Marine Fishes Flashcards
Why are marine fishes important?
- Feed on nearly all types of marine organisms
- The most economically important organisms
- Vital source of protein for millions of people
- Sportfishing
- Pets
What are characteristics of vertebrates/chordates?
Have a backbone (vertebral column or spine)
Dorsal Hollow Nerve Cord (spinal cord)
Notochord
Post-anal tail
Bilateral symmetry
Presence of an endoskeleton
What are the 3 groups of fishes?
- Jawless fish
- Cartilaginous fishes
- Bony fishes
What class are jawless fishes?
Class Agnatha
What are the types of jawless fish?
- Hagfish
- Slime eels
- Lampreys
What class are cartilaginous fishes?
Class Chondrichthyes
What are the types of cartilaginous fishes?
Sharks, skates, rays, and ratfishes
What are characteristics of jawless fish?
- Lack jaws
- Feed by suction with the aid of a round, muscular mouth and rows of teeth
- Body is cylindrical and elongated
- Lack paired fins and scales
What are characteristics of cartilaginous fishes?
- Ancient group
- Skeleton made of cartilage
- Movable jaws
- Well developed teeth
- Mouth is almost always ventral
- Paired lateral fins for efficient swimming
- Rough, sandpaper like skin because of the presence of tiny placoid scales
What invertebrate did fishes evolve from?
Chordate
What are characteristics of sharks?
- Fusiform body shape (spindle-shaped)
- Caudal fin or tail is well developed and powerful
- Heterocercal tail ~ upper lobe is longer than the lower lobe
- Usually two dorsal fins ~ first larger and triangular
- Paired pectoral fins are large and pointed
- 5 to 7 gill slits
- Powerful jaws have rows of numerous teeth
- Lost teeth are replaced by new teeth like a conveyor belt
- Found throughout the oceans depth, but most common in tropical coastal waters
What are benefits of sharks?
- Shark meat is eaten around the world
- Subject to disastrous fishing
- Fished for their oil
- Skin is turned into leather
- Skin is also used as sandpaper
- Fins are used for soup in the Orient
What are characteristics of rays and skates?
- Dorsoventrally flattened bodies
- Live on the bottom ~ demersal
- 5 paired gill slits on the underside of the body
- Pectoral fins are like wings
- Eyes are on the top of the head
What are characteristics of ratfishes or chimaeras
- 30 species
- Deepwater
- One pair of gill slits covered by a flap of skin
- Feed on bottom dwelling crustaceans and mollusks
What class are bony fishes?
Class Osteichthyes