Lecture 1: Introduction Flashcards
What are the three major groups of fish based on phylogeny?
- Agnatha (jawless fishes)
- Chondrichthyes (cartilaginous fishes)
- Osteichthyes (bony fishes)
Give two examples of jawless fish (Agnatha)
Hagfish and lampreys
What is the main characteristic of Chondrichthyes?
Cartilaginous skeletons instead of bones
What are the defining features of Osteichthyes (bony fish)?
-Bony skeleton
-Protective scales and mucus
-Swim bladder for buoyancy
What are the major sensory systems in fish?
1.Vision
2.Hearing and balance (otolith organ)
3.Lateral line system (mechanosensory)
4.Olfaction (chemoreception via nostrils)
How does caudal fin shape relate to fish behavior?
The shape of the caudal fin influences swimming behavior and efficiency.
What are the two types of fin rays in ray-finned fish (Actinopterygii)?
Soft rays
Spines
What is the lateral line system in fish?
A mechanosensory system that detects water movement and vibrations.
Name the 2 classes under Osteichthyes.
Actinopterygii (ray-finned fish)
Sarcopterygii (lobe-finned fish)
What type of fins are found in fish anatomy?
Pectoral fins
Pelvic fins
Dorsal fin
Anal fin
Caudal fin
Describe the pelvic fin position types in fish.
Abdominal: Positioned near the abdomen (primitive fishes).
Thoracic: Positioned below the pectoral fins.
Jugular: Positioned in front of the pectoral fins.
What are Agnatha? Provide key characteristics.
Jawless fish
Elongate, eel-like body
Pore-like gill openings
Cartilaginous skeleton
What does the term “monophyletic” mean, and why are fish not considered monophyletic?
Monophyletic refers to a group that includes an ancestor and all its descendants. Fish exclude tetrapods, making them paraphyletic.
What are the two main types of reproductive strategies in fish?
External fertilization (e.g., spawning eggs in water).
Internal fertilization (e.g., live-bearing fish).
