Questions and Answers
What is Andreolepis hedei?
fossil of bony fish
What class do ray-finned fish belong to?
Actinopterygii
Which group of fish achieved higher adaptive success than any other jawed fish?
Osteichthyes
Which two classes did the Osteichthyes split into early in their evolution?
Signup and view all the answers
What compound hardens the skeleton of most bony fishes?
Signup and view all the answers
Bony scales beneath a ______ cover their skin.
Signup and view all the answers
How do most species of bony fishes reproduce?
Signup and view all the answers
They show ______ like that of sharks and an ______ covering their gills.
Signup and view all the answers
What did the lungs of early Osteichthyes evolve into?
Signup and view all the answers
What is the function of the swim bladder?
Signup and view all the answers
What were the two sets of paired fins in the earliest bony fish?
Signup and view all the answers
What are the U-shaped series of bones connecting the fins to the skeleton called?
Signup and view all the answers
What provides strength but a small range of motion to the pectoral girdle?
Signup and view all the answers
How are the pelvic fins in modern bony fishes positioned?
Signup and view all the answers
What feature of the earliest bony fishes limited their range of motion?
Signup and view all the answers
What are the hardened struts that strengthened all fins called?
Signup and view all the answers
What developed about the vertebral bodies?
Signup and view all the answers
What developed below the vertebral bodies?
Signup and view all the answers
What do the neural and haemal spines protect?
Signup and view all the answers
What allows for finer motor control in fish?
Signup and view all the answers
The bony fishes evolved a more flexible fin and a ______.
Signup and view all the answers
What do the myomeres of bony fish increase?
Signup and view all the answers
What are some examples of Actinopterygii still in existence today?
Signup and view all the answers
In what infraclass are most bony fishes today classified?
Signup and view all the answers
What traits do teleosts share?
Signup and view all the answers
Unlike sharks, the jaw of bony fish is at the anterior terminal end.
Signup and view all the answers
What is the operculum?
Signup and view all the answers
What covers gills in bony fishes?
Signup and view all the answers
What do the fin rays support?
Signup and view all the answers
What function do fin rays serve?
Signup and view all the answers
What does homocercal mean?
Signup and view all the answers
How is the mouth of some fish described?
Signup and view all the answers
A superior mouth is an adaptation for what?
Signup and view all the answers
What is located above the mouth of bony fish?
Signup and view all the answers
The nostrils of bony fish are blind-ended.
Signup and view all the answers
What is inside the nostrils of bony fish?
Signup and view all the answers
What features are found behind the nostrils of bony fish?
Signup and view all the answers
What do the canals lined with sensory receptors of lateral lines detect?
Signup and view all the answers
What do the overlapping scales of bony fish get covered by?
Signup and view all the answers
What is the function of the mucous layer on fish scales?
Signup and view all the answers
Study Notes
Overview of Ray-Finned Fish (Class Actinopterygii)
- Andreolepis hedei is a notable fossil representing bony fish.
- The class Actinopterygii encompasses all ray-finned fish.
- Osteichthyes, the bony fish group, achieved remarkable evolutionary success.
Evolutionary Diversity
- Osteichthyes diverged into two main classes:
- Actinopterygii (ray-finned fish)
- Sarcopterygii (lobe-finned fish)
Anatomy and Physiological Traits
- Bony fishes possess a skeleton reinforced with calcium phosphate (Ca3(PO4)2).
- Their skin is covered by bony scales beneath a mucous layer, aiding in protection and reducing drag in water.
- Most bony fish are oviparous, relying on external fertilization for reproduction.
Sensory and Protective Features
- Possess a lateral line system for detecting water pressure changes, similar to sharks.
- Operculum, a bony plate, shields the gills, enhancing protection.
- Early Osteichthyes likely had lungs that evolved into a swim bladder, essential for buoyancy control.
Fins and Movement
- The earliest bony fish had paired pectoral and pelvic fins connected by girdles, providing structural support.
- Modern bony fish have pelvic fins repositioned for improved swimming control.
- All fins are strengthened by lepidotrichia, or fin rays, allowing for flexibility and maneuverability.
Skeletal Structure
- Long neural and heal spines evolved to protect the spinal cord and dorsal aorta.
- Spinal enhancements created muscle separation, facilitating finer motor control.
Physical Adaptations
- The evolved homocercal (symmetrical) caudal fin supports better swimming agility.
- Myomeres arranged in a zigzag pattern amplify muscle contractions against the vertebral column.
Present-Day Ray-Finned Fish
- Modern ray-finned fish include sturgeon, gar, perch, and paddlefish.
- Most contemporary bony fishes belong to the teleostei infraclass, characterized by several distinctive traits.
Teleost Biology
- Teleosts exhibit circular, overlapping scales, homocercal tails, swim bladders, and advanced jaws enabling varied feeding strategies.
- Unlike sharks, the jaws of teleost fish are located at the anterior end for optimized surface feeding.
Sensory Structures
- Superior mouths adapted for surface feeding are complemented by blind-ended nostrils equipped with chemoreceptors for sensing chemicals in water.
- Large lidless eyes enhance visual capabilities, which are critical for survival.
Protective Features and Functionality
- Lateral line canals contain sensory receptors that detect minute water changes and bioelectric fields, improving awareness of surroundings.
- Scales overlap and are coated with a mucous layer to minimize friction and protect against pathogens.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Test your knowledge with these flashcards about the Ray-Finned Fish, which fall under the class Actinopterygii. Explore key terms and definitions related to the evolution and classification of these fascinating bony fish. Perfect for students and enthusiasts alike!