ch 11 phylum chordata Flashcards
(23 cards)
4 major anatomical characteristics of chordates
spinal cord, notochord, pharyngeal slits, post anal tail
three classes studied in subphylum vertebrata
angatha, chondrichthyes, osteichthyes
class agnatha
jawless fish
class chondrichthyes
sharks and rays
class osteichthyes
bony fishes
what characteristics do all vertebrates have
nerve cord, central nervous system, complete digestive system, closed circulatory system, endoskeleton
physical characteristics of jawless fishes
no jaws, body is cylindrical, no paired fins or scales, lack true vertebral column, cartilaginous skeleton
characteristics of hagfish
feed on dead or dying fish, exclusively marine, no vertebrae, produce large amounts of mucus
characteristics of lampreys
parasitic, primarily freshwater, have vertebrae
what are the advancements seen in classes chondrichthyes and osteichthyes
-highly efficient gills
-scales cover body
-paired fins
-wide variety of jaw and feeding types
-lateral line and sensory organs
-streamlined body
examples of cartilaginous fishes
sharks, skates, rays, chimeras
osmoconformer
can regulate internal salinity to match salinity of surroundings
physical characteristics of cartilaginous fishes
skeletons made of cartilage, placoid scales, claspers, reproduction
characteristics of sharks
fusiform, spindle shaped bodies
caudal fin
tail fin
pectoral fin
steering fins
dorsal fins
fin on the back
shark adaptations to the marine world
countershading (ventral side is lighter than the dorsal side), osmoconformers (high concentration of salts and urea in blood), gills absorb oxygen from water
shark life history traits
-slow growing
-long live
-mature late in life have long gestation periods
-small number of young
-wait a long time to reproduce again
threats to shark populations
shark finning; potential increases in diseased, unfit, and unhealthy prey individuals
physical characteristics of skates and rays
-have dorso-ventrally flattened bodies
-5 pairs of gill slits on ventral side of body
-demersal (live on bottom)
-pectoral fins are greatly extended and resemble wings
differences between skates and rays
-skates have 2 dorsal fins; rays have no dorsal fins
-skates have a muscular tail; rays have a whip-like tail usually with a prominent stinger
characteristics of chimeras (ratfishes)
- approximately 30 species
-one pair of gill slits, covered by flap of skin
-demersal (bottom dwelling)
-have long, rat-like tail
