Turtles

Question 1

What are the 2 lineages of turtles?

Answer 1

Cryptodires and pleurodires

Question 2

What defines a cryptodire?

Answer 2

They retract the head into the shell by bending the neck in a vertical S shape. Largest group (include aquatic and terrestrial)

Question 3

What defines a pleurodire?

Answer 3

They retract the head by bending the neck horizontally. Only found in southern hemisphere. All species at least partially aquatic.

Question 4

What is the birth type and parent care of turtles?

Answer 4

All lay eggs and none exhibit parental care after hatching

Question 5

Can turtles have rapid population growth?

Answer 5

Not usually, they are long-lived

Question 6

Why are turtles a conservation concern?

Answer 6

• sex is determined by temperature of the embryos

- they have a poor capacity for rapid population growth

Question 7

What kind of bodies do terrestrial turtles have?

Answer 7

High domed shells, elephant-like feet (or spade-like for burrowing)

Question 8

What kind bodies do box turtles have?

Answer 8

Flexible regions of plastron (lower shell), which allow front and rear lobes to be pulled upward to close the openings of the shell

Question 9

What body type does the African pancake tortoise have?

Answer 9

Flat, flexible shell with reduced ossification. It wedges itself into rock crevices to avoid predation

Question 10

What kind of bodies do aquatic turtles have?

Answer 10

Low carapaces (upper shells) that offer little resistance when moving through water

Question 11

What type of shell do snapping turtles and mud/musk turtles (all cryptodires) have? Why?

Answer 11

They are less streamlined because they prowl bottoms of ponds and slow rivers. They also have reduced plastrons (makes them more agile)

Question 12

What do snapping and musk turtles use for protection?

Answer 12

Strong jaws

Question 13

Cryptodires are apparently soft-shelled turtles. Why do they have reduced ossification?

Answer 13

They want a lighter shell to be a fast swimmer (feet are large and webbed as well)

Question 14

What type of predators are most cryptodires?

Answer 14

Ambush predators (long neck allows them to reach out to seize prey)- stay partly buried in debris in ponds to wait

Question 15

Snake-necked turtle (pleurodire) have what kind of adaptation for feeding?

Answer 15

Long slender necks to catch fish with a sudden dart of the head

Question 16

What are the adaptations of the matamata of South America?

Answer 16

Highly camoflauged- flaps of skin on head are highly sensitive to vibrations of fish prey. They abruptly open mouth and expand throat to suck in prey.

Question 17

Which of the 2 groups of turtles are marine turtles?

Answer 17

Cryptodires

Question 18

What is the largest marine turtle and some facts about it?

Answer 18

The leatherback (2m long). Has a larger distribution than any other ectothermal amniote. Dives more than 1000m. Feeds on jelly fish.

Question 19

What are the 3 hypotheses for turtles’ phylogenic position?

Answer 19

1. origin among parareptiles, sister group of reptiles
2. sister group of lepidosaurs
3. sister group of archosaurs

Question 20

What is the basic structure of a turtle?

Answer 20

Shell is dermal bone (59 plates). Ribs are fused to shell and are external to girdles. Limbs are inside ribs and they have horny beaks instead of teeth

Question 21

How do turtles breathe?

Answer 21

Lungs are attached to the carapace dorsally and laterally. The weight of the viscera keeps the diaphragmatic sheet stretched downward. Turtles produce pressure changes in lungs by contracting muscles- inhalation and exhalation require this

Question 22

What type of respiration does the Australian Fitzroy River turtle use?

Answer 22

Cloacal respiration:

• orifice is 30mm in diamter. Turtle holds cloaca open, large sacs open from the wall of the cloaca and have many villi.
• Turtle pumps water into and out of the sacs 15 times per minute. rarely needs to surface to breathe

Question 23

How long do small species vs large species live?

Answer 23

Small turtles live 7-14 years. Large tortoises and sea turtles live at least as long as humans

Question 24

Are turtles endo- or ecto- thermic?

Answer 24

mainly ectothermic

Question 25

How do turtles regulate temperature?

Answer 25

Emerge from water to bask and heat up (to speed digestion, growth, egg production)- also increases calcium deposition in bones and shell

Question 26

The bulk of large species of turtles provides thermal inertia. Give an example of turtle behaviour because of this?

Answer 26

Large tortoises require large object for shade so they don’t overheat. Largest individuals fight for most shade.

Question 27

What are some behaviours and adaptations occur for courtship?

Answer 27

Colour markings to ID species and sex. Vocalizations during mating. Pheromone glands.

Question 28

How do turtles fight?

Answer 28

Biting, ramming, hooking to flip opponent. These all decide social heirarchy

Question 29

How do tortoises mark their territory?

Answer 29

Fecal pellets (olfactory sense)

Question 30

Are turtles oviparous or viviparous?

Answer 30

Oviparous- eggs with soft, flexible shells

Question 31

How long does embryonic development take?

Answer 31

40-60 days

Question 32

How do females deposit their egg clutch?

Answer 32

Use hindlimbs to excavate a nest in sand or soil and deposit clutch of 4-100 eggs

Question 33

When would eggs need to go through diapause?

Answer 33

When eggs get laid in fall and wait through the winter- then hatch in spring

Question 34

How are moist nest conditions different than dry?

Answer 34

Moist nest conditions give rise to larger, faster hatchlings (bc water is needed for metabolism of yolk). Hatchlings in dry nests emerge earlier, smaller, and have unmetabolized yolk in gut

Question 35

What are the 3 types of temp dependent sex determination in turtles?

Answer 35

1. males at high temps
2. females at high temps
3. females at low and high, males at intermediate

Question 36

How is there synchronous hatching date of turtles who have had temp differences in eggs?

Answer 36

Slow embryos have a catch-up period right before hatching that results in this

Question 37

How is emergence continued in egg hatching?

Answer 37

Vibrations produced by first embryos stimulate other embryos to initiate emergence. Positive feedback cycle

Question 38

What is the benefit of synchronized egg hatching?

Answer 38

May saturate predators and increase chances of some nestlings surviving

Question 39

What do hatchlings do right after coming out of the egg?

Answer 39

Dig themselves out of the hole and wait for cool night temperatures to fully emerge

Question 40

What animals might be predators between hatching and the water?

Answer 40

Crabs, foxes, racoons

Question 41

Why do most baby turtles spend most of their juvenile life in concealment?

Answer 41

They are “bite sized” with soft shells. They float in the current and hide in drift lines

Question 42

How many nesting sites does the “green turtle” have?

Answer 42

4 in the Caribbean and South Atlantic- congregate at these during nesting season. These breeding grounds don’t have enough food so they can only be there during breeding

Question 43

How do adults navigate?

Answer 43

Chemosensory cues (ex. plume of island scent). They also use magnetic orientation at distances of “10 s of km” from destination (idk)

Question 44

What do juveniles use to navigate?

Answer 44

Light, wave direction, and magnetism