vert bio exam 2

what are nasolabial grooves used for?

chemoreception to find mates

what are the two special characters of plethodontids?

• nasolabial grooves

• no lungs

  • most plethodontids live in cold, fast moving water with a high O2 content; lungs would be a disadvantage (not needed + would make them too buoyant)

What are the three possible life cycles of salamanders?

• completely aquatic

• completely terrestrial

• terrestrial adults and aquatic larvae

is salamander reproduction internal or external?

internal

• via spermatophores released into the water by the male

• no true copulatory organ

what are frogs and toads modified for? What modifications do they have for this purpose?

jumping

• long pelvic girdle

• limbs and digits elongate

• forearm bones fused

what mechanism do tree frogs use to stick to trees?

wet adhesion

• via mucus on toes

What allows for frogs and toads to protrude their tongues?

Specialized muscles

• genioglossus and submentalis (flick out)

• hyloglossus (pull back in)

What helps amplify frog sounds?

their tympanum

what is intercalary cartilage?

cartilage between the toe bones of tree frogs

• allows for bending without loss of adhesion

Is frog fertilization internal or external?

• external (via amplexus (copulatory embrace)) for a vast majority of frogs

• one group (tailed frog) have a modified copulatory organ and internal fertilization

How do frogs care for young (3 ways)?

• egg guarding

• egg/tadpole carrying (in back of mouth)

• gastric brooding (no extant species)

What two diseases threaten amphibians?

chytridiomycosis (fungus)

• prevents gas exchange through skin

ranavirus (viral disease)

• hemorrhaging of skin and organs

how did chytridiomycosis spread around the world?

the frog that spread it initially was used in laboratory testing (pregnancy tests) resulting in it ending up all around the world

What are temporal fenestrae?

holes in the side of the skull, providing room for jaw muscles to grow bigger & have more surface area to attach to

• allows for better jaw movement

how many temporal fenestrae in diapsids?

2

What are the four derived characters of amniota?

• lateral flange on pterygoid bone

• keratin based structures on skin

• costal ventilation of lung

• amniotic egg

what is the benefit of the amniotic egg?

allows for egg laying on land

What is the main general character of amniota?

more developed egg compared to earlier species (more layers)

• allantois (nitrogenous waste storage)

• yolk (stores nutrients)

• chorion, amnion (store water, protect from shock, allow for gas exchange once fused)

what group lack shells on their eggs (mostly)?

mammals

why do amniotes need a rigid trachea?

rib ventilation (present in amniotes) requires negative pressure; no support = trachea collapses

What is costal ventilation?

negative pressure system sucking air in; ribs expand, increasing lung volume and lung suction; positive pressure pushes air out as lung volume decreases

What are the two derived characters of sauropsids?

• uric acid nitrogenous waste

• beta keratin in skin

what are parareptiles?

extinct mesosaurs and their relatives

what is the derived character of diapsida?

two temporal fenestrae

what are the two main derived characters of squamata?

• hemipenes

  • male copulatory organs

• determinant growth

  • growth plates that will fuse at maturity (once mature, growth stops)

What are the two main groups of lepidiosauria?

• Rynchocephalia (tuataras)

• squamates (snakes, lizards)

what extant group retains the full diapsid skull?

Rhychocephalia (tuataras)

what traits separate snakes and lizards?

• lizards have ear holes, snakes dont

• lizards have moveable eyelids, snakes dont

• lizards have two lungs, snakes have one

• lizards have multiple rows of ventral scales, snakes tend to only have one

what is significant about the squamate skull?

increased cranial kinesis as a result of reduced quadratojugal

what are chromatophores?

pigment cells that can be changed depending on mood, physical condition, etc

What is caudal autotomy?

the tail can break off easily as a result of built-in fracture planes on the vertebrae

• bone will not regrow; once a break happens, it cannot grow back

in what 4 ways can tail loss harm lizards?

• decrease growth (energetically expensive)

• worsen reproduction (energetically expensive)

• decrease social status (tails are a social indicator)

• cant do it again (cant regrow breakable bone)

What is the forked squamate tongue used for?

chemoreception

why have snakes and some lizards secondarily lost legs?

they inhabit dense underbrush where no legs allows for better maneuverability

what do lizards consume?

• plants (large lizards)

• small verts/inverts (small lizards)

What is dry adhesion?

molecular level attachment via toe pads divided into lamellae

what is unique about chameleon tails?

• prehensile

  • grab stuff

• cannot break like other lizards

What is the fear of snakes?

ophidiophobia

How do snakes consume prey?

jaws can move separately, allowing for a back-and-forth consumption of prey by protracting and retracting sides of the jaws

What are loreal pits? what snakes have them?

• infared heat sensing organs

• found in boas and vipers

What are three consumption strategies of snakes?

• sieze and swallow

• constriction

• use of venom → waiting for prey to die

what kind of fertilization do snakes have?

internal

• mostly egg layers

Where is viviparity seen in squamates?

skinks, boas, vipers

• found in colder climates

• increases survivability and embryonic development

• results in female producing fewer offspring & being more vulnerable when carrying young

What is parthenogenesis?

reproduction without fertilization

• results in an all-female population

• likely originated from interspecies hybridization

How many temporal fenestrae do turtles have?

Zero

• it is believed that they once had them, but secondarily lost them

What is the derived trait of testudinia?

• skull with emarginated posterior

  • analagous to temporal fenestrae

what are the general traits of testudinia?

• shell

• loss of teeth

How do turtles ventilate their lungs?

lungs attached to guts; muscles can push/pull/spread guts to increase/decrease lung volume

• turtles have fused ribs, and cannot breathe traditionally

what two environmmental factors influence turtle reproduction?

• Temperature

  • influences rate and size of offspring (environmental s*x determination)

• humidity

  • more humid = more water for eggs = higher survivability

what are the 3 main types of ESD, and what species most commonly and have them?

1A turtles

• Male low temp, Females High temp

1B Tuatara

• Females low temp, Males High temp

2 Crocs

• Females at low and high temp, males at intermediate temp

what ESD type is most threatened by climate change?

1B

What are anadromous migrations?

live in oceans and return to freshwater to spawn

What are catadromous migrations?

Live in freshwater and return to oceans to spawn

In what 3 potential ways do actinopterygii care for their young?

• nest attendance

  • males protect, clean, and aerate eggs

• brooding

  • carrying in mouth, pouches, or attached to body

• direct feeding

  • some produce skin secretions for larvae to eat

What are the three main threats for freshwater actinopterygii conservation?

• pollution

  • acid mine drainage, coal silt, etc

• habitat degradation

  • construction of dams

• invasive species

  • asian carp, common carp, rainbow trout

What is the main threat for ocean actinopterygii conservation?

Overharvest

• fishermen overestimate how abundant spp. are

• attempts to farm fish instead have inadvertently spread disease and waste

What are the three derived characters of sarcopterygii?

• monobasic fins

  • muscular lobes at fin base

• intracranial joint

  • may improve suction + biting force

• cosmoid scales

  • thick, dentine-like scales

Why is little known about actinista?

they inhabit deep benthic zones

what is estivation? what group undergoes estivation?

“hibernation” (reduction of physiological properties and metabolic rate) in response to environmental conditions (heat and drought)

done by dipnoi (lungfish)

For what 3 reasons did tetrapods move to land?

• less predators

• less competition

• more food opportunities

  • plants, arthropods

What is the derived character of tetrapoda?

4 limbs w/carpals, tarsals, and digits.

What are zygapophyses?

contact surfaces on the front and back of tetrapod vertebrae

What are occipital condyles?

articulating surfaces on the cranium of sarcopterygians that assist with head movement

what is the stratum corneum?

a layer of dead, keratinized cells on the sarcopterygian epidermis that prevent dessication

What are pedicellate teeth?

inward bending teeth in amphibians that assist with prey swallowing

what is aposematic coloration?

bright colors to advertise distastefulness to predators

what is mullerian mimicry?

false aposematic coloration evolved by non-toxic amphibiansw

what two bones are found in the inner ear of amphibians? what does each bone specialize in detecting?

• Columnella

  • high frequency sounds from air

• operculum

  • low frequency vibrations from ground

What are the 4 main forms of amphibian respiration?

• cutaneous gas exchange

  • highly vascularized skin

  • found in salamanders

• paired lungs

  • buccal pumping of oxygen

  • found in frogs, toads

• buccopharyngeal exchange

  • lining of mouth+pharynx vascularized

  • found in lungless salamanders

• gills

  • efficient in water

  • salamander (larvae and some adults)

How do caecilians move around?

annuli (dermal folds)

What is paedomorphosis? what are the two types of paedomorphosis?

retention of larval traits in s*xually active adults

• obligate

  • fully aquatic species

• faculative

  • depends on environmental conditions (ex. delaying metamorphosis or breeding until more favorable conditions arrive to maximize offspring production)

Identify the name (scientific and common) of each tetrapod group; also provide the defining character(s) for each group

1. Tetrapoda [vertebrates] (4 limbs w/carpals, tarsals, digits)

2. Amniota [mammals, birds, reptiles] (lateral flange, modified vertebrae, keratinized skin layers, costal ventilation, amniotic egg)

3. Sauropsida [“reptiles'“, lizards, birds] (keratinized skin, uric acid waste)

4. Diapsida [“Reptiles,” lizards, birds] (two temporal fenestrae)

5. Lissamphibia [amphibians] (variable respiration, pedicellate teeth, mucous glands, operculum)

6. Synapsida [mammals and relatives] (one temporal fenestrae)

7. Parareptiles [mesosaurs and relatives] (secondarily evolved to be aquatic; extinct]

What are the three orders under lissamphibia?

• Gymnophonia (caecilians)

• Urodela (salamanders)

• Anura (frogs)

Identify the name (scientific and common) of each diapsid group; also provide the defining character(s) for each group (NOTE: The three unmarked groups are not covered on this exam and do not need to be identified at this time)

1. Diapsida [“Reptiles,” lizards, birds] (two temporal fenestrae)

2. Lepidiosauria [lizards, snakes, tuatara] (overlapping keratin scales)

3. Rhynchocephalia [Tuatara] (full diapsid skull)

4. Squamata [lizards, snakes] (paired copulatory organs, no true erectile tissue, determinate growth)

5. Testudinia [Turtles] (skull w/emarginated posterior, shell)