AECL 366 Exam 3 Part 1

Class Amphibia

frogs, toads, salamanders; scaleless permeable skin

Salamanders

Defining Features: larvae have external gills, adults have lungs. Internal fertilization.

Food: Larvae and adults eat invertebrates

Habitat: Aquatic for larvae, Forest for adults

Mudpuppies

Features: 2 life stages- External gills on larvae and adult stages

Food: Invertebrates in all stages

Habitat: aquatic, lakes and slow-flowing rivers.

Newts

Features: 3 life stages- Larvae-eft-adult, produces a toxin through their skin.

Food: Mainly Invertebrates

Habitat: Woodland and associated aquatic systems

Larvae is aquatic with external gills, eft stage are terrestrial (with lungs), and adults are mainly aquatic.

Benefits and costs of mudpuppy's life history strategy

Benefits: No need to risk habitat change

Costs: viable population can only occur in large aquatic ecosystems

Benefits and costs of eastern newt life history strategies

Benefits: Eft stage allows a viable population in landscapes with small pond; access to different resources.

Costs: viable population only possible in large forests with small ponds, leaving the water can increase predation

benefits and costs of tiger salamander life history strategies

Benefits: typical adult= populations can occur in landscapes with small ponds, access to different resources. Neotenic adult (retains gills) = no need to rest habitat change

Costs: leaving the water can increase predation; fitness depends on following the developmental pathway that maximizes survivorship.

Most important causes of salamander population declines

1- Ecosystem/Habitat degradation: Aquatic pollution (Toxic effects of nitrogen, synthetic chemicals, nutrients which can enable algae blooms and produce oxygen depletion) Climate change (thermal stress and habitat loss)

2- Emerging Diseases: Rotavirus (ecosystem degradation increases disease susceptibility)

3-Ecosystem/habitat destruction: Wetland, grassland, woodland elimination (transition to agriculture and urban development).

4- Ecosystem/Habitat fragmentation: Decreased habitat size (increases distance between suitable habitats which can reduce genet flow.

Frogs and toads

Larvae has gills and tail, adults have lungs and no tail. External fertilization

True Toads (bufonidae)

Warty skin, paranoid gland, produces a bufotoxin

Food: Larvae eat microorganisms (algae, fungi, bacteria), adults eat invertebrates.

American Toad

Has a bufotoxin, high pitch trill vocalization, eggs in a string manner

Tree Frogs (Hylidae)

Small body adults with suction cups on toes.

Food: Larvae eat microorganisms, adults eat invertebrates.

True Frogs (Ranidae)

Stood skin, large body

Habitat: permanent aquatic systems; adults remain near water systems

food: larvae eat microorganism and adults consume invertebrates and small vertebrates.

True toads hibernation

Habits: Hibernation in ground, burrow below frost line

Adaptations: Thicker skin leads to less desiccation

tree frogs hibernation

Habits: Hibernation near or on soil surface

Adaptation: Glucose in circulatory systems preventing cells from freezing

true frogs hibernation

Habits: Hibernates on bed or bottom of pond/lake

Adaptations: Highly permeable skin that allows the gain of oxygen

Important causes of frog and toad population declines

1- Ecosystem Destruction: Habitat loss; for example, the northern leopard frog- the destruction of their natural habitat ponds/lakes reduces the space for viable populations, it also has an impact on their food requirements, invertebrates.

2- Habitat Fragmentation: Reduced habitat size can reduce population size which can increase extinction vulnerability due to low genetic diversity (low ability to adapt and survive external situations). Increased distance between suitable areas decreases gene flow via de in or our movement of individuals.

3- Habitat/ecosystem degradation: Nutrient pollution; nitrogen its toxic in high concentrations, lots of nutrients can lead to alage blooms that (some) can generate toxins, other can cause oxygen depletion.

4- Emerging diseases: Parasite- toadfly (affects true toads). Ranavirus (virus) affects most amphibians and some fishes.

Ecosystem services lost with declines of amphibian populations

Biological control of insects: Insects that can consume/destroy harvestable resources (crops/trees) or insects that can carry out pathogens such as mosquitoes (northern leopard frog).

Class reptilia

Scaly, non permeable skin; juveniles and adults have similar appareinces and resource requirements, internal fertilization

Turtles

Features: Body covered by shell, lay eggs, hibernate in ground burrow or pond bed. Long lifespans, low reproductive rates (K-selective)

Snapping turtle

Habitat: Aquatic; migrate across terrestrial habitats, eggs deposited in soft soil away from water.

Food: vertebrates (fish) aquatic plants, and carrion.

Temperature dependent sex determination (TDSD).

Painted turtle

Habitat: Wetlands/lakes, migrate across terrestrial habitats, lay eggs in soft soil.

Food: Plants, invertebrates, carrion

TDSD

Blading's turtle

Habitat: Aquatic (shallow with abundant plants), migrate through terrestrial habitats, lay eggs in soft soil

Food: Invertebrates, plants, fish

TDSD

Spiny softshell turtle

Habitat: Aquatic ecosystems with soft bottom substrate, eggs deposited in sandbars, near water.

Food: Invertebrates (crayfish), invertebrates (fish), and plants.

NOT temperature dependent sex determination

Nest failure increasing due to more intense/frequent flooding, drowning the eggs, decreasing reproduction.

Important causes of title population declines

-Ecosystem destruction

-Ecosystem fragmentation

-Ecosystem degradation: Pollutants- bioaccumulation/magnification of systemic chemicals can have genotoxic effects (affects DNA)

-Climate Change:temperature dependent sex determination- increasing temperatures lead to unbalanced sex ratios; more extreme rainfall increases severity and frequency of flooding that can alter reproduction (soft shell turtle) nest failure.

Over harvest: mostly of any K-selected species- life history characteristics= old/late sexual maturity age, low reproductive rates.

Ecosystem services lost by a decline in turtle populations

Protection of aquatic resources: consumption of dead organisms (fish) by some turtle species reaches the concentration of nitrogen in water. Harvest (can serve as food).

Lizards

reptiles with long bodies and tails, movable eyelids, and usually four legs.

Prairie Skink

Features: Dark stripe on side of body, breeding males have orange throat

Habitat: Grassland, ideally with plenty of cover and near water.

Food: Invertebrates/insects

Snakes

No external ear opening, no movable eyelids, no limbs

Hibernate below frost line

Timber Rattlesnake

Habitat: rocky woodland

Food: primarily small mammals, but also amphibians and other snakes

-Neurotoxic venom

Ringneck snake

Habitat: woodland, mainly wet

Food: Mainly invertebrates, can eat small amphibians

Smooth green snake

Habitat: Grassland

Food: invertebrates- insects

-serves as a biological control agent

Bull snake

Habitat: Grassland

Food: vertebrates, primarily rodents- kills by constriction

-Can rattle tail and hiss as a defense mechanism

Plains garter snake

Habitat: grassland, more abundant near wetland

Food: Invertebrates - insects, and some amphibians and mice

Western fox snake

Habitat: prairies and woodlands were structures are abundant, near aquatic ecosystems

Food: Primarily rodents

Northern water snake

Habitat: Aquatic systems

Food: vertebrates- fish and amphibians

-contains and aticoagulant in saliva

Brown snake

Habitat: Grassland and Woodland

Food: Invertebrates

-Most tolerant to altered landscapes

Reasons of snake population declines

Ecosystem/Habitat loss: Example, Plains Garter Snake- Requires grassland by an aquatic system, new development increases habitat loss, which also means loss of food (amphibians and insects)

Habitat degradation: Pesticides and synthetic chemicals- heavy dogae can act as genotoxins which leads to DNA alterations

Snakes ecosystem services

Bull snake consumes rodents that can carry human pathogens or that are "pests" to humans.

Smooth green snake: consumes insects that can possibly damage harvestable resources

Dorsalventrally compressed

Likely living in benthic zones, feeding at the bottom

Laterally compressed

likely in midwater habitat

Fish with terminal mouth

midway feeders

fish with subterminal mouth

bottom feeders

fish with epiterminal mouth

surface feeders

fish with barbels

Can serve as sensors: likely in fish feeding at the bottom of lenthic systems, possibly with high turbidity

Lampreys

No jaws, no scales with smooth skin

Habitat: Rivers and streams, larvae are benthic

Food: Adults are ectoparasites of fish, larvae eat microorganism

Sturgeon

Habitat: benthic areas of rivers

Food: venatic invertebrates and algae

-Harvested for meat and eggs; globally endangered

paddle fish

habitat: Large rivers

Food: zooplankton

Gars

Habitat: lakes and slow flowing rivers, rooted plant beds

Food: fish

-Eggs are poisonous to humans and other mammals

Gizard Shad

Habitat: lakes and rivers with muddy benthic

food: zooplankton and benthic microorganisms

Trout

habitat: cold streams and lakes

food: fish, benthic invertebrates, terrestrial insects

pikes

habitat: lakes, slow flowing rivers

food: fish and other vertebrates