Transcript Maxilla Excluded From the Gape

Lab 2
Fish Evolution and Wisconsin Fish Families
• Lecture
– Major taxonomic groups
– Functional and anatomical
evolution
– Nomenclature
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Lab
– Compare traits of families
– Identification of Wisconsin
fishes to family level
– Start taxonomic key
assignment
Evolution of Major Groups of Vertebrates
The width of the branches indicate the relative number of recognized genera for a
given time level on the vertical axis. Time in millions of years.
Cenezoic
425
Cretaceous
135
Jurassic
180
Triassic
230
Permian
280
Carboniferous
345
Devonian
400
Silurian
425
Ordivician
500
Cambrian
570
Evolution of Major groups of Fishes
The width of the branches indicate the relative number of recognized genera
for a given time level on the vertical axis. Time in millions of years.
Cenezoic
425
Cretaceous
135
Jurassic
180
Triassic
230
Permian
280
Carboniferous
345
Devonian
400
Silurian
425
Ordivician
500
Cambrian
570
Taxonomic Nomenclature
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Kingdom – Animalia
Phylum – Craniata
Class – several
Order – in fishes, always ends with -iformes
Family – in fishes, always ends with -idae
Genus – complex nomenclatural conventions
Species – complex nomenclatural conventions
Jawless Fishes
Superclass: Agnatha
500 mybp
• Jawless (agnathous)
• Bony armor
• Muscular feeding
pump
Jawless Fishes
Hagfishes (Order: Myxiniformes)
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Notochord (no vertebrae)
Cartilaginous cranium
30-35 extant species
Harvested commercially
Jawless Fishes
Lampreys (Order: Petromyzontiformes)
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Cartilaginous skeleton
Dorsal, anal, and caudal fins
Lateral line system
Well-developed eyes
Jawed Fishes
Superclass: Gnathostomata
400 mybp
• Composed of:
– Sharks and their kin (Class: Chondricthyes)
– Lobe-finned fishes (Class: Sarcopterygii)
– Ray-finned Fishes (Class: Actinopterygii)
longnose gar (Lepisosteus osseus)
Jawed Fishes
Class: Chondrichthyes
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Sharks, rays, chimaeras
850 extant species
Cartilaginous skeleton
Placoid scales
Spiral valve intestine
Bony Fishes
Class: Osteichthyes
• Diverse assemblage
• Lungs or swimbladder
• Bony skeleton
Lobe-Finned Fishes
Class: Sarcopterygii
Lemur
• Characterized by fins with bony, leg-like
supports
• Coelacanths (Subclass: Coelacanthimorpha)
• Lungfishes (Subclass: Dipnoi)
• Tetrapods arose from Sarcopterygians
Latimeria
Neoceratodus
Ray-finned fishes
Class: Actinopterygii
• Characterized by improved scales, pelvic and pectoral girdles, jaws,
swim bladders, and branchiostegal rays
• Fins attached by rays
• Contains 96% of all living fish species (>25,000)
• Sturgeons, paddlefishes, bichirs and reedfish (Subclass: Chondrostei)
390 mybp
• Gars and bowfin (Subclass: Neopterygii) 225 mybp
– All true bony fishes (Division: Teleostei)
bowfin (Amia calva)
lake sturgeon (Acipenser fulvescens)
ornate bichir (Polypterus ornatipinnis)
True Bony Fishes
Division: Teleostei
130 mybp
• Characterized by cycloid or ctenoid scales, three or
four lower jaw bones per side, increased cranial
complexity, swim bladders (usually)
• Compose 95% of all extant species (~24,000)
• Four subdivisions:
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Osteoglossomorpha (Bony tongues)
Elopomorpha (Tarpons, eels)
Clupeomorpha (Herrings)
Euteleostei (Teleosts)
Bony tongues
Subdivision: Osteoglossimorpha
• Composed of one Order: Osteoglossiformes
– Bonytongues (Superfamily: Osteoglossidae)
– Mooneyes, featherbacks, and knife fish (Superfamily:
Notopteridae)
– Elephant fish (Superfamily: Mormyroidei)
Arapaima Arapaima gigas
Mooneye (Hiodon tergisus) Boulengeromyrus knoepffleri
Tarpon, Eels
Subdivision: Elopomorpha
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Characterized by leptocephalus larvae
Tarpons, ladyfish (Order: Elopoformes)
Bonefish (Order: Albuliformes)
Eels (Order: Anguilliformes)
leptocephalus
bonefish (Albula vulpes)
Two eels
tarpon (Megalops atlanticus)
Herrings
Subdivision: Clupeomorpha
• 4 Families (2 are well known)
– Herrings, shads, sardines and menhaden (Family: Clupeidae)
– Anchovies (Family: Engraulidae)
• Characterized by a connection between the swim bladder
and the ear
bay anchovy (Anchoa mitchilii)
alewife (Alosa pseudoharengus)
Teleosts
Subdivision: Euteleostei
• 30 orders, 374 families, >3,500 genera,
>19,000 Species
• Poorly characterized
• We’ll focus on 4 Euteliost superorders:
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Ostariophysi
Protacanthopterygii
Paracanthopterygii
Acanthopterygii
Superorder: Ostariophysi
• Dominate continental freshwaters
• Minnows, carps, and suckers (Order: Cypriniformes)
• Catfishes (Order: Siluriformes)
Northern hog sucker (Hypentelium nigricans)
White sucker (Catostomus commersoni)
Common carp (Cyprinus carpio)
Black bullhead (Ictalurus melas)
Superorder: Protacanthopterygii
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Popular commercial and recreational fish
320 species worldwide
Pikes, mudminnow (Order: Esociformes)
Salmon, trout, whitefish (Order: Salmoniformes)
Smelt (Order: Osmeriformes)
Cisco (Coregonus artedi)
Northern pike (Esox lucius)
Brook trout (Salvelinus fontinalis)
Rainbow smelt (Osmerus mordax)
Superorder: Paracanthopterygii
• Oddballs in Wisconsin
• Trout-perch, pirate perch (Percopsiformes)
• Burbot (Gadiformes)
Trout-perch (Percopsis omiscomaycus)
Burbot (Lota lota)
Pirate perch (Aphredoderus sayanus)
Superorder: Acanthopterygii
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Most speciose superorder among vertebrates
Killifish (Order: Cyprinidontiformes)
Silversides (Order: Atheriniformes)
Sticklebacks (Order: Gasterosteiformes)
Sculpins (Order: Scorpaeniformes)
Bass, sunfish, perch, darters, drum
(Order: Perciformes)
Brook stickleback (Culea inconstans)
Mottled sculpin (Cottus bairdi)
Rainbow darter (Etheostoma caeruleum)
Blackstripe topminnow (Fundulus notatus)
Pumpkinseed (Lepomis gibbosus)
Brook silverside (Labidesthes sicculus)
Major Trends in Fish Evolution
• Increased cranium and jaw sophistication
– Branchiostegal rays
– Maxilla separation
• Increased efficiency of movement
– Loss of external armor
– Fin placement and morphology
– Air bladders
• Simplification of skeletal system
Branchiostegal Rays
•Maintains a flexible
seal between operculum
and body as oral cavity
expands
•Increases efficiency of
respiration and allows
for suction feeding
Advances in Fish Feeding
Mechanisms
“Primitive”
PM
MX
MX
PM
“Derived”
Advances in Fish Feeding
Mechanisms
Brook trout – primitive,
maxilla included in gape
Largemouth bass – derived,
maxilla excluded from gape
Largemouth Bass Jaw Protrusion
Decreases distance between predator and prey
Increases the amount of suction force generated
PM
PM
MX
MX
Extreme Jaw Protrusion!
Shovelnose
sturgeon
Loss of
external
armor
Channel
catfish
Movement of Pelvic Fins From
Abdominal to Thoracic Position
“Primitive”
“Derived”
Abdominal
Position
Thoracic
Position
Caudal Fin Evolution
Heterocercal
caudal fin
Homocercal
caudal fin
Air Bladders
• Lungs evolved before air bladders
• Two types of air bladders:
– Physostomous
• Connected to the foregut by the pneumatic duct
• On many primitive fish
– Physoclistous
• Detached from the gut, inflated through gasses in
the blood
• On many derived fish
Vertebrae Simplification
caudal
1/3
abdominal
2/3
abdominal
1/2
abdominal
1/3
caudal
1/2
caudal
2/3
Primitive condition
(60-75 vertebrae)
Intermediate
condition
Derived condition
(24 vertebrae)
Caudal Complex Simplification
Bowfin (Amia calva), photo by John Lyons
Giant snakehead
Compare these fishes
Giant snakehead (Channa micropeltes)
Bowfin (Amia calva)