1. Adhesive locomotion: walking on glue -- sliding on snot
Lecture 8, Jan. 27
Scutigera
Adhesive locomotion: walking on glue -- sliding on snot
Sidewinding and serpentine snakes
Fish swimming shapes
Jumping onto dogs

2. Arthropod of the day: Class Chilopoda: house centipede
Legs moved in a metachronal
stepping wave:
one step-cycles after another -- just out of phase;
opposite is a synchronal wave:
all in synchrony.
The movement of Nereis parapodia during swimming is metachronal.

3. sidewinders Only certain portions of the body
wave are placed in contact with the substratum

4. Crotaline movement in snakes
The snake puts down body ‘segments’ at B and lifts them up at A [tractor]; the snake is not sliding its ‘segments’ along the ground
What would happen when a crotaline snake tried to employ sidewinding in water?

5. Fish swimming Webb, Paul W. 1984. Form and function
in fish swimming. Scientific American 251:
Sfakiotakis M., Lane D.M., Davies J.B.C Review of fish swimming modes for aquatic locomotion. IEEE Journal of Oceanic Engineering 24:
Fish swimming

6. Thrust: forces that tend to advance the fish; drag: forces that tend to retard it
Retrograde body wave pushes back against
the water; creates a reaction force resolvable
into two components: one lateral and the other propelling the animal forward: thrust; lateral forces of the right and left sides tend to cancel out.
Propulsive element: small segment of body
Inclination of reaction force is toward the head
The farther back a propulsive element is located the steeper this incline toward the head; thus more of the reaction force is thrust as one moves posteriorly out along the tail.
Rearward elements are moving through a greater displacement – in the same time – so they needs must go faster.
Change medium to ‘pegs’: snake locomotion serpentine on land

7. Undulation and oscillation; ribbon fin; feathering, draw strokes, flexible canoe paddle. In oscillation a fin attached by a short peduncle (base) moves rapidly back and forth to propel without any wave motion.
Diversity of fish body shapes relate to locomotion: corners of the triangle: tuna sustained cruising, strong ‘narrow necking’; butterfly fish for maneuvering, plate in water; pike or barracuda for acceleration.

8. Pedal locomotion in Gastropoda
Mantle cavity has been converted into a lung: hence ‘pulmonate snails’ of which slugs are just one type; edges of mantle cavity sealed to back except for pneumostome opening; roof of mantle cavity vascularized, no gill. >16000 species.
From Wikimedia Commons
Arion ater, black slug

10. Denny, M. 1980. The role of gastropod pedal mucus in locomotion
Denny, M The role of gastropod pedal mucus in locomotion. Nature 285:
See also: Barnes, Invert. Zool.
7th ed, p. 363.
Monotaxic and ditaxic species

11. The schnauzer and the blood-sucking ectoparasite
Adaptiveness of flea side-to-side body flattening; flea setae (hairs) orientation

12. Rothschild, M. et al. 1973. The flying leap of the flea
Rothschild, M. et al The flying leap of the flea. Scientific American 222:

14. Rebound resilience of the protein
resilin is 97%
Fleas can jump 100 X its body length
Accelerates from rest to 1 metre p sec
in a distance of 0.4 mm; extends its legs in about 8/1000 th of a second.
Power rate of doing work
Resilin located in the pleural arch
Energy loaded into pleural arch and held there by catches
Release is by body width change.

15. The trochanteral depressor is located a relatively long way from the trochanter; it originates on the notum and inserts on the trochanter (B, C). The insertion is via a massive tendon-like apodeme and this attaches anterior to the (dicondylic) axis of the trochanteral rotation (see blue dots in A, B, C). So the contraction of the trochanteral depressor pulls the trochanter, rotating it forward on the coxa and extending it (= depressing it) against the substratum.