Records of Three Immature Gelatinous Specimens for the Turkish Mediterranean Coast with an Emphasis on Alternative Pathways

Abstract

From samples for the phytoplankton collected from the sea surface water of 67 stations along the entire Turkish Mediterranean coast during June-July 2019, three juvenile gelatinous organisms were recorded. Two cnidarian-hydrozoan species (Podocorynoides minima and Gastroblasta raffaelei) and one ctenophore (Bolinopsis cf. vitrea) occurred near Mersin Bay. The specimens were determined at the juvenile or eumedusoid stages. Referring to the literature, Gastroblasta raffaelei was presumably about 4-5-day old (1.05 x 1.56 mm in elliptical diameter), and Podocorynoides minima about a stage of liberated eumedusoid (0.327 x 0.316 mm in bell diameter x height). The specimen of Bolinopsis cf. vitrea was measured to be 11 mm in lobate (total) length and 8.6 mm in body width. Interestingly, all species were found at different locations close to each other on the set of the water rim current speeding easterly up to about 0.5 m s-1. Gastroblasta raffaelei and Podocorynoides minima were first recorded on the Turkish Mediterranean coast. Early-staged specimens of these three species were described and discussed for their diagnostic structures with their occurrence in the Turkish Mediterranean Sea after the hydrozoans were reported in the Sea of Marmara, the ctenophore in the Black Sea, and other seas of the Mediterranean basin. The present study also discussed possible and presumable pathways of recent increased Turkish Mediterranean records of specimens that have been observed in the West Mediterranean Sea and the Adriatic Sea.

Keywords

• new records
• gelatinous species
• turkish mediterranean waters