Bio 346 - Freshwater Eco. (Chpt 25) --> Zoobenthos Flashcards
Epifauna
The fauna of the sediment surface
Infauna
Those of the surgical sediment
Hyporheic fauna
Is part of a continuum that ranges from the fauna of the sediment surface of lakes to the floodplain fauna of the groundwater adjacent to many lotic systems
Macrobenthos
Consists of the organisms that live at the bottom of a water column and are visible to the naked eye
Meibenthos
Are small benthic invertebrates that live in both marine and freshwater environment
- They are medium size
Megabenthos
Largest invertebrates
How would estimate rates of community production and respiration or contaminant flow in food webs?
Size based community descriptions together with info on the systematic changes in metabolism with size
What makes for the best estimate of biomass?
Density
- Can use fewer samples
What happens to biomass specific reduction as biomass increases?
Decreases
What are 4 different categories of feeding groups?
- Filter feeding
- Deposit feeding
- Scarping
- Shredding
What kind of feeders are dominant when turbulence is low?
Deposit feeders and collectors are predominant
What kind of feeders are dominate in shallow flowing water and turbulent littoral?
Scrapers
What kind of feeders are dominate in streams?
Shredders
- Do well due to low primary production
Depositional boundary depth
Separate zones of fine and coarse sediment, thermocline
What happens at greatest macrophyte density?
Greatest zoobenthic species richness
Littoral zone
- Often dominant by macrophytes
- Most productive regions of lakes
- Largest number of animal species, biomass, diversity a d secondary production
- Subdivided into 3 zones (upper, middle and lower littoral)
Upper littoral
Reaches from the shoreline sprayed by waves in wind-exposed lakes to where the emergent macrophytes disappear
Middle littoral
Extends down from the lower edge of the upper littoral zone to the depth where rooted submerged macrophytes disappear
Lower/ sublittoral zone
Extends from from the lower edge of the middle littoral zone to the bottom of the euphoric zone
What is the bottom on the littoral zone best indicated by?
Deposition Boundary Depth (DBD)
What does DBD stand for?
Deposition boundary depth
Deposition boundary depth
Separates the zones of fine and course sediments
As macrophyte biomass increases, what do the zoobenthos become more associated with?
Plants
- Rather than sediments
Profundal zone
Is a deep zone of an inland body of freestanding water (like a lake or pond) located below the range of effected light penetration
What is growth rate highly dependent on? (3 things)
- O2 levels
- Primary production
- How much nutrients are sinking to the bottom
Profundal community biomass increases with the increase of what?
Trophic status
- Followed by decrease at epilimnetic Chl-a [ ]
What are the 4 negative effects on profundal zones?
- Sampling depth
- Lake demand depth
- Slope
- Colour
What are 2 positive effects on profundal zones?
- Mean depth: max depth ratio
2. Temp
What do top down and bottom up effects influence?
Community composition
