Carpediemonas membranifera Ekebom et al., 1996

Lee, Won Je & Patterson, David J., 2000, Heterotrophic flagellates (Protista) from marine sediments of Botany Bay, Australia, Journal of Natural History 34, pp. 483-562 : 549-550

Carpediemonas membranifera Ekebom et al., 1996

(fi gures 24e, 25h -i)

Description. Cell elliptical or obovate, 3-6 Mm long, with a longitudinal ventral groove which extends most of the cell length. When squashed, the cell is pliable. Two fl agella unequal in length emerge from the anterior distal part of the cell; the anterior fl agellum bent over backwards is as long as the cell and beats sti ffl y. The acronematic posterior fl agellum is about 2.5 -4 times the cell length, beats actively in the ventral depression and usually lies in the depression. Usually moves by skidding with the anterior fl agellum beating with a stiff paddling motion. Cells consume bacteria. Commonly observed in anoxic conditions. Description based on observation of 80 cells.

Remarks. It would appear that in their description of Carpediemonas membranifera as Percolomonas membranifera, Larsen and Patterson (1990) included two species; one usually measuring 6 Mm or less and the other measuring 6 Mm or more. The type micrograph depicts the smaller species, which now bears the name C. membranifera . It has a relatively long posterior fl agellum, moves by skidding with the anterior fl agellum beating in a paddling motion. It was transferred to the new genus Carpediemonas by Ekebom et al. (1996) because unlike con fi rmed species in Percolomonas , it had only two fl agella. Ultrastructural studies (Simpson, unpubl. data) have con fi rmed that this is an amitochondriate protist unrelated to Percolomonas . The larger species resembles Cryptobia bialata of Ruinen (1938) and is here referred to as Carpediemonas bialata .

This species has been described from marine sites in Australia and Brazil ( Larsen and Patterson, 1990; Ekebom et al., 1996; Bernard et al., 1999). Carpediemonas membranifera is distinguished from C. bialata by its smaller size, the absence of the moving membrane and the relatively long posterior fl agellum. It consumes bacteria ( Larsen and Patterson, 1990; Ekebom et al., 1996) and usually occurs in large numbers with Cafeteria marsupialis and Carpediemonas bialata .