LAB QUIZ #2 Flashcards
Sharks, Osteichthyes (69 cards)
What are the main 2 classes of Superclass Gnathastoma?
class Chondrichthyes and class Osteichthyes.
What are the 2 subclasses of Class Chondrichthyes?
subclass Elasmobranchii and subclass Holocephali.
What are the 2 subclasses of Class Osteichthyes?
subclass Actinopterygii and subclass Sarcopterygii.
What are the main anatomical features of Chondrichthyes?
- placoid scales
- 2-chambered heart
- cartilaginous skeleton
What anatomical features aid in buoyancy in Chondrichthyes?
combination of:
- fin placement
- oily liver
- cartilaginous skeleton
Subclass Elasmobranchii
sharks, skates, rays, and sawfish.
What are common anatomical features of Subclass Elasmobranchii?
- 5-7 gill slits
- spiracle (to bring water over gills)
- sub-terminal mouth
- hyostylic or amphiphilic jaw suspension
- ampullae of lorenzini (electroreception)
- cloaca
- claspers (in males)
- internal fertilization
Hyostylic Jaw Suspension
mandibular arch is not clearly attatched to the cranium, but connected by the hyoid arch.
Amphystylic Jaw Suspension
the upper mandibular arch is attatched to the cranium and the lower mandibular arch is connected to the hyoid arch.
PRIMATIVE
- frilled shark, 7-gilled shark
What is the difference between skates and rays?
skates:
- thick tail
- oviparous
rays:
- thin tail
- stinging spine
- viviparous
Subclass Holocephali
“whole head”
chimera and ratfish
What are common anatomical features of Subclass Holocephalii?
- 4 gill slits w/ single opening
- holosylic suspension
- oviparous
- NO CLOACA
- claspers on forehead
- slime coat (no scales)
Holostylic Jaw Suspension
upper mandibular arch is fused to the cranium and lower mandibular arch is suspensed from the upper.
- hyoid arch seperate
What are the general characteristics of Osteichthyes?
- 1st appearance of endochondrial bone
- operculum
- swim bladder (offset bone density, can be air or fat)
What is the main function of the operculum?
increase suction through buccal pumping, which increases flow of water over the gills.
most efficient.
Subclass Actinopterygii
ray-finned fishes
- derived
- fins supported by bony rays
- placement of pectoral fins are not conductive to limb developement.
Subclass Sarcopterygii
lobe-finned fishes
- ancestral
- fins supported by bone in fleshy stalks
- placement of paired pectoral and pelvic fins lead to the tetrapod limb.
Heterocercal Tail
dorsal and ventral lobes are not the same size.
chondrichchthyes
Homocercal Tail
dorsal and ventral lobes are the same size.
osteichthyes
What are the main points to remember about the Muscular System in sharks?
- only contract in a single plane
- increase in musculature allows increase in movement
Horizontal Septum
- lies between the epaxial and hypaxial muscles
- allows for movement within a single plane
Muscle Groups:
Epaxial = dorsal to the horizontal septum.
Hypaxial = ventral to the horizontal septum.
- inc. some vertebral muscles, diaphragm, abdominal muscles, and limb muscles.
Linea Alba = connective tissue separating the L and R myomers midventrally.
Abductor Muscles
pull a structure away from the midventral line.