تعريف، ووصف لجنس البطلينوس (Patella, Linnaeus 1758) من بطنيات القدم، وتوزيعه علي الشواطئ الصخرية الغربية لليبيا

تهدف الدراسة لتعريف، ووصف جنس البطلينوس Patellaالمنتشر على الساحل الجنوبي من البحر الأبيض المتوسط بسواحل ليبيا من خلال معرفة أنواع البطلينوس بالشواطئ الصخرية للساحل الغربي لليبيا. أُجريت خمس رحلات لشواطئ (جودائم ، ديلة " الزاوية المدينة " ، المطرد ، صرمان، وصبراتة) من شهر ديسمبر 2018 إلى إبريل 2019. جُمعت عينات الدراسة من تلك المناطق ، وذلك بطريقة التجميع اليدوية، وصنفت بالرجوع إلى مجموعة من المراجع الخاصة بالتصنيف. وبناء عليه توصلت النتائج إلى التعرف على ثلاثة أنواع من البطلينوس، منها نوع مهدد بالانقراض حسب منظمة .UNEP ومن حيث التوافر سُجل النوع Patella caerulea في كل الشواطئ محل الدراسة؛ ويعزى ذلك إلى قدرتها على تحمل التقلبات الموسمية، وسُجل توافر النوع Patella rustica بكثرة في سواحل منطقتي جوددائم وديلة، وأقل توافر له في شاطيء صبراتة. ويعد هذا النوع من أكثر الأنواع البحرية اللافقارية المهددة بالانقراض في الشواطئ الصخرية الغربية للبحر الأبيض المتوسط بسواحل ليبيا.

Impact of Marine Aquaculture on the Microbiome Associated with Nearby Holobionts: The Case of Patella caerulea Living in Proximity of Sea Bream Aquaculture Cages

Aquaculture plays a major role in the coastal economy of the Mediterranean Sea. This raises the issue of the impact of fish cages on the surrounding environment. Here, we explore the impact of aquaculture on the composition of the digestive gland microbiome of a representative locally dwelling wild holobiont, the grazer gastropod Patella caerulea, at an aquaculture facility located in Southern Sicily, Italy. The microbiome was assessed in individuals collected on sea bream aquaculture cages and on a rocky coastal tract located about 1.2 km from the cages, as the control site. Patella caerulea microbiome variations were explained in the broad marine metacommunity context, assessing the water and sediment microbiome composition at both sites, and characterizing the microbiome associated with the farmed sea bream. The P. caerulea digestive gland microbiome at the aquaculture site was characterized by a lower diversity, the loss of microorganisms sensitive to heavy metal contamination, and by the acquisition of fish pathogens and parasites. However, we also observed possible adaptive responses of the P. caerulea digestive gland microbiome at the aquaculture site, including the acquisition of putative bacteria able to deal with metal and sulfide accumulation, highlighting the inherent microbiome potential to drive the host acclimation to stressful conditions.

Population Characteristics of the Limpet Patella caerulea (Linnaeus, 1758) in Eastern Mediterranean (Central Greece)

Limpets are pivotal for structuring and regulating the ecological balance of littoral communities and are widely collected for human consumption and as fishing bait. Limpets of the species Patella caerulea were collected between April 2016 and April 2017 from two sites, and two samplings per each site with varying degree of exposure to wave action and anthropogenic pressure, in Eastern Mediterranean (Pagasitikos Gulf, Central Greece). This study addresses a knowledge gap on population characteristics of P. caerulea populations in Eastern Mediterranean, assesses population structure, allometric relationships, and reproductive status. Morphometric characteristics exhibited spatio-temporal variation. Population density was significantly higher at the exposed site. Spatial relationship between members of the population exhibited clumped pattern of dispersion during spring. Broadcast spawning of the population occurred during summer. Seven dominant age groups were identified, with the dominant cohort in the third-year class. Significant negative allometric relationships were exhibited between morphometric characteristics. Differences in growth patterns among populations were indicated.