marine reptiles

Question 1

what species are classed as marine reptiles

Answer 1

turtles
snakes
iguana
crocodiles

Question 2

what are some characteristics of marine reptiles

Answer 2

approx 80 species
- air breathing
- ectothermic
- body covered with scales
- oviparous= lay eggs on land

Question 3

outline the geological history of sea turtles

Answer 3

• tortoises are one of the oldest reptile group
• found in the fossil record 200 million years ago
• common in cretaceous 130 mya

Question 4

outline turtle anatomy

Answer 4

one of the most derived vertebrates
encased in bone, limbs inside the ribs and horny bones instead of teeth

Question 5

what is used to identify turtle species ID

Answer 5

Scutes + shape of shell and head = species ID

Question 6

compare turtles to tortoises/terrapin morphology

Answer 6

Turtle= flat shell, 4 flippers, cant retract head or flippers

Tortoise= shape varied, 4 limbs, can retract head and flippers

Question 7

how many species of sea turtle are there

Answer 7

7 all with a specialist diet of sponges, crabs, molluscs and other inverterbrates
- green turtle- herbivore
- leather back - obligate planktivore

Question 8

outline the general structure of turtle shells

Answer 8

• apart of the skeleton and does not match up
  1) dorsal carapace = dermal bone
  2) ventral plastron = dermal ossifications
  3) carapace bone covered

Question 9

outline the general shell structure of soft shelled families

Answer 9

no peripheral ossifications and epidermal scutes
distal ends of ribs in flexible connective tissues
carapace and plastron covered in skin

Question 10

outline the shell structure of leatherback turtles

Answer 10

carapace of soft cartilage
plastral bones reduced to a thin rim around plastron edges
oestoderm overlays thick blubber layer overlapping ribs etc

Question 11

outline endothermy in leatherback turtles

Answer 11

maintain a body temp at 25 degrees even in subpolar waters
thick insulating layer of adipose tissues
counter current heat exchangers maintain the heat generated by swimming muscles inside the limbs preventing hyperthermia

Question 12

define gignathermy

Answer 12

large, bulky ectothermic animals are more easily able to maintain a constant, relatively high body temperature than smaller animals

Question 13

what are the 7 species of sea turtle

Answer 13

1) leatherback
2) Australian flat back
3) green turtle
4) hawksbill
5) kemps ridley
6) olive ridley

Question 14

outline the characteristics of sea turtles

Answer 14

all have same basic morphology
all breathe air
all lay eggs in spring/summer
none exhibit parental care
ecotherms

Question 15

outline the life history patterns of sea turtles as described by Bolten 2003

Answer 15

1) complete development in the neritic zone = flat back
2) development in oceanic and neritic zone = logger head, green, hawksbill and kemps ridley
3) complete development in oceanic zone = olive ridley and leatherback

Question 16

how are sea turtles distributed in the ocean

Answer 16

leatherbacks can tolerate cool waters and hard shelled species prefer warmer

Question 17

what are some selection pressures on both K and r traits

Answer 17

r selective = egg laying, high clutch frequency with extended nesting season

k selective = long distance migration

Question 18

outline the anatomy of sea snakes

Answer 18

eye with fixed lens
thin forked tongue
distinct scales with ventral scutes extended across body
males have longer tails than females

Question 19

what are some adaptations of sea snakes

Answer 19

• fully marine execpt the laticauda
• laterally flattened body with paddle like tail
• wide range of habitats
• indo-pacidic
• all omnivorous
• carnivorous

Question 20

outline some population traits in sea snakes

Answer 20

• all but one have k selected traits
• pop is highly clustered as dispersal is limited
• cutaneous respiration
• bites can be fatal to humans

Question 21

outline some characteristics of the saltwater croc

Answer 21

red list = least concern
australia, indian ocean and some western pacific islands
-highly predatory
can grow over 7m

Question 22

outline some characteristics of the american croc

Answer 22

vulnerable
tolerates sea water and can be found in lagoons and other costal regions
males larger than 6,
feed mostly on fish

Question 23

outline some characteristics of the marine iguana

Answer 23

vulnerable
12 yr life span
one species specific to the Galapagos
most time in water
females forage in intertidal region and males in subtidal

Question 24

what are some adaptations to marine iguanas

Answer 24

lots of time basking to warm up from dives
low food availability so respond by shrinking
cartilage and connective tissues forms 10% of length so they reabsorb bone matter
females shrink more than males