Zoology Exam 2 Flashcards
What are the synapomorphies of the Bony Fishes?
- Patterns of lateral line canals.
- Similar opercular and pectoral girdle dermal bone.
- Fin webs supported by bony dermal rays.
- Endochondral bone.
What are the two lineages of the bony fishes?
Sarcopterygii and Actinopterygii
What are the features of the Sarcopterygii
- Long, cylindrical bodies.
- Heterocercal tail.
- Paired fleshy, scaled fins with bony central axis.
- Massive jaw muscles.
- Cosmine (derived from dentine) covered body.
- Abundant during the Devonian.
- Durophagous.
- Originally all marine.
How may genera of Lobe Finned fishes are there?
• Three that are distributed in South America, Africa, and Australia.
What are the characteristics of the lung fishes?
- Dorsal, caudal, and anal fins fused.
- Caudal fin symmetrical.
- Design result of paedomorphosis.
- Estivation
What are the two lineages of Sarcopterygii
Actinistia and Dipnoi
What are the features of the Actinistia?
• Intracranial joint between anterior and posterior halves of
skull.
• Lack maxilla.
• Symmetrical caudal fin with three lobes.
• Swim bladder filled with fat.
• Rostral organ (electroreceptor).
• Viviparous.
What are the origins or ancestral features of actinotergyii?
• Ancestral forms small with single dorsal fin and forked,
heterocercal caudal fin.
• Outer coating of scales covered with ganoine.
• Rays derived from elongate scales aligned end to end.
What is the biology of Actinoterygii?
• Upper and lower lobes of caudal fin nearly symmetrical.
• All fin membranes supported by fewer bony rays.
• Increased flexibility of fins.
• Lower jaw supported by hyomandibula.
• Adductor mandibulae capable of large size.
• Coronoid process of lower jaw adds torque to bite.
• In derived neopterygians, opercular bones connected to
mandible and assist with lower jaw depression.
Explain the evolution of suction feeding in The Jaws of Actinoterygii?
Hyomandibula capable of lateral movement.
• Increasing volume of orobranchial chamber and
generating suction.
Explain the evolution of protrusible jaws in Actinoterygii
- Evolved independently three or four times.
- Premaxilla slides forward over cranium.
- May improve hydrodynamic efficiency and grasping
Explain the evolution of pharyngeal teeth of Actinoterygii
- Pharyngeal plates associated with gill arches.
- Fusion of plates with arches produced pharyngeal jaws.
- Used to hold and or manipulate prey.
Who are the extant members of Actinoterygii?
Polypteriformes, Acipenseriformes,
Lepisosteiformes,
Ammiformes,
Teleostei
What are the features of the Polypteriformes?
Dorsal finlets, recoil aspiration, pectoral fins with fleshy bases, heterocercail tails, interlocking scales with ganoine
What are the features of the Acipenseriformes?
STURGEONS: large,active, benthic predators lack endochondral bones heterocercal bones protrusible jaw
Paddlefish:
elongated and flattened rostrum
possible electrodetection