Fishes Flashcards
How long ago did fishes first appear?
500 million years ago
List 5 characteristics that the Subphylum Vertebrata makes them different from other Chordates?
- Vertebral Column/backbone
- Spinal Chord
- Skull
- Bilateral Symmetry
- Usually 2 pair of appendages
Fishes are in what Phylum?
Chordata
Vertebrates include which animals?
- Fishes
- Amphibians
- reptiles
- Birds
- Mammals
What is the scientific study of fishes called?
Ichthyology
Why are fish important?
- Ecosystem
- Food
- Economy
- Recreation
How many species are in the Vertebrates?
40,000
The Class Agnatha is under which subphylum?
Vertebrata
Jawless Fishes are in what Class?
Agnatha
What do jawless fishes lack compared to other fishes?
- Jaws
- Paired fins
- scales
What fishes are under the class Agnatha?
- Lampreys
- Hagfish
Where do Lampreys live?
Young lampreys live in freshwater. Adults live in the ocean
How do Lampreys feed?
They use their mouth as a suction cup on larger fish
Where do Hagfish live?
The ocean.
Hagfish, How do they feed and what do they feed on?
They are scavengers that feed on dead animals that fall to the sea floor
What do Hagfish use for defense?
Slime on their body
Hagfish skin is sometimes used for what?
Leather products
In the Class Chondrichthyes what kind of fish are in this group?
Sharks and Rays
What is the skeleton made of in the Chondrichthyes?
Cartilage
How is Cartilage different from bone?
Cartilage is soft, elastic and flexible. Bone is tough, inelastic and inflexible.
What is the benefit of having paired fins?
- Steering
- Stability
In Sharks, what does it mean to be fusiform?
pointy at the end, round in the middle
In Sharks, what does it mean to be countershaded?
Dark on the dorsal surface and light on the ventral surface
How many gills slits do sharks usually have?
5-7
What is a spiracle and what is it’s function?
To take in water and ventilate the gills
In a shark which fins are paired?
The pectoral and pelvic fins
What is the function of the pectoral fin?
For steering and lift
What is the function of the pelvic fins?
For stability
What is the function of the caudal fin?
propulsion through the water
Explain what it means for a caudal fin to be heterocercal?
The upper lobe is longer than the lower lobe
Why do some shark species need to keep swimming?
because their gills only work when water is flowing across their membranes
What will happen if shark stop swimming?
they die
How can some species of shark rest on the sea floor?
They have the ability to open and close their mouth to pump water and force it across their gills
What happens when a shark loses a tooth?
it is replaced
What is the largest species of shark?
- Basking Shark
- Whale Shark
how does the basking shark and whale shark feed, and what does it feed on?
- filter feeding
- plankton
Rays and Skates, Describe their body shape.
- Bodies are flattened with pectoral fins
- elongated tails
- gill slits on their ventral surface
Rays and Skates, where they generally live?
The ocean
What does demersal mean?
bottom dweller
On rays and skates, where are the gill slits located?
On the ventral surface
Rays and Skates, Describe their pectoral fins
Enlarged and attached to the sides of the body
Describe why some rays are called stingrays.
some have a spine used for defense that stings
How do rays feed and what do they feed on?
- teeth are flatted for crushing mollusks and crustaceans
- filter feeding for plankton
- electric charge
How are rays teeth different than those of a shark?
they’re flattened
How are skates different than rays in terms of how they give birth?
Rays are viviparous while skates are egg laying oviparous
Describe placoid scales
very teeth like
What are placoid scales also called?
dermal denticles/ skin teeth
What is the function of nares?
nostril openings for smells
What are Ampullae of Lorenzini?
minute gel filled pores that detect weak electrical fields
Ampullae of Lorenzini, what is their function?
used to sense the environment and find prey
What is the lateral line and what is its function?
series of sensory organs that detect water pressure and vibrations
Describe claspers and cloaca, and explain their function.
- Claspers found on males.
- Cloaca found on females.
- Used for reproduction
What is oviparous?
Lay the egg in the environment
What is viviparous?
Live birth with placental(maternal) nourishment
What is ovoviviparous?
Live birth but young live off a yolk sac. No placental nourishment.
What Class are the Bony Fishes?
Osteichthyes
Osteichthyes, What is their skeleton made of?
bone
What is a fin ray?
Supports the fin. Made of cartilage or spiny and made of bone
What is the swim bladder and what does it allow bony fishes to do?
- an internal organ
- buoyancy
What is the operculum?
- A bony plate that covers the gills.
- Opens to let water out
Explain what it means for a caudal fin to be homocercal?
Equal lobes on top and bottom
Describe the kind of scales found in bony fishes
- Cycloid
- Ctenoid
How are bony fish scales different from the placoid scales of sharks?
bony fish scales are flat and smooth
Describe the types of senses of bony fishes.
- Good eyesight/color vision
- Good sense of smell
- touch and nerve receptors
- some have barbels around their mouths
- Lateral line systems
What are barbels?
whiskers that help feel for their food
What is the function of the lateral line (shakes have this too)?
to sense changes in water pressure, currents, vibrations and movements
What is warning coloration?
brightly colored to warn predators that they are dangerous
What is disruptive coloration?
bars or stripes that help to break up their outline
what is cryptic coloration?
fancy name for camouflage
What does it mean for a fish to be anadromous? Give an example.
they live in the ocean as adults but migrate to fresh water rivers for reproduction. Salmon.
What is the typical life cycle of a salmon?
- Breeding adults swim up a freshwater river
- Find their breeding ground
- female will lay eggs, male will fertilize
- Eggs hatch
- Young swim downstream to the ocean
How do salmon benefit forest ecosystems?
- Feeds bears, scavengers, insects and insect eaters
- Decompose into nitrogen and add it to the soil or water
- Adds Periphyton that feeds invertebrates
- invertebrates feed young salmon
What are ray-finned fish?
fins supported by fin rays
What are lobe-finned fish?
fleshy lobes for fins with bone and muscle
What is the evolutionary significance of the lobe-finned fishes?
- they can walk on land, related to amphibians
- their swim bladder can convert oxygen into their blood system.
How many feet long is the Horn Shark?
3 feet
Which reproduction is the Horn Shark?
Oviparous
How do you identify a horn shark?
- prominent ridges over it’s eyes
- spines on the base of the dorsal fin
How long does a female Leopard Shark grow?
6 feet
How do you identify a Blue Shark?
- pointed snout
- long pectoral fins
How long does a White Shark get?
12-15 feet
What’s the difference between a Ray and a Shark?
A ray’s gills are on the ventral surface
How long do the male Leopard Sharks grow?
2-3 feet
How long are Blue Shark?
7-10 feet
California Sheephead are sequential hermaphrodite, which means?
it is first one sex, then another
What is mutual symbiosis?
larger
fish gets a cleaning and the Señorita gets a meal.
