Biology: Fish and Vertebrate Groups

Living bony fishes; a monophyletic group consisting of Sarcopterygii and Actinopterygii.

Living bony fishes plus extinct acanthodians; probably paraphyletic.

A group containing a common ancestor and all of its descendants.

A group containing a common ancestor but not all of its descendants.

A shared derived characteristic that unites a group.

A structure derived from the anterior alimentary canal (gut) that develops into lungs or a swimbladder.

The presence of a gas-filled bladder derived from the gut.

Respiration by allowing early osteichthyans to obtain oxygen from air.

Lungs.

Buoyancy regulation through the swimbladder; some also use it for respiration.

Sarcopterygians have paired, ventral bladders; actinopterygians typically have singular, dorsal bladders, with exceptions such as polypterids.

They develop from the same embryonic structure, use the same developmental genes, and are lined with surfactant.

A swimbladder connected to the gut by a pneumatic duct.

The connection between the gut and a physostomous swimbladder, allowing gas to enter or leave.

A swimbladder not connected to the gut; gas levels are regulated through its lining.

The structure involved in adding gas to a physoclistous swimbladder.

“Wonderful net”; associated with gas secretion into the swimbladder.

The region involved in gas reabsorption from a physoclistous swimbladder.

The lobe-finned fishes and their tetrapod relatives.

Enamel and lobate paired fins attached to the body through a single bone.

A highly mineralized tissue that lacks collagen and is laid down in a single layer.

It is the hardest vertebrate substance and, once lost, cannot be replaced.

An enamel-like substance found in non-sarcopterygian vertebrates.

The outermost layer of ganoid scales.

The outermost layer of placoid scales and teeth in chondrichthyans.

An enameloid forming a cap on the tip of actinopterygian teeth.

Sarcopterygian fins attach through a single basal element; actinopterygian fins ancestrally attach through multiple basal elements.

The ray-finned fishes.

Cladistia, Chondrostei, and Neopterygii.

The subclass containing Polypteriformes (bichirs and reedfish).

The subclass containing Acipenseriformes (sturgeons and paddlefishes).

The subclass containing all remaining ray-finned fishes, including gars, bowfins, and teleosts.

Branchiostegal rays, acrodin, and micropyle(s).

Rays associated with the gill membrane and characteristic of ray-finned fishes.

A canal in an actinopterygian egg through which sperm enters.

Usually one; acipenseriforms may have up to seven.

Guide sperm toward the micropylar canal.

The hypothesis recognizing Holostei, the group containing gars and bowfin.

The single order of Cladistia.

The family containing Polypterus and Erpetoichthys.

Africa.

Ganoid scales, multiple dorsal finlets, a short dorsal fin continuous with an abbreviated heterocercal caudal fin, lobed paired fins, nostrils on short stalks, a spiracle, and two gular plates on the lower jaw.

An absent fifth gill arch, a spiral intestine, and a segmented notochord with vertebral centra present.

Lobed paired fins and external gill filaments in larvae and juveniles, along with actinopterygian features.

They possess actinopterygian features, their eggs have a micropyle, and DNA studies support their relationship to ray-finned fishes.

The order containing sturgeons and paddlefishes.

Polyodontidae (paddlefishes) and Acipenseridae (sturgeons).

A long rostrum, a typically present spiracle, and a heterocercal caudal fin.

An absent opercle, a large subopercle, a spiral intestine, an unsegmented notochord, and no vertebral centra.

Yes. Their endoskeleton is largely cartilage, but they have bone, especially in the well-developed dermal skeleton.

Juveniles have teeth, but adults lack teeth.

Vertebral centra are absent, but neural and hemal arches and spines are present; the notochord remains unsegmented in adults.

The family of sturgeons.

Five rows of bony scutes, two pairs of rostral barbels, and an inferior, highly protrusible mouth.

Fish spend much of their time in marine or coastal waters and migrate into freshwater to spawn.

Migration entirely within freshwater.

Acipenserinae includes sturgeons with a spiracle and coastal or freshwater species; Scaphirhynchinae includes freshwater sturgeons without a spiracle.

The family of paddlefishes.

An elongated rostrum, ampullary organs (at least in Polyodon), and a large flap of skin extending from the operculum.

The Mississippi paddlefish; a planktivore found in the Mississippi River drainage.

The Chinese paddlefish, formerly found in the Yangtze River drainage; declared extinct in 2022 according to the lecture.

Sensory organs in paddlefish rostrums similar to the ampullae of Lorenzini in cartilaginous fishes.

Dams and impoundments that disrupt migration routes.

Sturgeons are polyploid, and their mitochondrial DNA evolves very slowly.

Osteichthyes, Sarcopterygii, Actinopterygii, Cladistia (Polypteriformes), and Chondrostei (Acipenseriformes).