Diversity and Systematics Flashcards
what is a fish? (rough definition)
a poikilotherm, aquatic chordate with appendages developed as fins, whose chief respiratory organs are gills and whose body is usually covered with scales
poikilotherm
an organism that regulates its body temperature by behavioral means
behavioral means of body temperature regulation
basking or burrowing
fish diversity in different water types
- freshwater 41.2%
- marine 58.2%
- diadromous 0.6%
diadromous
live or reproduce in fresh or salt water depending on the season of sampling
properties of water
- density
- water is nearly incompressible
- nearly universal solvent
- low light penetration
density as a property of water
- structural support
- fish are neutrally buoyant, energy directed toward swimming
- streamlined shape of fish reduces resistance
- water resists motion
how fish use water being nearly incompressible
- used by fish in lateral line system for hearing
- suction feeding and respiration creates negative pressure
negative pressure
forces water into buccal cavity over the gills
water as a universal solvent
- water contains dissolved gases and nutrients
- 1 to 8 ml of O2 per liter of water
low light penetration
- light penetrates to about 1000m
- photic zone
- wavelengths are differentially absorbed
photic zone
portion of water column with enough light for photosynthesis
taxonomy definition
theory and practice of describing biodiversity
taxonomy characteristics
- arranging it into a system of classification
- devising identification keys
natural classification
best represents the phylogenetic history of an organism and its relatives
alpha taxonomy
species descriptions based on unique characteristics
beta taxonomy
arrangement of species into a system of classification
merisitic characteristics definition
countable morphological structures
merisitic characteristic examples
- lateral line scales
- spines
- rays
- gill rakers
gill rakers
catch plankton and filter them down throat
morphometric characteristics definition
measurable morphological structures
morphometric characteristic examples
- standard length
- fin length
- head length
- eye diameter
standard length
- measured from mouth to start of tail
- commonly used to measure fish
- often occur in ratios
other alpha taxonomy characteristics
- anatomical
- color / pattern
- sexual dimorphism
- cytological
- molecular
