Mothers transfer information via eggs: effect of mothers' experience with predators on offspring

Parents play an important role in creating phenotypic variation in their offspring through genetic and environmental mechanisms. For example, mothers can influence their offspring via hormonally-mediated maternal effects. In this study, offspring of mothers that had been exposed to a predator during oogenesis (experimental) were compared to offspring of mothers that had not been exposed to a predator (control). I measured the consequences of maternal exposure to predation risk on the number and size of eggs, egg cortisol content, metabolic rates of eggs, and the growth and behavior of juvenile threespined sticklebacks (Gasterosteus aculeatus). Exposure to a predator during oogenesis caused females to produce larger eggs and heavier clutches, but there was no effect on the number of eggs per clutch. The concentration of cortisol was higher in experimental eggs than control eggs. Experimental eggs also breathed faster soon after fertilization, but the difference between control and experimental eggs in oxygen consumption attenuated over time. Standard length of juveniles increased over the course of the experiment, but there was no effect of treatment on growth during the period when the fry were measured. Shoaling behavior, an antipredator response, was measured from photographs, and was estimated as the nearest neighbor distance between individuals in each tank. Experimental females shoaled more tightly together prior to a mild disturbance. Both control and experimental juveniles shoaled more tightly together immediately following and two minutes after a mild disturbance. Altogether, these results suggest that the effect of mothers on their offspring might depend on a mothers' experience with stressors in the environment, and that mothers might manipulate the development, growth, and behavior of their offspring to match their future environment.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Natural Res & Env Sciences

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2010

Author dc:creator

• Giesing, Eric R.

Contributors dc:contributor

• Warner, Richard E.
• Bell, Alison M.

• cortisol
• maternal effects
• offspring
• maternal experience

Statement dc:rights

• Copyright 2010 Eric Richard Giesing

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/15984

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/15984