Three new species of Oriopsis Caullery and Mesnil, 1896 and a new species of Amphiglena Claparede, 1864 (Polychaeta: Sabellidae: Sabellinae) are described: Oriopsis anneae is described from the Florida Keys (USA), O. androgyne from a barrier reef island of Belize, and O. paramobilis from Aldabra Atoll (Seychelles). Oriopsis anneae is gonochoric, has three pairs of radioles, 8 thoracic chaetigers and up to 12 abdominal chaetigers. Females have a pair of spermathecae, ventrally, at the base of posterior peristomial ring collar. Males have sperm with long nuclei, split into four rods. Oriopsis androgyne is a simultaneous hermaphrodite with three pairs of radioles, 8 thoracic chaetigers and 5 abdominal chaetigers. Mature individuals have oocytes in thoracic chaetigers 5-6 and sperm and spermatids in the following 4 chaetigers. No sperm storage organs were found. Oriopsis paramobilis is gonochoric, has three pairs of radioles, 8 thoracic chaetigers and up to 5 abdominal chaetigers. Females have a pair of spermathecae in the radiolar crown. Males have sperm with long nuclei, and an elongate midpiece. All species of Oriopsis described here have lateral ducts, from sperm-bearing segments, for sperm to exit to the water. Amphiglena nathae, described from two islands of Seychelles, Indian Ocean, has up to 6 pairs of radioles, 8 thoracic chaetigers and up to 25 abdominal chaetigers. This species, like several other species of Amphiglena, is a simultaneous hermaphrodite with oocytes and developing sperm present in the first few abdominal chaetigers. Developing sperm are also present in several chaetigers posterior to oocyte-bearing segments. A pair of spermathecae were found at the base of the dorsal lips. This species broods larvae, each in an egg capsule, until they have 8 thoracic chaetigers when they hatch and swim away. |