Exam 2 Flashcards
Describe the lateral line system distribution on the head and body of a typical fish
- Lateral line sensory cells are concentrated on the head of a fish
- Then they extend in a thin line down the sides of a fishes body unitl it reaches the base of the caudal fin
What are 3 advantages of schooling behavior in fish?
- Decreased likelihood of individual being eaten
- increased reproductive success (more mates)
- Increased hydrodynamic efficiency
T/F: a fish with a gut about 1.8 times its body length would typically be a herbivore
False
What are important functions of pharyngeal teeth
- Break down components like cellulose
- Separate edible and inedible material
When a fish sits still and doesn’t eat it will starve to death. What are two energetic costs that drain the stored reserves of the fish in such a situation?
- maintenance metabolism
- tissue turnover
Static color patterns
–long-term coloration that can be used to determine species, gender, maturity etc
Dynamic color patterns
–can change and usually involve the quick exposure of a previously hidden structure
T/F: and iteroparous fish will spawn once and die
False
Polygynous mating system
-One male mates with many females
Monogamous mating system
-a pair stays together of the entire breeding system, and sometimes for life
What are 2 advantages of the primary care giver being a male in fishes
- females can work on producing more gametes
- The male can assure that the fish is his and noones elses
Provide an example of a type of fish that practices provisioning of their young
- Discus fish
- provide nutritional slime for young
What are 3 mechanisms for fishes to orientate during migration in the open ocean, hundreds of km from any shoreline
- Temperature fluctuations
- Oceanic currents (magnetic fields)
- Day-night cycles of daylight
Explain the concept of ‘point of no return’ as it applies to larval fish
- after a fish hatches, there is a critical period of 1-2 days during which they need to find food to survive
- past this point (the point of no return) even if they do find food, it will be too late and they will die
What will happen to the internal circadian rhythms of a fish if it is kept completely in the dark for many days
-it will gradually shift over time
Why are most fishes counter-shaded
- incumbent light shining from the surface above illuminates the darkened top, making them appear nearly invincible
- viewed from the top they blend in with the dark surface
- viewed from the bottom they blend in with the bright surface
T/F: most fish swallow their food whole and tail first
False
In what ways are sharks more advanced in the reproductive style compared to a typical fish
- many sharks provide embryo nutrition
- a placental-like organ provides nourishment for a developing fetus
T/F: catadromy is more common in temperate than in tropical latitudes
False
Why might newly hatched fish larvae have difficulty maintaining a nicely polarized school
- their sensory organs are not fully developed yet
- especially in their lateral line and eyes
Why do many kinds of fishes have dark, vertical pigment bars across their eye
-most predators use the eye of prey as a target to bite, so disgusing the eye helps them to avoid predators
On coral reefs, there is a quiet period just at sundown where there are very few fish moving, why?
-diurnal fish are going to sleep, and nocturnal fish are just waking up, so there is little action
What are 3 ways that fishes discourage capture or avoid being swallowed once they have been captured by a predator
- Having spines
- Having cryptic colorations (eye spots)
Which pigments are derived only from the diet in fishes
Carotenoids
Why are otolith bones generally better than scales for aging long-lived fishes
they are not reabsorbed back into the body
T/F: adult spawing salmon will remember odors that they experienced at the time of smolting
true
Which 2 sensory systems are most important for fishes to maintain a polarized school
- Lateral line system
- vision
Promiscuous mating system
-both the male and female have multiple mates
Harem mating system
-males will have multiple female partners
Functions of courtship in fishes
- fitness evolution
- species recognition
- synchronicity
T/F: a protandrous fish species is an example of a sequential hermaphrodite system
True
What are primary differences between direct and indirect ontogeny of fishes
- Direct: the process by which larvae will resemble the mature adult and grow directly into one
- Indirect: involves multiple larval stages, each of which look different from the mature adult
T/F: egg size in fishes is positively related to average egg abundual in fishes
False
Explain how suction feeding in higher teleost fishes works
- fish creates pressure in the mouth without opening
- when mouth is opened, the vaccum sucks in the water near the mouth
- Water is expelled from their gills with more pressure and the prey is swallowed
T/F: most fish masticate their food before swallowing
false
Why do fishes in rivers and streams rarley have pelagic eggs
-because rivers and streams require eggs that will stick to a surface or buried in a substrate
Differences between eggs of marine fish vs freshwater
- Marine: pelagic eggs, thinner than FW eggs. Also smaller and not adhesive
- FW: demersal eggs, larger, thicker, and adhesive
what are 2 reasons for fish to sleep during certain times of each day
- Save energy when not optimal conditions
- reduces risk of predation when fish who can see are at an advantage
Give two example of dynamic color patterns in fish
- warning colorations activated by some defense mechanisms
- reflective scales
In temperate regions, many annual cycles of fishes are keyed to the seasonal temp changes what might be the comparable dominant environmental influence on season patterns in the tropics
-the rainy season because the temp is more constant leaving periods of precipitation to dictate optimal spawning and migration times
T/F: a sequential hermaphrodite fish might change its sex as it grows
True
What is the difference between color patterns based on pigments versus structural colors
- Pigments can develop through several methods
- Structural colors can be used for species identification and are more constant
Why might it be easier for the fish to evolove a great diversity of feeding modes compared to birds
- there are a greater diversity of available niches for fish to exploit
- Fish have also been around for longer so they have had more time to diversify
why do polarized fish schools nearly always have one size of fish present
- allows for improved schooling and better organization between individuals
- since fish depend on vision and lateral line, uniform size improves the relay of info
If you want to age an old fish, whats the best way
- the otolith
- because it does not reabsorb phosphates
what might be the most basic or primitive mode of spawining
- releasing egg and sperm into the water and having them find each other
- no parental care
In tropical habitats, fishes with a crepuscualr behavior are uncommon compared to temperate zones, why
- tropics have a very small twilight times compared to temperate
- these fish wouldnt have enough time to hunt
what is the meaning and significance of the flex stage
-it is one step of morphological process where the larvae’s end vertebrae turns upward and is fused
why is it important for evolutionary diversification to have many bones and muscles
- allows for many forms of feeding that can arise
- could be important because of the vast majority of food in the ocean
Why are bioluminescent bacteria concentrated on belly rather than randomly on fish
-so that when a predator looks up at the fish it will blend in with the light coloration coming from above
what are 3 significant advantages for a fish having a large body size at the time of spawning
- indicates a higher fitness level and ability to produce more offspring
- also can give an advantage when competing for a mate
what might be the comparable dominant environmental influence on season patterns in the tropics
oxygen availability
