BIOL 228 Exam Questions and Answers Already Passed Latest Update 2025-2026
Order Caudata (Urodela) - Answers • (Latin, Caudatis, having a tail)
• Salamanders, newts and allies
• Approx. 350 species
Found in almost all northern temperate
regions
• Also tropical Americas
• Typically small (15 cm)
• Although not all
• Megalobatrachus
• Japanese giant salamander
over 1.5 m
Order Caudata - Answers Body with head, trunk and tail
• No scales
• Limbs usually set at right angles to the
body
• Fore and hind limbs equal size
• Limbs may be rudimentary in aquatic or
burrowing species
• Carnivorous
• Most eat only things that are moving
• Prey on worms, small arthropods and
molluscs
Caudata breeding behaviour - Answers • Most salamanders are metamorphic
• Aquatic larvae, terrestrial adults
,• Internal fertilization
• Male produces sperm in a spermatophore,
placed on a leaf or stick
• Female recovers sperm in her vent
• Aquatic species lay eggs in water, often in
clusters
• Eggs hatch to produce aquatic larvae with
external gills and finlike tail
• Terrestrial species deposit eggs in small
clusters under logs or soil, or in tree holes
• May guard eggs - parental care
• Direct development - young hatch as
miniature adults - "pond" is in the egg!
Paedomorphosis - Answers • A persistent trend in salamander
evolution is the retention into adulthood
of features only present in ancestral
juveniles
• Some adult features are consequentially
eliminated
• 'Neoteny' is a more general term used
Perennibranch Caudata - Answers (permanently gilled, never metamorphose)
• Become sexually mature while retaining
gills, aquatic habit and other larval
characters
• Fully aquatic; with limbs weak or absent
, • Necturus (mud-puppy)
• Siren (siren)
Caducibranch Caudata - Answers • Latin caducus, falling
have capacity to metamorphose- but won't necessarily
• Typically with gills lost in late larvae
• Often terrestrial
• Some with gill clefts retained, others
with them completely lost
• Examples: axolotl, Amphiuma,
Salamandra, Triturus
Axolotl
Ambystoma mexicanum - Answers • Reaches sexual maturity with larval morphology
• 3 pairs of gills, prominent dorsal and caudal fins,
slender, fully developed limbs
• May metamorphose to a terrestrial form when
ponds dry up (or under iodine treatment)
Caducibranch
Caudata
• Amphiuma (congo eel) - Answers • Completely aquatic
• Eel-like body, extremely small limbs each with
only 3 digits; 1 pair of gill clefts retained
throughout life
• Loose gills before maturity, breath with lungs
• Periodically point nostrils out of water to get air
Caducibranch Caudata
Order Caudata (Urodela) - Answers • (Latin, Caudatis, having a tail)
• Salamanders, newts and allies
• Approx. 350 species
Found in almost all northern temperate
regions
• Also tropical Americas
• Typically small (15 cm)
• Although not all
• Megalobatrachus
• Japanese giant salamander
over 1.5 m
Order Caudata - Answers Body with head, trunk and tail
• No scales
• Limbs usually set at right angles to the
body
• Fore and hind limbs equal size
• Limbs may be rudimentary in aquatic or
burrowing species
• Carnivorous
• Most eat only things that are moving
• Prey on worms, small arthropods and
molluscs
Caudata breeding behaviour - Answers • Most salamanders are metamorphic
• Aquatic larvae, terrestrial adults
,• Internal fertilization
• Male produces sperm in a spermatophore,
placed on a leaf or stick
• Female recovers sperm in her vent
• Aquatic species lay eggs in water, often in
clusters
• Eggs hatch to produce aquatic larvae with
external gills and finlike tail
• Terrestrial species deposit eggs in small
clusters under logs or soil, or in tree holes
• May guard eggs - parental care
• Direct development - young hatch as
miniature adults - "pond" is in the egg!
Paedomorphosis - Answers • A persistent trend in salamander
evolution is the retention into adulthood
of features only present in ancestral
juveniles
• Some adult features are consequentially
eliminated
• 'Neoteny' is a more general term used
Perennibranch Caudata - Answers (permanently gilled, never metamorphose)
• Become sexually mature while retaining
gills, aquatic habit and other larval
characters
• Fully aquatic; with limbs weak or absent
, • Necturus (mud-puppy)
• Siren (siren)
Caducibranch Caudata - Answers • Latin caducus, falling
have capacity to metamorphose- but won't necessarily
• Typically with gills lost in late larvae
• Often terrestrial
• Some with gill clefts retained, others
with them completely lost
• Examples: axolotl, Amphiuma,
Salamandra, Triturus
Axolotl
Ambystoma mexicanum - Answers • Reaches sexual maturity with larval morphology
• 3 pairs of gills, prominent dorsal and caudal fins,
slender, fully developed limbs
• May metamorphose to a terrestrial form when
ponds dry up (or under iodine treatment)
Caducibranch
Caudata
• Amphiuma (congo eel) - Answers • Completely aquatic
• Eel-like body, extremely small limbs each with
only 3 digits; 1 pair of gill clefts retained
throughout life
• Loose gills before maturity, breath with lungs
• Periodically point nostrils out of water to get air
Caducibranch Caudata
