Lesson 4

Question 1

what is the importance of water being so dense

Answer 1

it provides an extremely supportive environment
- able to stay motionless in the vertical column
- more viscous than air –> harder to move fast
—— water solubilized a much lower concentration of oxygen compared to air
——– easier to take a big breath of air than if you take a big breath of water (if a water breathing animal) –> harder to get the oxygen you need
- temperature wise - aquatic environments are more stable

Question 2

physical properties of water that differ in the air

Answer 2

• diffusion
• sound propagation and sound production
• water is denser

Question 3

gills (buccal pump)

Answer 3

• mouth is opened and water is sucked in
• openings close
• with muscular contractions, the cavity is reduced in size, causing a positive pressure
• water is forced out through the gills

Question 4

gills (ram ventilation)

Answer 4

• no pumping
• by swimming through the wate – ventilates through gills
• speed at which animal swims or the speed at which water is pumped in – ventilations occurs
• if it needs to swim very fast with mouth open to catch prey (ways to regulate it so it doesn’t hyperventilate)

Question 5

Lamella

Answer 5

helps regulate ventilation
- primary lamella –> little tiny process that forms individual channels
—-abductor muscles can contract and relax
—- when relaxed, processes on gills spread out and water is driven acrosses –> enhancing water uptake
—– when constricted —- a lot of water just flows past —- reduces the exchange within the gill tissue

Question 6

all vertebrates are fish

Answer 6

yes— the words are synonyms

Question 7

water in the gills flow

Answer 7

• opposite to the flow of blood
• medially to latterally (almost all aquatic fishes)
• unidirectionally

Question 8

countercurrent flow

Answer 8

• establishes a current for gas exchange
• non concurrent
  —- blood and water do not flow in the same direction
• when water first enters –> it is at its highest percent oxygen
• blood interacting with it is at its lowest percent oxygen !!!!!!!! because of this , a very strong concetration gradient occurs — strong diffusion
• high to low
• countercurrent flow enables a constant gradient

Question 9

perch

Answer 9

gulps in water from its mouth and oxygen diffuses

Question 10

hydrostatic

Answer 10

use for bladder gas exchange
- can adjust whole body density

Question 11

sensory (vision)

Answer 11

• if water is clear - vision is good –> but if murky –> problems
• in water - there is less refraction because the light is not coming through the air —> it’s coming through water - image does not get focused as it should be

Question 12

sensory (vision) - humans?

Answer 12

• if water is clear - vision is good –> but if murky –> problems
• in water - there is less refraction because the light is not coming through the air —> it’s coming through water - image does not get focused as it should be

Question 13

other organisms (vision)

Answer 13

additional refraction by cornea

Question 14

anableps

Answer 14

• 4 eyed fish
• strangely shaped eye and lens –> able to lurk on the surface - air and water

Question 15

fishes with a lateral line system

Answer 15

• capable of detecting slight movements in the water
• can detect if a predator is there through the change in pressure that is pushing the water towards them
• also can use for navigation – get around objects

Question 16

how does the lateral line system work

Answer 16

• composed of neuromast cells in the neuromast organ
• a lateral line that runs just under the surface of the organism -
• has pores
• cupula
  ——–pressure change in the lateral line causes pressure change in the cupula
  ——–lateral line system concists of the same senseoy hairs in cillia that is found in the ear

Question 17

experiment where the shark is catching its prey

Answer 17

flounder is buried under the mud
— shark still gets its prey (maybe can smell?)
put shark under a shield that blocked the vertial transmission of smells
— shark still got prey
when used electrical insulation
— shark did not get prey
when buried live electrode
— targeted electodes

SHOWS that sharks use electrical stimulus

Question 18

many species with electroreception

Answer 18

system is homologous with portions of the lateral line system
- absent in the bowins, gar, and teleostei

Question 19

how many times would you predict that ampulary reception evolved in phylogeny

Answer 19

1 time

Question 20

comparison of chondrichthyans neuromasts (sensory cell or organs) and electroreceptors
(NEUROMASTS)

Answer 20

receptor cells - kinicilium and stereocilia

Innervation - afferent and efferent

function - mechanoreception

simulus - water movements

role - orientation, swimming, coordination

Question 21

comparison of chondrichthyans neuromastts (sensory cell or organs) and electroreceptors
(ELECTRORECEPTORS)

Answer 21

receptor cells - cilium, no sterocilia

innervation - afferent only

function - electroreception

stimulus - DC, low freq, AC

role - electrolocation

Question 22

salmon

Answer 22

• you don’t need constant input, you have a mechanism to habituate
• initially neuromast sends signal to the brain - but once the signal is processed - the brain sends signal back saying “im good” and the signal is not linger being sent to the brain (afferent and efferent innervation ) –> bidirection communication

Question 23

is their information sent back to the brain from electroreceptors

Answer 23

nope

Question 24

teleosts

Answer 24

• weakly electric fish
• thrive in tirbutaries of the amazon
• often dark muddy water with lots of objects in them
• tubulence
• make use of electrolocation
• fish emits an electrical signal – generation instead of seeing – producing electrical currents – then recieving the signal that would come back at different wavelenght - similar to electrolocation
• also used for communication and attracting mates
• jamming avoidance reponse
• in communication signals in eletric fishes

Question 25

water and ion exchange in an aquatic enviornemnt

Answer 25

nephrons (overview) - functional portion of kidney where water and ion exchange occurs - blood supply comes in via afference arteriole and branching into capilary - lot of water and ion exchange occurs bwtween cells - ultrafiltrate ---- everthing that is coming in the blood leaves the blood except for the calls and some large molecules ---- water/hormone/salts/plasma

Question 26

how do teleost maintain that much higher concentration of water compared to their surroundings --- how is it that it avoids getting high concnetration of salts within the blood (freshwater)

Answer 26

in freshwater teleosts, Na+ and Cl- are being actively pumped out of the DCT, membrane is not permeable to H2O - not everything moves across membrane by diffusion - energy is used in surrounding cells to pump things against their concentration gradient - but hin this case the kidney will move things against - ^^ that's what's happening eith sodium and chloride ions - Na+ and Cl - are being pumped out of the cell - sets up water and salt concentrations outside the cell that pulls water out - water passively moves outside the nephron

Question 27

marine salt and water concenrations

Answer 27

- in the PCT - in the collecting tubule (CT) - waater continues to flow down its concentration gradient but not for freshwater - the CT membrane for freshwater is not permeable to water molecules - anything in the CT will het excreted

Question 28

summary of water and ion concentraton

Answer 28

in both fishes water flows passively, depends on the degree to which these more distal membranes are more permeable to water marine --> more permeable ----- water is able to flow back into the blood freshwater --> take up a lot of salt in their food Marine --> form very little urine, drink sea water

Question 29

role of temperature in a variety of animal behavior

Answer 29

- chemical reactants are temperature dependent - want to speed up a reaction to a point by adding heat to it - chemical reactions are the underlying basis for so many fundamental animal behaviros - optimal temp to maximize these various behaviors

Question 30

some fishes have capacity for regional heteothermy and regional ectothermy

Answer 30

- able to control temp in different parts of their body - animal is much warmer at its core - able to maintain current throguh blood vessels from periphery to core --- then blood makses loop and runs back adjacently ^^^ similar to countercurrent gas exchange) --- as water temp gets cooler, the fish temp also gets cooler - but not as fast ---- countercurrent heat exchange slows the rate of heat loss