. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. FEEDING BEHAVIOR OF P. CARNIl' 303 10 ou O o> CL CD o i_ CL> _Q E 13. 20 40 60 80 100 120 Hours FIGURE 1. Growth curve of Paranophrys carnivora. Results are based on three replicate cultures. Table III, Artemia homogenate and the E. aerogenes suspension elicited a positive chemosensory response, whereas the alga Dunaliella parva elicited none. These re- sults were obtained with ciliates that had been previously cultivated on each of the diets indicated. When Chlorococcum sp. was offered instead of D. parva, the
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. FEEDING BEHAVIOR OF P. CARNIl' 303 10 ou O o> CL CD o i_ CL> _Q E 13. 20 40 60 80 100 120 Hours FIGURE 1. Growth curve of Paranophrys carnivora. Results are based on three replicate cultures. Table III, Artemia homogenate and the E. aerogenes suspension elicited a positive chemosensory response, whereas the alga Dunaliella parva elicited none. These re- sults were obtained with ciliates that had been previously cultivated on each of the diets indicated. When Chlorococcum sp. was offered instead of D. parva, the same results were obtained. Since Enterobacter was routinely cultivated on brain heart agar, it was thought that its effect could have been due to the presence of some dissolved ingredients from the growth medium in the suspension. Indeed, brain heart infusion did elicit a posi- tive chemosensory response in capillary experiments. To determine whether the bac- teria themselves are effective, they were washed by centrifugation and offered to the ciliates in a capillary tube. After repeated rinsings in ASW, neither the bacterial pellet nor the supernatant gave a positive result. However, when the washed pellet was suspended in fresh ASW, incubated for up to 48 hours at 18°C, and then centrifuged again, the resulting supernatant elicited a chemosensory response. This indicates that washed bacteria excrete with time an effective substance or release such a factor upon disintegration. Positive results were obtained with other microbiological growth media, such as proteose peptone and casein hydrolysate. In dialysis experiments with proteose pep- tone, Paranophrys was found to be attracted to those molecules which were able to pass through the cellophane membrane, , amino acids. In further capillary tests to screen individual amino acids, only L-histidine, of the various amino acids tested, was as effective as betaine, a substance previously found to elicit a chemosensory respo
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
