Clade Osteichthyans Flashcards
Osteichthyans
Bony fish and tetrapods (amphibians, avian and non-avian reptiles, and mammals)
What is a fish?
A paraphyletic group of aquatic vertebrates that use gills for respiration
jawless fish, cartilaginous fish, and bony fish, and excludes tetrapods
Osteichthyans Shared Derived Traits
- Lungs or lung derivatives that maintain neutral bouancy of fish
- Operculum: a plate of dermal bone that protects the gill arches and gills and ventilate gills when stationary
- Maneuverable fins
Characteristics of Extant Bony Fish
Fully ossified (bony) endoskeleton
Lateral line system
Reproduce via external fertilization
Four Groups of Bony FIsh
- Ray-finned (Actinopterygii)
- Lobe-finned fish (Sarcopterygii)
- Coelacanths
- Lungish
- Clade Tetrapods
Actinopterygii
Clade Osteichythyans
Ray-finned fish with fins supported by elongated, flexible bony rays connects to basal bony elements
Includes 99% of bony fish species
Sarcopterygii
Clade Osteichthyans
Lobe-finned fish with flashy, lobed fins, distinct from the ray-like fins and distinct fleshy, muscular pectoral and pelvic fins
Three surviving lineages are Coelacanths (living fossils), lungfish (gas exhange via gills and lungs and have two lungs), and tetrapods