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Reduced performance of prey targeting in pit vipers with contralaterally occluded infrared and visual senses.

Chen Q, Deng H, Brauth SE, Ding L, Tang Y - PLoS ONE (2012)

Bottom Line: Both visual and infrared (IR) senses are utilized in prey targeting by pit vipers.Visual and IR inputs project to the contralateral optic tectum where they activate both multimodal and bimodal neurons.Performance was significantly poorer when only a single eye or pit was available.

View Article: PubMed Central - PubMed

Affiliation: Department of Herpetology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China.

ABSTRACT
Both visual and infrared (IR) senses are utilized in prey targeting by pit vipers. Visual and IR inputs project to the contralateral optic tectum where they activate both multimodal and bimodal neurons. A series of ocular and pit organ occlusion experiments using the short-tailed pit viper (Gloydius brevicaudus) were conducted to investigate the role of visual and IR information during prey targeting. Compared with unoccluded controls, snakes with either both eyes or pit organs occluded performed more poorly in hunting prey although such subjects still captured prey on 75% of trials. Subjects with one eye and one pit occluded on the same side of the face performed as well as those with bilateral occlusion although these subjects showed a significant targeting angle bias toward the unoccluded side. Performance was significantly poorer when only a single eye or pit was available. Interestingly, when one eye and one pit organ were occluded on opposite sides of the face, performance was poorest, the snakes striking prey on no more than half the trials. These results indicate that, visual and infrared information are both effective in prey targeting in this species, although interference between the two modalities occurs if visual and IR information is restricted to opposite sides of the brain.

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Related in: MedlinePlus

Performances of eight occluded conditions.Plots showing distances (cm) and angles (°) of individual strikes (unfilled symbols) and mean values (filled symbols) in the occlusion conditions: A: Binocular occlusion (blue unfilled circles and red filled circle) vs. bilateral pit organ occlusion (green unfilled triangles and red filled triangle). B: Left eye and pit occlusion (blue unfilled circles and red filled circle) vs. right eye-pit occlusion (green unfilled triangles and red solid triangle). C: Contralateral occlusion of the left eye and right pit organ (blue unfilled circles and red filled circle) vs. contralateral occlusion of the right eye and left pit organ (green unfilled triangles and red solid triangle). D: Unilateral opening of only the right pit (blue unfilled circles and red filled circle) vs. unilateral opening of only the left pit organ (green unfilled triangles and red filled triangle).
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pone-0034989-g002: Performances of eight occluded conditions.Plots showing distances (cm) and angles (°) of individual strikes (unfilled symbols) and mean values (filled symbols) in the occlusion conditions: A: Binocular occlusion (blue unfilled circles and red filled circle) vs. bilateral pit organ occlusion (green unfilled triangles and red filled triangle). B: Left eye and pit occlusion (blue unfilled circles and red filled circle) vs. right eye-pit occlusion (green unfilled triangles and red solid triangle). C: Contralateral occlusion of the left eye and right pit organ (blue unfilled circles and red filled circle) vs. contralateral occlusion of the right eye and left pit organ (green unfilled triangles and red solid triangle). D: Unilateral opening of only the right pit (blue unfilled circles and red filled circle) vs. unilateral opening of only the left pit organ (green unfilled triangles and red filled triangle).

Mentions: Parameter values are tabulated in Table 1. The distribution of strikes including strike distances, and angles are depicted in figures 1 and 2. All snakes used in the experiments exhibited strong motivation to hunt prey as indicated by repeated tongue flicks. Overall more than 95% of strikes were successful. On most trials, snakes only struck at prey once and waited for the prey to die before consuming it.


Reduced performance of prey targeting in pit vipers with contralaterally occluded infrared and visual senses.

Chen Q, Deng H, Brauth SE, Ding L, Tang Y - PLoS ONE (2012)

Performances of eight occluded conditions.Plots showing distances (cm) and angles (°) of individual strikes (unfilled symbols) and mean values (filled symbols) in the occlusion conditions: A: Binocular occlusion (blue unfilled circles and red filled circle) vs. bilateral pit organ occlusion (green unfilled triangles and red filled triangle). B: Left eye and pit occlusion (blue unfilled circles and red filled circle) vs. right eye-pit occlusion (green unfilled triangles and red solid triangle). C: Contralateral occlusion of the left eye and right pit organ (blue unfilled circles and red filled circle) vs. contralateral occlusion of the right eye and left pit organ (green unfilled triangles and red solid triangle). D: Unilateral opening of only the right pit (blue unfilled circles and red filled circle) vs. unilateral opening of only the left pit organ (green unfilled triangles and red filled triangle).
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3351397&req=5

pone-0034989-g002: Performances of eight occluded conditions.Plots showing distances (cm) and angles (°) of individual strikes (unfilled symbols) and mean values (filled symbols) in the occlusion conditions: A: Binocular occlusion (blue unfilled circles and red filled circle) vs. bilateral pit organ occlusion (green unfilled triangles and red filled triangle). B: Left eye and pit occlusion (blue unfilled circles and red filled circle) vs. right eye-pit occlusion (green unfilled triangles and red solid triangle). C: Contralateral occlusion of the left eye and right pit organ (blue unfilled circles and red filled circle) vs. contralateral occlusion of the right eye and left pit organ (green unfilled triangles and red solid triangle). D: Unilateral opening of only the right pit (blue unfilled circles and red filled circle) vs. unilateral opening of only the left pit organ (green unfilled triangles and red filled triangle).
Mentions: Parameter values are tabulated in Table 1. The distribution of strikes including strike distances, and angles are depicted in figures 1 and 2. All snakes used in the experiments exhibited strong motivation to hunt prey as indicated by repeated tongue flicks. Overall more than 95% of strikes were successful. On most trials, snakes only struck at prey once and waited for the prey to die before consuming it.

Bottom Line: Both visual and infrared (IR) senses are utilized in prey targeting by pit vipers.Visual and IR inputs project to the contralateral optic tectum where they activate both multimodal and bimodal neurons.Performance was significantly poorer when only a single eye or pit was available.

View Article: PubMed Central - PubMed

Affiliation: Department of Herpetology, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, China.

ABSTRACT
Both visual and infrared (IR) senses are utilized in prey targeting by pit vipers. Visual and IR inputs project to the contralateral optic tectum where they activate both multimodal and bimodal neurons. A series of ocular and pit organ occlusion experiments using the short-tailed pit viper (Gloydius brevicaudus) were conducted to investigate the role of visual and IR information during prey targeting. Compared with unoccluded controls, snakes with either both eyes or pit organs occluded performed more poorly in hunting prey although such subjects still captured prey on 75% of trials. Subjects with one eye and one pit occluded on the same side of the face performed as well as those with bilateral occlusion although these subjects showed a significant targeting angle bias toward the unoccluded side. Performance was significantly poorer when only a single eye or pit was available. Interestingly, when one eye and one pit organ were occluded on opposite sides of the face, performance was poorest, the snakes striking prey on no more than half the trials. These results indicate that, visual and infrared information are both effective in prey targeting in this species, although interference between the two modalities occurs if visual and IR information is restricted to opposite sides of the brain.

Show MeSH
Related in: MedlinePlus