Buoyancy and locomotion

sinking components of animal tissue

proteins and skeleton/structural elements

floating components of animal tissue

lipids, some fluids, gas-filled cavities

strategies to reduce sinking

low density bodies, reduction of heavy structures, gas bladders, generate lift with propulsion and fats/oils

what is the purpose of ornate body structures on phytoplankton?

increase drag without adding weight so it can stay in one zone

how does alteration of body fluids reduce density?

osmoregulation allows the animal to control the weight of the fluid inside the cells (more solutes = denser)

what do diatoms store instead of starch?

fat

where is the gas bladder located in fish?

near the spine

what percent of the body volume does the gas bladder make up?

5%

types of gas bladders in fish

physostome and physoclist

physostome gas bladder

connected to exterior via esophagus; change depth rapidly by gulping air/releasing gases

physoclist gas bladder

not connected to exterior; limited in depth change by slow filling/emptying of bladder

nekton

any aquatic organism that swims without touching the bottom of the

do nektons have high or low reynold’s numbers when swimming?

high

red muscles

oxidative. rich in myoglobin for endurance

white muscles

glycolytic. rapid acceleration and burst swimming

swimming forces

lateral flexures move back along fish → water adjacent to fish is propelled backwards → creates forward thrust

physical limitations to swimming

pressure drag and friction drag

ways to reduce drag

mucus, smooth scales (denticles), hydrodynamic shape, pulse-glide swimming

name the fish body form

anguilliform. entire body flexed in undulating waves. eels. 

name the fish body form

carangiform. body thrown into shallow wave. oval body and keeled tail. tuna.

name the fish body form

ostraciform. inflexible body. small oscillation of tail. cube fish. 

name the fish body form

rajiforme. undulatory waves passed through extended pectorals. rays.