Cephalodella sp. Anatomy and Behavior
This is a field sample of the monogonate rotifer Cephalodella sp. that shows several behavioral features including crawling and swimming motion, and bowing and sweeping behavior for ingestion of biofilm material. Rarely observed features such as buccal cilia around the mouth and muscle bands are also shown using slow motion video recording.
Cephalodella is a rotifer of the poorly defined family Notommatidae (3). Their preferred environment is a solid substrate (5) and maximum abundance for most species is neutral or acidic freshwater (1), consistent with harvest of this specimen in New Jersey where freshwater is usually slightly acidic (2).
Water that had accumulated in a plastic container was collected using a Pasteur pipette to draw material from the surface of submerged leaf litter, then transported to the laboratory in an Eppendorf tube. Approximately 50 µl of water were dropped onto a microscope slide and a cover slip was applied. This was examined using conventional bright-field microscopy. When Cephalodella was located, its motion was recorded using a Pupil Cam attachment (Ken-A-Vision, Kansas City, MO). Cephalodella moves very rapidly making focus and manipulation of stage direction extremely difficult. This was overcome by use of slow motion. Focus was also difficult when two organisms were present in the same field of view; however these images were retained to allow a comparison of size between Cephalodella and protozoa or cyanobacteria.
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