What Is the Impact of Microplastics and Lipid Regulators on Marine Meiofauna? Case Study of Polyvinyl Chloride, Atorvastatin, and Simvastatin

A microcosm experiment was carried out to provide a deeper insight into the toxic mechanisms exerted by two lipid regulator agents, as well as their interactions with the polyvinyl chloride microplastic on marine meiofauna. Two concentrations of Atorvastatin “A” and of Simvastatin “S”, (i.e., 0.6 mg.kg−1 and 6 mg.kg−1), as well as a single dosage of polyvinyl chloride microplastics “P” at 20 mg.kg−1, separately and their combined mixtures (“AP” and “SP”) were used on coastline dwelling marine meiofauna, with a main focus on nematodes. The results showed a significant reduction in meiofauna abundance in treatments compared to control. SIMPER analysis highlighted a significant decrease in the abundance of epigrowth feeders (2A), which possess conical (co) tails, and indistinct (id) amphideal foveas compared to control microcosms, reflected mainly in the decrease in abundance of the species Prochromadorella longicaudata. Furthermore, the contamination with microplastic affected only the omnivores-carnivores guild. Another finding of the current experiment is that the mixtures of microplastic with drugs lead to synergic interactions that increased their toxic effects on marine nematode communities.

Marine mites (Acari: Hydrachnidia) of the Mediterranean Sea: Descriptions of two new species, key for identification and future prospects

This paper provides a current overview of the diversity of the marine water mite family Pontarachnidae of the Mediterranean Sea. The checklist includes ten species from two genera, i.e. Litarachna Walter, 1925 and Pontarachna Philippi, 1840. Two species i.e., Litarachna muratsezgini sp. nov. and Pontarachna turcica sp. nov. from the Gulf of Antalya (Levantine Sea, Turkey), are described as new for science. Moreover, the key for the identification of Mediterranean Pontarachnidae species and a brief discussion on the current gaps and future prospects of our knowledge of this important but neglected component of the marine meiofauna are given.