ABSTRACT
An investigative study was conducted during September 2017 along the eastern Red Sea coasts (Jeddah, Saudi Arabia). During this study, 5 stations were prospected and samples of sediment were especially collected in order to study their meiobenthic organisms. Results showed important variations of the environmental factors between stations mainly for salinity measurements that were clearly higher at Shuaiba lagoon (47.70 psu). Meiofauna densities ranged from 218.50 to 485.25 ind.10 cm-2. Nematodes, Polychaeta, Foraminifera and Ostracoda were the most abundant among the 14 taxa registered. The highest densities of meiofauna were related to high levels of organic matter in Al Saif bay station while the lowest were observed in Shuaiba lagoon station with muddy sediments, low dissolved oxygen and high salinity. Statistical analyses showed that dissolved oxygen rate had a positive effect on Polychaeta, Turbellaria, Gastrotricha and Tardigrada whereas Arachnida, Mollusca and Brachiopoda were respectively affected by organic matter and salinity.