OSTEICHTHYES-SUBCLASS-ACTINOPTERYGII

Paired fins thin,broad, without fleshy basal lobes, and supported by dermal finrays.
One dorsal fin, may be divided.
Caudal fin without epichordal lobe.
Olfactory sacs not connected to mouth cavity.
Popularly called ray- finned fishes. divided into three infraclasses or super orders CHONDROSTEL HOLOSTEI AND TELEOSTEI.
SUPERORDER A. CHONDROSTEI
Mouth opening large.
Scales ganoid.
Tail heterocercal.
e.g ray-finned fish or cartilaginous ganoid.
ORDER 1. POLYPTERIFORES
Rhomboid ganoid scales and pectrol fins.
Dorsal fin of eight finlets.
Ossified skeleton.
e.g polypterus(bichir)
ORDER 2. ACIPENSERIFORMES
Scales less .
Skleton cartilaginous.
e.g acipenser(sturgeon), polyodon(paddlefish)