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
Teleostei: Elopomorpha
Diagnostic features
Unique, shared development
Leptocephalus larval stage in marine environment
Often shrink during metamorphosis into juvenile before reaching adulthood
Teleostei: Elopomorpha
Diagnostic features
Diverse adult forms- Anguilliformes
Long slender body
Usually lack pelvic fins, and sometimes pectoral fins as well
Typically has highly mobile pharyngeal jaw
Teleostei: Elopomorpha
Diagnostic features
Diverse adult forms- Non-Anguilliformes
Have a more typical actinopterygian body form
Otocephala
Clupeomorpha
Species
About 400 species
Otocephala
Clupeomorpha
Habitat
Mostly marine
Some species are anadromous
Otocephala
Clupeomorpha
Diet
Adult, feed on plankton
Otocephala
Clupeomorpha
Diagnostic features
Silvery, teleost body shape
Often lack lateral line, except on the head
Tend to form large schools in fish
Octocephala: Ostariophysi
Species
Over 10k species
Mostly from the clade Otophysi
Make up 80 percent of freshwater actinopterygian species
Octocephala: Ostariophysi
Diagnostic features
Alarm substance in the skin (Schrekstoff)
Members of Otophysi have a Weberian apparatus (series of bones connecting the gas bladder to inner hear, for improved hearing
Schrekstoff alarm
Highly sensitive
Can be detected from fresh wounds
Can be detected from fecal matters of predators
Ostariphysi: Siluriformes
Species
Over 2800 species
Ostariphysi: Siluriformes
Habitat
Almost all species are freshwater dwellers
Found worldwide, including southern Canada
Ostariphysi: Siluriformes
Diet
Omnivore with a wide range
Ostariphysi: Siluriformes
Diagnostic features
Have sensory barbels around the jawed mouth
Often carry adipose fin caudal to the dorsal fin
Most species have small body, but some can grow beyond 3m
Most have bony plates and fin spines for protection (may be venomous)
Ostariphysi: Cypriniformes
Species
About 4k species including zebrafish
Ostariphysi: Cypriniformes
Habitat
Almost all species are freshwater dwellers
Found worldwide except South America and Australia
Ostariphysi: Cypriniformes
Diet
Specialized for suction feeding
Ostariphysi: Cypriniformes
Diagnostic features
Lack oral teeth
Ostariphysi: Gymnotiformes
Species
Over 100 species
Ostariphysi: Gymnotiformes
Habitat
Freshwater dwellers
North and South America
Ostariphysi: Gymnotiformes
Diet
Most are carnivorous
Ostariphysi: Gymnotiformes
Diagnostic features
Body tapers toward the caudal fin, resembling a knife
Capable of electrogenesis.
At least on species (electric eel Gymnotus electicus) can generate a powerful discharge
Teleostei: Euteleostei
Species
Over 20k species traditionally classified into over 300 families
Teleostei: Euteleostei
Diagnostic features
Anatomical, functional, and behavior diversity provide few, if any, clear diagnostic features
Euteleostei: Salmoniformes
Species
Over 200
Euteleostei: Salmoniformes
Habitat
Most are anadromous marine dwellers, but some are fully freshwater
North and South America
Euteleostei: Salmoniformes
Diet
Most are omnivorous predators
Euteleostei: Salmoniformes
Diagnostic features
Typically have an adipose fin caudal to the dorsal fin
Euteleostei: Esociformes
Species
About 10
Euteleostei: Esociformes
Habitat
Freshwater dwellers
Northern Hemisphere
Euteleostei: Esociformes
Diet
Ambush carnivorous predators
Euteleostei: Esociformes
Diagnostic features
Dorsal and anal fins positioned close to the caudal fin (they act collectively to provide a powerful lunge)
Euteleostei: Acanthomorpha
Habitat
Freshwater and marine dwellers
Euteleostei: Acanthomorpha
Diagnostic features
Carry spines on dorsal, anal, and pelvic fins
Physoclistous connection with the gas bladder
Maxilla lacks teeth
All have ctenoid scales
Pectoral fins positioned dorsally on the trunk, and pelvic fin positioned nearly ventral to the pectoral fin
Pleuronectiformes
Bottom dwellers with compressed body
Specialized development in which left/right eye migrate to the other side of the body
Exocoetidae
Enlarged pectoral fins and heterocercal caudal fin for prolonged gliding
Xiphiidae
Sharp, elongated rostrum for hunting fish
Ostrciidae
Rigid body with bony armor and/or spines
Spines can be venomous
Gobiiformes
Multiple air breathing adaptation
Ipnops murrayi (sleepy eye)
Enlarged, naked retina
Chaunacidae
Modified paired fins for “walking” and stabilizing body on substrates
