Faunistic Study of Ascidians (Chordata: Tunicata) From The northern Limit of Suez Canal, Port Said, Egypt

Subphylum: Tunicata, Class Ascidiacea comprises ascidians either colonial or solitary species which have received little research attention in Port Said coasts, Egypt, despite their high biodiversity in the study area. Fouling samples were collected and some environmental parameters were also measured seasonally during the period from (August) 2023 to (June) 2024. Moreover, morphological and taxonomical characterizations of different ascidian specimens were carefully examined to be identified. The study revealed 14 ascidians species, six of them were confirmed as first records and one probably to be first record if identified to species level during the current study period. These species belong to five families: Polyclinidae, Didemnidae, Styelidae, Pyuridae and Ascidiidae, which were collected from different anchors: piers, nets, marinas, and wooden poles attached with the other fouling. Winter and spring 2024 exhibited the highest number of ascidian species (12 species in both), while summer 2023 exhibited the lowest number of species (only8 species). Additionally Aplidium grisiatum Kott, 1998 and Polyclinum constellatum Savigny, 1816 were the most dominant species. During the study period, the physico-chemical parameters of the water and the associated fauna played significant roles in the variations of number of the species among the ascidian’s community.