTQ (428.45, 502.53, and 518.53 Da, respectively). Peptides synthesized from these sequences exhibited cytotoxicity on HeLa cells with median effect concentration (EC50) values of 8.6, 4.9, and 5.6 mmol/L, respectively, up to 5.8-fold stronger than the anticancer drug 5-fluorouracil. When tested at their respective EC50, AGAPGG, AERQ, and RDTQ showed only 16%, 25%, and 11% cytotoxicity to non-cancerous Hek293 cells, respectively. In conclusion, AERQ, AGAPGG, and RDTQ are promising candidates for future development as peptide-based anticancer drugs.

Sarcoglaucins A-I, new antifouling cembrane-type diterpenes from the South China Sea soft coral Sarcophyton glaucum

Nine new cembrane diterpenes, named sarcoglaucins A-I (1–9) along with three known analogues, trochelioid (10), 7α-hydroxy-Δ8(19)-deepoxysarcophine (11), and (−)-sartrochine (12), were isolated from the soft coral Sarcophyton glaucum collected at Xisha Islands in the South China Sea.

Isoprenoids from the Soft Coral Sarcophyton glaucum.

Five new isoprenoids, 3,4,8,16-tetra-epi-lobocrasol (1), 1,15β-epoxy-deoxysarcophine (2), 3,4-dihydro-4α,7β,8α-trihydroxy-Δ2-sarcophine (3), ent-sarcophyolide E (4), and 16-deacetyl- halicrasterol B (5) and ten known compounds 6‒15, were characterized from the marine soft coral Sarcophyton glaucum, collected off Taitung coastline. Their structures were defined by analyzing spectra data, especially 2D NMR and electronic circular dichroism (ECD). The structure of the known compound lobocrasol (7) was revised. Cytotoxicity potential of the isolated compounds was reported, too.

Assesment of Anticarcinogenic Activities of the Soft Coral Sarcophyton Glaucum Extract on Mouse Leukemia In Vivo and In vitro

Marine environment biodiversity opens up new horizons in the quest for bioactive compounds that could be utilized as antitumor agents. Use of bioactive compounds from marine organisms has been used extensively in the past for the treatment of different diseases including cancer. The molecular mechanisms by which natural product extracts inhibit human cancer cell growth are essentially unknown. Soft Coral Sarcophyton glaucum is an important folk medicinal marine. It has anti-oxidant, anti-carcinogenic, and free radical scavenging properties. The objectives of present study are to investigatimg in vitro the antiproliferative activity of sarcophine extract on mouse Leukemia cells (L1210), also, we shall evaluate in vivo the antitumor activity of the soft coral S. glaucum extract against Mouse Leukemia cells (L1210), on mice (Swiss albino mice). The antiproliferative and cytotoxic activities of the S. glaucum were determined using the trypan blue dye exclusion and the WST-1 cell proliferation tests. The underlying possible mechanism of cell death was investigated whether it is necrotic or apoptotic by single cell gel electrophoresis (comet assay) and dual acridine orange/ethidium bromide (AO/EB) staining. The antitumor activity of the S. glaucum extract against mouse leukemia cell line, L1210, grown as ascites in mouse model. In vitro Results showed that S. glaucum inhibited L1210 cancer cells proliferation and induced apoptosis and that the apoptotic activities. The mechanism underlying cell death was due to induction of apoptosis, which was associated by DNA damage and morphological changes of the treated cells. In vivo study indicated that S. glaucum has ability to suppress cancer progression in treated animals. These findings indicate that the S. glaucum extract can be a candidate agent for fighting cancer.

Top ten most accessed AMOR articles in 2015/2016

<p>In 2015/2016, Advances in Modern Oncology Research published a total of 67 articles over eight issues in two separate volumes. These published articles, consisting of editorials, reviews, case reports, and original research, have collectively accumulated 26,320 views as of December 2016. A total of 54 authors and 160 peer-reviewers from across the globe contributed to the journal in its first full year of publication. The journal’s top ten most accessed articles are:</p><p>1. Indoles as anticancer agents (Vol. 1 Issue 1) <br /> <br />2. Pharmacometrics and systems pharmacology of immune checkpoint inhibitor nivolumab in cancer translational medicine (Vol. 2 Issue 1) <br /> <br />3. Hepatocellular carcinoma (HCC); aetiological considerations (Vol. 1 Issue 1) <br /> <br />4. Oligoadenylate synthetase 1 (OAS1) expression in human breast and prostate cancer cases, and its regulation by sex steroid hormones (Vol. 2 Issue 2) <br /> <br />5. Antiproliferative effects of cembranoid derivatives obtained from Red Sea soft coral Sarcophyton glaucum on human colorectal cancer cell lines (Vol. 1 Issue 1) <br /> <br />6. Paraneoplastic pemphigus: A trait d’union between dermatology and oncology (Vol. 1 Issue 2) <br /> <br />7. Cancer cell metastasis; perspectives from the focal adhesion (Vol. 1 Issue 1) <br /> <br />8. Threshold-based parametric analysis of diffusion-weighted magnetic resonance imaging at 3.0 Tesla to identify men with prostate cancer (Vol. 1 Issue 2) <br /> <br />9. Economic burden of patients with inoperable advanced breast cancer receiving early or late capecitabine or trastuzumab as second-line treatment: A population-based study (Vol. 1 Issue 2) <br /> <br />10. Non-coding RNAs: New therapeutic targets and opportunities for hepatocellular carcinoma (Vol. 2 Issue 1)</p>

Effects of coral extracts on survivorship, swimming behavior, and settlement of Pocillopora damicornis larvae

Coral larvae released into the water column encounter different dissolved chemical cues secreted by organisms on the substratum that are engaged in spatial competition. These cues initiate vital biological processes in the larvae. In this study, the effects of crude extracts from the scleractinian corals Pocillopora damicornis and Porites cylindrica, and the soft coral Sarcophyton glaucum, on the survivorship, swimming behavior, and settlement of Pocillopora damicornis larvae were evaluated. High concentrations of heterospecific coral extracts caused a significant decline in both larval survivorship and settlement whereas conspecific extracts did not result in any larval mortality. Exposure to heterospecific extracts resulted in repulsion of larvae as indicated by a transient change in larval morphology and sustained swimming in the upper water column. In contrast, the conspecific extract enhanced larval exploration of both the water column and substratum and was able to induce larval settlement. These results suggest that chemical cues emanating from conspecifics and other coral species are capable of altering the biology of coral larvae, thus potentially influencing settlement behavior and species distribution on the reef.

Growth Rate Assessment of Alcyonacean <i>Sarcophyton glaucum</i> from Northern Hurghada, Red Sea, Egypt

Eighteen specimens of the soft coral Sarcophyton glaucum have been collected and tagged to determine the growth rate using the weight variations technique and to investigate the reproductive season histologically. Six colonies were totally weighed and 12 fragments (produced from three colonies) were marked and weighed. Some samples showed sever shrinkage that lead to death. The maximum semiannual growth rate was recorded in summer (30.05 gm/6 m). The average monthly growth reached 3.95 gm/month. Many factors affect the growth rate such as water currents, turbidity, sedimentation, temperature and reproduction process. The studied species is a dioecious species (unisex), where the Autozooid polyps are the reproductive organs while siphonozooids are sterile. Female gonads were observed to develop at late July before male gonads which began at late September. Larvae releasing started at late January and the gonads are completely spawned in February. Fertilization occurs internally to form planulae larvae which librated completely in February. The oogenesis exhibited prolonged about 23 months, which gave rise to oocytes of different developmental stages in female colonies at any given time, and a spermatogenic cycle of only 10 - 12 months.