72 Christopher King Beachy 



extensive variation in propagule size in amphibians. Such variation 

 has been interpreted as an "evolved tactic" (Capinera 1979) that 

 ensures that viable offspring are produced in variable habitats. In 

 many species of amphibians with complex life cycles, vitellogenesis 

 occurs in the terrestrial habitat. The female then may not be able 

 to receive environmental cues that indicate the size of eggs she 

 should produce to ensure survival of offspring in the aquatic 

 habitat. Because offspring can be exposed to a habitat that is variable, 

 there should be an optimal range in offspring size within an 

 individual female's clutch. As habitat variability decreases, the range 

 should decrease because of consistent selection for an optimal 

 phenotype. 



Egg size also varies among clutches. A single female might 

 produce clutches with very different mean egg sizes (Kaplan 1987). 

 Kaplan and Cooper (1984) showed that in species that cannot "predict" 

 the stability of the environment in which their larvae will grow and 

 develop, the most efficient strategy will be to randomly produce a 

 few large eggs or many small eggs. Interclutch variation in egg size 

 in a female's lifetime (or within a population at one time) can 

 outweigh the intraclutch variation of a female's single clutch. 



Egg size has been shown to influence characters that relate to 

 larval survival in salamanders (Kaplan 1980, 1985; Petranka 1984). 

 Kaplan (1985) showed that in the newt Taricha torosa (Rathke, 1883) 

 egg size can have profound effects on hatching size and growth 

 rate. Thus, egg size might affect timing of metamorphosis. If so, 

 then an optimal egg size can be selected for given a stable (or 

 permanent) larval environment. In an unreliable environment, an 

 optimal range of egg sizes might be the best strategy to maximize 

 parental fitness. In T. torosa, large eggs produce large hatchlings 

 that begin feeding sooner than smaller larvae. When fed ad libitum, 

 larger larvae will metamorphose at an earlier time and at a larger 

 size than conspecifics hatched from small eggs. In food-limited 

 situations, larvae from larger eggs still metamorphose at a larger 

 size but at a later time than larvae from small eggs. This interaction 

 among egg size, food availability, and habitat reliability suggests 

 that the optimal egg size can vary from season to season. 



I present data on variation in egg size in five species of 

 salamanders. Three questions are explored: (1) Does a species that 

 uses temporary larval environments exhibit greater intraclutch 

 variation in egg size than species that use more permanent larval 

 habitats, such as mountain streams? (2) Is the total population 

 variation in egg size greater in a species that uses temporary larval 

 environments than in species that use mountain streams? (3) Is the 



