Molecular phylogeny of three mudskippers (Gobiidae) from the Persian Gulf and Gulf of Oman (Makran)

Presented is a phylogenetic reconstruction of mudskippers using sequences of the mitochondrial COI and cytb genes. The phylogeny combines the sequences of 12 species from GenBank with those of three species (Boleophthalmus dussumieri, Periophthalmus waltoni and Scartelaos tenuis) collected from the coastal area of the Persian Gulf and Oman (Makran) Sea and sequenced for the first time. Based on the Maximum likelihood and Bayesian methods, Periophthalmus forms a separate clade that is the sister lineage to a group formed by all remaining genera. The subfamilies Oxudercinae and Amblyopinae established on the basis of morphological characters have been shown to be paraphyletic and their use as taxonomic units is no longer recommended. The evolution of Periophthalmus waltoni, Periophthalmus barbarous and Boleophthalmus dussumieri is discussed based on molecular phylogenetic reconstruction.     

Antibiotic activity of lectins from marine algae against marine vibrios

Saline and aqueous ethanol extracts of marine algae and the lectins from two red algal species were assayed for their antibiotic activity against marine vibrios. Experimental studies were also carried out on the influence of environmental factors on such activity, using batch cultures. The results indicated that many of the saline extracts of the algal species were active and that the activity was selective against those vibrios assayed. The algal extracts were active against Vibrio pelagius and the fish pathogen V. vulnificus, but inactive against V. neresis. Algal lectins from Eucheuma serra (ESA) and Galaxaura marginata (GMA) strongly inhibited V. vulnificus but were inactive against the other two vibrios. The antibacterial activity of algal extracts was inhibited by pretreatment with various sugars and glycoprotein. Extracts of the two red algae, E. serra and Pterocladia capillacea, in saline and aqueous ethanol, inhibited markedly the growth rate of V. vulnificus at very low concentrations. Culture results indicated that metabolites active against V. vulnificus were invariably produced in P. capillacea over a wide range of temperature, light intensity, and nutritional conditions. Enhanced antibacterial activity occurred when P. capillacea was grown under higher irradiance, severe nutrient stress and moderate temperature (20 °C), reflecting the specific antibiotic characteristics of this alga. The strong antibiotic activity of lectins towards fish pathogenic bacteria reveals one of the important roles played by algal lectins, as well as the potential high economic value of those marine algae assayed for aquaculture and for biomedical purposes.     

The production of antimicrobial compounds by British marine algae I. Antibiotic-producing marine algae

Using five species of bacteria as the test organisms, 151 species of British marine algae have been screened for the production of antibiotics. Of these, Asparagopsis armata, Bonnemaisonia asparagoides, Bonnemaisonia hamifera, Chondrus crispus, Dilsea carnosa, Gloiosiphonia capillaris, Sphondylothamnion multifidum, Desmarestia aculeata, Desmarestia ligulata, Laminaria digitata, Dictyopteris membranacea, Dictyota dichotoma, Halidrys siliquosa and most members of the family Rhodomelaceae appear to possess outstanding antibacterial properties. Although the production of antibiotics would appear to be a characteristic of several families, it has not been possible to establish any major correlation between taxonomy and antibiotic production. In the case of two closely related and morphologically similar species, Chondrus crispus and Gigartina stellata, the former possesses considerable degrees of antimicrobial activity whilst the latter exhibits no such activity. The results also indicate that the production of antibiotics by the algae is affected by the season of the year.     

Antitumor activity of marine algae

Powdered tissue from 46 species of air-dried marine algae (four green, 21 brown and 21 red algae) were screened for antitumor activity. Significant activity against Ehrlich carcinoma was found in the brown algae Scytosiphon lomentaria (69.8% inhibition), Lessonia nigrescens (60.0%), Laminaria japonica (57.6%), Sargassum ringgoldianum (46.5%), the red algae Porphyra yezoensis (53.2%) and Eucheuma gelatinae (52.1%) and the green alga Enteromorpha prolifera (51.7%). Five brown and four red algae showed appreciable antitumor activity against Meth-A fibrosarcoma. To identify specific molecules with antitumor activity, 15 kinds of polysaccharide preparations of seaweed origin and 24 kinds of lipid fractions extracted from various seaweeds were tested. Appreciable inhibition of Ehrlich carcinoma was found for fucoidan preparations from Undaria pinnatifida and Sargassum ringgoldianum, for carrageenans and for porphyran. Several glycolipid and phospholipid fractions from brown and red algae were effective against Meth-A fibrosarcoma.     

A revision of the marine algae of São Tomé and Principe (Gulf of Guinea)

In all 101 species and varieties of marine algae are mentioned for S. Tomé and Príncipe. These records arise from examination of the material in the herbarium of the Botanical Institute of the University of Coimbra, together with material collected in 1956 by Dr C. A. Thorold. From the latter material there are 17 new records for the island of S. Tomé.
No new species have been described, but Acantkophora ramulosa Kütz. is emended, and Bryopsis densa Pilger and Struvea multipartita Pilger are reduced to the synonymy of Bryopsis pennata var. secunda and Struvea anastomosans respectively.
Information on the climate and tides of the islands is given, and a series of 'seasonal coincidences' likely to influence coastal marine conditions is described for the Gulf of Guinea.     

Assessment of heavy metal pollution and ecological risk in marine sediments (A case study: Persian Gulf)

This study was made to determine the pollution status and potential ecological risk of heavy metals in sediment of Persian Gulf. Surface sediments were collected seasonally by Peterson grab, and the concentrations of heavy metals were measured by using inductively coupled plasma–optical emission spectrometry (ICP–OES). The range concentrations obtained in mg/kg were 10,800–22,400 for Fe, 5.32–10.12 for Pb, 24.63–42.38 for Ni, 22.52–39.46 for Cu, and 31.64–47.20 for Cr. The concentrations of Pb, Ni, Cu, and Cr have been found lower than the Interim Sediment Quality Guidelines and probable effect level values suggesting that heavy metal contents in sediments from area of study would not be expected to cause adverse biological effects on the biota. The obtained enrichment factor values for various metals were between minimal enrichment (Pb = 0.5) and extremely enrichment (Cu = 3.11). The values of I_geo for Pb, Ni, Cu, and Cr were characterized under no pollution (0). The highest value of potential ecological risk index (RI) (8.36) was observed at St. 4 while the lowest value (5.25) was detected at station 6. Based on potential ecological RI, the Persian Gulf had low ecological risk.     

In vitro antimicrobial activity against Pseudomonas aeruginosa and acute oral toxicity of marine algae Gracilaria changii

Methanol extract of the Gracilaria changii has been screened for antimicrobial activity against Pseudomonas aeruginosa. Antimicrobial activities were carried out using disc diffusion assay and broth dilution method against P. aeruginosa. The methanol extract of G. changii showed a good antimicrobial activity against P. aeruginosa with MIC (Minimum Inhibitory Concentration) value of 6.25 mg/ml. Exposure of P. aeruginosa cells to 6.25 mg/ml of methanol extract of G. changii resulted in complete inhibition of the bacterial cells. The main abnormalities noted via SEM and TEM studies were the alterations in morphology and cytology of the bacterial cells. The main reason for this deterioration was discussed. The effect of the methanol extract on the growth profile for the bacteria was also done and confirmed the bactericidal effect of the G. changii methanol extract on P. aeruginosa by changing the normal growth profile of P. aeruginosa. In an acute toxicity study using mice, the median lethal dose (LD₅₀) of the extract was greater than 2000 mg/kg, and we found no pathological changes in macroscopic examination by necropsy of mice treated with extract. We conclude that G. changii might be safely used as an antimicrobial agent.     

Diterpenoid metabolites from pacific marine algae of the order Caulerpales (Chlorophyta)

Chemical investigations of two new species of Udotea, reinvestigation of Tydemania expeditionis and Chlorodesmis fastigiata from Guam and Saipan, Marianas Islands, as well as studies of Caulerpa brownii from Southern Australia, have led to the isolation of four new related diterpenoids and several previously described metabolites. These metabolites possess antimicrobial activities and inhibit cell division in the fertilized sea urchin egg bioassay.     

Biodiversity and community structure of Late Pleistocene foraminifera from Kish Island, Persian Gulf (Iran)

The raised coral reef sequences at Kish Island provide a rare window into the depositional setting and paleoenvironment of a high-latitude, shallow-water coral reef that developed under turbid conditions in the Persian Gulf during Marine Isotope Stage 7 (~200 to 250?ka). Six sedimentary facies and eight foraminiferal assemblages can be identified throughout the sequence. A ninth assemblage can be defined for the modern subtidal realm. At the base of the sequence is a marl rich in hyaline foraminifera (Elphidium, Ammonia, Asterorotalia, Bulimina, Nonion, and Quinqueloculina) and ostracods, which was deposited in about 30–40?m water depth in a turbid deltaic setting. Shallowing resulted in the marl becoming sandy, and changing to a mollusc-rich facies with rare foraminifera (mostly smaller miliolid taxa) that formed the substrate for coral recruitment. The coral marl layer contains many large corals embedded in situ in an aggregate and coralline algae-rich marl. Two abundance peaks in the foraminifera occur at the base and mid-way through this layer, which also correspond to a change from Murrayinella-dominated to Placopsilina-dominated assemblages, indicating deepening and more open-marine conditions, but elevated turbidity. Towards the top of the layer, abundance of foraminifera decreases and miliolid foraminifera become dominant. The top-most layer is dominated by coral and mollusc fragments and has an Amphistegina-rich reef-related assemblage. Of the Late Pleistocene foraminiferal assemblages, the Murrayinella-, Pararotalia-, and Placopsilina-dominated assemblages are no longer present in the modern gulf for unknown reasons. Of the other five assemblages, only the Amphistegina assemblage is found within proximity to the modern Kish Island. The Elphidium and Asterorotalia-Bulimina assemblages are from deeper areas of the gulf. The Ammonia and Quinqueloculina assemblages occur in lagoonal sediments on the Arabian side of the gulf. Like the modern Persian Gulf, the diversity of foraminifera was low (~80 common species) during the Pleistocene and does not correlate with foraminiferal abundance.     

Genetic verification of native brown trout from the Persian Gulf (Catak Cay River, Tigris basin)

Analysis of the mtDNA control region in six individual brown trout Salmo trutta from the Catak Cay River (Tigris basin) revealed a single, new, haplotype, 1·0 to 1·5% divergent from five other Da lineage haplotypes analysed, that groups with the Danubian clade with low bootstrap support. This highly divergent haplotype combined with unique phenotypic characteristics underscores the novelty and native status of this population, which has probably been isolated from other brown trout lineages for at least several hundred thousand years.     

Sulfated polysaccharides from marine green algae Ulva conglobata and their anticoagulant activity

Sulfated polysaccharides from the green algae Ulva conglobata were isolated and prepared by extraction in hot water, precipitation with ethanol and purification by ion-exchange and size-exclusion column chromatography. The characterizations of the sulfated polysaccharides were defined, and containing 23.04–35.20% sulfate ester groups, 10.82–14.91% uronic acid and 3.82–4.51% protein. Gas chromatography analysis shows that the sulfated polysaccharides from Ulva conglobata are mainly consisted of rhamnose with variable contents of glucose and fucose, trace amounts of xylose, glactose and mannose. The anticoagulant properties of the sulfated polysaccharides were compared with those of heparin by studying the activated partial thromboplastin time using normal human plasma. The sulfated polysaccharide from Ulva conglobata collected in Qingdao, China is the most potent among the sulfated polysaccharides tested. The mechanism of anticoagulant activity mediated by the sulfated polysaccharides is due to the direct inhibition of thrombin and the potentiation of heparin cofactor II.     

Solea stanalandi,a new sole from the Persian Gulf

A new soleid flatfish,Solea stanalandi, is described from two specimens collected in 1–7 m in the Persian Gulf near Dhahran, Saudi Arabia. It is distinctive among species of the genus in having 57–59 dorsal rays, 46 anal rays, 104–106 pored scales in the straight portion of the lateral line to the caudal-fin base, a body depth of 2.45–2.5 in standard length, a large black spot on the outer half of the pectoral fin of the ocular side, and a similar narrower dark spot on the pectoral fin of the blind side.