Arabian Gulf Coast Research Articles

A multi-isotopic evaluation of groundwater in a rapidly developing area and implications for water management in hyper-arid regions

Management of water resources in hyper-arid areas faces vital challenges in a global climate change context. Consequently, understanding the effects on groundwater sources can help mitigating the problem of water scarcity and the negative impact of human intervention on the environment. A case study area in the hyper-arid climate of the United Arab Emirates, was tackled here with the focus on applying stable isotopes as tools for evaluating groundwater sources and quality assessment. The results of major ions indicate variable increase in groundwater salinity moving away from Al Hajar Mountains recharge areas to the discharge areas (Arabian Gulf coast). The data of stable isotopes (δ18OH2O, δ2HH2O, δ18ONO3, δ15NNO3, δ18OSO4, δ34SSO4, δ11B) suggest impact of paleo-groundwater in the abstractions of the wells nearest to the coast. Nitrate isotopes indicate farming activities sources that can be masked due to the contribution from the nitrate-poor paleo-groundwater. Nitrate reduction processes are expected near to the recharge front. Sulphate and boron isotopes further suggest that influence of ancient evaporite dissolution in salinization. Management efforts should be focused on the diffuse sources of quality mitigations that can be vital in fingerprinting local and regional (transboundary) effects.

Macrofaunal assemblage in the intertidal area of Saudi Arabian Gulf Coast

The Saudi Arabian Gulf coast is witnessing many industrial, recreational and other developmental activities. Impact of these activities on the intertidal macrofaunal communities of this region has not been documented well. Thirty four stations falling under four zones along this coast were sampled to study the benthic macrofaunal community. A total of 81 taxa were recorded and the species richness varied between the zones. Among the 48 polychaetespecies found, Exogone heterosetosa, Dialychone collaris, Ophelina longicaudata, Paraprionospio pinnata, Perinereis falsovariegata and Scololepis squamata were dominant. Species such as Littoraria scabra, Bullia vittata, Incatella cingulata, Meretrix meretrix, Donax sp. and Maoricardium setosum were dominant among the twelve gastropod species. The thirteen species of macrofauna identified to occur in all the zones comprised eight species of gastropods besides two species each of amphipods and isopods and one species of cumacean. ANOSIM showed significant differences in assemblage overall among the four zones and in pairwise comparison. Distance based linear modeling (DISTLM) showed the environmental parameters to explain 55.67% of the variability in macrofauna with variables such as pH, salinity, temperature, pebble and gravel showing significant relationship with macrofauna and explained higher variability. The alpha diversity values were comparatively lower in zone 3 which had high anthropogenic pressure. Shannon–Wiener​ diversity, Margalef richness and more importantly the M-AMBI showed the healthy nature of the study area. The findings of the present study are helpful in tracing the future changes in the intertidal habitat due to anthropogenic activities in this fast developing geographical area.

Chloride diffusion models for Type I and fly ash cement concrete exposed to field and laboratory conditions

The exposure temperature significantly affects the diffusion of chloride ions in concrete, and, as such, it must be taken into consideration in the development of service-life prediction models for structures exposed to chloride-bearing environments. Most of the earlier studies have used cement paste to assess the effect of exposure temperature on chloride diffusion. In the reported study, chloride diffusion in Type I and fly ash (20% fly ash) cement concrete was evaluated under field and laboratory conditions. The laboratory concrete specimens were exposed to chloride solution maintained at four temperatures (22, 35, 50 and 60 °C) for 365 days. Beam specimens were exposed in the tidal zone of a marine exposure site, along the Arabian Gulf coast, for up to 10 years to study the chloride diffusion in the field specimens. The coefficient of chloride diffusion (Da) in the concrete specimens exposed to 22 or 35 ᵒC in the laboratory was less than that in the concrete specimens exposed to 50 and 60 ᵒC. The Da for Type I cement concrete specimens increased by 3.6 times as the temperature was increased from 22 to 60 ᵒC while this increase was 2.3 times for the fly ash cement concrete specimens for a similar increase in the temperature. The Da decreased with the period of exposure in the field specimens. The values of activation energy that can be used for predicting the chloride diffusion for exposure temperature within the range of 22–60 °C were developed based on the laboratory data. In addition, mathematical models were developed relating the coefficient of chloride diffusion in the field and laboratory concrete specimens. The developed models can be utilized to ascertain chloride diffusion in field specimens, utilizing the laboratory values, and hence calculate the useful service-life of structures.

Effect of sampling time on the heavy metal concentrations of brown algae: A bioindicator study on the Arabian Gulf coast

Macroalgae have often been studied as bioindicators for heavy metal pollution on sea coasts including the Arabian Gulf. On the Arabian Gulf coasts, heavy metals are continuously being released by industrial activities and therefore, pollution monitoring is needed. Biomonitoring studies using macroalgae has given highly different assessments due to the variability in algal species and sampling time points. We carried out a systematic monthly sampling of brown algae (Phaeophyta) from three locations on the western coast of the Arabian Gulf between September and February 2018. One urban area (Uqair) and two oil refining areas (Ras Tanura and Jubail) were monitored due to they have a common brown macroalgae species composition. The incidence of Cystoseira myrica, C. trinodis C. osmundacea, Hormophysa cuneiformis, Sargassum aquifolium, S. latifolium, S. filipendula and Padina boryana varied among the sites and with the time of year within the sites. The concentrations of Co, Cd and Pb varied among the sampling sites, the algal species and the sampling time points remarkably. A tentative time-trend increasing towards February was observed for some species. However, it appeared that neither optimum sampling time point, nor superior brown algae species could be recommended. The highest heavy metal accumulation was observed in Padina boryana. However, this species grew only on the two oil polluted sites. We concluded that some brown algae species can be used for biomonitoring heavy metal pollution on the western coast of the Arabian Gulf. The species incidence should be monitored systematically and the species used should be chosen locally and sampled at the same time of the year.

The method of historical writing for western travelers in Al-Ahsa of 1328- 1353 AH/ 1910- 1934 AD: منهج الكتابة التاريخية عند الرَّحالة الغربيين في منطقة الأَحْسَاءَ من الفترة 1328ــ1353هـ/ 1910ــ1934م

This study seeks to provide a vision as travel literature is an art of Arab literature and a source of archaeological resources to write history. to present a varied picture of the approach of western globetrotters writings about the Arabian Peninsula in general, and the Al-Ehsa'a region and its people in particular, the importance of which is due to its distinguished location on the Arabian Gulf coast that links the west with the East. As the writings of Western globetrotters approaches was drawn up by different points of view in order to reach an appropriate approach for the study of trips literature in general, and to shed light on the methodology of these globetrotters in their writings and their impressions about the Al-Ehsa'a region and to be able to extract an integrated history for the region. To achieve these two aims, it is necessary to review the academic studies concerned with the research. In this study, the researcher used the ethnohistorical approach, which is an approach based on following the methods of the descriptive ethnographic approach, by examining the content of the writings of globetrotters as a research sample, and then following the description through the reality of the observations, and on collecting the scientific material from the books of western globetrotters during that period, and Then study and analyze it. To elicit and extract conclusions from their books as globetrotters and researchers, but in death they only came to collect information and present it to their countries, while they left us with a historical legacy that reveals the extent of their interest in studying Muslim societies, and informs us to know what was in the past after examining and checking it. The most important recommendations: to Establish centers for writing foreign studies, examining and auditing them.

Spatial distribution and potential ecological risk assessment of some trace elements in sediments and grey mangrove (Avicennia marina) along the Arabian Gulf coast, Saudi Arabia

AbstractTo assess trace element concentrations (Zn, Cu, Pb, Cr, Cd and Ni) in the mangrove swamps along the Saudi coast of the Arabian Gulf, thirteen samples of surface sediment and leaves of grey mangrove, Avicennia marina were collected and analyzed. The detected trace element contents (μg g-1) in surface sediments were in the following descending order according to their mean values; Cr (49.18) > Zn (48.48) > Cu (43.06) > Pb (26.61) > Ni (22.88) > Cd (3.21). The results showed that the average concentrations of Cd and Pb exceeded their world average concentration of shale. The geo-accumulation, potential ecological risk and toxicity response indices demonstrated that trace elements have posed a considerable ecological risk, especially Cd. The inter-relationships between physico-chemical characters and trace elements suggests that grained particles of mud represent a noteworthy character in the distribution of trace elements compared to organic materials. Moreover, the results revealed that Zn was clearly bioaccumulated in leaf tissues A. marina. Dredging, landfilling, sewage effluents and oil pollution can be the paramount sources of pollution in the area under investigation.

Role of vegetated coastal ecosystems as nitrogen and phosphorous filters and sinks in the coasts of Saudi Arabia

Vegetated coastal ecosystems along the Red Sea and Arabian Gulf coasts of Saudi Arabia thrive in an extremely arid and oligotrophic environment, with high seawater temperatures and salinity. Mangrove, seagrass and saltmarsh ecosystems have been shown to act as efficient sinks of sediment organic carbon, earning these vegetated ecosystems the moniker ‘blue carbon’ ecosystems. However, their role as nitrogen and phosphorus (N and P) sinks remains poorly understood. In this study, we examine the capacity of blue carbon ecosystems to trap and store nitrogen and phosphorous in their sediments in the central Red Sea and Arabian Gulf. We estimated the N and P stocks (in 0.2 m thick-sediments) and accumulation rates (for the last century based on 210Pb and for the last millennia based on 14C) in mangrove, seagrass and saltmarsh sediments from eight locations along the coast of Saudi Arabia (81 cores in total). The N and P stocks contained in the top 20 cm sediments ranged from 61 g N m−2 in Red Sea seagrass to 265 g N m−2 in the Gulf saltmarshes and from 70 g P m−2 in Red Sea seagrass meadows and mangroves to 58 g P m−2 in the Gulf saltmarshes. The short-term N and P accumulation rates ranged from 0.09 mg N cm−2 yr−1 in Red Sea seagrass to 0.38 mg N cm−2 yr−1 in Gulf mangrove, and from 0.027 mg P cm−2 yr−1 in the Gulf seagrass to 0.092 mg P cm−2 yr−1 in Red Sea mangroves. Short-term N and P accumulation rates were up to 10-fold higher than long-term accumulation rates, highlighting increasing sequestration of N and P over the past century, likely due to anthropogenic activities such as coastal development and wastewater inputs.

Wind-driven flow dynamics off the Northwestern Arabian Gulf Coast

This study investigates the wind-driven hydrodynamics and their influence on the water properties (temperature and salinity) in the Northwestern Arabian/Persian Gulf, off the Kuwaiti Coast. Understanding the effects of wind-driven hydrodynamics on the abrupt changes in water properties and offshore transport is key in determining the fate of the Gulf's environmental sensitive species and distribution of coastal contaminants offshore. Observational meteorological and hydrographical data were collected from mid-October 2013 to mid-January 2014 at two locations. Using time series of the observed water-current profiles, we show that three wind events (order of 2–3 days) with wind directions parallel to the coast generated significant volume transports (1.96 m2/s) in the upper layer directed perpendicular to the coast. The ensuing upwelling/downwelling effects appear to be generally confined to the near coast region (16 km offshore), with cooler waters observed during upwelling and warmer waters during downwelling. Further offshore (Qarooh Island, 44 km offshore) the thermal structure was found to be strongly influenced by a warm ‘tongue’ that extended across the Northern Gulf. The progression and retreat of the ‘tongue’ was found to be in close response to the general wind direction during two wind events. Numerical simulations of the thermal structure at Qarooh, using a one-dimensional model based on the two equation k-ε turbulence model, showed an overall good agreement between the observations and simulations during the three wind events. In particular, the along-shore volume transports which followed the general wind direction were captured well in the simulation. However, the inability of the model to reproduce effects related to the coastal boundary resulted in a poor matching of simulated and observed cross-shore transports.

Ground Improvement Using Dynamic Compaction in Sabkha Deposit

The sabkha soil spreads extensively in the Arabian Gulf Coast region. Sabkha is known as a geotechnically problematic soil because of its loose density, soft consistency, high salinity and water content, and occurrence of fine sands and clays. It is generally highly compressible and requires ground improvement for highway and railway construction. The purpose of this study is to provide a guideline for dynamic compaction to improve the bearing capacity of the coastal sabkha deposit. The ground behavior during dynamic compaction was evaluated for various compaction energy conditions using numerical analysis, and field dynamic compaction tests were also performed and compared with the numerical analysis results. It was found that the bearing capacity of sabkha deposit can be effectively improved by dynamic compaction. However, care must be taken to ensure that excessive porewater pressure is sufficiently dissipated during the application of dynamic compaction because the permeability is pretty low due to the high salt content in groundwater in the sabkha area.

High levels of heavy metals in Western Arabian Gulf mangrove soils.

Major development along the Western Arabian Gulf coast has disturbed the marine environment, and led to increased concentrations of heavy metals in the coastal soils. The amount of 13 of these metals (Ag, Al, As, Cd, Cr, Cu, Fe, Mn, Mo, Ni, Pb, V and Zn) in Avicennia marina branches and leaves as well as in rhizosphere soil samples from two Bays 70km apart (Tarut Bay; Saudi Arabia and Tubli Bay; Bahrain) wasquantified. Heavy metal concentration in the two bays were similar and higher than those reported in other regions suggesting a generalized heavy metal pollution in the area. These concentrations are much higher than the international permissible limits of soil contaminations except for Iron and Manganese which were within the limits. The results indicate that marine environments in the area need recovery plans and monitoring.

Gone with the wind: dune provenance and sediment recycling in the northern Rub’ al-Khali, United Arab Emirates

The Rub’ al-Khali dune field in southern Arabia is the largest sand sea in the world. Deciphering the palaeoenvironmental history of the Rub’ al-Khali is critical to understanding its role as a barrier to human migration, dispersal and settlement. To determine sediment provenance and transport pathways, we combined data from a geological mapping project with traditional heavy mineral optical point-counting methods, heavy mineral geochemical fingerprinting and detrital zircon U–Pb geochronology of Miocene and Quaternary sediments in the United Arab Emirates (UAE). Detrital zircon U–Pb age spectra demonstrate that most Neogene and Quaternary sediments in the UAE are ultimately sourced from the Precambrian Arabian Shield. Heavy mineral and geochemical signatures indicate that the dune sands are locally recycled from the deflation of Miocene sandstones and Quaternary siliciclastic palaeodunes exposed along the Arabian Gulf coast, whereas carbonate palaeodunes along the Gulf coast are derived from the deflation of sediments deposited by the Tigris–Euphrates River system in the Gulf during Pleistocene lowstands. In the eastern Emirates, Miocene and Quaternary alluvial fan deposits emanating from the Hajar Mountains have an ophiolitic heavy mineral signature. The data reveal new insights into the origin and development of the Rub’ al-Khali dune field. Supplementary material: A map, details of the geochronology methods and a full dataset are available at https://doi.org/10.6084/m9.figshare.c.4290350

Distribution and Temporal Trends of Western Reef Heron (Egretta gularis) Populations along the Arabian Gulf Coast of Abu Dhabi, United Arab Emirates

The Arabian Gulf Coast of Abu Dhabi, United Arab Emirates, consists of highly productive seagrass (Halodule universis, Halophila ovalis and Halophila stripulacea) and mangrove (Avicennia marina) habitats that are essential breeding and non-breeding areas for vast numbers of waterbirds. Due to their dependence on these coastal habitats, waterbirds such as the Western Reef Heron (Egretta gularis) can act as important bioindicators of ecosystem health. The estimated global population size of Western Reef Herons is roughly 10,000 to 100,000 individuals. While populations are currently considered stable, many important breeding and overwintering areas of the Western Reef Heron remain unprotected. Line transect counts were conducted at study sites along the Arabian Gulf Coast of Abu Dhabi monthly throughout 2006-2015. Using a mixed effects model, it was found that both year (F1, 1132 = 29.15; P = < 0.001) and month (F11, 1132 = 2.32; P = 0. 011) had significant influences on the number of birds counted at any given site; however, there was no statistically significant interaction between year and month (F11,1132 = 1.24; P = 0.253). While there was an overall non-significant decrease in counts across years (t495 = -1.40; P = 0.163), there were significant inverse relationships between year and count at the Al Aryam (t485 = -13.55; P = < 0.001) and Abu Al Abyad (t485 = -2.23; P = 0.026) sites, suggesting annual relative abundance is declining in these areas. Further research and monitoring of the Abu Dhabi Western Reef Heron population is recommended due to continued destruction and degradation of critical waterbird habitat.

Human, Urban and Environmental-Induced Alterations in Mangroves Pattern along Arabian Gulf Coast, Eastern Province, KSA

Human, Urban and Environmental-Induced Alterations in Mangroves Pattern along Arabian Gulf Coast, Eastern Province, KSA

Organic carbon sequestration and storage in vegetated coastal habitats along the western coast of the Arabian Gulf

Certain coastal ecosystems such as mangrove, saltmarsh and seagrass habitats have been identified as significant natural carbon sinks, through the sequestration and storage of carbon in their biomass and sediments, collectively known as ‘blue carbon’ ecosystems. These ecosystems can often thrive in extreme environments where terrestrial systems otherwise survive at the limit of their existence, such as in arid and desert regions of the globe. To further our understanding of the capability of blue carbon ecosystems to sequester and store carbon in such extreme climates, we measured carbon sediment stocks in 25 sites along the Western Arabian Gulf coast. While seagrass meadows and saltmarsh habitats were widely distributed along the coast, mangrove stands were much reduced as a result of anthropogenic pressures, with 90% of stands having been lost over the last century. Carbon stocks in 1 m deep surface sediments were similar across all three blue carbon habitats, with comparable stocks for saltmarsh (81 ± 22 Mg Corg ha−1), seagrass (76 ± 20 Mg Corg ha−1) and mangroves (76 ± 23 Mg Corg ha−1). We recorded a 38% decrease in carbon stocks between mature established mangrove stands (91 Mg Corg ha−1) and recently planted mangroves (56 Mg Corg ha−1). Mangroves also had the lowest carbon stock per total area owing to their very limited spatial coverage along the coast. The largest stock per total area belonged to seagrass beds as a result of their large spatial coverage within the Gulf. We employed 210Pb dating to determine the sediment accretion rates in each ecosystem and found mangrove habitats to be the most efficient carbon sequesters over the past century, with the highest carbon burial rate of the three ecosystems (19 g Corg m−2 yr−1), followed by seagrass (9 g Corg m−2 yr−1) and saltmarshes (8 g Corg m−2 yr−1). In this work, we describe a comprehensive comparison of sediment stocks in different blue carbon ecosystems within a single marine environment and across a large geographical area, and discuss our results in a global context for other blue carbon ecosystems in the dry tropics.

Saddleback Deformities in Fish Species Collected from the Arabian Gulf Coast of Jubail City, Saudi Arabia

The saddleback syndromes were observed in several commercial fishes obtained from Saudi Arabian coast of the Arabian Gulf. These deformities resulting in missing dorsal spines or rays, sometimes accompanied by a depression in the dorsal profile, were found in ten fish species from seven families. Other morphological abnormalities such as scale disturbances, lateral line deformity, and kyphosis, the presence of a lesion, slight ambicoloration, and supraneural deformities accompanying the saddleback deformity were also observed. The occurrence of similar deformities across such a spectrum of fishes from the same location suggests that the abnormalities were induced by something in the environment common to all these species.

Bio-accumulation of Polycyclic Aromatic Hydrocarbons in the Grey Mangrove (Avicennia marina) along Arabian Gulf, Saudi Coast

Abstract The Arabian Gulf is considered as one of the most important sources for the crude oil all over the world. Due to the vast oil exploration and exploitation, huge amounts of organic pollutants infiltrate to the gulf. An important class of organic pollutants is polycyclic aromatic hydrocarbons (PAHs). One of the marine habitats in Arabian Gulf area is the mangrove stands, that are undoubtedly impacted by all anthropogenic factors like oil industries and sewage discharge. In the monitoring framework for mangrove ecosystem along Saudi coasts, nine mangrove stands were examined for the accumulation of PAHs in the Arabian Gulf coast. PAHs were measured using Gas Chromatography-Mass Spectrometry. The mean values detected for total PAHs in mangrove sediments, roots and leaf were 105.39, 680.0 and 282.4 ng/g, respectively. The trend of total PAHs concentrations in all sites showed the descending order: roots &gt; leaf &gt; sediments. Despite the sandy nature and low organic carbon contents of the mangrove sediments, moderate values of PAHs were detected in the major sites. PAH bio-accumulation factors for roots are higher than that in leaf. The diagnostic ratios revealed that the sources of PAHs are mainly pyrogenic, except for Damam and Damam Port that were found to be petrogenic.

Monitoring metal levels in water and multiple biomarkers in the grouper ( Epinephelus tauvina) to assess environmental stressors on the Arabian Gulf coast of Saudi Arabia.

In this field study, the levels of heavy metals (Pb, Fe, Co, Cu, and Zn) in water and a suite of biochemical and histological biomarkers in the grouper ( Epinephelus tauvina) were assessed at four sites in the Arabian Gulf. Samples were taken from a relatively non-urban reference site, called Salwa (S1), and three effluent-dominated sites, namely Al-aziziyah in southern Dammam city (S2), the Al-Jubail coast (S3), and Manifa (S4). Toxic metals, namely Pb and Co (at all sites) and Fe (at S3), were elevated in water samples relative to the internationally permissible limits. In fish, induced levels of heat shock protein 70 (HSP70) in the liver at S3 and S4 were higher than those of the reference fish at S1. Additionally, the level of the lipid peroxidation (LPO) product (malondialdehyde (MDA)) was significantly increased in gills (at S3) and liver (at S2 and S3). There was an inhibition of catalase activities in the gills of fish from S2 to S4 and significantly higher activity levels of superoxide dismutase in the gills of fish from S4. Histopathological features such as aneurysms in gill vessels, deformed gill lamellae, increases in liver melano-macrophage centers, and hepatocellular necrosis were most abundant at sites where significant pollution problems exist (i.e. S2-S4). The results reveal that the eastern coast of Saudi Arabia, in the Arabian Gulf, is still contaminated, as indicated by elevated HSP70, LPO content and numbers of histological lesions, and that monitoring of contaminants and their effects should be continued in this region.

Avicennia marina biomass characterization towards bioproducts

Avicennia marina is the only naturally occurring mangrove specie in the arid Arabian Gulf coast of the United Arab Emirates (UAE). Due to the water scarcity of this arid-region, A. marina is a precious biomass resource for the UAE that does not require fresh water for growing, and is able to grow in the Arabian Gulf high salinity conditions, over 40g/kg. This non-fresh water lignocellulosic arid-region bioresource may be used for the production of high valuable chemicals. The objective of the present manuscript is to characterize the lignocellulosic composition of Arabian Gulf A. marina, as a first attempt to highlight its importance in a biobased economy in arid regions. Avicennia marina stem, leaves and pneumatophors samples were collected from two locations in the United Arab Emirates. A. marina samples were chemically characterized for sugar composition, ash content and byproducts using standardized protocols. The analysis revealed that A. marina arabinan, xylan, glucan and lignin composition ranges, in g/100g_TS (TS: total solids), between 1-22, 5-18, 10-31, and 21-48, respectively. The highest composition of xylan and glucan (g/100g_TS) was obtained for stems and pneumatophors, 45 and 38, respectively. Xylan and glucan are the polymeric precursors for the production of high value chemicals, e.g. furfural and hydroxymethylfurfural (HMF), respectively. Under the characterization conditions, it was obtained furfural and HMF (g/100g_TS) in the ranges of 0.05-0.42, and 0.45-2.1, respectively.

Morphological and molecular divergence between Crenidens crenidens (Forsskål, 1775) and C. indicus Day, 1873 (Perciformes: Sparidae) and notes on a Red Sea endemic lineage of C. crenidens

Additional data, resulting from examination of newly collected material from the Red Sea, east coast of Africa, Arabian Gulf, Pakistan, and western coast of India, and a phylogenetic analysis of the COI barcoding region, confirms Crenidens crenidens (Forsskal) and C. indicus Day as valid species. The latter species was earlier regarded as a subspecies of C. crenidens. In addition, the analyses herein show that specimens from the Red Sea form a distinct monophyletic sub-clade within C. crenidens, characterized by low genetic divergence from specimens from the southwestern Indian Ocean. Close comparison of 34 morphological characters showed that specimens from South Africa and Mozambique differ from Red Sea specimens only in having slightly longer pelvic fins [4.6–4.9 in standard length (SL) vs. 4.8–6.1 in SL]. Examination of additional specimens of both species provided more assessment of inter- and intraspecific variation in meristic and morphometric characters. A new set of characters that help to distinguish C. indicus from C. crenidens is proposed: the former species has a deeper body and caudal peduncle; more scales between fifth dorsal-fin spine and lateral line; scales on top of head extending forward to vertical through posterior margin of pupil; longer pelvic fins; lips with tiny cirri; caudal fin blackish distally; and usually with obvious black spot at pectoral-fin axil. Crenidens indicus was previously reported from central Oman, Arabian Gulf, to Pakistan; herein its presence from the western coast of India, Gujarat and Mumbai (= Bombay), is confirmed. Descriptions of C. crenidens and C. indicus based on material examined, photographs of alive and fresh fishes and an updated key to the three known species of Crenidens are provided.

First Record of Abnormal Body Coloration in Fishes Obtained from Jubail Area, Arabian Gulf, Saudi Arabia

Three specimens of the family Epinephelidae and two specimens of the family Haemulidae with abnormal coloration, were obtained from Jubail City, Saudi Arabia, Arabian Gulf coast. The epaulet grouper Epinephelus stoliczkae specimens were obtained from the fish market at Jubail City originated from Sultanate of Oman, while the two haemulid species, Plectorhinchus stoliczkae and P. sordidus were collected from the Saudi Arabian waters of the Arabian Gulf at Jubail City. These are the first documented cases of color aberration in those species. A description of the color anomalies is provided.