Dragonflies (Insecta,Odonata) from the Red Sea Hills and the main Nile in Sudan

Twenty-one species of dragonflies are recorded from the Nile and the Red Sea Hills in the Sudan. The majority are species of africotropical origin, but wide-ranging and tolerant of strongly fluctuating environmental conditions. A small but significant fraction is restricted to the Nile Valley, and another fraction, found only in the Red Sea Hills, is composed of Eremian species of Palaearctic origin. Besides adults, the last-instar larvae of Pseudogrion niloticum and of Paragomphus pumilio are described and figured.     

Induced spawning and embryonic and early larval development of bonefish (Albula vulpes)

Bonefish (Albula vulpes L.) are a highly prized sport fish. Despite their economic importance, populations in the Florida Keys and Caribbean are in decline, with the early life history undescribed. Injections of carp pituitary extract into A. vulpes during the advanced stages of ovarian development induced ovulation and spawning. Embryos were sampled hourly until hatching into undeveloped, yolk-sac leptocephalus larvae. These larvae survived 56 h post-hatch, when myomeres and eyes were developing but not the mouth. These results inform future research on the reproduction and early life history of A. vulpes.     

Neomerinthe bathypevimensis sp. nov. from deep waters of the southern Red Sea

A new species of scorpionfish Neomerinthe bathyperimensis is described from a single specimen, dredged in deep waters of the southern Red Sea. The type specimen is aberrant in that it lacks the anal-fin spines and their supporting pterygiophores. This is the first record of the genus from the Red Sea and the north-western Indian Ocean.     

Phylogenetic diversity of bacteria associated with the mucus of Red Sea corals

Coral reefs are the most biodiverse and biologically productive of all marine ecosystems. Corals harbor diverse and abundant prokaryotic communities. However, little is known about the diversity of coral-associated bacterial communities. Mucus is a characteristic product of all corals, forming a coating over their polyps. The coral mucus is a rich substrate for microorganisms. Mucus was collected with a procedure using sterile cotton swabs that minimized contamination of the coral mucus by surrounding seawater. We used molecular techniques to characterize and compare the bacterial assemblages associated with the mucus of the solitary coral Fungia scutaria and the massive coral Platygyra lamellina from the Gulf of Eilat, northern Red Sea. The bacterial communities of the corals F. scutaria and P. lamellina were found to be diverse, with representatives within the Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria and Epsilonproteobacteria, as well as the Actinobacteria, Cytophaga-Flavobacter/Flexibacter-Bacteroides group, Firmicutes, Planctomyces, and several unclassified bacteria. However, the total bacterial assemblage of these two corals was different. In contrast to the bacterial communities of corals analyzed in previous studies by culture-based and culture-independent approaches, we found that the bacterial clone libraries of the coral species included a substantial proportion of Actinobacteria. The current study further supports the finding that bacterial communities of coral mucus are diverse.     

First record of the paedomorphic fish Schindleria (Gobioidei, Schindleriidae) from the Red Sea

A male specimen of the paedomorphic fish Schindleria sp. was collected by plankton net, in February 2005, from a reef lagoon from Hurghada on the Egyptian coast of the northern Red Sea. This is the first record of the Schindleriidae in the Red Sea.     

Biogeography of pelagic bacterioplankton across an antagonistic temperature-salinity gradient in the Red Sea

The Red Sea is a unique marine ecosystem with contrasting gradients of temperature and salinity along its north-to-south axis. It is an extremely oligotrophic environment that is characterized by perpetual year-round water column stratification, high annual solar irradiation, and negligible riverine and precipitation inputs. In this study, we investigated whether the contemporary environmental conditions shape community assemblages by pyrosequencing 16S rRNA genes of bacteria in surface water samples collected from the northeastern half of this water body. A combined total of 1855 operational taxonomic units (OTUs) were recovered from the 'small-cell' and 'large-cell' fractions. Here, a few major OTUs affiliated with Cyanobacteria and Proteobacteria accounted for ～93% of all sequences, whereas a tail of 'rare' OTUs represented most of the diversity. OTUs allied to Surface 1a/b SAR11 clades and Prochlorococcus related to the high-light-adapted (HL2) ecotype were the most widespread and predominant sequence types. Interestingly, the frequency of taxa that are typically found in the upper mesopelagic zone was significantly elevated in the northern transects compared with those in the central, presumably as a direct effect of deep convective mixing in the Gulf of Aqaba and water exchange with the northern Red Sea. Although temperature was the best predictor of species richness across all major lineages, both spatial and environmental distances correlated strongly with phylogenetic distances. Our results suggest that the bacterial diversity of the Red Sea is as high as in other tropical seas and provide evidence for fundamental differences in the biogeography of pelagic communities between the northern and central regions.     

Marine molluscs and fish as biomarkers of pollution stress in littoral regions of the Red Sea, Mediterranean Sea and North Sea

The intensive development of industry and urban structures along the seashores of the world, as well as the immense increase in marine transportation and other activities, has resulted in the deposition of thousands of new chemicals and organic compounds, endangering the existence of organisms and ecosystems. The conventional single biomarker methods used in ecological assessment studies cannot provide an adequate base for environmental health assessment, management and sustainability planning. The present study uses a set of novel biochemical, physiological, cytogenetic and morphological methods to characterize the state of health of selected molluscs and fish along the shores of the German North Sea, as well as the Israeli Mediterranean and Red Sea. The methods include measurement of activity of multixenobiotic resistance-mediated transporter (MXRtr) and the system of active transport of organic anions (SATOA) as indicators of antixenobiotic defence; glutathione S-transferase (GST) activity as an indicator of biotransformation of xenobiotics; DNA unwinding as a marker of genotoxicity; micronucleus test for clastogenicity; levels of phagocytosis for immunotoxicity; cholinesterase (ChE) activity and level of catecholamines as indicators of neurotoxicity; permeability of external epithelia to anionic hydrophilic probe, intralysosomal accumulation of cationic amphiphilic probe and activity of non-specific esterases as indicators of cell/tissue viability. Complete histopathological examination was used for diagnostics of environmental pathology. The obtained data show that the activity of the defensive pumps, MXRtr and SATOA in the studied organisms was significantly higher in the surface epithelia of molluscs from a polluted site than that of the same species from control, unpolluted stations, providing clear evidence of response to stress. Enhanced frequency of DNA lesions (alkaline and acidic DNA unwinding) and micronucleus-containing cells was significantly higher in samples from polluted sites in comparison to those from the clean sites that exhibited genotoxic and clastogenic activity of the pollutants. In all the studied molluscs a negative correlation was found between the MXRtr levels of activity and the frequency of micronucleus-containing hemocytes. The expression of this was in accordance with the level of pollution. The complete histopathological examination demonstrates significantly higher frequencies of pathological alterations in organs of animals from polluted sites. A strong negative correlation was found between the frequency of these alterations and MXRtr activity in the same specimens. In addition to these parameters, a decrease in the viability was noted in molluscs from the polluted sites, but ChE activities remained similar at most sites. The methods applied in our study unmasked numerous early cryptic responses and negative alterations of health in populations of marine biota sampled from the polluted sites. This demonstrates that genotoxic, clastogenic and pathogenic xenobiotics are present and act in the studied sites and this knowledge can provide a reliable base for consideration for sustainable development. Received: 2 March 1999 / Received in revised form: 2 August 1999 / Accepted: 3 August 1999     

Absence of post-Miocene Red Sea land bridges: biogeographic implications

In a large number of studies concerned with species movements between Africa and Eurasia, including the migrations of hominids out of Africa, a frequently‐cited dispersal route is across a hypothetical land bridge in the southern Red Sea, which is suggested to have emerged during glacial sea‐level lowstands. This paper, however, unequivocally demonstrates that palaeoceanographic and palaeoecological data are incompatible with the existence of Red Sea land bridges since the Miocene. The case is made by presenting the first quantitative history of water depth above the Red Sea sill for the last 470,000 years, a time period that includes the four most recent glacial–interglacial cycles, and by discussing the predictable consequences of any land bridge formation on the Red Sea sedimentary and microfossil records. The absence of post‐Miocene Red Sea land bridges has extensive implications for biogeographic models in the Afro‐Arabian region. Genetic, morphometric and palaeontological patterns reported in the literature cannot be related to dispersals over a land bridge, or in the case of marine organisms, separation of the Red Sea from the Indian Ocean by a land bridge. If such patterns in terrestrial species are only congruent with a southern Red Sea dispersal route, then they need to be considered in terms of sweepstake rafting, anthropogenic introduction, or in the particular case of the Out‐of‐Africa migration by modern humans, seafaring. The constraints imposed by our palaeoenvironmental record on biogeographic reconstructions within and around the Red Sea will hopefully encourage both the review of previous works and the preference for multidisciplinary approaches in future studies.     

Ultrastructure and phylogeny of Glugea arabica n. sp. (Microsporidia), infecting the marine fish Epinephelus polyphekadion from the Red Sea

A new microsporidian species, Glugea arabica n. sp., is reported infecting the intestinal wall of the marine teleost Epinephelus polyphekadion (=microdon) collected from the Red Sea coast off Saudi Arabia, and described on the basis of microscopic and molecular procedures. Spherical blackish xenomas formed parasitophorous vacuoles completely packed with several parasitic developmental stages, including spores. The nuclei were monokaryotic in all developmental stages. Spores were ellipsoidal to pyriform and measured 6.3 ± 0.3 (5.9–6.6) μm in length and 3.3 ± 0.4 (2.9–3.7) μm in width. A lamellar polaroplast surrounded the uncoiled portion of the polar filament, which extended into the spore's posterior pole and formed 27–29 coils organized in three or four rows. The posterior vacuole, located at the spore's posterior pole, appeared surrounded by the polar filament coils and displayed an irregular matrix composed of light material, in which was located the posterosome. Molecular analysis of the rRNA genes, including the ITS region, was performed using maximum parsimony, neighbor-joining and maximum likelihood methodologies. The ultrastructural features observed, in combination with the molecular data analysed, suggests the parasite to be a new species of the genus Glugea.     

Some toxicological characteristics of three venomous soft corals from the Red Sea

Three common Red Sea soft corals (Cnidaria: Anthozoa), Nephthea sp, Dendronephthya sp and Heteroxenia fuscescens sting humans. Nematocyst venoms of each animal are lethal to mice and hemolytic to human erythrocytes. However, these hemolysins are partially inhibited by known anti-hemolytic agents. Venoms and their gel chromatography-separated fractions have different dermonecrosis and vasopermeability potency in mouse skin. The venom of Heteroxenia fuscescens (Hf) was more lethal (LD50: 0.7 mg/kg), with one prominent 97-kDa protein fraction (LD50: 0.55 mg/kg). Hf venom was more hemolytic, more dermonecrotic, and had more vasopermeable factors than that of the two other species. SDS polyacrylamide gel electrophoresis of soft coral whole venoms and fractions showed different protein molecular masses ranging from 200 to less than 6 kDa. High IgG titers were assayed from venom-sensitized mice blood sera. Enzyme-linked immunosorbent assays (ELISA) marked significant immunological cross-reaction between the studied soft coral venoms and their bioactive fractions.     

Ecological observations on mangroves of the Red Sea shores of the Sudan

An ecological survey of the mangrove vegetation in the littoral salt marshes of the Red Sea coast of the Sudan was made during short periods between 1980 and 1982. Avicennia marina (Forsk) Vierh occurs in pure stands of different dimensions in four types of locations. In each location, the responses of Avicennia are expressed in the degree of compactness of aggregation, canopy, height and regeneration potential. Grazing by camels is the primary agent in degradation of accessible locations; salt pans and to a limited extend cutting contribute in part to the process of degradation. The badly damaged aggregations may benefit from protection through control of grazing by nomadic camel tribesmen.     

Population fluctuation and vertical distribution of meiofauna in the Red Sea interstitial environment

The composition and distribution of the benthic meiofauna assemblages of the Egyptian coasts along the Red Sea are described in relation to abiotic variables. Sediment samples were collected seasonally from three stations chosen along the Red Sea to observe the meiofaunal community structure, its temporal distribution and vertical fluctuation in relation to environmental conditions of the Red Sea marine ecosystem. The temperature, salinity, pH, dissolved oxygen, and redox potential were measured at the time of collection. The water content of the sediments, total organic matters and chlorophyll a values were determined, and sediment samples were subjected to granulometric analysis. A total of 10 meiofauna taxa were identified, with the meiofauna being primarily represented by nematodes (on annual average from 42% to 84%), harpacticoids, polycheates and ostracodes; and the meiofauna abundances ranging from 41 to 167 ind./10 cm². The meiofaunal population density fluctuated seasonally with a peak of 192.52 ind./10 cm² during summer at station II. The vertical zonation in the distribution of meiofaunal community was significantly correlated with interstitial water, chlorophyll a and total organic matter values. The present study indicates the existence of the well diversified meiofaunal group which can serve as food for higher trophic levels in the Red Sea interstitial environment.     

Food of Iago omanensis, a deep water shark from the northern Red Sea

Stomach contents of 252 lago omanensis were examined. Sharks were collected in deep water between 150 and 450 m depth off the Marine Laboratory of Eilat. This species feeds on benthopelagic fishes, deep water cephalopods, crustaceans, benthic molluscs and polychaetes. Cephalopods were the main food of I. omanensis , except during the summer when fishes (mainly myctophids) were ingested in greater quantity. Stomachs also contained terrigenous plant matter, animal remains and large quantities of mud. Prey taxa included two new cephalopod records for the Red Sea.     

Feeding and growth of the pearl oyster Pinctada margaritifera (L.) in Dongonab Bay,Red Sea

Plankton samples and gut contents of P. margaritifera were analysed monthly from April 1972 to March 1973. Coscinodiscus sp. was the most ingested food by pearl oysters of all ages. However, food variety increased as the oyster grew older. Experiments confirmed the absence of food selectivity in P. margaritifera. Unlike the young ones, the adult showed reduced growth during summer (July–September), which coincides with its spawning season.     

Bryozoa from northern Red Sea,Egypt: 1 Crisia (Cyclostomata)

Seventy-five bryozoan species were picked from shallow bottom sediments (0–33 m depths) at five sites in the northern Red Sea: El Fanader, Hurghada Harbour, Makkadi Bay, Al Qweh Lagoon and El-Humrawen. Crisia specimens (Cyclostomata) are common and exhibit different variations. Six species were recognised among the specimens collected: Crisia eburnea (Linnaeus), Crisia elongata (Milne-Edwards), Crisia hornesi Reuss, Crisia sertularoides (Audouin), Crisia tenuis MacGillivray and Crisia hurghadaensis n. sp. The present paper deals with these Crisia species; other bryozoan taxa recovered will be published later. Biogeographic study reveals that three of these species are cosmopolitan, and represented by common to abundant occurrences (C. elongata, C. eburnea and C. hornesi). Two species are local endemics, and represented by only rare occurrences (C. sertularoides and C. hurghadaensis n. sp.). One species (C. tenuis) is Indo-Pacific, and is recorded here for the first time in equatorial waters.     

Exploring the taxonomic and functional diversity of marine benthic micro-Eukaryotes along the Red Sea coast of Jeddah city

BackgroundsDiverse marine habitats along Jeddah's Red Sea coast support rich biodiversity. Few studies have been done on its diverse communities, especially its microbial counterparts. Metagenomic analysis of marine benthic micro-eukaryotic communities was performed for the first time on the Red Sea coast of Jeddah. This research looks into their community structure and metabolic potential.MethodsNext-generation sequencing was used to examine the micro-eukaryotic communities of seven sedimentary soil samples from four Jeddah coast locations. After isolating DNA from seven benthic sedimentary soil samples, the 18S rDNA V4 regions were amplified and sequenced on the Illumina MiSeq. It was also verified using an Agilent Technologies 2100 Bioanalyzer with a DNA 1000 chip (Agilent Technologies, Fisher Scientific). A standard curve of fluorescence readings generated by qPCR quantification using the Illumina library was achieved using the GS FLX library. Metagenomic data analysis was used to evaluate the microbial communities' biochemical and enzymatic allocations in studied samples.ResultsBlast analysis showed that the top ten phyla were Annelida, Eukaryota, Diatomea, Porifera, Phragmoplastophyta, Arthropoda, Dinoflagellata, Xenacoelomorpha Nematoda, and uncultured. Annelida was also found in the highest percentage (93%), in the sample M followed by Porifera (64%), the most abundant in the control sample then Eukaryotes (61%), Phragmatoplastophyta (55%), Arthropoda, and Diatomea (the least common) (32%). community diversity analysis: using Shannon and inverse Simpson indices showed sediment composition to be effective. Also, PICRUST2 indicated that the most abundant pathways were pyruvate fermentation to isobutanol, pyrimidine deoxyribonucleotide phosphorylation, adenosine ribonucleotide de novo biosynthesis, guanosine ribonucleotide de novo biosynthesis, NAD salvage pathway I, the super pathway of glyoxylate bypass and aerobic respiration I (cytochrome c).ConclusionResults showed that high throughput metagenomics could reveal species diversity and estimate gene profiles. Environmental factors appear to be more important than geographic variation in determining the structure of these microbial communities. This study provides the first report of marine benthic micro-eukaryotic communities found on the Red Sea coast of Jeddah and will serve as a good platform for future research.     

Increased 5-Hydroxytryptamine and Norepinephrine Release from Rat Brain Slices by the Red Sea Flatfish

The effect of the Red Sea flatfish toxin pardaxin was examined on K+-evoked and on basal release of either [3H]norepinephrine or [3H]5-hydroxytryptamine from preloaded rat cortical slices. The K+-induced release of the neurotransmitters was stimulated in a dose-related manner at concentrations ranging from 0.5 to 4 micrograms/ml. Basal release of the two transmitters was elevated to a lesser extent. Although the stimulation of evoked release was approximately equivalent for the two neurotransmitters, the response to 5-hydroxytryptamine was reversible whereas that of norepinephrine was not washed by 20 min of superfusion. The mechanisms involved in producing these actions of pardaxin are not known; however, they may be mediated by changes in electrolyte fluxes across the neuronal membranes.     

Vertical zonation of coral reef fishes in the Sudanese Red Sea

The vertical zonation of 38 species of fish inhabiting coral reefs in the Sudanese Red Sea is described. A marked degree of vertical zonation of the fishes is shown to exist. The usefulness of a depth oriented survey method for studying reef fish is discussed in relation to these results.General relationships between vertical zonation and species diversity are noted.