CHAPTER 6
 SUMMARY AND CONCLUSIONS

 Food availability is arguably one of the most fundamental and often-cited modulators of

phenotypic and life-history plasticity. For my dissertation, I addressed questions about the effects

of changes in food availability during different life stages in two taxa. In Chapters 2-4, I

evaluated the physiological and morphological responses to short-term (e.g., 12-week)

differences in food availability in a species (the green turtle, Chelonia mydas) that experiences

nutritional stochasticity during the juvenile stage in the wild. To elucidate long-term responses to

differences in food availability, I conducted a lifespan study using a more tractable animal model

(the Indian stick insect, Carausius morosus). A summary of the major findings of my work can

be found in Table 6-1.

 Animals living in nutritionally stochastic environments demonstrate a variety of

adaptations, including the capacity for compensatory growth (CG) (Wilson and Osbourn 1960,

Reid and White 1977), that enable them to capitalize when conditions are favorable for growth

and reproduction. Although CG has been documented in turtles and lizards (Bjorndal et al. 2003,

Caley and Schwarzkopf 2004), my work is the first to assess the mechanistic basis for this

growth pattern in reptiles. One of the most salient findings to emerge from my work on C. mydas

was the fact that CG is effected via enhanced food conversion efficiency (FCE) rather than

hyperphagia. This result stands in direct contrast to most CG studies in fish (reviewed by Ali et

al. 2003).

 Additionally, working at the Cayman Turtle Farm afforded me a unique opportunity to

investigate growth dynamics in green turtles without sampling animals taken from the wild. As a

result, I was able to elucidate the effects of intake and growth rates on a number of parameters

(e.g., body composition, digestive tract morphology, nucleic acid content, and antioxidant