RHABDITIS (CRUSTORHABDITIS) STASILEONOVI (BELOGUROV) FROM BEACH HOPPERS (TALITRIDAE, AMPHIPODA) FROM THE PACIFIC COAST OF NORTH-AMERICA

Material collected from intersegmental spaces beneath the dorsal plate s (pereonites) of beach hoppers from the Pacific Coast of North Americ a is herein referred to Rhabditis (Crustorhabditis) stasileonovi (Belo gurov, 1977) Sudhaus & Nimrich, 1989 (Rhabditida; Rhabditidae). This s pecies, hitherto known only on the basis of female anatomy, was descri bed from beach wrack in the Commander Islands by Belogurov (1977) who proposed a new genus, Marispelodera, for it. Sudhaus and Nimrich (1989 ) reported the species from beach wrack on Vancouver Island but referr ed the species to the subgenus Rhabditis (Crustorhabditis). Females ar e exceptional in that the tail is extremely short and rounded. Males d escribed herein agree in all essential respects to the subgenus Rhabdi tis (Crustorhabditis) and therefore corroborate Sudhaus and Nimrich's (1989) interpretation. Adult and larval worms were collected from inte rsegmental spaces of Megalorchestia californiana, M. benedicti and Tra skorchestia traskiana from beaches near Bamfield, B. C., Canada. Larva e only were collected from the above three hosts and Megalorchestia co rniculata from Santa Barbara, California, USA, but larvae were culture d to adulthood on agar plates. The material from the mio localities di ffered in minor morphological details and in life history : in Canada, larvae, males and ovoviviparous females occurred on hosts, whereas in California, only larvae occurred on hosts, and females cultured from these larvae were oviparous.