EXAM 1 Flashcards
what is herpetology?
the study of reptiles and amphibians
amphibians and reptiles are both ____________, which means…
ectotherms
they get their body warmth from their environment, but can still regulate their body temperature
what are the 3 major groups of amphibians?
- Anura
- Caudata
- Gymnophiona
what animals are Anura?
frogs and toads (~7,400 species) no tail, mating call, tadpoles. (toads are typically terrestrial while frogs are aquatic).
what animals are Caudata?
salamanders (~770 species) smallest body size, no mating call, no tadpoles, tail w/ 4 legs
what animals are Gymnophiona?
caecilians (~215 species) all tropical, no limbs, no call, no tadpoles
how are Caudata, Anura, and Caecilians related?
Anura and Caudata are more closely related to one another than to caecilians
what are the 4 major groups of reptiles?
- Squamata
- Rhynchocephalian
- Testudines
- Crocodilian
what type of animals are squamates?
lizards and snakes
lizards: ~7,300 species
snakes: ~4,000 species (limb-lost lizards)
what type of animals are Rhynchocephalians?
tuatara (1 species from New Zealand that is a close relative of squamata and they look like a lizard)
what type of animals are testudines?
turtles and tortoises
(~360 species, have a shell, turtle = aquatic mostly, tortoise = terrestrial)
what type of animals are crocodilians?
crocodiles and alligators
(~26 species, more closely related to birds, snout shape differs between croc and alligators)
what are amphisbaenians?
leg-less lizard group
what is a high SA:V ratio (smaller size) better for?
better for ectotherms
what is a low SA:V ratio (larger size) better for?
better from endotherms
what do snakes do to conserve their body heat?
snakes coil their body to reduce SA to conserve heat
what animals are vertebrates?
-fish: a paraphyletic group of aquatic vertebrates
-mammals
-amphibians
-reptiles
-birds
what are the important features of vertebrates?
-a skull with a large brain and paired sensory organs
-well developed circulatory system powered by a ventral heart
-internal organs suspended in large coelom (body cavity)
-vertebral column replaces notochord in adults, rigid skeleton for support
what are Osteichthyes and what are their synapomorphies?
“bony fishes”
-jaws lined by 3 tooth-bearing “dermal” bones
1) dentary (lower jaw)
2) premaxilla (upper jaw, front and middle)
3) maxilla (upper jaw, sides)
what are the 2 major groups of Osteichthyes?
- Actinopterygians
- Sarcopterygians
what are Actinopterygians?
ray finned fishes
~31,000 species
-most successful group of vertebrates
-includes most fish that we eat and keep in aquariums
what are Actinopterygians’ synapomorphies?
-single dorsal fin
-ray-fin (fins with no bony or muscular support)
what are Sarcopterygians and what do they encompass?
lobe-finned fishes
-includes tetrapods (reptiles, amphibians, birds, and mammals), lungfish and coelacanths
what are Sarcopterygians synapomorphies?
-enamel on teeth (hard white stuff that covers the bone of the tooth)
-development of bony supports for pectoral and pelvic fins
what are Actinistia?
coelacanths
-were a common and diverse group of fish common in the fossil record and were thought to be extinct until one species was re-discovered in 1938 off the coast of Africa. in 1997, a second species was discovered near the Indonesian Island of Sulawesi
what is the synapomorphy of Actinistia?
tri-lobed tail
what are Dipnoi?
lungfish
-were common in the fossil record but now reduced to one family, 3 genera, and 6 species.
-all live in freshwater
-have modified swim bladder that lets them breathe air
-no internal fertilization
-mostly carnivorous and feed on mollusks and crustaceans with hard shells
what are the synapomorphies of Dipnoi?
-skull highly modified for eating hard prey
-loss of regular teeth, but teeth on palate modified for crushing
what is the origin of tetrapods associated with? what are the synapomorphies?
the origin of tetrapods is associated with the shift from aquatic to terrestrial locomotion, using four limbs (pods).
-shoulder (pectoral) girdle separated from skull (= can move head)
-ankle and wrist joints
-stapes (important bone in auditory system)
what is Tiktaalik?
large shallow water fish that is supposedly the missing “intermediate taxa” between fishes and land creatures.
-shift from being aquatic to terrestrial was gradual
what 4 major changes are necessary for a fish to live on land?
- Movement: wrist-ankle joints allow weight to be placed on end of limb; joints at elbow-knee allow limb to bend; attach limb girdles to vertebral column, make vertebral column sturdier
- Respiration: many fish gulp air, but gills must be lost
- Feeding: separation of head and pectoral girdle creates neck and allows greater flexibility of head
- Sense organs: evolution of inner ear to detect sound, rather than lateral-line system to detect pressure changes in water
what are phylogenies?
they depict the evolutionary history of a group of organisms. they’re hypotheses that answer the question “what is it?” while also showing how different traits evolve.
-based on DNA sequence analysis and analysis of anatomical features
what are branches and nodes?
branches = species, lineage (some ancestral, some extant species)
node = two branches split
what are extant species? what are ancestral species?
extant = living species that we see today
ancestral = extinct species that we infer from phylogenies
what is a polytomy?
node where relationships are uncertain (>2 branches from one node)
-we use polytomies to show aspects of phylogeny that we are unsure about.
what is a resolution?
dichotomous tree (2 branches from one node) consistent with polytomy
what are terminal units and what can they be?
terminal units = tips of branches.
-terminal units can be species, individual organisms, populations, or groups of species (genera, phyla, or families)
what does monophyletic mean?
all species descended from a common ancestor
what does paraphyletic mean?
species in group share common ancestor, but some descendants of that ancestor are excluded
what does polyphyletic mean?
species in group that do not share a recent common ancestor (sometimes hard to distinguish from paraphyletic)
what is a character?
a feature of an organism that can be described, usually one that varies among species
(character = DNA sequence character)
what is a character state?
different forms of the variable feature
(states = A, G, C, T)
what are taxa (plural of taxon)? what are terminal taxon?
taxa = named groups (species, genus, etc…)
terminal taxon = basic unit of the analysis (individual, species, etc.)
what is an ingroup?
set of species we are interested in (individual, species, etc.)
what is an outgroup?
set of species outside the group of interest (but still closely related to them)
what is a data matrix?
set of characters for a set of taxa
what is the phylogenic method?
algorithm used to construct a tree; usually done on a computer
what is basic parsimony?
- group taxa based on shared, derived character states (synapomorphies)
- out of many possible trees, pick the one with the fewest changes (“steps”)
what are synapomorphies in amphibians and amniotes?
-many osteological synapomorphies in amphibians & amniotes involve loss of bones and making holes (foramina) in skull
-many may be associated with making skull lighter, more flexible, and allowing for more muscles
how did the diet evolve for vertebrates + tetrapods?
-carnivory is typical for most groups
-true herbivory (feeding on leaves, not just fruits and seeds) often requires many adaptations (ex: need bacteria in gut to break down plant cell walls)
how did reproduction evolve for tetrapods?
-direct development and internal fertilization are not ancestral in vertebrates, but they are common in many groups
-evolved many different times
-most groups lay eggs
-viviparity (live-bearing) has evolved many times in many groups
-many groups failed to evolve viviparity, despite being very old and/or diverse
why are osteological synapomorphies important?
they let us infer phylogeny of both living and fossil taxa
what is homoplasy?
when there has been evolutionary changes more than once
what is parallelism?
trait evolves twice in separate groups/species
(wings in birds and bats)
what is reversal?
derived state changes back to primitive condition (whales going back into water)
(loss of limbs in lizards)
many synapomorphies show lots of __________
homoplasy
describe the difference between the Temnospondyl and Lepospondyl
the Temnospondyl has many more structural pieces than Lepospondyl
what are 4 Lissamphibia synapomorphies?
(Lissamphibia = living amphibians)
- pedicellate teeth
- opercular apparatus (allows organisms to feel vibrations) (caecilians used to have an opercular apparatus and then lost it in extant species)
- two occipital condyles (connects skull and vertebral column)
- missing skull bones, large orbitals (holes)
what is paedomorphosis?
the retention of juvenile characters in adult stages
-gonads mature while having juvenile characters
ex: some adult salamanders retain gills
paedomorphosis is a type of _____________
heterochrony: change in timing of development
what is the evidence of paedomorphosis?
-missing skull bones that are last to form in ancestor
-large orbits (sensory organs develop early)
-bicuspid pedicellate teeth (juvenile char. in ancestor)
-small body size
how many families and species are in caecilians?
10 families
~215 species
do all caecilians look alike or is there variation among species?
they all look alike
all caecilians are _________, but some are also _________; most thought to eat ____________
burrowers
aquatic
earthworms
what type of areas do caecilians live in?
-wet tropical areas found all over the world (almost never invade temperate regions)
-many families occur on multiple continents
-phylogeny suggests that they have spread repeatedly across the world, but only in tropical areas
what are the synapomorphies of caecilians?
-no limbs
-elongate body
-eye is reduced, absent, or covered over by bone
-sensory tentacle between eye and nostril
-retroarticular process on lower jaw
describe caecilians’ sensory tentacles
-located between eye and nostril
-retractable
-thought to have originated from modified eye components
-still not clear how it works/how it is used
describe caecilian jaw closing mechanism
they have an enlarged interhyoideus muscle that uses retroarticular process as a lever and closes jaw
1. contract interhyoideus
2. pull down on retroarticular process
3. raises lower jaw; closes mouth
describe caecilian larvae
-caecilian metamorphosis is not very dramatic
-some larvae appear to be suction feeders
-life history is still fundamentally similar to frogs and salamanders
which caecilian family has:
-young that seem to feed off of secretions from their mother’s skin
-young that have specialized curved teeth for scraping and jaw muscles; mothers skin becomes wrinkled
Herpelidae
what caecilian family has:
-eggs have very little yolk, not enough to last through development so eggs “hatch” inside of the mother and young swim around in the oviduct
-hatchlings eat their mothers’ oviductal lining by scraping the lining with specialized “multicuspate” teeth which are shed and replaced soon after birth
-mother caecilians also secrete special cells from their oviductal lining to feed their young
Typhlonectidae
what are other cool facts about Typhlonectidae?
-largest lungless tetrapod
-unique among tetrapods in that the internal nares are sealed off (seemingly no air flow between nostrils and mouth)
-there is a giant, lungless typhlonectidae from South America that is up to nearly 1m long
what idea do caecilians demonstrate?
“niche conservatism” – specialization to one climatic regime limits dispersal and determines biogeographic patterns
-niche conservatism is a repeated theme in many different groups of organisms, but Caecilians are a good example because they are so old (~200 million years old)
how many families and species are in Caudata?
10 families
~767 species
do most caudatas look similar? if not, what is the exception?
most caudatas look alike, except for paedomorphic families that get huge (Cryptobranchidae, Proteidae) or huge and eel-like (Amphiumidae, Sirenidae)
where do Caudata live?
-found in temperate North America, Europe, and Asia but one species-rich group in New World tropics (lots of families in the US)
-mostly terrestrial, burrowing and aquatic (freshwater); some arboreal
describe the diet of salamanders
carnivorous, feed mostly on insects and other invertebrates
most species of salamanders are ___________, and most are _______-___________ ___________ ____________
plethodontids
direct-developing tropical species
what are the two main synapomorphies of salamanders?
- tuberculum interglenoideum (a process on the atlas that articulates with skull; the atlas is the vertebra that connects your head to your neck)
- anterior process of pterygoid bone “free” (not contacting other elements of the skull)
______ __________ is very important in salamanders
life history
what are the 3 important evolutionary life history traits of salamanders?
- most families of salamanders have typical amphibian life cycle (but only ~25% of species do)
(aquatic eggs -> aquatic larvae -> terrestrial adults) - direct development: many salamanders lack aquatic larval stage: terrestrial eggs –> terrestrial adults
- paedomorphosis: the terrestrial adult stage is lost, and the aquatic larval stage is not lost
what are characteristics of paedomorphic salamanders: both larvae and adults?
larvae + paedomorphs:
-aquatic, gills, no eyelids, feed by suction
adults:
-terrestrial, no gills, eyelids, feed using tongue
describe why paedomorphosis is a continuum and is not exactly “straight-forward” among salamanders
different paedomorphic salamander taxa show different proportions of larval vs. adult traits
-some are nearly identical to typical larvae (external gills, no eyelids); only “adult” trait is sexually mature gonads
-some are nearly identical to adults, and have very few larval traits
draw/describe salamander phylogeny (among families)
three most basal groups:
cryptobranchidae –> hynobiidae –> sirenidae
–> salamandroidea (“advanced salamanders” w/ 7 different families within)
(see google doc for answer)
how many genera and species are a part of the family Hynobiidae?
-9 genera, 86 species
describe the physical characteristics of the family Hynobiidae
-mostly small (100-200mm)
-terrestrial
describe the life history traits of the family Hynobiidae
-breed in water
-external fertilization
-generally have ancestral life cycle: terrestrial adults, aquatic eggs and aquatic larvae
where do Hynobiidae live?
-found mostly in northern Asia, including Japan, Korea, Russia, and northern China
-a few species in Himalayas, Iran and Afghanistan
-almost all temperate, not in tropics
how many genera and species are a part of the family Cryptobranchidae?
2 genera, 4 species
describe the physical characteristics of the family Cryptobranchidae
-largest salamanders in the world
-Cryptobranchus reaches 0.75m
-Andrias reaches 1m (total length)
describe the life history traits of the family Cryptobranchidae
-respiration through skin folds (reduced gills)
-external fertilization
-partially paedomorphic; but have many adult traits
where do Cryptobranchidae live?
-live in mountain streams
-one genus in eastern U.S. (the Hellbender: Cryptobranchus alleganiensis)
-one genus in Asia (Andrias) with one species in Japan, and at least two in China (more species in china are now extinct due to human consumption)
how many genera and species are a part of the family Sirenidae?
2 genera (Siren and Pseudobranchus), 5 species
describe the physical characteristics of the family Sirenidae
-eel-like body, no hindlimbs or pelvic girdle
-forelimbs well-developed
-Siren are large (up to ~1m)
-Pseudobranchus are small (100-200mm)
describe the life history traits of the family Sirenidae
-aquatic
-paedomorphic
-biology poorly known overall; some evidence suggesting parental care (females guard eggs)
where do Sirenidae live?
-live in swamps, ponds and ditches
-found in eastern U.S., mostly in the southeast
-some Sirens live in semi-arid areas and may “estivate” (burry) themselves in mud if water dried up; secretes substance that hardens into a cocoon around itself to prevent from desiccation
what is the 1 main synapomorphy of Salamandroidea (“advanced salamanders”)?
internal fertilization: male deposits “spermatophore” which female picks up with her vent (cloaca)
how many genera and species are a part of the family Proteidae?
-2 genera, 8 species
-1 genus in North America: Necturus (w/ 7 species) (mudpuppies and waterdogs)
-1 genus in Europe: Proteus (olm) (w/ 1 species)
describe the physical characteristics of the family Proteidae
Necturus: adults relatively large (100-500mm)
Proteus: more elongate body, reduced eyes, and reduced number of digits (3 fingers, 2 toes)
describe the life history traits of the family Proteidae
-paedomorphic: adult morphology looks very much like larvae of other salamander families
Proteus (olm): average adult life span is 68.5 years, and some may live for over a century
where do Proteidae (both Necturus and Proteus live?
-North America and Europe (temperate)
Necturus:
-1 species widespread in the east and 6 others found in the southeast U.S.
-fully aquatic, found in ponds, lakes and streams (down to 27m)
Proteus:
-live in caves
how many genera and species are a part of the family Salamandridae?
-21 genera, 128 species
describe the physical characteristics of the family Salamandridae
-small body size (up to 200mm)
describe the life history traits of the family Salamandridae
-generally transforming (not paedomorphic)
-a few species are terrestrial, some are aquatic for all or much of their lives (typically called newts)
-many species are variable in their habitat preferences over the course of their lives (terrestrial most of the year but aquatic in breeding season)
where do Salamandridae live?
-North America (only 2 genera), Europe, and Asia (highest diversity of genera/species)
-2 genera in North America: Taricha on West coast and Notophthalmus in the east
describe reproduction among Salamandridae
-generally have aquatic eggs and larvae, but a few genera have direct development
-depending on population females either: 1. lay eggs that hatch into aquatic larvae (may take up to 2 years to transform) or 2. are viviparous, give birth to fully metamorphosed young
describe the typical life cycle of the red-spotted newt (Notophthalmus viridescens)
aquatic egg -> aquatic larvae -> terrestrial eft stage -> aquatic adult
-different variations of adult morphology depending on the conditions (
why are some of the salamandrids so brightly colored?
both genera have highly toxic skin, associated with some interesting evolutionary biology including:
-aposematic
-mimicry
-co-evolution
___________: many animals have coloration that blends in with their background
cryptic
_________: some animals have coloration that has evolved to become more conspicuous against a given background
aposematic
aposematic is associated with what?
aposematic is associated with being venomous, toxic, or otherwise unpalatable
-predator learns to avoid aposematically colored prey
both Taricha and Notophthalmus have aposematic coloration, describe each
Notophthalmus is aposematic during its eft stage
Taricha has aposematic coloration on its belly
(both are very unusual among salamanders in that they are active during the daytime)
why might it be advantageous to be aposematically colored only on their ventral (belly) side (Taricha (and most other newts) for example)?
allows salamanders to blend in with their environment from above (be cryptic), but if they encounter predators, they can show their ventral side using their Unken Reflex and warn predators that they’re toxic and should be avoided to hopefully avoid predation
what is one consequence of “training” predators to avoid a color pattern?
it becomes advantageous for other species to adopt the same color pattern (mimicry)
what are the two types of mimicry?
- batesian mimicry: mimic is palatable, model is unpalatable
- mullerian mimicry: both mimic and model are unpalatable
around the San Francisco Bay area, Taricha granulosa (rough skinned newt) is the most toxic, what species closely mimics that species (esp. eye color)?
Ensatina eschscholtzii
what is co-evolution?
two species evolve in response to each other
what have newts co-evolved with?
garter snakes (Thamnophis sirtalis)
what basic idea does the co-evolution of newts and garter snakes demonstrate?
geographic mosaic theory of coevolution: strengths of co-evolution varies geographically, such that there are “hotspots” and “coldspots” in different places
what is a hotspot vs. coldspot?
hotspot: strong reciprocal selection between species
coldspot: weak reciprocal selection between species
describe the poison and strength of poison in rough-skinned news (Taricha granulosa)
-deadly poison called tetrodotoxin (TTX) in some populations that blocks the sodium channels in muscles
-one adult newt has enough poison to kill 25,000 white mice, strong enough to kill a person
-found from California to British Columbia
describe the interaction between garter snakes (Thamnophis sirtalis) and newts (Taricha granulosa)
-garter snake is the only predator that eats newt; found throughout most of the U.S.
-some populations in the same area as newts have a resistance to TTX
-snakes that eat newts cannot move for 30 minutes to 7 hours (have to “detox”)
the San Francisco garter snake is a very brightly colored subspecies of T. sirtalis with very limited geographic range, why are they so brightly colored?
because of their newt diet, they are able to sequester the TTX toxins in their own body and use the bright coloration to warn other predators to avoid eating them when they’re in their detox “stuck” phase
Red efts (in eastern NA) also have their own mimic, Pseudotriton, which has its own toxins. what type of mimicry does this species exhibit?
mullerian mimicry –> toxic species have the same coloration
many European newts engage in elaborate __________ ___________
courtship behavior –> males may have bright coloration and develop seasonal coloration and even crests; evolve through sexual selection
sexual selection favors what type of traits?
traits that increase reproductive success, but not necessarily survival; some traits may reduce survival
why are the crests of European newts very unusual for sexually selected traits?
they seem to grow and be resorbed after each season (ex of phenotypical plasticity: same genotype produces different phenotypes under different conditions)
how many species and genus are part of the family Dicamptodontidae?
-1 genus, 4 species (all in Pacific Northwest)
describe the physical characteristics of Dicamptodontidae
-large body size (up to 350mm
-largest terrestrial salamander in the world
describe the life history traits of the family Dicamptodontidae
-3 species transforming (aquatic larvae -> terrestrial adult)
-1 species paedomorphic
-can eat mice and other small vertebrates
how many species and genus are part of the family Ambystomatidae?
-1 genus, 32 species
where do Ambystomids live?
-15 species in the U.S.
-17 species in Mexico (Mexican species are all in montane (temperate) regions –> example of niche conservatism)
describe the physical characteristics of Ambystomatidae
-moderately large (130-350mm)
describe the life history traits of the family Ambystomatidae
-all species and most populations in U.S. have ancestral life cycle –> aquatic eggs, aquatic larvae, terrestrial adults
-many species in Mexico and some populations in U.S. are paedomorphic (no terrestrial stage, breed as larvae)
why are Ambystoma’s called “mole salamanders?”
they spend most of their lives underground and only emerge to breed (usually in ponds in early spring)
-many species are widespread and common, but rarely seen
which Mexican paedomorphic species is a very famous model system in many areas of biology and is a classic example of paedomorphosis?
Ambystoma mexicanum (axolotl)
what is “special” about the Ambystoma tigrinum complex?
-they show very interesting variability among and within populations
-occurs in many environments not inhabited by other salamanders, including southwestern desert (only salamander “species” in AZ)
-some populations and some individuals within populations are paedomorphic (breed as aquatic larvae)
-some have incredibly high growth rates (become sexually mature and 150mm in length in 1-2 months)
Ambystoma tigrinum complex also has a _________ _________ ________
killer cannibal morph
describe this killer cannibal morph and under what conditions they develop under
-morph has large size, broader head, and enlarged teeth
-cannibal morph develops when larvae are overcrowded, but details vary among populations
what is this killer cannibal morph an example of?
phenotypical plasticity (individuals with same genotype develop different phenotypes based on environmental cues)
paedomorphosis, accelerated development, and cannibal morph often occur in populations in the desert southwest, why do you think these strategies appear often in the desert species?
due to high variability among climatic/environmental conditions (drought, high density due to monsoon seasons)
in the northeastern U.S. what is special about Ambystomas?
all “species” are female –> individuals can be diploid, triploid, or tetraploid
-formed from hybridization of two or more diploid, bisexual species
-a single individual may combine genomes from 3 different diploid species
these species appear to be ______________
gynogenetic
what does it mean to be gynogenetic?
-unisexual female produces unreduced (2n) eggs
-eggs are unfertilized but need sperm to “activate” embryogenesis
-unisexual females mate with diploid males but sperm usually does not enter egg
-sperm is accidentally incorporated in some cases, leading to higher ploidy levels and unusual genome combinations
how many genera and species are in the family Rhyacotritonidae?
-1 genus, 4 species
describe the physical characteristics of Rhycotritonidae
-small body size (90-120mm)
describe the life history traits of Rhycotritonidae
-all transforming (aquatic larvae -> semi-aquatic adult, no gills)
where do Rhycotritonidae live?
-all found in the Pacific Northwest
-live in mountain streams
how many genera and species are in the family Amphiumidae?
-1 genus, 3 species
describe the physical characteristics of Amphiumidae
-the 3 species differ in body size and toe number (one species has 3 toes, one species has 2 toes, and another species has 1 toe)
-elongate, eel-like, with reduced limbs (possibly associated with burrowing)
describe the life history traits of Amphiumidae
-paedomorphic, but with mixture of some adult and some larval traits
-paedomorphic species generally considered to have many traits that are characteristic of juveniles of other species
-females guard eggs; eggs are on land
where do Amphiumidae live?
all species found in southeast U.S.
-aquatic, found in swamps, ponds and slow streams
many paedomorphic salamanders have the ___________ _______ _________
largest body sizes (non-juvenile trait)
how many genera and species are in the family Plethodontidae?
-28 genera, ~493 species (~2/3 of all salamanders)
where do Plethodontidae live?
-most genera and species in North America (~200) and Middle America (~250); but some also in Europe (2 genera, 8 species), Korea (1 genus, 1 species), South America (2 genera, ~30 species)
-only group of salamanders with many species in the tropics
-dominant group of salamanders in North America
-many are found in Appalachian streams and California woodlands
describe the life history traits of Plethodontidae
-most species have direct development; but also contains species that are biphasic (terrestrial adult, aquatic larvae) and a few that are paedomorphic
-some paedomorphic cave-dwelling species in eastern US
-species can be terrestrial, arboreal, semi-aquatic, and aquatic
what is the important synapomorphy of Plethodontidae?
absence of lungs: gas exchange occurs through the skin and throat
what are the “ancestral” requirements for projectile feeding in salamanders?
-large, moist, fleshy tongue
-head close to prey
-tongue with sticky trough
advanced tongue projection in some salamanders is linked to what?
-linked to respiratory mode: lungless
-hyobranchial apparatus can be modified
-at least 4 independent origins
where does the retractor muscle originate in advanced tongue projection?
originates on the pelvic bone
which main clades or groups of salamanders are monophyletic?
- Desmognathinae
- Bolitoglossini
(one common ancestor for the entire clade)
how many times did direct development evolve in the major groups of salamanders?
2 times
describe the relationship between body mass, metabolic rates and ectothermic/endothermic organisms
endotherms: a larger body mass = lower metabolic rate vs. a smaller body mass = much higher metabolic rate
ectotherms: a larger body mass = very low metabolic rate vs. a smaller body mass = a slightly higher metabolic rate
salamanders are a critical part of which ecosystem and why?
New Hampshire woods –> they are a critical base of the food web and feed a grand number of birds and other animals
how many families and species are a part of the order Anura?
54 families, ~7,450 species
most amphibians are __________, and most are __________________
anurans
neobatrachians (advanced frogs)
(96% of species belong to a clade called Neobatrachia)
the base of anura phylogeny has many ________ families with few species; most __________ are tropical or species-rich temperate + tropical clades (includes most species and families in U.S.)
temperate
neobatrachians
what do frogs show remarkable variation in?
life history:
-many have external fertilization with aquatic eggs and larvae, but there are also many derivations (direct development, plus putting eggs and larvae in strange places)
-a few are live bearing (viviparous) with internal fertilization
do most frogs look alike?
yes, most frogs look alike, however details of how they look depends on their microhabitat
what are the synapomorphies of anurans? (know at least 4)
- no tail (caudal vertebrae fused to form urostyle, which fits inside of pelvic girdle)
- ankles are fused and elongated
- jumping ability
- specialized larvae (tadpoles)
- reduced number of vertebrae (8-9)
- no teeth on lower jaw
- skull with large orbits (reduction in skull bones to make it lighter)
what are the 4 main ecomorphs of anurans?
- terrestrial
- burrowing
- arboreal
- aquatic (not marine)
(found almost worldwide, except Antarctic)
describe the Anuran diet
-carnivorous as adults (mostly invertebrates like insects)
-typically are not carnivorous as larvae (eat algae and detritus)
draw the general anuran phylogenic tree
see google doc
Basal clades of frogs are __________-______ relative to Neobatrachia
species-poor
what are the four basal clades of frogs?
- Leiopelmatoidea (5 species)
- Discoglossoidea (22 species)
- Pipoidea (42 species)
- Pelobatoidea (~300 species)
how many families, genera and species are a part of the clade Leiopelmatoidea? what are the families?
2 families, 2 genera, and 5 species
families = Ascaphidae (tailed frogs) and Leiopelmatidae
where might you find Ascaphidae? Leiopelmatidae?
Ascaphidae: Pacific Northwest, in mountain streams
Leiopelmatidae: New Zealand, in forests
what makes Leiopelmatoids unique among frogs?
- they have ribs (all other frogs lack ribs)
- 9 presacral vertebrae (presacral = before the pelvis); all other frogs have 8 or fewer
how many families, genera and species are a part of the clade Discoglossoidea? what are the families?
2 families, 5 genera, 22 species
1. Bombinatoridae (2 genera)
2. Alytidae (3 genera)
compare the two Bombinatoridae genera (Bombina and Barbourula)
Bombina: brightly colored bellies, small, aquatic egg-layers, skin secretions cause sneezing fits
Barbourula: very rare, large, aquatic, found in
mountain streams in the Philippines and Borneo (tropical), one species is lungless
what is unique about the genera Alytes (midwife toads, 6 species, a part of the family Alytidae)?
the males carry their eggs on their back, and they use burrows (terrestrial)
how many families, genera and species are a part of the clade Pipoidea? what are the families?
2 extant families, 5 genera, 42 species
1. Rhinophrynidae
2. Pipidae
adult pipids and rhinophrynids are very dissimilar, but tadpoles share many unusual features, such as what?
loss of usual tadpole mouthparts and presence of sensory tentacles near mouth
describe Rhinophrynidae
-1 genus, 1 species: Rhinophrynus dorsalis (but many extinct taxa)
-South Texas to Central America
-terrestrial, burrowing, ant specialists, have tadpoles
describe Pipidae
-4 genera, 41 species
-Africa and South America
-aquatic, most have tadpoles, but some have direct
development (only aquatic frogs with direct development)
what are the 7 bizarre features of Pipidae?
-flattened body, splayed limbs (shove food into mouth)
-no tongue
-claws on toes (like amniotes)
-lateral line system (like fish)
-non-pedicellate teeth
-can call and hear underwater
-bizarre skull
what species are widely used in biological and medical research?
Xenopus laevis
-is considered “the model frog” by many researchers, but pipids are probably the most unusual frogs in their
morphology, development, and behavior
-is also a polyploid
what species is the only (known) aquatic frog with direct development?
Pipa pipa
-eggs develop in females back and hatch as small froglets
how many families, genera and species are a part of the clade Pelobatoidae? what are the families?
4 families, ~300 species
1. Scaphiopodidae
2. Pelobatidae
3. Pelodytidae
4. Megophryidae
describe Scaphiopodidae (American spadefoot (toads))
-2 genera: Spea and Scaphiopus, 7 species (all in North America)
-burrowing, terrestrial, and have tadpoles
-some species that live in extreme desert conditions may stay buried for years (Scaphiopus couchii)
what do some desert species of Spea have?
a killer cannibal morph in tadpoles (phenotypically plastic example)
describe Pelobatidae (European spadefoots)
-1 genus (Pelobates); 6 species all in Europe, North Africa, and Central Asia
-burrowing, terrestrial, and have tadpoles
describe Pelodytidae (Parsley frog)
-1 genus (Pelodytes), 4 species,
-Europe and southwest Asia
-terrestrial and have tadpoles
describe Megophryidae
-13 genera, 287 species
-all in tropical or subtropical Asia
-terrestrial, and have tadpoles
-some have large “horns” and other interesting morphological features
what are the different synapomorphies of Neobatrachians from other (primitive) frogs?
-have “neopalatine” bone in skull (braces the
upper jaw against the skull)
-one wrist bone (third distal carpal) fused to other
wrist bones
-two obscure muscle characters
what is the difference between inguinal amplexus and axillary amplexus?
inguinal amplexus: male grabs female around the waist when mating (basal frogs)
axillary amplexus: male grabs female behind forelimb when mating (advanced frogs)
basal/primitive frogs have _________ pupils and advanced frogs have ___________ pupils
vertical
round or elliptical
what are the 6 families that a part of the Neobatrachian phylogeny?
- Heleophrynidae (6 species)
- Myobatrachidae (135 species)
- Hyloidea (>4100 sp.)
- Nasikabatrachidae (2 species)
- Sooglossidae (4 species)
- Ranoidea (>3000 sp.)
describe Heleophrynidae
-2 genera, 6 species (Hadromophryne, Heleophryne)
-live in mountain streams in South Africa
-aquatic tadpoles
describe Myobatrachidae
-Australia and New Guinea
-along with hylids (treefrogs) major radiation of frogs in Australia
-mostly terrestrial or burrowing, a few aquatic
-reproductive modes depend on subfamily
describe the different types of reproductive modes of Myobatrachidae (dependent of the subfamily)
-many species make a “foam nest” where eggs are deposited
-many species have direct development
-males have “hip pockets” for tadpoles (Australian pouched frog (Assa)
-one recently extinct genus would brood eggs and tadpoles inside of their stomach (in females) and would come out of mouth
describe Sooglossidae
-2 genera, 4 species
-found only on Seychelles Islands (off the coast of Madagascar off the coast of Africa)
-terrestrial (forest floor)
-some species are tiny (9-18mm)
-some species have direct development and parental care
-one species has non-feeding tadpoles that travel on males back
describe Nasikabatrachidae
-new family of frogs first reported in 2003
-2 species, 1 genus from southern India
-burrower that breeds in streams
how many families are part of Hyloidea?
7 families (Hylidae, Bufonidae, and Dendrobatidae are 3 of them)
what are the synapomorphies of Hyloidea?
-lacks any morphological synapomorphies, supporting
evidence is all molecular
-most families and species found in New World, but two families have some species in Old World (Bufonidae, Hylidae)
-phylogeny of families is very uncertain
-until recently, the largest family (Leptodactylidae) was not monophyletic
describe Rhinodermatidae
-1 genus, 3 species (Rhinoderma); one species probably extinct
-found along streams in temperate South America
-eggs laid on land, guarded by male
-in one species male carries tadpoles to water, in other species male carries tadpoles in throat patch throughout development
describe Leptodactylidae
-previously the largest family of amphibians (>1,200 species), but it was an illusion; many leptodactylids were not closely related to each other
-now recognized as several different families, but taxonomy of families is still somewhat chaotic
describe Ceratophryidae (formerly apart of Leptodactylidae)
-3 genera, ~12 species
-found in tropical South America
-frog-eating carnivores with massive heads and fang-like teeth
-ceratophrys = terrestrial, Lepidobatrachus = aquatic
-have big carnivorous tadpoles
describe Telmatobiidae
-1 genus, ~63 species
-exclusively in South America at high elevations in the Andes
-many species are aquatic; have tadpoles
describe Terrarana
-clade of 5 families with >1,200 species
-very diverse in South America and Middle America, but also a few species in southern U.S. (several in Texas, one in AZ); as many as 25 species in sympatry in the Andes
-most terrestrial or arboreal (and brown)
-all have direct development
describe Leptodactylidae
-13 genera, ~227 species
-most are terrestrial
-all lay eggs in foam nests, some have direct development
-most diverse in South America, one species extends into south Texas
describe Hylidae (treefrogs)
-53 genera, 1040 species
-most arboreal, a few aquatic and some are terrestrial
-most species and genera in South American and Middle America, small radiation (~210 species) in Australia and New Guinea; some species in Europe, Asia, and North America
-all produce tadpoles, many lay eggs on plants over water
-some lay eggs in bromeliad axils or other environments with little food, mother lays unfertilized eggs to feed tadpoles (oophagous tadpoles)
describe how red-eyed treefrogs demonstrate adaptive phenotypic plasticity
-Phyllomedusines lay eggs on leaves over water
-tadpoles fall into water when they hatch out of egg
-snakes eat eggs; tadpoles in egg can detect vibration and hatch when snakes attack
-tadpoles that hatch too early are eaten by fish
-phenotypic plasticity in hatching time; tadpoles stay in egg as long as possible unless snake attacks
what are the 3 species of treefrogs in southeastern Arizona?
- Hyla arenicolor
- Hyla wrightorum
- Smilisca fodiens
describe Centrolenidae (glass frogs)
-12 genera, ~160 species
-most are small, found on leaves and branches over streams
-most found on slopes of Andes in South America, but some range into Central America
-eggs are laid on leaves over water, males guard eggs
-tadpoles hatch and fall into stream, burrow into mud or gravel at bottom of stream
-male glass frogs are territorial and fight for calling sites on leaves near streams
describe Bufonidae (toads)
~52 genera, ~630 species
-found all over the world except Australia
-most genera found in South America; evolved in South America and spread elsewhere
-toads lack teeth, many have parotoid glands that contain toxins
-most are terrestrial; many occur in dry areas
-a few are semi-arboreal or semi-aquatic
-most have tadpoles, but a few have direct development; one African genus is viviparous
-Eggs, tadpoles, and metamorphs often very small (and black)
describe Dendrobatidae (poison-arrow frogs)
-20 genera, ~340 species
-terrestrial or semi-arboreal
-almost all found in tropical South America; a few in Central America
-typically lay eggs on land
-tadpoles carried to water on back of adult; develop in water
-many species have bright aposematic coloration; other species do not (traditionally in genus Colostethus)
-aposematic coloration has evolved multiple times (old
Colostethus is paraphyletic); appears to be associated with toxicity
where do Dendrobatids get their toxicity?
-toxicity appears to be associated with specializing on feeding on ants (non-toxic species eat few ants)
-alkaloids in skin derived from ants and “sequestered” by frogs
-frogs born in captivity are not toxic
what genus of Dendrobatids is very toxic?
-Phyllobates
-one individual of Phyllobates terribilis has enough toxin to kill 10–12 people
-traditionally used by indigenous people in western Colombia to tip arrows (but this is the only place where this is done and Phyllobates is the only
dendrobatid used)
why might the color patterns in poison arrow frogs be so variable?
-their color pattern variation makes it more challenging for other species to mimic
-may be a disadvantage to be many different colors because predators have to learn to avoid so many different coloration patterns
what are native species?
all organisms that have occurred, now occur, or may occur as a result of natural processes
what are non-native species?
organisms living in areas where they don’t naturally exist
ex: wildflowers and vegetables
what are invasive species?
species that cause harm to the environment, economy, or human, animal and plant health typically non-native
ex: wild pigs, American bullfrogs (Rana catesbeiana)
what characteristics make a good invader?
-be mobile
-have no natural predators
-be a generalist (eat the native species is a bonus)
what are the impacts of American bullfrogs?
-disease spread
-voracious predators (can eat whatever can fit into their mouth including birds, snakes, small mammals, fish, each other, and other amphibians)
-eggs and tadpoles unpalatable to most predators
-high dispersal potential (have been known to move up to 10.2km (6.34 miles) in one year)
-high reproductive potential (females can lay around 40,000 eggs per clutch, and up to 2 clutches a year)
what is one of the leading causes of amphibian decline?
-chytridiomycosis (chytrid fungus)
-spread through skin touching and in bodies of water
-currently no cure
what are the eradication steps for invasive species?
- learn about their ecology (how far can they disperse, when/where do they reproduce, what’s the smallest size that they can reproduce)
- eradication efforts (what areas are of highest concern, when to target tadpoles and juveniles)
- monitoring (create a buffer zone = a collar of land around a previously eradicated area monitored to keep out invasions from outside sources)
- reintroduction of native species
- more monitoring
what are 3 takeaways from Emma’s invasive species lecture?
- partnerships, timing, getting funding, and coordination is super important
- there is still hope! there are a lot of entire jobs in invasive species (both plants and animals)
- not all non-native species are invasive species
describe Hemiphractidae (marsupial treefrogs)
-mostly arboreal
-almost all found in tropical South America, a few in Central America
-6 genera, ~120 species
-most have direct development, a few species in 2 genera have tadpoles, in all species, eggs are placed on females back
why are Hemiphractidae called marsupial treefrogs?
in 2 genera (Gastrotheca, Flectonotus), a “pouch” develops to enclose their eggs
what families encompass the Ranoidea?
Ranidae (true frogs), Rhacophoridae, Mantellidae, Hyperoliidae, Hemisotidae, Microhylidae
what are some synapomorphies of Ranoidea?
-highly modified pectoral girdle (Firmisternal “firmer” pectoral girdle for jumping)
-most families and species found in the Old World (Eastern Hemisphere), but two families have some species in the New World (Microhylidae, Ranidae)
describe Ranidae
-includes all ranoids in Europe and in the New World; all New World ranids belong to genus Rana (sometimes called Lithobates)
-New World Rana mostly aquatic, semi-aquatic or terrestrial
-all have tadpoles
~26 genera, ~410 species
describe Rhacophoridae
~21 genera, ~444 species
-tropical treefrogs of Asia; one genus (Chiromantis) extends into Africa
-many species build foam nests in trees over water; tadpoles drop into water; other species lack foam nests; some have direct development
what is a unique feature associated with Rhacophoridae?
-some species in Asia have webbed feet and can glide from tree to tree (sometimes called flying frogs)
describe Mantellidae
-endemic radiation of ranoids in Madagascar
-includes terrestrial, aquatic, arboreal (Boophis), fossorial (Laliostoma) species
-includes species with tadpoles and direct developers
-one genus (Mantella) has evolved skin toxins and aposematic coloration like dendrobatids
~12 genera, ~234 species (dozens more undescribed)
describe Hyperoliidae
-tropical treefrogs of Africa; one genus is terrestrial
(Kassina)
-most lay eggs in water
-one genus (Tachynemis) lays eggs on ground near water, tadpoles crawl on ground into water
-one genus (Afrixalus) glues leaves around eggs; eats eggs of other frogs
-18 genera, ~230 species
describe Hemisotidae
-burrowing frogs of tropical African savannas
-burrow headfirst (unlike most other burrowing frogs), which dig themselves in feet first
-have tadpoles and parental care
-dig nest chamber near pond for eggs; chamber may flood, or female may carry tadpoles to pond
-1 genus (Hemisus), 9 species
describe Microhylidae
-found nearly worldwide
-very diverse on Madagascar and New Guinea
-58 genera, ~720 species; 11 subfamilies
-terrestrial, arboreal, or fossorial
-tadpoles or direct development
-tadpoles in most species lack cornified denticles in mouth
what are some of the reproductive strategies that have evolved in frogs?
Carry on back
Carry in pouch
Bury inside back
Place in hip pocket
Place in stomach
Place in throat pouch
Place in foam nests
Place on leaves over water, fold leaves over eggs
Place in bromeliads and treeholes, feed infertile eggs
Place eggs on land/leaf and guard
Place eggs on ground near water
Place eggs in nest chamber near pond
Place eggs on ground, carry tadpoles to water
Place eggs in temporary ponds
what drives these mechanisms?
predation pressures (especially from aquatic fish and other predators)
what is adaptive radiation?
the rapid evolution of many different ecomorphs and species
-often occurs on islands with few other species to fill up the niches
-possible anuran examples: mantellids in Madagascar, hylids in Australia
what is an ecomorph?
phenotype associated with utilizing particular ecological niche, such as different microhabitats
what are characteristics of treefrog (arboreal) ecomorph?
-expanded toe pads
-high climbing ability
what are characteristics of aquatic ecomorph?
-webbed feet
-large leg muscles
-high velocity, acceleration and power during swimming
what are characteristics of burrowing ecomorph?
-large metatarsal tubercle (allows them to dig)
-short legs (more power for digging)
-better burrowing ability
what are characteristics of terrestrial ecomorph?
-has intermediate morphology and
performance
-phylogeny shows that most ecomorphs usually evolve
from terrestrial ecomorph ancestor
this concept of ecomorphs demonstrates what concept?
parallel evolution, meaning that these ecomorphs have evolved many different times depending on different ecological niches and different evolutionary pressures
In the New World, most niches are filled by _________
In the Old World, most niches are filled by __________
hyloids
ranoids
(there is some dispersal of both hyloids and ranoids
between continents, especially in northern temperate zones)
within a given continent or region, a given niche for a given ecomorph may be filled by which two processes?
- evolution of the ecomorph there (in-situ evolution)
- by dispersal of an ecomorph that evolved elsewhere into the region
the overall process by which a given location acquires its ecomorphs is called ____________ ____________
community assembly
where is the origin of the treefrog (hylids) ecomorph?
South America (New World)
where is the origin of the aquatic (ranids) ecomorph?
Africa (Old World)
where do Hyloids dominate? where do Ranoids dominate?
-Hyloids dominate New World tropics and Australia
-Ranoids dominate tropical Asia and Africa
-temperate North America, Europe, and Asia are mixed
there are 4 main frog families in Tucson area, what are they and what ecomorphs do they represent?
- Hylidae (arboreal from South America)
- Bufonidae (terrestrial from South America)
- Ranidae (aquatic from Asia)
- Scaphiopodidae (burrowing from Eurasia)
