Exploring Sheraoh Island at South-Eastern Qatar: First Distributional Records of Some Inland and Offshore Biota with Annotated Checklist

Sheraoh island is the most remote among Qatari islands, nearly 73.5 km south-eastern of the mainland of the peninsula. In March 2010, a preliminary general survey of the species was conducted. Observations were made partly by wading and snorkeling in the intertidal zone and partly by surveying the inland habitats. In total the 31 species were recorded, 4 species of halophyte plants: Halopeplis perfoliata, Suaeda vermiculata, Salsola baryosoma and Zygophyllum qatarense, one unexpected terrestrial mammal: the cape hare Lepus capensis, 2 species of visiting birds: Motacilla flava and Anthus campestus and one species of sea bird. Phalacrocorax nigrogularis, one dolphin species: Sousa chinensis. The largest richness was found in the marine habitats, 3 species of sea weeds: Colpomenia sinusa, Padina boergesenii and Sargassum boveanum, 3 species of corals: Anomastraea irregularis, Platygyra lamellina and Porites harrisoni, 2 species of nudibranchs: Chromodoris cazae and Chromodoris sp. (unidentified)., 4 crab species: Hermit crab (unidentified), Etisus laevimanus, Grapsus albolineatus and Lambrus prensor, 4 species of echinoderms: Pentacentral mammillatus, Ophiothela venusta, Diadema setosum and Echinometra mathaei, 5 species of bony fish: Doryrhamphus sp. (larva), Cypserulus oligolepis, Lethrinus nebulosus, Cephalopholis miniatus and Hemiramphus marginatus, one species of sea snakes: Hydrophis sp. The most striking result is to collect an unknown nudibranch species and to report the cape hare which is unexpected inhabitant. All figures of this study are published for the first time in Qatar. *Corresponding author: Mahmoud M Kardousha, Department of Biological and Environmental Sciences, Qatar University, Doha, PB Box 2713, Qatar, Tel: +97444034540; E-mail: mkardousha@qu.edu.qa Received May 03, 2016; Accepted May 13, 2016; Published May 23, 2016 Citation: Kardousha MM, Al-Muftah A, Al-Khayat JA (2016) Exploring Sheraoh Island at South-Eastern Qatar: First Distributional Records of Some Inland and Offshore Biota with Annotated Checklist. J Marine Sci Res Dev 6: 191. doi:10.4172/2155-9910.1000191 Copyright: © 2016 Kardousha MM, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Introduction
Although there is a growing number of marine ecosystem studies of Qatari waters, the islands have not received much attention. There have been a few publications on island' biodiversity in the region, but with the exception of recent studies on the Qatari lizards [1] and vegetation [2], there are no (to our knowledge) first hand records of biodiversity in Sheraoh island except few observations have been recorded by some visitors [3]. Islands are important priorities for biodiversity conservation that hold more than one-fifth of the world's plant species and about one-quarter of the world's threatened mammals and onethird of the world's threatened birds [4]. In Qatar, the most prominent islands are located in the north and eastern side of Qatari peninsula. They include Rakan island, Halul island, Al-Aaliya island, Al-Safliah island, Al-Ashat island and Sheraoh island. They play a crucial role as resting and breeding sites for different types of seabirds, nesting sites for the green and hawksbill turtles and some of them harbor coral reefs around which host a highly rich diversity of marine species. There is a growing number of studies focusing on islands biodiversity in Qatar. Vegetation (Halul island [2], lizards (three islands were investigated: Halul, Al-Alia and Al-Safliyah [1] and the coral reefs and associated biota of Halul and Al-Safliyah islands [5,6]. In addition, Halul island is a very important island for nesting hawksbill turtles and different sea birds [3]. The biodiversity of Sheraoh island had never been studied and the only information available is visitor observations related to nesting activities of hawksbill turtles [3]. Thus, the current study is the first biodiversity survey of the island. There is a need of further research to help in setting a conservation agenda for the wild life of Arabian Gulf islands.

Qatari islands
The archipelago of Qatar peninsula, south of Arabian Gulf, is located between the latitude 24 o 27' and 26 o 10' North and longitudes 50 o 45' and 51 o 40' East with an area of 11,521 km 2 . The most prominent islands are located north, north-eastern and south-eastern sides of the peninsula. summarizes the Qatari islands with its latitudes and longitudes. The Sheraoh island is the most remote island in the southeastern side ( Figure 1). It is located at the far margin of Qatari waters. The island has different biotypes including rocky shores, intertidal and subtidal sand banks, shallow lagoons and coastal sand dunes (Figures 2 and 3) (Table 1).

Two days' cruise to sheraoh island
The observations were made during 2 days' field work in March 2010. The survey was conducted partly by wading and snorkeling in the intertidal zone and by surveying the inland habitats. Two benthic samples were collected offshore. Samples were preserved in plastic collection jars containing 5% seawater-diluted formalin, brought to the laboratory, sorted, and identified. Some specimens were photographed in situ. All specimens were investigated by using Stereo-microscope and identified based on the available atlases, field guides and publications such as marine biota [7], sea shore organisms [8], fishes [9], halophytes [10] and corals [11,12].

• Mammals
One unexpected mammalian species, the cape hare Lepus capensis was seen running very fast and camouflaged under shrubs. A discovered skeleton with stiff tufts of hairs between the pads of the feet obviously indicating that the Cape hare is a common inhabitant on the island ( Figure 10). A dolphin skeleton was also found with well-defined long beak and prominent teeth, the upper jaw is shorter than the lower and backbone is humped. These features characterize the endo-pacific humped back dolphin Sousa chinensis ( Figure 11).

Coastal area assemblage
Along the coastal area, many pieces of coral skeletons were observed scattered everywhere which indicated the dominancy of three species, Anomastraea irregularis, Platygyra lamellina and Porites harrisoni. The brown algae were plentiful along the coastal area and three species were dominated, Colpomenia sinusa ( Figure 12), Padina boergesenii ( Figure  13) and Sargassum boveanum ( Figure 14). Rocks in the upper intertidal zone were covered by green algae (Figure 15).

Intertidal and subtidal biotopes
The assemblage of intertidal and subtidal diversity was found highly enriched by different types of marine biota.

• Nudibranchs
Two species of nudibranchs were collected from subtidal zone, Chromodoris cazae ( Figure 20) and un-specified nudibranch related to genus Chromodoris which is characterized by prominent red spots and yellow margin ( Figure 21).

Offshore biotype
Five species of bony fish was encountered, a larval stage of pipe

Results
A total of 32 species were collected/ encountered along the inland, coastal, and tidal areas of the island during the expedition with different groups and species (Table 2).

Inland assemblage
The vegetation of the island was found to be dominated by halophyte communities with Halopeplis perfoliata (Figure 4

Discussion
Qatari islands are numerous, and most of them are located nearshore of the main land of the peninsula. The most remote ones are Halul and Sheraoh islands which are located at northeastern and southeastern of Qatar respectively. The islands are usually flat, made of calcareous rock and covered by sand. There is very limited information available on Sheraoh island, although, it is described as a heaven for sea birds, nesting turtles specially the hawked bill types and small fringed reefs [3]. Due to its isolation and long distance from the mainland, Sheraoh island has not been visited by many people. Only fishermen and a few others visit the islands and they typically do not stay long. It is not frequently disturbed, the island still maintains very large breeding  fish Doryrhamphus sp., flying fish Cypserulus oligolepis, Lethrinus nebulosus, Cephalopholis miniatus and Hemiramphus marginatus. One marine reptile was also observed from the vessel, the common Arabian Gulf sea snakes, Hydrophis sp.                      aggregations of seabirds and sea turtles that have been lost from the mainland and islands near the mainland.
The Arabian Gulf and Qatari islands are extremely important as nesting sites for green and hawksbill turtles. In addition, they are of international importance for seabirds that either breed on the islands or rest there during their annual migrations. The islands also host other species from different biota. The reefs around the islands host a rich diversity of marine species including algae, seagrass, coral, invertebrates, fishes, turtles, and occasionally sea snakes and marine mammals [12].
One of the most interesting species which was collected from Sheraoh' biota was one unidentified species of nudibranchs that is characterized by prominent red wide spots and yellow margin. It is probably related to Australian species Chromodoris splendida [13]. No organized study of nudibranchs in Qatar has yet been undertaken, however, some collections have been reported. As far as references have revealed, 6 species have been collected from Qatari waters, Chelidonura livida, Flabellina rubrolineatus, Chromodoris annulata, C. obsolete, C. cazae and C. sp16 [14][15][16]. Chromodoris cazae has only reported from Arabian Gulf, specifically from Qatar and United Arab Emirates [17].
The observations and collecting of coral skeletons and algal remains from intertidal zone indicated that there is a high diversity of corals and algae in the surrounding waters. The skeletal material of coral reefs was found covering a wide area of coastal region. The scattered skeletons            were dominated by the brain coral Platygyra lamellina and Porites harrisoni which are the most common Arabian Gulf corals [12,18,19].
Among the more active offshore animal types are the crabs which mostly with high distribution near sand and rocky coastal areas. The rock crab Etisus laevimanus, the mottled crab Grapsus albolineatus and the parthenopid crab Lambrus prensor were common along the coastal area. The prominent erected sand towers of Ghost crabs also common along the coastal area [20].
We were unexpected to find a population of Cape hare Lepus capensis at the island. The cape hare is a common mammalian member of Arabian Peninsula including Qatar. However, its presence in a remote isolated island like Sheraoh was unexpected. The Cape hare has been recorded also from Al-Saflia island [3]. It could be interesting to study this population using DNA techniques to trace its phylogeny. This will empathize if this population was introduced to the island or if it has been isolated for a long period. As islands near the mainland are commonly disturbed by human presence, the remote and isolated Sheraoh island could be used for studies on natural ecosystem on undisturbed islands [20].