portrait

Description:

Portrait (right side) of Loxodes magnus, the largest species in the karyorelict ciliate genus, Loxodes. This individual is 500? long. Loxodes magnus is brown to orange. The cell body is elongate, rounded anteriorly and posteriorly and highly laterally compressed. The anterior is bent ventrally forming a short beak-like rostrum. Very flexible. Somatic ciliature on the left side is restricted to a marginal kinety. On the right surface there are regular longitudinal kineties (seen here). The slit shaped cytostome is located in a ventral concavity posterior to the rostrum (seen here). A thin cone of dark fibrils forms a primitive cytopharynx at the posterior end of the cytostome (seen here). There are from 3- 31 small macronuclei and a similar number of micronuclei scattered through the cell. Refractile concretions of barium sulfate occupy several Müller's vesicles on the dorsal side. These probably act as statoreceptors, orienting the organism in the gravitational field. There are also subcortical pigment granules, which may have chemo- and phototactic functions. L. magnus lacks contractile vacuoles. Found in polysaprobic habitats. Feeds on cyanobacteria, algae, flagellates and other ciliates. From organically enriched freshwater pond sediment near Boise, Idaho. DIC optics.