Lec 11 part b Flashcards
Polyteriformes
Extant species
11-13 species of Polypterus (bichirs)
1 species of Erpetoichthys (reedfish)
Polyteriformes Habitat
North and central Asia
Quiet and somewhat stagnant freshwater
Polyteriformes Diet
Bichirs are ambush piscivores
Reedfish mainly hunt invertebrates
Polyteriformes Diagnostic features
Long slender, eel like body
Accessory air-breathing organ
Series of dorsal finlets instead of single dorsal fin
Ganoid scales
Acipenseriformes: Acipenseridae(sturgeon) extant species
25 species in four genera
Acipenseriformes: Acipenseridae habitat
Fresh and epicontinental water from the northern hemisphere
Acipenseriformes: Acipenseridae diet
Carnivore
Suction feeder
Acipenseriformes: Polyodontidae (paddlefish)
Extant species
1 species from Polyodon
Acipenseriformes: Polyodontidae (paddlefish)
Habitat
Freshwater from the USA
Acipenseriformes: Polyodontidae (paddlefish)
Diet
Filter feeder using gill rackers
The now extinct Chinese is a suction carnivore
Acipenseriformes
Diagnostic features
Relatively large body
Notochord is not replace
Most of the skeleton is cartilaginous, though it could be partially ossified
Carry bony armor plates under skin
Flat rostrum capable of electroreception
Highly asymmetrical heterocercal caudal fin
Additional features in paddlefish
Bony armor plates are star shape, termed stellate bones
Holostei: Lepisosteiformes
Extant species
7 Species of gars in two genera (Lepisosteus and Aractosteus)
Holostei: Lepisosteiformes
Habitat
Quiet and stagnant freshwater from North and Central America
Holostei: Lepisosteiformes
Diet
Ambush piscivore
Holostei: Lepisosteiformes
Diagnostic features
Somewhat slender body, can grow to several meters
Modified heterocercal caudal fin
A single gas bladder with some capacity for respiration
Thick ganoid scale
Holostei: Amiiformes
Extant species
1 species, Amia calva
Holostei: Amiiformes
Habitat
Low hydrodynamic freshwater environment
Found from eastern North America, including Quebec
Holostei: Amiiformes
Diet
Carnivorous predator capable of suction feeding
Holostei: Amiiformes
Diagnostic features
Bony gular plate between lower jaws
Modified heterocercal caudal fins
A single gas bladder with some capacity for respiration
Secondarily reduced ganoid scales (enamel layer is absent)
Teleostei
Contain more than 95 percent of known extant actinopterygians
Adapted to a wide range of environment
Hox duplications may have occurred near the origin of teleosts
Many examples of homology and analogy
Diagnostic features of teleost
Modified heterocercal and homocercal caudal fins
Fin rays are typically long and flexible
Highly protrusible jaws connected by skin fold
Pharyngeal teeth on the mobile branchial arches
Carry cycloid or ctenoid scales
Teleostei: Osteoglossmorpha
Diagnostic features
Lower part of the hyoid arch carry true teeth
Teleostei: Elopomorpha
Species
Over 800 species, mostly from the clade Anguilliformes
Teleostei: Elopomorpha
Habitat
Mostly marine dwellers, but some live in freshwater after reaching adult stage
Teleostei: Elopomorpha
Diet
Typical carnivorous predators