On finding of a new polychaete species (Magelona mirabilis, Polychaeta, Magelonidae) larva in the Blask Sea

摘要

A brief description of Magelona larva, identified as Magelona mirabilis from the Sevastopol bay, is given. It is similar to M. mirabilis from the Mediterranean Sea and the English Channel. This larva is of 3.75 mm long and contains 24 setaceous segments. Its left tentacle (of 0.5 mm long) is longer than the right one. Two-ridge papilla is observed at its distal part. The M. mirabilis larva differs from M. papillicornis in specific pattern of coloration: two dark eyespots at the prostomium base and brown patches around eyes and near the tentacle base. The pigmentation appears at the level of the 5th setiger. It is worth noting the presence of few long peristompal bristles at the tentacle base. The M. mirabilis larva is described in the Blask Sea for the first time.