herpetology exam 2

Uroplatus phantasticus

One of the smallest leaf-tailed gecko species, has a horned head, red eyes and a tail with notches that helps it mimic the look of decaying leaves. Madagascar.

Tiliqua scincoides scincoides

Largest members of this family. Aposematically colored tongue – defensive behavior. Eastern Australia

Chrysopelea paradisi

Completely arboreal, can glide!!

Trichobatrachus robustus

Retractable “claws” that pierce the skin, males grow hairy dermal papillae during breeding season

ornate crevice-dragon (ctenophorus ornatus)

example of long-term water balance

peringuey’s adder (bitis peringueyi)

exhibits hydrophobic scale properties; water collection mechanism causing water droplets to bead up on the body surface and flow into channels formed between coils of the body

mojave rattlesnake (crotalus scutulatus)

exhibits rain-harvesting behavior; during rainstorms, the snake repositions its body like a coiled garden hose, maximizing the area exposed to rain and allowing water to collect between the coils.

australian thorny devil (moloch horridus)

has a rain harvesting stance that uses its scales to change the waters flow

texas horned lizard (phrynosoma cornutum)

capillary flow carries harvested water, and its jaw movement pulls a little water from the channels into the lizard’s mouth

african hinge-back tortoise (kinixys homeana)

exhibits water collecting posture during rainfall events. It raises the rear of its carapace, extending its neck and forelegs, having the scutes form a gutter, directing the water to the tortoise’s mouth

spadefoot toad (spea)

inhabit dry desert regions in the American Southwest, spending about 9 months of the year in burrows. Hydration begins in June and fluctuates throughout the seasons.

waxy leaf frog (phyllomedusa sauvagii)

secrete a protective waxy layer made of lipids; helps prevent water loss by maintaining cutaneous resistance

mojave desert tortoise (gopherus agassizii)

acts as an example for how urine/plasma change hydration levels depending on the season

sea krait (laticauda/elapinae)

live in coastal areas, obtain freshwater from springs and streams

sea snakes (hydrophiinae)

obtain water depending on rainfall

Qabs

radiation absorbed by the surface of an animal

S

intensity of solar radiation

A

surface area of the animal in m^2

vfs

view factor for solar radiation; proportion of the animal’s surface that the sun shines on

A

absorptivity to solar radiation; proportion of solar energy striking the surface that is absorbed rather than reflected

M

metabolic heat production

R

infrared radiation received or emitted by the surface of an animal. The difference between the surface temperature of the animal surface and the temperature of the object in the environment.

The area of the animal exposed to the thermal radiation (surface area x view factor)

Infrared emissivity (how readily a surface radiates and absorbs infrared radiation

C

heat gained or lost by convection to the fluid surrounding an animal (the fluid is air for terrestrial animal and water for an aquatic animal)

The convective coefficient of the animal is determined by the velocity of air movement and the size of the animal

LE

heat gained by condensation or lost by evaporation

Depends on permeability of the skin, the humidity of the air, and the rate of air movement

G

heat gained or lost by conduction through direct physical contact of an animal with the substrate it is resting on (soil, rock, tree trunk, etc.). Temperature difference between the animal and the medium

Tact

activity temperature

EWL

evaporative water loss.

coleonyx reticulatus

the presence of multiple lizards in the same site reduces evaporative water loss by increasing relative humidity.

Neutral Orientation

the ribs are relaxed and the sun is overhead

Positive Orientation

the ribs are spread, making the body nearly circular. Faces away from the sun and extends the forelegs so that its body surface is nearly perpendicular to the sun’s rays. Take in sunlight.

Negative Orientation

the ribs are compressed to make the body narrow. Faces into the sun and extends its forelegs so that its body is nearly parallel to the sun’s rays. Also cooling its head by panting. Cool down.

Cloacal Cooling

evaporative water loss by the cloaca, utilized by the Gila Monster.

Heliothermy

temperature determined by solar radiation

Thigmothermy

temperature determined by surrounding environment (ie. soil, rocks)

andean toad (rhinella spinosa)

exemplifies that basking in large groups is warmer, while solitary toads are cooler

hyla arenicolor and litoria meiriana

exemplifies motionless water-conserving posture

bokermannohyla alvarengai

forages on rocks, its large surface-to-volume ratio promotes evaporative cooling and fast rehydration.

Kleptothermy

gaining heat from other organisms

Muscular Thermogenesis

heat produced via spasmodic contractions of the muscles. Metabolic rates increase with snake brooding clutches.

Digestive Thermogenesis

temperature increasing due to digestion.

leatherback sea turtle (dermochelys coriacea)

example of metabolic heat, which gains heat from muscular activity as it swims and digestion of jellyfish.

Buccopharyngeal Region

salamanders in the family plethodontidae carry out all gas exchange via the skin and buccopharyngeal region

Cutaneous Respiration

all amphibians practice breathing through the skin

hellbender (cryptobranchus alleganiensis) and lake titicaca frog (telmatobius culeus)

have highly vascularized skin folds where the current brings in water

african hairy frog (trichobatrachus robustus)

grows filaments of skin that have an extensive blood supply increasing the surface area available for gas exchange with water

smooth newt (lissotriton vulgaris)

crests and tail fins in males increase aquatic gas exchange and courtship display

Paedomorphic salamanders

(pseudobranchus, necturus, proteus, and some ambystoma) retain gills as adults

Positive-Pressure Ventilation

air is forced into the lungs by raising the pressure in the buccopharyngeal region above the pressure in the lungs

chinese soft-shelled turtle (pelodiscus sinensis)

buccopharyngeal respiration accounts for two-thirds of the aquatic oxygen uptake

Terrestrial Reptiles

generally take single breaths separated by periods without breathing (apneic periods), last from seconds to a minute or so

Aquatic Species

alternate periods of continuous ventilation with apneic periods which last from minutes to an hour or more

A lizard cannot breathe and run simultaneously

savannah monitor lizard (varanus exanthematicus)

using a gular pump to supplement lung ventilation during locomotion on a treadmill

Paired Lungs

the ancestral condition for reptiles

Vascular Lung

well supplied with blood vessels. Walls are elaborated into chambers - a large surface area for gas exchange. Evolved in half of the extant snake families.

Saccular Lung

lacks partitions or other structures to increase the surface area, has a limited blood supply. Appears to regulate airflow

Inspiration

a posterior movement of the liver that is produced by contraction of the diaphragmaticus muscles, which originate on the pelvis

Expiration

several abdominal muscles pull the liver forward, compressing the lungs and forcing air out.

central american whiptail lizard (holcosus festivus)

temperature affects sprint speed and escape from predators.

american toads (anaxyrus americanus)

loss of body water affects locomotion.

Ascaphidae

most primitive living frogs - highly derived mode of fertilization. Perhaps an adaptation to breeding in rapidly flowing water. Male cloaca modified to form a permanently extended copulatory organ

Eleutherodactylidae - 2 species

one is viviparous and the other has terrestrial eggs and direct development

Inguinal Amplexus

ancestral; morphologically primitive groups of frogs. Around the waist

Axillary Amplexus

most derived from anuran families. Grasps behind forelimbs

Cephalic Amplexus

dendrobatidae. Around head

male african bullfrogs (pyxicephalus adspersus)

remain with their tadpoles until metamorphosis and defend them against potential predators

Lecithotrophy

yolk reserves

Matrotrophy

maternal secretions

Dermophagy

females guard their eggs in terrestrial nests. The young hatch with specialized dentition which they use to tear of and eat the outermost layer (stratum corneum) of their mother’s skin

Hybridogenesis

genome of the female parent passes unchanged from one generation to the next

Kleptogenesis

females that steal genomes from males of other species resulting in three outcomes - the sperm initiates development of the embryo but isn’t incorporated to the embryo’s genome, the sperm is sometimes incorporated resulting in offspring with a higher ploidy level, or the sperm replaces one of the original genomes in the hybrid offspring.

Vitellogenesis

synthesized in the mother’s liver transported by the circulatory system to the maturing eggs

Lecithotrophy

supports embryonic development until the eggs hatch into larvae that can acquire their own food

Ancestral Condition

aquatic deposition of eggs, larval development, and absence of paternal care

Hybridogenesis

genome of the female parent passes unchanged from one generation to the next

Cryptobranchidae

males are highly territorial and defend nest sites

Hynobiidae

males clasp egg sacs and release sperm onto them. Aggressively defend the egg sacs from other males

Sirenidae

males lack specialized cloacal glands; females lack spermatheca. Males defend nests

Temporary Ponds

All individuals exhibit the ancestral life history in which larvae hatch in the spring and metamorphose in response to drying of the pond in the summer

Permanent Ponds

Frequently delay metamorphosis and breed as larvae, later metamorphosing into terrestrial adults