Flashcards in Lecture 1 - Fish Habitats Deck (41)
What is a fish?
Poikilothermic, aquatic chordate with appendages (when present) developed as fins, whose chief respiratory organs are gills and whose bodies are usually covered with scales.
Definition of a fish:
________ aquatic ______ with appendages (when present) developed as _____, whose chief respiratory organs are _____ and whose bodies are usually covered with ______.
What does poikilothermic mean?
Internal temperature regulated by the environment.
What are the two reasons that fish are not cold blooded?
1 - Fish in warm water have warm blood
2 - Some fish (e.g. tuna) can increased their body temperature above ambient using different sorts of muscles to heat blood up
A chordate is any animal with ____ ____ at some point in development; a dorsal _______ _____ cord; a _______ at some point in development, and a _____-_____ tail.
All _______ are _______ but not all ________ are ________.
(Chordates or vertebrates)
All vertebrates are chordates.
Not all chordates are vertebrates.
What are the ecological factors that fish have to worry about?
Food, predation, invasive species, spawning habitats.
What are the environmental parameters fish have to worry about?
Salinity, how much water is present, temperature, light intensity, pH, depth, DO
What drives species diversity locally?
Temperature, depth (to some extent), light intensity - diel cycling, turbidity levels
Variation in turbidity levels can vary due to natural and anthropogenic factors. Explain.
Natural - some fish prefer murky waters and some prefer clear waters
Anthropogenic - stirring up sediment
Sturgeon are a massive, long-lived local fish. They were though to be locally extinct but, have a made a resurgence locally. Explain and indicate which is the most important factor.
1 - Dr. Pitcher started revamping spawning habitats
2 - Decreased turbidity (most important.
3 - Increased quality of environmental parameters
What are the outer ranges of salinity in which fish can survive.
0 - 140 ppt
At 140 ppt, what occurs?
Salt crystallizes out of solution
Why does depth matter? i.e. what factors are related to depth?
1 - Light (the deeper you go, the less light there is)
2 - Temperature (Deeper water will generally be colder' up to a certain point)
3 - Pressure - increases linearly with depth (1atm/10m)
Describe the temperature ranges in which fish can be observed.
-2°C to 40°c
What are the issues at the upper range of the temperature spectra? The lower range?
High temps. - cellular degradation and denaturation of proteins
Low temps - freezing
Most fish do better at ____ temperatures than _____ temperatures.
There is roughly ____ distribution of fish species between marine and freshwater systems, however there are more in ______ environments compared to _________.
Why are there more marine fish than freshwater fish?
1 - Fish evolved in marine environments and then moved to freshwater
2 - There is more seawater than there is fresh
Why is there so little freshwater?
Much of the freshwater is unavailable under the form of glaciers
What drives species diversification in freshwater?
These are highly productive environments.
Why are freshwater environments highly productive?
Lots of nutrient input from land
_________ drives species diversification. (Related to food)
What areas are productive in strictly marine environments?
What is an estuary? What type of water is located there?
What are they important for?
Estuaries are a combination of both fresh and saltwater and are the locations where freshwater meets the ocean.
They are composed of brackish water, i.e. are within 0-32 ppt (32 being open ocean and 0 being freshwater)
Estuaries are important nursery grounds for marine fish.
Define a lotic environment.
High flowing environment with lots of water flow. River or stream.
Define a lentic environment.
Low flowing environment. Characteristics of a lake.
Why do we care about flow?
It can drive species diversification since flow affects morphology.
In a higher flow environment, the fish needs to be more hydrodynamic.
In a lake system, the fish can be more blobbed shaped.
What are the different oceanic habitats (related to depth)?