52 terms

Marine Fishes


Terms in this set (...)

jawless fishes (most primitive living fishes)
lampreys, hagfishes
cartilaginous fishes
1) elasmobranchii (sharks, rays, skates)
2) holocephali (ratfishes)
bony fishes
1) sarcopterygii (coelacanths)
2) actinopterygii (ray-finned fishes)
chordates with a backbone that encloses a nerve/spinal cord
heterocercal caudal fin
upper lobe is longer than the lower lobe (sharks)
fishes that live on the bottom
have whiplike tail that usually has stinging spines at the base for defense
reproduction of skates vs. rays
skates~ lay egg cases
rays~ birth live young
have only one pair of gill slits covered by a flap of skin, some have a long rat-like tail
scales of cartilaginous fishes vs. bony fishes
cartilaginous~ placoid scales (tiny, pointed)
bony~ cycloid/ctenoid scales (thin, flexible, overlapping)
gill cover, a flap of bony plates and tissue that protects the gills
homocercal caudal fins
the upper and lower lobes of the tail are generally the same size (bony fishes)
fin rays
bony spines that support the thin-membraned fins of bony fishes
swim bladder
gas-filled sac just above the stomach and intestine that allows bony fish to adjust buoyancy
bony fishes
largest group of living vertebrates
bony skeleton, gills covered by an operculum, highly maneuverable fins, protrusible jaws, swim bladder
scientific study of fishes
body shape of bony fishes
varies as an adaptation to habitat (both living and nonliving factors)
special cells in skin where the colored pigments of bony fishes are found
structural colors
result when a special surface reflects only certain colors of light.
consequence of crystals that act as tiny mirrors
special chromatophores where the crystals are contained
warning colorations
bright colors; when fish use colors to advertise that they are dangerous, poisonous, or taste bad
cryptic coloration
camouflage; blending with the environment to deceive predators or prey
disruptive coloration
the presence of color stripes, bars, or spots that help break up the outline of a fish; confuse predators or prey
form of disguise in open water; have dark backs and light bellies so they blend in with the sky from below and the ocean from above
bands of muscle that help with sideways undulation locomotion
fish locomotion
fishes usually swim with sideways undulations of the body and tail.
the pectoral fins and tails of sharks have an important role in buoyancy control.
the fins and tail of bony fishes are highly maneuverable and important in swimming.
fishes that feed primarily on seaweeds and plants
shapes of intestines
carnivorous~ short, straight
fishes that eat seaweed~ long, coiled
anus; where undigested food exits from
gills and gas exchange
gas exchange in the gills is highly efficient.
the surface area of gills is greatly increased by lamellae, and the flow of water through them is in a direction opposite to that of blood.
gas exchange
the absorption of oxygen to be used in respiration and the elimination of carbon dioxide
the movement of molecules form areas of high concentration to areas of low conentration
marine fishes and homeostasis
marine fishes keep a constant internal environment and check water loss through the osmoregulatory activities of the kidneys, gills, and other mechanisms
central nervous system
brain & spinal cord
coordinates & integrates all body activities and stores information
whisker-like organs near the mouth of many bottom feeders that have taste buds
nictating membrane
sharks; clear eyelid used to reduce brightness and protect the eye during feeding
lateral line
fishes; enables them to detect vibration in the water & allows them to avoid obstacles and predators, detect prey, orient to currents, and keep their position in a school
the diffusion of water across a selectively permeable membrane
the active control by an organism of its internal solute concentration
ampullae of Lorenzini
cartilaginous fishes; sense organs in the head that detect weak electrical fields to locate prey and help in navigation
sensory organs of fishes
eyes, olfactory sacs, taste buds, inner ears, lateral line...
sense organs of many invertebrates consisting of one or more grains or hard bodies surrounded by sensitive hears and used to orient the animal with gravity
patterns or schooling
1) traveling
2) feeding on plankton
3) encirclement of a predator
4) streaming to avoid a predator
anadromous fishes
spend most of their lives at sea but migrate to fresh water to breed (ex: salmon)
catadromous fishes
breed at sea and migrate into rivers to grow and mature (ex: freshwater eels)
sex hormones
produced in the gonads
stimulate the maturation of gametes and may cause changes in color, shape, and behavior before breeding
release is triggered by environmental factors
simultaneous hermaphrodites
ex: hamlet
can produce sperm and eggs at the same time
sequential hermaphroditism
sex reversal;
protandry~ individuals begin lives as males put change to females
protogyny~ females change into males
ex: sea basses, groupers, parrotfishes, wrasses
Sargasso Sea
the area of the Atlantic Ocean north of the West Indies that is characterized by masses of drifting Sargasso weed, a brown seaweed
reproduction in fishes
involved many adaptations that help individuals get together for mating that include migrations, the display of particular colors as sex signals, and courtship behavior
oviparous cartilaginous fishes
43% of cartilaginous fishes, release eggs into the water
ovoviviparous vs. viviparous
cartilaginous fishes;
eggs develop inside the female, which gives birth to live young
ovoviviparous~ female just carries eggs inside her for protection, doesn't provide extra nutrients
viviparous~ nutrition for development of eggs is provided by direct contact with reproductive tract of female