Fish Behavior Flashcards
Describe four general methods of fish communication.
Visual: displays, colors, threatening or mating, or camouflage
Auditory: sounds like croaker for spawning and intimidation
Chemical: pheromones for mating, marking, or warnings
Electrical: independently evolved in 5 orders to communicate/mate, navigate, or hunt/protect
Name and describe 6 common colour patterns in fishes and their functions
Red coloration: attract mates or a warning colour
Disruptive coloration: breaks up the outline of the fish for camouflage
Countershading: blend in with natural lighting Light on bottom, dark on top
Eye spots: confuse predators about which side of the fish is the face
Lateral stripes: blend together and confuse predators when schooling
Polychromatic: color variation in a population
What is polychromatism among male guppies?
Guppies have two types of males: brightly colored and dull-colored. They breed at different times in the reproductive season. The brightly colored males are more like to get eaten by predators so they spawn first which is the opposite for the dull males.
Define aggregation
Any group of fish
Define shoal
Group of 1 specific species of fish
Define school
A group of fish moving together in the same direction
Examples of cyclic behaviors in fishes
Daily patterns can be what time are the fish most active: diurnal, nocturnal, and crepuscular.
Monthly patterns are lunar and semilunar.
Seasonal patterns can be related to tropical rivers.
What is the function of diadromy?
Major migrations allow for more larval habitat, reduced competition, less cannibalism, and allows access to more resources.
Diadromy acts as a tool connecting marine and freshwater ecosystems. It also allows insight to the transitions between life histories of marine and freshwater habitats.
Define anadromy
Freshwater birth, saltwater growth, freshwater reproduction
Define catadromy
Saltwater birth, freshwater growth, saltwater reproduction
Define Amphidromy
Like anadromy and catadromy but the growth/adult period is spent in both freshwater and saltwater areas
How do the anadromous Pacific salmon navigate and return to their native streams with high fidelity?
Smell or olfactory discrimination of their home stream and magnetic compass.
Describe five specific behaviors shown to predators when fishes are in aggregations
Compact: increases protection by making the little fish look bigger
Flash expansion: creates a confusion effect
Vacuole: “bubble” of avoidance around a single predator
Group jump: creating distance from predator
Mobbing: fish swam the predator to cause confusion
