Practice question

Class Actinopterygii comprises ray-finned fishes, largest vertebrate radiation with over 30,000 species including minnows, perches, cods and seahorses. Median and paired fins supported by slender bony lepidotrichia or ceratotrichia derived from dermal bone, permitting fine control, folding and versatile locomotion, lacking fleshy muscular lobe of Sarcopterygii. Lungfishes belong to Dipnoi, coelacanths to Actinistia within lobe-finned group, cartilaginous fishes to Chondrichthyes. Whole-genome duplications including teleost-specific duplication fueled diversification, ecological dominance in freshwater and marine habitats, economic importance and varied body plans distinguishing actinopterygians.