CFP Fish Biology & Physiology 1 — Questions and Answers
Question 1: What is the primary function of the lateral line system in fish?
- Detecting light intensity and color
- Sensing water pressure changes and vibrations (Correct answer)
- Regulating buoyancy in the water column
- Filtering particles from water during feeding
Correct answer: Sensing water pressure changes and vibrations
The lateral line system detects changes in water pressure, vibrations, and water movement, helping fish sense nearby objects, predators, and prey without visual contact.
Question 2: Which scale types are most commonly found in teleost (bony) fishes?
- Placoid scales
- Ganoid scales
- Cycloid and ctenoid scales (Correct answer)
- Cosmoid scales
Correct answer: Cycloid and ctenoid scales
Cycloid and ctenoid scales are characteristic of most modern teleost fishes; cycloid scales have smooth edges while ctenoid scales bear small spines (cteni) on their posterior margin.
Question 3: What is the primary function of the swim bladder in most bony fishes?
- Aiding in food digestion
- Producing sounds for communication
- Regulating buoyancy to maintain depth (Correct answer)
- Filtering metabolic waste products
Correct answer: Regulating buoyancy to maintain depth
The swim bladder functions as a hydrostatic organ, allowing teleost fish to achieve neutral buoyancy at various depths without expending constant muscular energy.
Question 4: Which physiological process allows marine teleost fish to maintain proper internal ion concentrations while living in saltwater?
- Osmoregulation (Correct answer)
- Thermoregulation
- Photoperiodism
- Chemotaxis
Correct answer: Osmoregulation
Osmoregulation allows marine teleosts to balance internal salt and water concentrations by drinking seawater and actively excreting excess ions through specialized chloride cells in their gills.
Question 5: What structural feature of fish gills enables highly efficient oxygen extraction through countercurrent exchange?
- Blood and water flow in the same direction across lamellae
- Blood and water flow in opposite directions across lamellae (Correct answer)
- Blood and water flow perpendicular to each other across lamellae
- Water flows bidirectionally across stationary blood channels
Correct answer: Blood and water flow in opposite directions across lamellae
Countercurrent exchange occurs when blood flows in the opposite direction to water across the gill lamellae, maintaining a continuous oxygen concentration gradient that maximizes oxygen uptake efficiency.
Question 6: What term describes fish capable of tolerating a wide range of environmental salinity levels?
- Stenohaline
- Euryhaline (Correct answer)
- Anadromous
- Catadromous
Correct answer: Euryhaline
Euryhaline fish can tolerate wide salinity variations (e.g., salmon, striped bass), while stenohaline fish are restricted to a narrow salinity range and cannot survive large shifts in salinity.
Question 7: Which specialized sensory organs in sharks detect extremely weak electrical fields produced by prey muscle contractions?
- Lateral line neuromasts
- Ampullae of Lorenzini (Correct answer)
- Inner ear otoliths
- Pineal photoreceptors
Correct answer: Ampullae of Lorenzini
The ampullae of Lorenzini are electroreceptor organs unique to cartilaginous fishes that can detect the faint bioelectric fields produced by the muscle contractions of nearby prey animals.
CFP Fish Biology & Physiology 1
What is the primary function of the lateral line system in fish?