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When can embryos learn? A test of the timing of learning in embryonic amphibians.

Sehr EK, Beasley LN, Wilson KW, Gall BG - Ecol Evol (2016)

Bottom Line: There was no significant difference in number of movements or time spent moving among any of the treatments.There was no difference in survival or refuge preference between individuals; however, all individuals preferred vegetated over open areas regardless of treatment type.We discuss hypotheses for the absence of embryonic learning in this species and suggest it may be the result of the intensity of the predator-prey interaction between the predator, large marbled salamander larvae, and the prey, spotted salamander larvae.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology Hanover College Hanover Indiana 47243.

ABSTRACT
Learning is crucial to the survival of organisms across their life span, including during embryonic development. We set out to determine when learning becomes possible in amphibian development by exposing spotted salamander (Ambystoma maculatum) embryos to chemical stimuli from a predator (Ambystoma opacum), nonpredator (Lithobates clamitans), or control at developmental stages 16-21 or 36-38 (Harrison 1969). Once exposures were completed and embryos hatched, we recorded the number of movements and time spent moving of individuals in both groups and all treatments. There was no significant difference in number of movements or time spent moving among any of the treatments. The groups that were exposed to predator stimuli and a blank control at stages 36-38 were also tested to determine whether there was a difference in refuge preference or difference in survivorship when exposed to a predator (marbled salamander). There was no difference in survival or refuge preference between individuals; however, all individuals preferred vegetated over open areas regardless of treatment type. We discuss hypotheses for the absence of embryonic learning in this species and suggest it may be the result of the intensity of the predator-prey interaction between the predator, large marbled salamander larvae, and the prey, spotted salamander larvae.

No MeSH data available.


Related in: MedlinePlus

Total observations (N = 117) of individuals on each side of the experimental chamber (open or refuge) of both blank and predator treatments. Spotted salamander (Ambystoma maculatum) larvae were observed more frequently in refuge (aquatic vegetation) than in open areas of the test arena (df = 1, χ2 = 45.5, P < 0.005).
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ece32018-fig-0001: Total observations (N = 117) of individuals on each side of the experimental chamber (open or refuge) of both blank and predator treatments. Spotted salamander (Ambystoma maculatum) larvae were observed more frequently in refuge (aquatic vegetation) than in open areas of the test arena (df = 1, χ2 = 45.5, P < 0.005).

Mentions: The frequency of observations in the open or in refuge was the same for the two chemical cue treatments (df = 1, χ2 = 1.24, P = 0.266, Table 2) demonstrating that individuals exposed as embryos to either predatory chemical stimuli or to a control spent a similar proportion of time in refuge. Additionally, regardless of predator treatment, all larvae were observed more frequently in refuge than in the open (df = 1, χ2 = 45.5, P < 0.005, Fig. 1).


When can embryos learn? A test of the timing of learning in embryonic amphibians.

Sehr EK, Beasley LN, Wilson KW, Gall BG - Ecol Evol (2016)

Total observations (N = 117) of individuals on each side of the experimental chamber (open or refuge) of both blank and predator treatments. Spotted salamander (Ambystoma maculatum) larvae were observed more frequently in refuge (aquatic vegetation) than in open areas of the test arena (df = 1, χ2 = 45.5, P < 0.005).
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Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4834331&req=5

ece32018-fig-0001: Total observations (N = 117) of individuals on each side of the experimental chamber (open or refuge) of both blank and predator treatments. Spotted salamander (Ambystoma maculatum) larvae were observed more frequently in refuge (aquatic vegetation) than in open areas of the test arena (df = 1, χ2 = 45.5, P < 0.005).
Mentions: The frequency of observations in the open or in refuge was the same for the two chemical cue treatments (df = 1, χ2 = 1.24, P = 0.266, Table 2) demonstrating that individuals exposed as embryos to either predatory chemical stimuli or to a control spent a similar proportion of time in refuge. Additionally, regardless of predator treatment, all larvae were observed more frequently in refuge than in the open (df = 1, χ2 = 45.5, P < 0.005, Fig. 1).

Bottom Line: There was no significant difference in number of movements or time spent moving among any of the treatments.There was no difference in survival or refuge preference between individuals; however, all individuals preferred vegetated over open areas regardless of treatment type.We discuss hypotheses for the absence of embryonic learning in this species and suggest it may be the result of the intensity of the predator-prey interaction between the predator, large marbled salamander larvae, and the prey, spotted salamander larvae.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology Hanover College Hanover Indiana 47243.

ABSTRACT
Learning is crucial to the survival of organisms across their life span, including during embryonic development. We set out to determine when learning becomes possible in amphibian development by exposing spotted salamander (Ambystoma maculatum) embryos to chemical stimuli from a predator (Ambystoma opacum), nonpredator (Lithobates clamitans), or control at developmental stages 16-21 or 36-38 (Harrison 1969). Once exposures were completed and embryos hatched, we recorded the number of movements and time spent moving of individuals in both groups and all treatments. There was no significant difference in number of movements or time spent moving among any of the treatments. The groups that were exposed to predator stimuli and a blank control at stages 36-38 were also tested to determine whether there was a difference in refuge preference or difference in survivorship when exposed to a predator (marbled salamander). There was no difference in survival or refuge preference between individuals; however, all individuals preferred vegetated over open areas regardless of treatment type. We discuss hypotheses for the absence of embryonic learning in this species and suggest it may be the result of the intensity of the predator-prey interaction between the predator, large marbled salamander larvae, and the prey, spotted salamander larvae.

No MeSH data available.


Related in: MedlinePlus