The antipredatory behavior of the aquatic diving beetle, Coptotomus venustus (Say) (Coleoptera: Dytiscidae) in response to fish predation /
The purpose of this research was to determine whether
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| Format: | Thesis Book |
| Language: | English |
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[Place of publication not identified] :
[publisher not identified] ;
1994.
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| Subjects: | |
| Online Access: | http://proxy.library.tamu.edu/login?url=http://proquest.umi.com/pqdweb?did=741965411&sid=1&Fmt=2&clientId=2945&RQT=309&VName=PQD |
| Summary: | The purpose of this research was to determine whether Coptotomus venustus would show a behavioral avoidance response to the visual, scent, or to both the visual and scent presence of a fish. The respiratory behavior of each group of beetles was monitored at 15 minute intervals. These experiments were conducted in the laboratory and in the field with 30 trials in each place. Before C. venustus were exposed to the experiments containing fish stimuli, they were observed over six 24 hour periods, at 20'C and 30'C, in chambers with white and black substrates. During each 24 hour period the beetles' respiratory behavior was also monitored for 60 minutes every two hours. Another part of the research was to determine whether the ratio of body size of Lepo7nis macrochz'rus size to beetle toxicity might limit the fish's ability to eat the beetles. Beetles were placed in a small aquarium, then exposed to three size groups of fish. Three trials were performed per size group. The 24 hour research study indicated that beetles selected the black substrate more than 50% of the time. The data also indicated that beetles moved from the substrate in the day to the water column at night. This diel pattern of movement was dependent on day-night cycle. Beetles indicated a slower activity level at 20'C versus the 30'C temperature. The laboratory experiments strongly indicated that beetles limited their activity in the water when fish were present visually, chemically, and both visual and chemically during the night. The beetles showed some response during the day with both visual and scent present, but the p- values (0.0361 and 0.0410) were suspect in terms of practical significance. The field experiments found that beetles reacted to all experiments during the day and night. However, beetles' activity in the water increased instead of decreased. There was evidence that this reaction was due to the many stimuli present in the natural pond water. The small and medium size fish made many strikes at the beetles but the beetles were never eaten during the allotted time. However, the largest fish made only a few strikes and did consume the beetles within the first six hours for each of the trials. |
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| Item Description: | Vita. "Major Subject: Zoology". |
| Physical Description: | xiii, 157 leaves : illustrations ; 28 cm. Issued also on microfiche from University Microfilms Inc. |
| Bibliography: | Includes bibliographical references. |