Concept questions Flashcards
When is a lake stratified? What seasons is a lake well stratified?
Mixing or layers of a lake, Spring and Fall = well stratified lake
What happens in the fall to a stratified lake (O2 distribution)?
Things are uniform, just like Spring, fish are free to go wherever.
What is the oxygen profile in a lake during the seasons and how does it impact where fish are found?
Where oxygen is found and where it is absent.
Oxygen is uniform in Spring/Fall, low (on bottom) during Winter/Summer - fish go where there is more oxygen
What seasons are most troublesome for benthic organisms like larval mayflies?
Summer/Winter bc of low oxygen and mixing
Why is it important to preserve ephemeral ponds?
Different species live in different habitats (IE - frogs), ideally have half and half.
For the most part, stuff flows into rivers - what are two counter examples?
Insect emergence, water evaporation
What distinguishes a marsh from a swamp?
Swamps have circulation of the water where marshes are standing water
Which habitats have sphagnum moss?
Bogs
What is in low supply in bog environments? Why? How have plants evolved to deal with that deficiency?
Very low nutrients (nitrogen) - plants have adapted by eating little insects, nutrient pellets.
What challenges face plants in bogs? What is the general way they have evolved to face this? 3 specific plants.
Low nutrients, low circulation, very acidic. Venus fly trap (something triggers their hairs and it gets trapped), sundew (leafs contain digestive enzyme produced by the glands - pray lands and gets wrapped into the plant) and pitcher plant (insects are attracted to the cavity formed by the cupped leaf, slippery rim moistened by condensation or nectar causes insects to fall in)
What challenges do aquatic organisms face in regards to the concentration of ions in their tissues?
Holding salt ion concentration (IE - potassium, K+)in tissues
Which drinks more water - fresh water fish or salt fish? Why? Which urinates more?
Ocean fish drink more (pump excess salt through gills or special organs), fresh water pee more (drink very little water but a lot of water comes in as it moves across gill membrane)
About what fraction solute is in the solution in animal tissue?
~ 1%
Marine fishes must fight the propensity of water and solutes to do what? What are the adaptations and consequences in response to this challenge?
Water lost due to osmosis, solutes dialyze in, ocean is a hypertonic environment.
it must fight propensity of (1) water lost due osmosis, and (2) solutes (salts) dialyze in
challenges: water out by osmosis - dehydrates, salts load in by dialysis, organism shrinks and dehydrates
adaptations and consequences: drinks lots of water, excrete (“pump”) excess salt through gills or special organs, very little highly concentrated urine
Is urine concentrated or dilute in freshwater fish? Why?
Dilute in freshwater fish, high concentrate in salt.
