Locomotion: Mechanisms, Behavior, and Energetics Flashcards
What is the anterior appendicular skeleton composed of in sea turtles?
flippers and triradiate pectoral girdle made up of two bones: the scapula and coracoid.
Where are the pelvic bones located in turtles?
inside the ribs and ventral vertebrae.
What morphological difference results from the repositioning of many bony structures in turtles?
rotation and repositioning of soft tissues, including muscles, nerves, and blood vessels.
How is the shoulder girdle aligned in turtles?
The scapula is aligned dorsoventrally and attaches to the carapace adjacent to the first trunk vertebra.
What bones form the glenoid fossa in the turtle shoulder girdle?
Two bones that form the glenoid fossa articulate with the head of the humerus.
Which bones make up the forelimb of sea turtles?
humerus, radius, ulna, carpals, metacarpals, five phalanges.
How are the radius and ulna in adult sea turtles modified?
short and functionally fused with fibrous connective tissue.
What is the flipper blade formed from?
widening and flattening of wrist bones and elongation of digits.
What type of bone is formed in the appendicular skeleton of Dermochelyidae and Cheloniidae turtles?
bone and cartilage.
What is a notable characteristic of the collagen composition in leatherback sea turtle long bones?
Leatherback long bones have extensive vascular channels indicative of chondo-osseus bone formation.
What is the growth rate of leatherback sea turtles?
Leatherback sea turtles have a growth rate unmatched among reptiles, achieving sexual maturity within approximately 9 years.
How much do adult leatherback sea turtles weigh?
Adult leatherback sea turtles can weigh up to 250 kg.
What do the subchondral surfaces of Caretta and Dermochelys humeri indicate?
Caretta humerus has a smooth subchondral joint surface, while Dermochelys humerus has roughened surfaces with large holes for blood vessels.
How does the cartilage morphology of leatherback turtles assist in their growth?
Their specialized vascularization enhances rapidly growing cartilage, allowing for faster growth.
What muscle originates on the plastron and is essential for swimming?
Pectoralis Major
What action does the Deltoideus muscle perform?
assists in movement of forelimb.
What locomotion mechanism is predominantly used by sea turtles?
thrust production using their limbs.
How do hatchling hard-shelled turtle species move?
synchronous movements of diagonally opposite limbs.
What is unique about the crawling motion of Dermochelys coriacea hatchlings?
“swing stance” limb cycle
What is the “crunch” motion employed by certain turtles when moving on land?
simultaneous protraction of forelimbs and sweeping back to propel the body forward.
What is the key characteristic of the crawl of adult Caretta caretta turtles?
alternating and simultaneous movement of diagonal pairs of limbs.
How can species of turtles be identified from their tracks?
presence of alternating tracks and the relative width of tracks.
What distinguishes the swimming motion of marine turtles?
simultaneous sweeping of forelimbs, creating asymmetrical gait.
What is the common locomotor pattern used by sea turtles?
The “powerstroke” is a common locomotor pattern that produces thrust during swimming.
How do post-hatchlings primarily swim after migrating offshore?
They rely on a “rear-flipper kick” method to propel themselves.
What is the activity pattern of Florida loggerhead turtles during their “frenzy” period?
Loggerhead turtles exhibit nearly continuous swimming during the first 24 hours after hatching.
How do the swimming behaviors of green turtle hatchlings change after 10 hours?
Their activity level decreases after 10 hours but remains steady for 24 hours.
Which turtles exhibit the highest rate of nocturnal activity?
Leatherbacks
What does a “frenzy” in baby turtles provide?
rapid escape mechanism when near shore.
Which limitation do humans have compared to leatherback turtles’ growth rates?
Humans grow at a relatively slow rate of 8 g/d, much slower than leatherback turtles.
What promotes the rapid ossification in turtle growth?
Rapid chondroblastic proliferation and hypertrophied cartilage cells
How are bone and cartilage structured in the appendicular skeleton of leatherback turtles?
They have a mix of cartilage and a relatively thick deposition of cortical bone surrounding a cellular bony core.
What is the unique feature of Dermochelys coriacea compared to other turtles?
They have distinctively roughened joint surfaces and large vascular holes in their bones.
On what aspect does the speed of leatherback turtle growth heavily rely?
increased energetic needs and specialized vascularization of cartilage.
What behavior do hatchlings from Florida’s green turtle exhibit?
They swim vigorously upon immersion but gradually decrease their activity level.
Describe the general swimming motion of turtles in aquatic environments.
utilization of forelimbs to simultaneously sweep water for propulsion.
How does the rear-flipper kick work in post-hatchling sea turtles?
paddling with hind flippers alone while the forelimbs remain flexed.
What do the characteristics of turtle tracks tell us?
species and size of the turtle based on track width and patterns.
How quickly can leatherback sea turtles grow, in terms of weight?
approximately 76 g per day.
What indicates that leatherback turtles have advanced bone structures?
Their ability to reach sexual maturity within 9 years
What anatomical feature aids flipper movement in sea turtles?
The muscles responsible for flipper protraction, retraction, abduction, and adduction
Which species of sea turtles are included in the families Dermochelyidae and Cheloniidae?
Species such as the leatherback sea turtle and the green sea turtle are included in these families.
How does bone structure differ between leatherback and hard-shelled marine turtles?
Leatherbacks have a unique mix of bone and cartilage while hard-shelled marine turtles possess more conventional bone structures.
