physiology and function Flashcards
(13 cards)
2 major foraging modes in reptiles and amphibians
- sit + wait (ambush)
- active foraging
physiological traits of sit-&-wait foragers
- low endurance
- high anaerobic capacity
- small heart
- low daily energy expenditure
physiological traits of active foragers
- high endurance
- high aerobic capacity
- large heart
- high daily energy expenditure
Acrochordus arafurae sexual dimorphism
linked to different foraging strategies
- males = active foragers
- females = sit-&-wait foragers
studying reptile & amphibian diet
- chance observation
- direct observations
- examining digestive system (live or dead - stomach flushing, palpation, fecal exam, dissection)
specific dynamic action (SDA)
energy expanded during digestion above basal metabolic rate, up to 30% of energy gained
- excess energy use above standard metabolic rate (SMR) before energy benefit from meal
snakes adapt digestive system after feeding
organs rapidly grow post feeding and atrophy after digestion
two types of mimicry in predation avoidance
- batesian (dishonest)
- mullerian (honest)
autotomy
self-amputation of body parts
- common on tails of lizards and salamanders
- minimum damage, partial/nearly full regeneration
- often fitness loss due to energy loss
defense of Phyrnosoma lizards
blood-squirting from eyes, containing chemicals from ant prey
TTX (tetrodotoxin)
neurotoxin used by Taricha newts
- sequestered from prey and within the amphibian’s skin
gravid Rhabdophis females protect offspring
by consuming toads to pass on sequestered toxins
predator avoidance strategies
escaping detection
- crypto’s
escaping identification
- aposematism / mimicry
escaping approach (fleeing)
escaping subjugation and capture
- physical + chemical defences + autotomy
