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Foraging behavior under starvation conditions is altered via photosynthesis by the marine gastropod, Elysia clarki.

Middlebrooks ML, Pierce SK, Bell SS - PLoS ONE (2011)

Bottom Line: However, photosynthetic animals, those capable of both heterotrophy and symbiotic photosynthesis, may have a delayed behavioral response due to their ability to photosynthesize.Compared to the control group, slugs starved 8 and 12 weeks displayed a significant increase in the proportion of slugs feeding and a significant decrease in photosynthetic capability, as measured in maximum quantum yield and [chl a].The 4 week group, however, showed no significant difference in feeding behavior or in the metrics of photosynthesis compared to the control.

View Article: PubMed Central - PubMed

Affiliation: Department of Integrative Biology, University of South Florida, Tampa, Florida, United States of America. mlmiddle@mail.usf.edu

ABSTRACT
It has been well documented that nutritional state can influence the foraging behavior of animals. However, photosynthetic animals, those capable of both heterotrophy and symbiotic photosynthesis, may have a delayed behavioral response due to their ability to photosynthesize. To test this hypothesis we subjected groups of the kleptoplastic sea slug, Elysia clarki, to a gradient of starvation treatments of 4, 8, and 12 weeks plus a satiated control. Compared to the control group, slugs starved 8 and 12 weeks displayed a significant increase in the proportion of slugs feeding and a significant decrease in photosynthetic capability, as measured in maximum quantum yield and [chl a]. The 4 week group, however, showed no significant difference in feeding behavior or in the metrics of photosynthesis compared to the control. This suggests that photosynthesis in E. clarki, thought to be linked to horizontally-transferred algal genes, delays a behavioral response to starvation. This is the first demonstration of a link between photosynthetic capability in an animal and a modification of foraging behavior under conditions of starvation.

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Percentage of slugs displaying feeding behavior after each starvation period.Data represent all slugs tested for each starvation treatment group.
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pone-0022162-g003: Percentage of slugs displaying feeding behavior after each starvation period.Data represent all slugs tested for each starvation treatment group.

Mentions: Significant differences in slug feeding behavior and length of starvation were clearly evident. Slugs from all treatments displayed some feeding behavior; however, slugs from the continuously fed control, as well as those starved for 4 weeks, were less likely to feed than slugs starved for 8 and 12 weeks (Figure 3). Thirty-three percent of slugs in both the control and 4 week starvation group displayed feeding behavior, compared to 73% and 69% of the slugs in the 8 and 12 week starvation period, respectively. The length of time that slugs were starved was significantly associatedwith the proportion of slugs displaying feeding behavior (p<0.001, F = 13.67) (GLM). Pair-wise Chi-squared goodness of fit tests indicated that slug foraging behavior in both the control and 4 week starvation treatments were not significantly different from each other, but both were different from slugs in the 8 (p<0.05, χ2 = 4.311) and the 12 (p<0.05, χ2 = 4.200) week starvation groups.


Foraging behavior under starvation conditions is altered via photosynthesis by the marine gastropod, Elysia clarki.

Middlebrooks ML, Pierce SK, Bell SS - PLoS ONE (2011)

Percentage of slugs displaying feeding behavior after each starvation period.Data represent all slugs tested for each starvation treatment group.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3140505&req=5

pone-0022162-g003: Percentage of slugs displaying feeding behavior after each starvation period.Data represent all slugs tested for each starvation treatment group.
Mentions: Significant differences in slug feeding behavior and length of starvation were clearly evident. Slugs from all treatments displayed some feeding behavior; however, slugs from the continuously fed control, as well as those starved for 4 weeks, were less likely to feed than slugs starved for 8 and 12 weeks (Figure 3). Thirty-three percent of slugs in both the control and 4 week starvation group displayed feeding behavior, compared to 73% and 69% of the slugs in the 8 and 12 week starvation period, respectively. The length of time that slugs were starved was significantly associatedwith the proportion of slugs displaying feeding behavior (p<0.001, F = 13.67) (GLM). Pair-wise Chi-squared goodness of fit tests indicated that slug foraging behavior in both the control and 4 week starvation treatments were not significantly different from each other, but both were different from slugs in the 8 (p<0.05, χ2 = 4.311) and the 12 (p<0.05, χ2 = 4.200) week starvation groups.

Bottom Line: However, photosynthetic animals, those capable of both heterotrophy and symbiotic photosynthesis, may have a delayed behavioral response due to their ability to photosynthesize.Compared to the control group, slugs starved 8 and 12 weeks displayed a significant increase in the proportion of slugs feeding and a significant decrease in photosynthetic capability, as measured in maximum quantum yield and [chl a].The 4 week group, however, showed no significant difference in feeding behavior or in the metrics of photosynthesis compared to the control.

View Article: PubMed Central - PubMed

Affiliation: Department of Integrative Biology, University of South Florida, Tampa, Florida, United States of America. mlmiddle@mail.usf.edu

ABSTRACT
It has been well documented that nutritional state can influence the foraging behavior of animals. However, photosynthetic animals, those capable of both heterotrophy and symbiotic photosynthesis, may have a delayed behavioral response due to their ability to photosynthesize. To test this hypothesis we subjected groups of the kleptoplastic sea slug, Elysia clarki, to a gradient of starvation treatments of 4, 8, and 12 weeks plus a satiated control. Compared to the control group, slugs starved 8 and 12 weeks displayed a significant increase in the proportion of slugs feeding and a significant decrease in photosynthetic capability, as measured in maximum quantum yield and [chl a]. The 4 week group, however, showed no significant difference in feeding behavior or in the metrics of photosynthesis compared to the control. This suggests that photosynthesis in E. clarki, thought to be linked to horizontally-transferred algal genes, delays a behavioral response to starvation. This is the first demonstration of a link between photosynthetic capability in an animal and a modification of foraging behavior under conditions of starvation.

Show MeSH
Related in: MedlinePlus