Marine Reptiles - Turtle Biology and Ecology

A complete set of vocabulary-style flashcards derived from lecture notes on Marine Reptile biology, encompassing iguanas, snakes, crocodiles, and specifically the diversity, anatomy, and ecology of sea turtles.

Prof Alex Ford

Professor at the UNIVERSITY OF PORTSMOUTH who delivered the lecture on Marine Reptiles.

Ectothermic

One of the four main characteristics of Marine Reptiles; also known as Poikilotherms.

Poikilotherms

A synonym for ectothermic organisms, listed as a primary trait of marine reptiles.

Air breathing

A characteristic of marine reptiles involving the use of lungs.

Salt glands

Organs used by marine reptiles for osmoregulation; known to be highly efficient in these animals.

Marine Iguanas

Scientifically known as Amblyrhynchus cristatus; a marine lizard endemic to the Galapagos Islands.

Amblyrhynchus cristatus

The scientific name for the Marine Iguana.

Galapagos Islands

The specific location just off the Equator where Marine Iguanas are endemic.

Herbivorous

The dietary classification of Marine Iguanas, which primarily eat seaweed and algae.

Seaweed

The primary food source for herbivorous Marine Iguanas.

Nose

The anatomical location of the salt-glands in Marine Iguanas used for osmoregulation.

Intertidally

The area where recent research suggests much feeding takes place for female and juvenile Marine Iguanas.

10-12m

The maximum depth large male Marine Iguanas can dive for feeding.

1 hour

The maximum duration large male Marine Iguanas can stay underwater during a dive.

8000ind/km

The population density of Marine Iguanas along some areas of the coast.

Cold water upwelling

Oceanic process that nourishes the algae across over $16$ islands where Marine Iguanas are located.

Fernandina/Isabela (Male weight)

Male Marine Iguanas in these islands can reach over $10+\,kg$ in weight.

Fernandina/Isabela (Female weight)

Female Marine Iguanas in these islands weigh less than $3+\,kg$.

Genovesa (Male weight)

Male Marine Iguanas on this island weigh approximately $1\,kg$.

Genovesa (Female weight)

Female Marine Iguanas on this island weigh less than $1\,kg$.

30g algae/day

The amount of food required to sustain a $1\,kg$ Marine Iguana.

Hindgut fermenters

Organisms that use endosymbiotic bacteria to help break down algae, such as Marine Iguanas.

Endosymbiotic bacteria

Bacteria present in the gut of Marine Iguanas to assist in the breakdown of algae.

Leks

Breeding areas guarded by territorial male Marine Iguanas.

Color (Marine Iguanas)

A physical characteristic of the iguana that is based on its diet.

1-6 eggs

The typical number of eggs laid by Marine Iguanas in the sand.

2 weeks

The duration for which female Marine Iguanas guard their eggs.

95 days

The length of the incubation period for Marine Iguana eggs.

Elapidae

The taxonomic family to which Sea Snakes belong.

69 species

The total number of Sea Snake species across two subfamilies.

Indian and Western Pacific Ocean

The warm coastal waters where Sea Snakes are mostly native.

Venomous

A key defense/predatory characteristic of Sea Snakes; described as 'High'.

Small fish

The primary prey for Sea Snakes.

Saltwater crocodiles, raptors and sharks

The few known predators of Sea Snakes.

Crocodylidae

The family of Saltwater Crocodiles, comprising $2$ genera and $13$ species.

6m

The size above which Saltwater Crocodiles are considered the largest reptiles.

Riverbanks

The location where Saltwater Crocodiles typically burrow.

Mound nest builders

The term describing the nesting habit of Saltwater Crocodiles using vegetation and soil.

Crocodyles porosus

The scientific name for Saltwater Crocodiles as presented in the lecture notes.

1000km

The distance from land at which Saltwater Crocodiles (Crocodyles porosus) can still be found.

Internal fertilisation

The method of fertilisation used by Saltwater Crocodiles.

Oviparous

The reproductive mode of Saltwater Crocodiles, meaning they lay eggs.

Parental care

A behavioral trait shown by crocodilians toward their eggs.

Archelon ischyros

Recognized as the world's largest sea turtle, now extinct.

Cretaceous Period

The geological period during which Archelon ischyros lived, roughly $70$ million years ago.

120 million years

The time ago when Sea Turtles shared a common ancestor with other turtles.

40 million years ago

The time ago when common ancestors of sea turtles existed, excluding leatherback turtles.

Cheloniidae

The family of modern hard-shelled marine turtles, including Loggerheads and Green turtles.

Dermochelyidae

The family of marine turtles that includes the Leatherback.

Toxochelyidae

An extinct family of marine turtles shown in the phylogenetic tree.

Protostegidae

An extinct family of marine turtles that included Archelon.

Evolutionary adaptations (Shell)

The shell became more streamlined for an aquatic life.

Evolutionary adaptations (Limbs)

Limbs required profound modifications to become flippers for swimming.

35 mph

The maximum swim speed reported for sea turtles.

Oviparity

The trait that prevented turtles from becoming entirely aquatic, requiring a return to land to lay eggs.

Forelimbs

Anatomy used by sea turtles to generate lift using strokes.

Hindlimbs

Anatomy used by sea turtles primarily for steering.

Leatherback lungs

Characterized by more dense construction, high surface area, dense parenchyma, and high levels of connective tissue.

Spongy and deep red

The color and texture of leatherback lungs due to extensive blood supply.

Medial surfaces

The specific surfaces of Kemp's ridley lungs that are attached tightly to the vertebral column.

Nucal plates

Bone plates located at the very front/neck edge of a generalized sea turtle shell.

Neural plates

The series of plates running down the center of the turtle's carapace above the vertebrae.

Pigal plates

Bone plates located at the rear of the sea turtle skeleton.

Plastron

The ventral (bottom) part of the turtle skeleton, including elements like the entoplastron and xiphiplastron.

Entoplastron

A specific skeletal element located in the anterior-central part of the plastron.

Xiphiplastron

The posterior-most bones of the turtle's plastron.

Caretta caretta

The scientific name for the Loggerhead turtle.

Chelonia mydas

The scientific name for the Green turtle.

Chelonia mydas agassizi

The scientific name for the Black turtle.

Eretmochelys imbricata

The scientific name for the Hawksbill turtle.

Lepidochelys kempii

The scientific name for the Kemp's ridley turtle.

Lepidochelys olivacea

The scientific name for the Olive ridley turtle.

Natator depressus

The scientific name for the Flatback turtle (referenced as Chelonia depressus on slide 27).

Dermochelys coriacea

The scientific name for the Leatherback turtle.

2300 km

The distance turtles from Brazil swim against the current to reach Ascension Island.

1-1.5 months

The time it takes for turtles to migrate from Brazil to Ascension Island.

Ascension Island

A small island (10 km in size) in the middle of the Atlantic used as a nesting ground.

Prefrontal scales (Hawksbill)

Identified by having $2$ pairs of prefrontal scales on the head.

Prefrontal scales (Green turtle)

Identified by having $1$ pair of prefrontal scales on the head.

Imbricated scutes

The overlapping scute pattern characteristic of the Hawksbill turtle.

4 lateral scutes

Identification feature shared by the Hawksbill and Green turtle carapaces.

5 lateral scutes

Identification feature found on Loggerhead and Kemp's ridley carapaces.

6 or more lateral scutes

Identification feature found on Olive ridley carapaces.

Inframarginal scutes (Pores)

Kemp's ridley and Olive ridley have $4$ of these with pores, while others lack pores.

Pelagic Nursery Stage

The phase in the sea turtle life cycle spent in the open ocean, lasting $5-20$ years.

50-80 days

The duration it takes for sea turtle eggs to hatch.

2 weeks (Nesting)

The interval at which females return to the nesting beach to lay another clutch.

Thermal tolerance range

For sea turtle embryos, this range is $25-27^{\circ}C$ to $33-35^{\circ}C$.

Tidal inundation

Environmental event that decreases temperature and oxygen levels in the sand column.

TSD

Acronym for Temperature Sex Determination.

Pivotal temperature

The temperature (approx $28-30^{\circ}C$) where the sex ratio of hatchlings is mixed or roughly equal.

Male hatchlings

Produced when incubation temperatures are cool (lower than the pivotal temperature).

Female hatchlings

Produced when incubation temperatures are warm (higher than the pivotal temperature).

Thermal sensitive period

The specific time during the middle third of incubation when sex is determined.

Social facilitation

Group co-operation during hatchling emergence to improve survival and efficiency.

Visual cues

The primary orientation mechanism used by hatchlings while on the beach.

Wave orientation

The orientation mechanism used by hatchlings in the wave refraction zone.

Magnetic orientation

The orientation mechanism used by hatchlings once they reach the open ocean.

Rhizostoma

A genus of jellyfish used as a indicator for leatherback turtle hotspots.

Rhizostoma octopus

Specific jellyfish species preyed upon by leatherbacks in Carmarthen Bay and Tremadoc Bay.