Chapter 6 - Major Radiation of Fishes Flashcards
(25 cards)
Osteichthyes
- Endochondrial bone - bone that develops from cartilage
- Operculum - bony gill covering that prevents backflow
Synapomorphies of Actinopterygii
- Parallel arrays of closely packed radial bones support the base of the fins
- Single dorsal fin
- Scales composed of ganoine (glassy, multilayered, mineralized tissue)
Order Polypteriformes - Birchir and Reedfish
- The most basal lineage of extant Actinopterygii
- Elongate, heavily armored fishes from Africa
- Flag-like dorsal finlets with spines
- Fleshy bases of pectoral fins
- Modified heterocercal tail
- Ganoid scales - shiny, enamol-like surface
- Well-ossified skeleton (ossify - to turn into bone)
- Paired ventral lungs
Clade Actinopteri
- Includes all actinopterygii, except the order Polypteriformes
- Synapomorphy for clade
- Swim bladder derived from lung
Order Acipenserformes - Derived Characters
- Endochondrial bone absent
Order Acipenserformes - Family Acipenseridae (Sturgeons)
- Large, active benthic fish
- Teeth absent in adults
- Five rows of enlarged armor-like scales along the body
- Reduced dermal skeleton
- Heterocercal tail armored with specialized series of scales
- Protrusible jaws
Order Acipenserformes - Family Polyondontidae (Paddlefish)
- Even greater reduction of dermal skeleton
- Greatly elongated and flattened rostrum
Synapomorphies of Neopterygians
- Upper pharyngeal teeth consolidated into tooth bearing plates
- Abbreviated heterocercal tail
Primitive Neopterygians - Order Lepisosteiformes (Gar)
- Elongated jaws
- Thick armor
- Needlelike teeth
Primitive Neopterygians - Order Amiiformes (Bowfin)
- Single species Amia calva
- Cycloid scales - thin, pliable scales formed of a thin sheet of bone-like material and underlying tissue
- Mobile maxilla (upper jaw)
Synapomorphies of Telostei
- Premaxilla mobile allows for protrusible jaw and greater suction
- Powerful movable pharyngeal jaws
- Homocercal tail - symmetrical and flexible tail that allows the fish to swim horizontally without using its paired fins
- More diverse paired fins
- Uroneaural - modified posterior neural arches that support the dorsal side
- Thin-scaled or lack scales entirely
Clade Osteoglossomorpha
- Found in tropical freshwaters
- Synapomorphy - Well developed teeth on the parasphenoid (one of the bones comprising the roof of the mouth)
Clade Elopomorpha
- Leptocephalus larva - specialized larva that are adrift currents for a long time
- Most are eel-like and marine
Clade Clupeomorpha
- Specialized mouth and gill straining apparatus for feeding on plankton
- Silvery scales
- Mostly marine schooling fish
Clade Euteleostei
- Vast majority of extant teleost are in the clade Euteleostei
- Nuptial tubercles - structures located on the head, body, or fins that are made of epidermal cells that helps the contact between males and females during mating by providing friction
Superorder Ostariophysi - Weberian Apparatus
Structure composed of small bones called ossicles (ear) that connects the swim bladder to the inner ear
Superorder Ostariophysi - Alarm Substance
Pheromone that is released into the water when the skin is damaged thus causing a fright reaction by nearby members
Superorder Ostariophysi - Adipose Fin
Small, fleshy, rayless fin found posterior to the dorsal fin
Clade Neognathi
- Synapomorphy
- Increased contact of the first vertebrae with the skull bone
- Most basal lineage is the family salmonidae (salmon)
Clade Acanthopterygii - Synapomorphies
- More mobile jaw
- Ctenoid scales - thin scales composed of bonelike material and characterized by a serrated margin
Acanthopterygii - Atherinomorpha (Flying Fish, Grunion, Needlefish, Guppies, and Swordtails)
Protrusible jaw that is modified
Acanthopterygii - Percomorpha (Perches, Sunfish, Cichlids, Flounders, etc.)
Pelvicfins with one spine and five soft rays; pelvic and pectoral girdles are joined
Synapomorphies of Sarcopterygii
- Paired fins with long muscular lobes extending below the body and have a bony central axis
- Pulmonary vein
- Scales made of cosamine (dentine-like material as opposed to enamel-like material)
Subclass Dipnoi
- Autostylic jaw suspension
- Teeth are scattered over the palate and fused into tooth ridges
- Diphyceral tail - tail is continuous with the dorsal and anal fins
- Thin scales embedded into the skin
- Internal lung structure
- Two-chambered atrium
- Pulmonary circulation (blood supply to the lungs)
- Bile salts (where it first evolved)
- Estivation - a period of dormancy that is usually induced by a lack of water. The fish burrow into the mud and metabolism is reduced
