Lecture 6- zooplankton Flashcards
what are the three aquatic environments for invertebrates?
- water (planktonic)
- hard surface (attatched)
- soft sediment (benthic)
what is the difference between metazooplankton and phytoplankton?
-metazooplankton= planktonic invertebrate organisms
phytoplankton=planktonic algae
what are the three major metazoplankton groups?
- cladocerans
- rotifers
- copepods
how does metazoplankton distribution differ between oceans and freshwater systems?
-rotifers and cladocerans are limited in marine settings, but abundant in others
describe the size of rotifers
-the smallest of all metazooplankton, going from 100-400 micometers in length
describe rotifer body divisions
-divided into: head, trunk, foot
what do rotifers use cillia for?
-rotifers have retained their cillia and utilise it for the movement of water and food towards their mouths. this way of acquiring food is similar to cillia
what type of feeders are rotifers?
filter feeders
how do rotifers acquire oxygen? why?
-via diffusion from the water due to a lack of a permanent heart or circulation system
how does the rotifer digestive system function?
-they have alimentary canals, so are able to take food in at the mouth, extract nutrients and expel it at the anus. they have kidneys and bladder so can urinate
in summary, what features do rotifers posses, and which are they lacking?
have: -alimentary canals -kidneys -bladder -cillias -permenant gut lack: -heart and circulation system
what do rotifers feed on?
- cilliates (main competitors)
- cyanobacteria
- protezoa
- small rotifers and crustaceans (large rotifers)
how do rotifers protect against predation? what is the other purpose?
-they produce Loricas out of KYTIN. these protect from predators and also increase flotation
how do rotifers form communities?
-they use their cillia to attach to one another and float through the water column
what are the three different rotifer forms?
- keratella
- kellicottia
- synchaeta