Isolation and Characterization of Two Chalcone Derivatives with Anti-Hepatitis B Virus Activity from the Endemic Socotraen Dracaena cinnabari (Dragon's Blood Tree).

Hepatitis B virus (HBV) infection is prevalent and continues to be a global health concern. In this study, we determined the anti-hepatitis B virus (HBV) potential of the Socotra-endemic medicinal plant Dracaena cinnabari and isolated and characterized the responsible constituents. A bioassay-guided fractionation using different chromatographic techniques of the methanolic extract of D. cinnabari led to the isolation of two chalcone derivatives. Using a variety of spectroscopic techniques, including 1H-, 13C-, and 2D-NMR, these derivatives were identified as 2,4'-dihydroxy-4-methoxydihydrochalcone (compound 1) and 2,4'-dihydroxy-4-methoxyhydrochalcone (compound 2). Both compounds were isolated for the first time from the red resin (dragon's blood) of D. cinnabari. The compounds were first evaluated for cytotoxicity on HepG2.2.15 cells and 50% cytotoxicity concentration (CC50) values were determined. They were then evaluated for anti-HBV activity against HepG2.2.15 cells by assessing the suppression of HBsAg and HBeAg production in the culture supernatants and their half maximum inhibitory concentration (IC50) and therapeutic index (TI) values were determined. Compounds 1 and 2 indicated inhibition of HBsAg production in a dose- and time-dependent manner with IC50 values of 20.56 and 6.36 µg/mL, respectively.

Diversity and composition of estuarine and lagoonal fish assemblages of Socotra Island, Yemen.

Estuarine and lagoonal surveys of Socotra Island and selected sites on the Hadhramout coast of Yemen were conducted with the objective of documenting and analysing fish diversity and assemblage structure. A total of 74 species in 35 families were recorded, among which 65 species in 32 families were from Socotra and 20 species in 17 families were from mainland Yemen. Twenty-one species represent new faunal records for Socotra. Including historic records re-examined in this study, the total fish species richness of estuaries and lagoons of Socotra Island reaches 76, which is relatively high compared to species inventories of well-researched coastal estuaries in southern Africa. Five species dominate the occurrence and abundance frequencies: Terapon jarbua, Hyporhamphus sindensis, Aphanius dispar, Ambassis gymnocephala and Chelon macrolepis. Rarefaction and extrapolation analyses suggest that the actual number of fish species inhabiting some of those estuaries might be higher than the one observed. Thus, additional sampling at specific sites should be conducted to record other less conspicuous species. Ordination and multivariate analyses identified four main distinct assemblage clusters. Two groups are geographically well structured and represent northern Socotra and mainland Yemen, respectively. The other two assemblage groups tend to be determined to a greater extent by the synchrony between physical (e.g. estuary opening periods) and biological (e.g. spawning and recruitment periods) variables than by geographical location. Finally, the single intertidal lagoon of Socotra represents by itself a specific fish assemblage. The high proportion of economically important fish species (38) recorded underscores the paramount importance of these coastal water bodies as nursery sites, and for sustaining vital provisioning ecosystem services.

Ethnopharmacological survey of endemic plants used in ethnomedicinal knowledge of Soqotra Island.

ETHNOPHARMACOLOGICAL RELEVANCE: Due to the long biogeographical isolation since ancient times, Soqotra Island (southern Yemen) is rich in medicinal endemic plants. However, information on their traditional therapeutic knowledge is scarce in scientific literature and still not completely documented. AIM OF THE STUDY: (1) Documentation and search the native traditional therapeutic knowledge focusing on the medicinal plants which are endemic to Soqotra (2) Identification of the important endemic plants treating diseases by quantitative analysis of the collected data. MATERIALS AND METHODS: Ethnobotanical data were collected from 105 local informants through open interviews, semi-structured questionnaires and field survey in February 1990 to document the traditional medicinal plants in Soqotra Island. Of them we reported in this study the data of the endemic species, due to their wide biodiversity in the island. The quantitative data were analyzed for use reports (URs) and the informant consensus factor (ICF). The reported diseases were classified according to the International Classification of Primary Care-2 (ICPC-2). New reported medicinal plants in this study were identified compared to literature review. The level of traditional Soqotri knowledge among Islanders was observed during 1990-2003. RESULTS: In the study, 86 medicinal endemic plants with 7654 therapeutic URs were explored for 69 ailments types belongs to 11 (ICPC-2) groups. The highest ICF value (0.99) were calculated for both eye and ear diseases categories, followed by general and unspecified ailments (0.98), digestive and skin (0.97 for each), and musculoskeletal ailments (0.96) among all diseases categories. While the highest URs (2276) were identified for skin diseases, followed by digestive diseases (URs = 2146). All the 86 recorded medicinal plant species were endemic to Soqotra, belonging to 57 genera and 29 families. Euphorbiaceae and Burseraceae were the dominant families, followed by Apocynaceae, Fabaceae and Asteraceae. Shrubs were the dominant growth form (41 species, 47.67%), followed by herbs (27; 31.4%), and trees (14; 16.28%). Leaves (45 species; 31.25%) were the most frequently used parts, followed by stems (34 species; 23.61%) and barks (species 23; 15.97%). The most cited preparation method was paste for 51 species followed by liquid exudates (48 species) and powder (26 species). Based on the comparative literature review, we recorded 36 new endemic medicinal plants and reported new traditional therapeutic uses for the remaining 50 endemic plants for the first time. On the other hand, all the reported endemic medicinal plants have been enlisted in the IUCN Red List of Threatened Species, of them 21 endemic species enlisted as highest threatened species. CONCLUSION: According to the quantitative data analyzed, Soqotra Island has a valuable traditional knowledge in several medicinal endemic plants that used by local people in the primary health care until the study time at 1990. This study emphasizes the importance of early time in documenting traditional indigenous knowledge before losing and to protect and conserve the endemic plants against highly endangered. Consequently, these ethnomedicinal data could be used in the future as guide for pharmacological and phytochemical studies to discover new therapeutic drugs.

Impact of Nesting Socotra Cormorants on Terrestrial Invertebrate Communities.

Seabirds and some inland waterbirds nest in densely aggregated colonies. Nesting activities for a duration of months could lead to large quantities of guano deposition that affects the soil chemistry, flora and fauna. We assessed the effects of nesting Socotra Cormorants on soil invertebrates on Siniya Island, United Arab Emirates. Artificial substrate traps were set in nesting and non-nesting areas to sample invertebrates both before and after nesting had occurred. Diversity of soil invertebrate taxa decreased significantly in nesting areas compared to non-nesting areas after the commencement of nesting. This indicated that nesting activities had a negative effect on diversity. Among selected taxa, isopods and spiders decreased significantly in response to nesting activities. In contrast, ants were likely affected by habitat while beetles did not change significantly in response to nesting activities, suggesting that their numbers probably fluctuated in relation to seasonality. Ticks increased significantly but only in non-nesting areas. Thus, the impact of nesting varied between taxa depending on life history and seasonality. Our observations reflect the dynamic nature of invertebrate abundance that is affected by seasonality and the hyper-abundance of nesting seabirds.

Exploring the historical distribution of Dracaena cinnabari using ethnobotanical knowledge on Socotra Island, Yemen.

BACKGROUND: In this study, we present and analyze toponyms referring to Socotra Island's endemic dragon's blood tree (Dracaena cinnabari) in four areas on the Socotra Archipelago UNESCO World Heritage site (Republic of Yemen). The motivation is the understanding of the past distribution of D. cinnabari trees which is an important part of conservation efforts by using ethnobotanical data. We assumed that dragon's blood trees had a wider distribution on Socotra Island in the past. METHODS: This research was based on field surveys and interviews with the indigenous people. The place names (toponyms) were recorded in both Arabic and the indigenous Socotri language. We grouped all toponyms into five different categories according to the main descriptor: terrain, human, plant, water, and NA (unknown). Also, this study identified current and historical Arabic names of dragon's blood trees of the genus Dracaena through literature review. RESULTS: A total of 301 toponyms were recorded from the four study areas in Socotra Island. Among names related to plants, we could attribute toponyms to nine different plants species, of which six toponyms referred to the D. cinnabari tree, representing 14.63% of the total phytotoponyms in the category. Three historical naming periods prior to 2000 could be identified. The most commonly used name for dragon's blood trees (D. cinnabari, D. serrulata, D. ombet) appears to be "ahrieb" "إعريهب" and its resin "dum al-akhawin" "دم الأخوين," while derived (mixed-cooked) products are called "eda'a" "إيدع," while regionally different names can be found. CONCLUSION: The place names that refer to D. cinnabari are herein suggested to represent remnant areas of once large populations. Therefore, the toponyms may support known hypotheses based on climate models that D. cinnabari had a wider distribution on Socotra Island in the past. This study also confirmed the historical importance of dragon's blood.

A new stygobiotic Stenasellus Dollfus, 1897 (Asellota: Stenasellidae) from Socotra Island, Yemen.

We describe a new species of Stenasellus Dollfus, 1897 (Isopoda: Asellota: Stenasellidae) from stagnant freshwater habitats in a cave on Socotra Island, Yemen. S. taitii n. sp. is the first endemic stenasellid found in Socotra, showing relatively closer morphological affinities to species from the Middle East (Oman, Iran) than from the African mainland, corresponding to the known paleogeographical connection of the archipelago to Southern Arabia. With notes on the protection of Socotran groundwaters.

Coastal fish diversity of the Socotra Archipelago, Yemen.

The Socotra Archipelago, located in the eastern Gulf of Aden, has a unique marine environment which combines tropical and 'pseudo-temperate' elements. Studies on the fish biogeography of the archipelago, partially framed in regional studies, have substantially outpaced critical elementary research on the archipelago's fish diversity. The present study seeks to close this gap and identifies the Socotra Archipelago as a major hotspot of coastal fish diversity in the Indian Ocean.       The archipelago supports unique coastal fish assemblages which are predominantly composed of coral-associated ("reef") species, in spite of the limited biogenic reef frameworks. A Preliminary Checklist comprises 682 species with confirmed records and a "Working List" includes an additional 51 records, totalling 733 faunal records in 108 families. The family Labridae is the most speciose, followed by Gobiidae, Pomacentridae, Serranidae and Chaetodontidae. The species richness of the archipelago is the highest when compared to adjacent Arabian ecoregions. The richness of the Acanthuridae, Chaetodontidae, Labridae, Pomacentridae and Pseudochromidae stand out as particularily high, and the richness of several families is as high as or higher than in the entire Red Sea. The total archipelagic richness is extrapolated at up to 875 species based on incidence-based richness models and expert opinion. Inshore fish inventories, covering 497 species, found between 14 and 132 species per site (x̄ = 66). Site diversity decreased across the archipelago from west to east and from north to south. Total fish diversity was highest around Socotra Island, followed by Abd al-Kuri Kal Farun and Darsa Samha. Occurrence frequencies were very unevenly distributed and dominated by Pomacentrus caeruleus and Thalassoma lunare, whilst many species were infrequent. The fish assemblages are dominated by species from the Indo-West Pacific and the north-western Indian Ocean. The assemblages are rich in rare species and hybrids, and include a low number of endemics (4-5), and a high number of species with far-reaching and Western Indian Ocean ranges.

A record of Notostraca on Socotra Island and the importance of local conservation of the habitat.

The first record of Triops Schrank, 1803 (Crustacea: Branchiopoda: Notostraca: Triopsidae) from Socotra Island is presented herein. Besides Madagascar and the current note, the genus is unknown from Indian Ocean islands. A brief morphological exploration indicates that the Socotran Triops cf. granarius (Lucas, 1864) (trachyaspis form) belongs to an African clade within this widespread Old World species complex and not to T. granarius s.str. from East Asia. Detailed morphological and molecular revision of the poorly studied Middle Eastern and Northern African populations in comparison to East Asian populations are needed to understand this group and the phylogenetic position and status of the Socotran tadpole shrimp. Found in a single locality (the archeological site Eriosh) in the rapidly changing coastal plains on Socotra, together with other large branchiopods (endemic Anostraca and unidentified Spinicaudata), the insular Triops population and the regionally neglected temporary lake habitat deserve a special protection status from a biodiversity conservation perspective. Triops cf. granarius is hereby suggested as a local flagship species for the conservation of temporary pool habitats on the island.

A new stygobiont species of Halocaridinides Fujino Shokita, 1975 (Crustacea, Decapoda, Caridea, Atyidae) from caves on Socotra Island (Yemen), with notes on the genus.

We describe a new species of stygobiont atyid shrimp of the genus Halocaridinides Fujino Shokita, 1975 from subterranean brackish and freshwater environments on Socotra Island (Yemen). This is the first atyid shrimp discovered in the Socotra Archipelago. This Socotran endemic is the second species of Halocaridinides recorded from an Indian Ocean island and the first to occur in non-anchialine environments. The new species is characterized by the absence of eye pigmentation, a reduced rostrum and the presence of a single spine in the uropodal exopod diaeresis. Morphological variability in the robustness of the first and the second chelipeds, particularly obvious in the chelae, may indicate local speciation or phenotypical plasticity. At both extremes of the variation, animals with most slender (tenuis type) or robust (robustus type) morphologies occur. We discuss the Indo-Pacific distribution of the genus and the potential origin of the new Socotran species. An amended diagnosis for the genus and a key to all species are included.

Feeding ecology of some fish species occurring in artisanal fishery of Socotra Island (Yemen).

The demersal species Lethrinus borbonicus, Lethrinus mahsena, Lethrinus microdon, Lethrinus nebulosus, Lutjanus bohar, Lutjanus gibbus, Lutjanus kasmira, Epinephelus fasciatus, Epinephelus stoliczkae, Carangoides gymnostethus and Euthynnus affinis are important coastal fishes species of the northern coast of Socotra (Yemen), exploited by local fishery. The biology and feeding ecology of these species are poorly known in the area. A total of 1239 specimens were sampled from the main fishing landing site of the island (Hadibo). Total length and weight were measured, stomach contents were analyzed, diet overlap, Fulton's Condition index, and trophic levels were estimated. C. gymnostethus, L. microdon and L. kasmira occupied the highest position (T=4.50), L. nebulosus occupied the lower one (TL=3.41). The role of the increasing abundance of small pelagic fish in the diet of many species after the upwelling event is evident, but also different feeding strategies are reported, according to fish ecology.

Coxiella-like endosymbiont in argasid ticks (Ornithodoros muesebecki) from a Socotra Cormorant colony in Umm Al Quwain, United Arab Emirates.

Coxiella burnetii is a pathogen causing Q fever in domestic animals and humans. Seabirds have been implicated as possible reservoirs of this bacterium in the Arabian Gulf and in the Western Indian Ocean. Recently, Coxiella species closely related to C. burnetii was detected from ticks collected from oil rigs used as roosting areas by Socotra Cormorants (Phalacrocorax nigrogularis) in the western Arabian Gulf. We collected ticks from the largest breeding colony of Socotra Cormorants in the United Arab Emirates on the eastern extreme of the species' breeding range to determine the prevalence of C. burnetii and evaluate its role as a wild reservoir. All ticks were identified as Ornithodoros muesebecki and genomic DNA was extracted from larval and nymph/adult tick pools. Multiplex PCR tests were performed targeting three C. burnetii specific genes. C. burnetii was not detected although a Coxiella-like endosymbiont was identified that was closely related to Coxiella symbionts from Ornithodoros capensis ticks. Because domestic and wild ungulates are the primary source of C. burnetii, we suggest that the presence of free-ranging, native and non-native ungulates in some off-shore islands in the Arabian Gulf could disseminate C. burnetii to seabirds. More comprehensive studies on seabird colonies are needed to better understand the diversity and prevalence of Coxiella symbionts and to establish if C. burnetii is endemic on some of these islands.

The coastal fishes and fisheries of the Socotra Archipelago, Yemen.

The Socotra Archipelago is situated in the Gulf of Aden where tropical and "pseudo-temperate" conditions combine to create a unique marine ecosystem. The diversity, ecology, productivity and fisheries of the coastal fish assemblages are still relatively understudied and no update of the scientific knowledge existed. The islands support unique coastal and coral-associated fish assemblages in spite of the limited biogenic reef frameworks. Fish diversity is the highest among comparable Arabian eco-regions, and fish biomass productivity high too by Indian Ocean standards. The production of the once traditionally-managed small-scale fishery is severely declining and whether it is sustainable nowadays is extremely doubtful. At a time when Yemen is torn apart by a severe political and humanitarian crisis it is timely to review and update the current state of knowledge for scientists and managers, and thereby ease access to existing information, facilitating follow-on studies and evidence-based conservation and fisheries management.

Cossidae of the socotra archipelago (yemen).

The faunistic composition of the family Cossidae (Lepidoptera) of the Socotra Archipelago is revised. Five species are recognized, including two new species (Mormogystia brandstetteri and Meharia hackeri), and dubious identifications and records are discussed. Adults and genitalia are illustrated and bionomic details, DNA barcodes and a synonymic checklist for Socotran cossids are provided. A review of their distribution reveals that at least 80 percent of Socotra's cossids are unique to the archipelago, which is renowned for its endemism. A checklist listing all the species from generas Meharia, Mormogystia, Aethalopteryx, Azygophleps, as well as the synonymy and distribution is provided.

Five new species of Triotemnus (Coleoptera, Curculionidae, Scolytinae) from Morocco and Yemen.

Fivenew species of the genus Triotemnus from Morocco and Yemen are described. Triotemnus is a new genus of Scolytinae for the Yemen region. External morphology of the new species and all morphologically related species of the genus were studied. While the new species from Morocco are morphologically similar to the known species from the corresponding region, all three newly described species from Yemen, mainly two of them living in Socotra, are morphologically very different from all other known species of the genus. Geographical distribution and the probability of endemicity are discussed.