L17 - Fishes

• What is a fish according to Berra (2001)?

  A poikilothermic aquatic chordate with fins
• What does poikilothermic mean?

  Animal whose internal temperature varies
• How many species of extant vertebrates are there approximately?

  ~67,000 species
• What percentage of extant vertebrates are fishes?

  ~50%
• What are the key morphological variations in fishes?

  • Body form/shape
  • Fin number/type
  • Fin placement
  • Mouth orientation
  • Presence of special features (e.g., adipose fin)
• What are the types of scales found in different fish groups?

  Placoid, cosmoid, ganoid, ctenoid, cycloid

  
• What are the functions of different fins in fishes?

  • Dorsal: balance/stabilization
  • Pectoral: directional changes
  • Pelvic: deceleration
  • Anal: stabilization
  • Caudal: propulsion/acceleration

  
• How does the shape of the caudal fin affect fish movement?

  Shape affects propulsion and maneuverability
• What is the primary function of a rounded caudal fin?

  Effective acceleration and maneuvering
• What is the function of a truncated caudal fin?

  Effective for rapid turning and speed bursts
• What does fusiform body shape indicate in fishes?

  Streamlined for efficient swimming
• What are the classes of extant vertebrates mentioned?

  • Agnatha (lampreys & hagfishes)
  • Chondrichthyes (sharks, rays, chimaeras)
  • Actinopterygii (ray-finned fishes)
  • Sarcopterygii (lobe-finned fishes)
• What is the order of lampreys in the superclass Agnatha?

  Order Petromyzontiformes
• What specialized sensory receptors are found in chimaeras?

  Mechanoreceptive lateral line canals
• What is the scientific name of the Atlantic sailfish?

  Istiophorus albicans
• What is the scientific name of the Australian lungfish?

  Neoceratodus forsteri
• What is the scientific name of the coelacanth?

  Latimeria chalumnae
• What is the significance of biofluorescence in fishes?

  It may aid in communication or camouflage
• What is the common name for Mola mola?

  Ocean sunfish
• What is the scientific name of the shortfin mako?

  Isurus oxyrinchus
• What is the common name for Simenchelys parasiticus?

  Pugnose eel
• What adaptations do lungfishes have for survival?

  Ability to aestivate during dry periods
• What is the common name for Cephaloscyllium ventriosum?

  Swellshark
• What is the order of the barbled dragonfish?

  Order Lophiiformes
• What is the order of the tripod fish?

  Order Lophiiformes
• What is the order of the bathypelagic fishes?

  Order Pleuronectiformes
• What is the significance of the lateral line in fishes?

  It detects water movements and vibrations
• How do fins contribute to fish locomotion?

  Fins provide stability and direction during swimming
• How do the morphological features of fishes relate to their environment?

  Features adapt to specific habitats and lifestyles
• If a fish has a flattened body shape, what type of environment is it likely adapted to?

  Bottom-dwelling environments
• What type of fin would you expect to find on a fish that needs to make quick turns?

  Truncated fin
• If a fish has a fusiform body shape, what advantage does it have?

  Efficient swimming in open water
• How does the presence of special features like barbels affect a fish's feeding strategy?

  They enhance sensory perception for locating food
• What role do adipose fins play in fish?

  They may assist in stabilization during swimming
• What is the primary function of the anal fin?

  Stabilization
• What is the primary function of the dorsal fin?

  Balance and stabilization
• What is the primary function of the pectoral fins?

  Directional changes
• What is the primary function of the pelvic fins?

  Deceleration
• What is the primary function of the caudal fin?

  Propulsion and acceleration
• What is the primary function of the lateral line?

  Detecting water movements and vibrations