The shore crab, Cyclograpsus aff. integer (Subfamily Cyclograpsinae, Family Varunidae: Superfamily Grapsoidea), is recorded for the first time from the Egyptian Red Sea coasts and from the entire Red Sea. This species is a small-sized crab, lives in burrows at the upper intertidal zone of the sandy-mud and sandy bottom mixed with small pebbles. The diagnostic characters with illustrations distinguished it from other closely allied species were given. All information on crab habitat, color, diagnostic and morphological characters of this species were given and discussed.
Coral reef health has declined significantly around the world as a result of anthropogenic activities and natural environment changes, such sewage pollution and climate change due to global warming. These significant threats can interrupt coral’s fluorescence yield and also modify the zooxanthellae performance, which can lead to bleaching events if prolonged stress. Nowadays, other than using zooxanthellae density to determine coral’s health, numerous study starts to focus more on observing the effective quantum yield, Y(II) of corals by using Pulse Amplitude (PAM) fluorometer, as it is an effective and non-lethal way in determining coral’s health. In this study, there are two objectives to be achieved which are i) To measure the effective quantum yield of Montipora sp. before and after nitrate and temperature stress and ii) To calculate the zooxanthellae density of Montipora sp. after nitrate and temperature stress. Montipora sp. that was exposed to high nitrate (HN), high temperature (HT) and high nitrate with high temperature (HNHT) treatment exhibited the decrement of their Y(II) reading and zooxanthellae density after 48 hours exposure. Major decrease of Y(II) resulted from the HN treatment while major drop of zooxanthellae is caused by HT treatment. For future studies, longer term experiment duration, various coral species and molecular studies should be done to understand the photoinhibition process and its effect to the coral body system.
Sharm Obhur, situated approximately 35 km north of Jeddah City along the Red Sea coast, is a prominent recreational area with diverse benthic habitats. Accurate mapping of seabed sediments is critical for characterizing marine ecosystems and elucidating benthic habitat distribution in this region. This study underscores the importance of assessing sediment distribution patterns in Sharm Obhur, particularly due to the prevalence of recreational activities and navigational traffic. This research investigates sediment dynamics in Sharm Obhur, a coastal creek near Jeddah, utilizing Multibeam Echo Sounder (MBES) backscatter data and grab sample analyses. The study focuses on understanding sediment distribution patterns and their implications for coastal management. MBES technology provides high-resolution data on seafloor composition and roughness, essential for assessing sediment types and bedforms. Through spatial alignment of MBES data with ground truth sediment samples, we analyze sediment characteristics and validate findings. Results indicate predominant sand presence with detectable mud in deeper channels and northern anthropogenically impacted areas. Gravel deposits correlate with coral formations near the creek edges. Tidal influence is evident, with increased sand presence at the creek entrance. The study demonstrates MBES backscatter's efficacy in mapping sediment distributions and seabed characteristics, benefiting marine science and coastal management. This research enhances knowledge of sediment transport processes, facilitating informed decision-making for sustainable coastal development and conservation efforts.
The Red Sea coast is overcrowded by many international and local harbors, particularly Shalateen harbor, that imposes environmental threats on the marine biota. The Shalateen ecosystem is assessed using benthic foraminifera, a sensitive proxy to environmental change. This study investigated the relationship between ecological parameters and benthic foraminifera distribution in the Shalateen site, a coastal area on the Red Sea facing increasing environmental deterioration. A total of 17 stations were sampled, and their benthic foraminiferal contents were analyzed. The findings revealed enriched benthic foraminiferal assemblages, dominated by Miliolida and Rotaliida, where counted morphological deformities in foraminiferal tests were observed and counted. Siamese twins, wrong direction of coiling, and aberrant chambers are the depicted test abnormalities. They are higher in the miliolids than rotaliids. A statistical analysis identified two distinct foraminiferal assemblages; group 1 is associated with shallow, high-energy habitats with elevated salinity and carbonate content, while group 2 occupies deeper waters with higher organic matter and finer sediments. The environmental-based foraminiferal indices (FAI, FI, FMI and AEI) highlighted that the stations in the nearby harbor have higher environmental impacts than the offshore stations. These findings provide crucial baseline data for future environmental management and conservation efforts in this vulnerable ecosystem.
No first crab of the genus Etisus has been described yet. Thirty five megalops of an Etisus sp. were collected from Obhur Creek, Jeddah, Saudi Arabia and reared in the laboratory upto first crab stage. These first crabs were identified using molecular barcode methods and morphologically described herein and compared with those of the two species of Xanthoidean crabs, Eurytium limnosum and Leptodius exaratus. Apart fromsome minor variations, three characters differentiate the first crabs of the present study with those of the other two species: presence of several minute spines on the basal segment of the peduncle of antennule, presence of crista dentate in the endopod of third maxilliped and serrated lateral margins of third abdominal segment.
