Брюхоногий моллюск Patella ulyssiponensis Gmelin, 1791 (Gastropoda: Patellidae) на Кавказском шельфе Черного моря: биологическая инвазия или восстановление нативной популяции?

Abstract

In Spring 2023, an abundant adult population of the gastropod mollusk Patella ulyssiponensis Gmelin, 1791was established since the middle of the last century in the area of the Sochi port. P. ulyssiponensis   also known as «limpet» is a conturobiont, crawling edible gastropod mollusk that is listed in the Black Sea Red Data Book, Crimea and Sevastopol Red Data Book of and is still missing on the shelf of Crimea, Ukraine, Romania, Bulgaria and Turkey. Mollusks have not been found on the Caucasian shelf since about the middle of the last century. The paper presents data on the distribution, morphological structure and settlement density of P. ulyssiponensis mollusks collected in the Sochi port area in June 2023.  According to the severity of the radial ribs and their association into bundles, the position of the crown, the morphometry of the shell itself, the color of the inner surface of the shell, the integrity or serration of the peristome, the species was assigned to Patella ulyssiponensis Gmelin, 1791. This species is known in the Black Sea as P. tarantino Sales Marschlins, 1793, P. caerulea var. tenuistriata Weinkauff, 1880 and P. pontica Milaschewitsch, 1914 (syn.). In earlier works on the Black Sea, it was combined with Patella caerulea Linnaeus, 1758 – endemic to the Mediterranean Sea (Chukhchin, 1984). The numerical density of species reached 240−320 ind./m² and was higher at the station located on the outer side of the southern pier. The individuals found by us were generally somewhat smaller than those previously noted for the Black Sea. The maximum length of the shell in the study area reached 43.0 mm, width – 17.3 mm, height – 20 mm. However, these individuals had a higher shell in comparison with those of the Black Sea population and the population from the northern part of the Aegean Sea, which is typical for the inhabitants of the water's edge. The ratio of the height of the shell to its length was 0.43±0.05 and 0.45±0.07 for the two studied habitats. Clam  P. ulyssiponensis The reinvention of P. ulyssiponensis to the northeastern part of the Caucasian shelf could have occurred by anthropogenic transfer by ships and by natural settlement. This finding, together with other aspects observed in the last years in the Black Sea ecosystem, illustrate positive changes in gastropod fauna from the caucasian Black Sea waters.

Keywords: Patella ulyssiponensis, distribution, morphometry, density, Sochi port area