Loxodidae

Portrait of Loxodes. Karyolectid ciliate. Laterally compressed. Slit-like curved cytostome just posterior to hooked "rostrum". Right surface is densely ciliated while left side has only marginal kineties. Numerous Müller's vesicles with refractile inclusions are seen at intervals along the dorsal margin. The function of these is unknown. They contain concretions of barium salts. Body flexible. Several freshwater species. From standing freshwater with abundant decomposing leaves near Boise, Idaho. Brightfield.

Portrait (right side) of Loxodes magnus, the largest species in the karyorelict ciliate genus, Loxodes. This individual is 755? 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. 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. Phase contrast.

Detail view of dorsum left side of Loxodes magnus, the largest species in the karyorelict ciliate genus, Loxodes. The termination of the right side kineties is seen here. Large orange refractile concretions of barium sulfate occupy several Müller's vesicles on the dorsal side in this image. These probably act as statoreceptors, orienting the organism in the gravitational field. There are also smaller subcortical pigment granules, which may have chemo- and phototactic functions (seen here). Several food vacuoles are visible. From organically enriched freshwater pond sediment near Boise, Idaho. DIC optics

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.

Portrait (left side) of Loxodes striatus, a medium-size karyorelict ciliate. Loxodes striatus is colorless to slightly brown. 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. In this species there are longitudinal pellicular striations on the left surface. The slit shaped cytostome is located in a ventral concavity posterior to the rostrum. A thin cone of dark fibrils forms a primitive cytopharynx at the posterior end of the cytostome (seen here). There are two spheroid macronuclei, one anterior and one in the mid body, each with an adherent micronucleus (neither seen well in this image). The arrangement of the macronuclei and the pellicular striations distinguish L. striatus from the similar L. vorax and L. rostrum. 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. Found in polysaprobic habitats. Feeds on cyanobacteria, algae, flagellates and other ciliates. From organically enriched freshwater pond sediment near Boise, Idaho. DIC optics.

Detail of the oral aperture and cytopharynx of Loxodes striatus (left surface), a medium-size karyorelict ciliate. Loxodes striatus is colorless to slightly brown. 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. In this species there are longitudinal pellicular striations on the left surface. The slit shaped cytostome is located in a ventral concavity posterior to the rostrum. A thin cone of dark fibrils forms a primitive cytopharynx at the posterior end of the cytostome (seen here). Many food vacuoles are seen. Found in polysaprobic habitats. Feeds on cyanobacteria, algae, flagellates and other ciliates. From organically enriched freshwater pond sediment near Boise, Idaho. DIC optics.

Detail of one of the two macronuclei of Loxodes striatus with its adherent micronucleus. There are two spheroid macronuclei, one anterior and one in the mid body, each with an adherent micronucleus. The arrangement of the macronuclei and the pellicular striations distinguish L. striatus from the similar L. vorax and L. rostrum. Many food vacuoles are seen. Found in polysaprobic habitats. Feeds on cyanobacteria, algae, flagellates and other ciliates. From organically enriched freshwater pond sediment near Boise, Idaho. DIC optics.

Detail of Loxodes striatus, a medium-size karyorelict ciliate. Loxodes striatus is colorless to slightly brown. 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. In this species there are longitudinal pellicular striations on the left surface. The slit shaped cytostome is located in a ventral concavity posterior to the rostrum. A thin cone of dark fibrils forms a primitive cytopharynx at the posterior end of the cytostome (seen here). There are two spheroid macronuclei, one anterior and one in the mid body, each with an adherent micronucleus (both seen well in this image). The arrangement of the macronuclei and the pellicular striations distinguish L. striatus from the similar L. vorax and L. rostrum. 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. Both the vesicles and pigment granules are seen here. Found in polysaprobic habitats. Feeds on cyanobacteria, algae, flagellates and other ciliates. From organically enriched freshwater pond sediment near Boise, Idaho. DIC optics.

Remanella (rem-ann-ell-a) is karyorelictid ciliate - so called because they have macronuclei which do not divide - and this is thought to be an ancestral trait. Remanella is common in marine sediments or associated with detritus, especially in areas with little oxygen. With a hook-shaped anterior end and a line of Muellers bodies along the convex dorsal side of the body. The Muellers bodies are globular inorganic deposits (usually pink or orange in colour) and are organelles which provide information on the orientation of the body. Phase contrast.

Remanella (re-man-ell-a) a karyorelict ciliate found in marine sediments, seems to prefer slightly anoxic zones. With the mouth located at the base of a hooked anterior end, dorsal side of body with granules in vesicles acting to determine the direction of gravitational pull. This species has an elongate body, Phase contrast micrograph.