LEC 25 - INTRO 2 ZPTON

Question 1

collection methods:
schindler
net

Answer 1

schindler:
net: can catch most dudes now bc zpton tend to be bigger

Question 2

zpton biomass. top-down or bottom-up control?

Answer 2

mostly bottom-up (controlled by nutrients) but we’ll get to grazing in a bit :)

Question 3

what is the ideal nutrient conditions for zpton growth?

Answer 3

mesotrophic

in oligo, there’s not enough ppton to eat
in eu, cyanobacteria are greedy and take everything (also decomp = O2 fall etc)

Question 4

key traits of heterotrophic nanoflagellates (HNAN)

Answer 4

• make up bulk of zpton biomass
• major consumers of bactera, picoppton, and other HNAN
• these are the mixotrophs from the ppton section (3 of them)

Question 5

key traits of ciliates

Answer 5

• larger than HNAN
• have cilia for motility but also for filter feeding
• consume smaller ppton (pico and nano)

Question 6

key traits of rotifers

Answer 6

• corona, for motility and filter feeding
• parthenogenic (unfertilized eggs hatch into clones) meaning short generation times + when conditions are good, the pop bursts

Question 7

key traits of crustacean zpton (cladoceran and copepod)

Answer 7

• macrozpton - bigger than other zpton

cladocerans
- filter feeders, w setae that continually beat to draw in water which captures food

copepods
- calanoid copepods: ‘filter feed’ but act more as a roomba sucking up whatever crosses they path
- cyclopoid copepods: active hunter

Question 8

of cladoceran and copepods, which are more effective filter feeders?

Answer 8

cladocerans (they have daphnia which are peak dudes)

Question 9

what does seasonal breakdown of zpton look like?

Answer 9

winter: not really much going on
smaller zpton arise first, feasting on smaller ppton which also arise first

spring:
as microppton bloom begins, microzpton booms follow shortly after

summer: after ppton have hit their blooms, macrozpton begin to thrive (mostly daphnia)

late summer/fall depends on if zpton fly to close to the sun and get eated
either way the end of summer has ppton that are mostly inedible, so zpton pop falls off

Question 10

what is the effect of zpton on ppton abundance? can grazing be beneficial to ppton, or is it all bad?

Answer 10

when just zpton are added, they graze down ppton

when nutrients are added, ppton rise like crazy

when zpton + nutrients are added, ppton still rises - presence of zpton stimulate biomass production
- waste excretions incr nutrient avail
- ‘sloppy eating’ where eating leaves scraps of nturients everywhere

Question 11

what makes bdelloid rotifers wild?

Answer 11

resistant to drying, and in general are very resistant

Question 12

what are crustacean characteristics?

Answer 12

respiration via gills

hard chitonous skeleton enforced w Ca

two pairs of antennae

segmented body + paired appendages

Question 13

what are ostracoda?

Answer 13

type of crustacean that superficially resembles a bivalve but internally is a crustacean

Question 14

what are branchiopoda?

Answer 14

small crust w ‘leaflike legs’
good at surviving bad condition (many can survive dessication, allowing them to survive tide pools; brine shrimp survive extremely saline conditions)

Question 15

in cladocerans, what are epippium? why are they important?

Answer 15

egg capsule that allows them to be dormant for so long - we’ve revived some from 600 years ago

Question 16

what about cladoceran anatomy makes them such efficient filter feeders?

Answer 16

thoracic limbs beat to create a water current, where food particles are trapped by fine setae