Capability Of Visual Discrimination Of Chinese Crocodile Lizard(Shinisaurus Crocodilurus)

Chinese crocodile lizard(Shinisaurus crocodilurus) belonging to Shiniasuridae, Shinisaurus. It is a single type species of monotypic genus. Shinisaurus crocodilurus is the national grade one pretection animal in China. Current researches on visual research are more common in mammals and fish. There has no study on visual discrimination of reptile in China. Through a series of visual discrimination experiments, the capability of visual discrimination of Chinese crocodile lizard was studied. These studies were important to skew into the ecological behavior of Chinese crocodile lizard. The main results were as following:1.The study of visual learning and memory. First, we tested what color Chinese crocodile lizard preferred to without any induction. Four color foam boards, including red, yellow, blue and green, were used to study the color preference of Chinese crocodile lizard. The responses of39Chinese crocodile lizards were observed. Results showed that the Chinese crocodile lizard preferred to blue. Then we conducted induction learning experiments. In this experiment only earthworm was placed in the red board. Each individual was fed15times with the earthworm placed on the red board. After that, we test the color preference of Chinese crocodile lizard without earthworms. The results showed that Chinese crocodile lizard preferred to red. The results indicate that the Chinese crocodile lizard can discriminate colors through vision and has the learning capability.2. Discrimination on live or dead food. We use a special tank with three equal parts, one side placed live tenebrio, on the other side placed dead tenebrio, and the Chinese crocodile lizards were placed in the middle part. The responses of54adult individuals and21sub-adults were observed. Each individual was placed twice in the middle part. The results showed that both adults and sub-adults stayed more time and visited more times toward to the part of live tenebrio. The results showed that Chinese crocodile lizard can decimate living or dead tenebrio by vision.3. Discrimination individual by vision. In order to understand the discriminating ability of Chinese crocodile lizard on familiar and unfamiliar individual through visual cues, the responses of30males and30females were observed. The results showed①Although the times of females visiting familiar male and familiar female had no difference, the total time of female visiting familiar male was significant higher than that of female visiting familiar female;②Both the times and total time of male visiting familiar female were significant higher than these of visiting familiar male;③Both the times and total time of male visiting familiar female were not significantly different from these of visiting unfamiliar female, and it is the same of female visiting familiar male and unfamiliar male. The results indicate that the Chinese crocodile can discriminate male and female only by visual cues, but can not discriminate familiar and unfamiliar opposite sex. Since Chinese crocodile lizard is sexual dimorphism, the discrimination on female and male may be relate with the sexual dimorphism...