Experimental Analysis of Allocation during Larval Development in Ambystomatid Salamanders

Area of Science:

• Ecology
• Evolutionary Biology
• Developmental Biology

Background:

• Environmental factors critically shape organismal life histories.
• Energy allocation strategies are key to understanding species' adaptations and survival.

Purpose of the Study:

• To investigate how food availability and temperature affect energy allocation in larval *Ambystoma maculatum* and *A. tigrinum*.
• To compare species-specific differences in energy allocation patterns.

Main Methods:

• Larval salamanders (*A. maculatum*, *A. tigrinum*) were subjected to varying food and temperature conditions.
• Measurements included metamorphic size, larval period duration, fat body mass, and gonad mass.
• Statistical analyses examined the influence of environmental factors on an energy allocation vector.

Main Results:

• Both food and temperature influenced the energy allocation vector (metamorphic size, larval period, fat body, gonad mass) in both species.
• High food and temperature accelerated growth, while low temperature delayed metamorphosis.
• *A. tigrinum* showed greater plasticity, with all four variables influenced by food and temperature, and an interaction effect.
• *A. maculatum* primarily showed a correlation between metamorphic size and fat body mass.

Conclusions:

• Energy allocation patterns are species-specific, with *A. tigrinum* exhibiting stronger interdependencies among life history traits.
• Environmental interactions on energy allocation vary between species, offering insights into life history variation.
• Understanding these allocation dynamics is crucial for predicting species' responses to environmental change.