Diversity of Fishes III

• Phylum Chordata– Superclass Agnatha

•Class Pteraspidomorphi †•Class Myxini (?)•Class Cephalaspidomorphi

– Superclass Gnathostomata•Class Placodermi †•Class Chondrychthyes •Class Acanthodii †•Class Sarcopterygii•Class Actinopterygii

Fish Taxa Diversity

Evolution of Fishes

Superclass Gnathostomata (still)

• Class Acanthodii † (“spiny sharks”)

– Cartilaginous skeletons with ossified pieces & characteristic spines

– Pelagic habitat (FW & SW)– Considered sister group of bony fish

Teleostomi or Osteichthyes(Bony Fishes)

Sarc

op

tery

gi

Actin

op

tery

gi

Superclass Gnathostomata

• Class Sarcopterygii (lobed fins)– Coelacanths and lungfishes– Osteolepimorphi †

• Class Actinopterygii (ray fins)- Ray finned fishes

Class Sarcopterygii

• Order Coelacanthiformes – Family Coelacanthidae (coelecanths)- Fleshy lobed fins- Characteristic osteological features (fig

13.6)- Choanae (internal nostrils)- 2 spp.

Latimeria chalumane (“Old fourlegs”)

• Marjorie Courtenay-Latimer (1939)• J. L. B. Smith

– 2nd specimen (1952)

• Comoro Islands (now Kenia, Madagascar, South Africa…)

• French embargo• Conservation issues• Live observations (nocturnal, 200m)• Ovoviviparous

• Mark Erdmann (1998)• Indonesia (Sulawesi)• Conservation issues• Genetics study• Live observations

Latimeria menadoensis (“King of the Sea”)

Other Coelacanth Locations?

Meso-american silver jewelry1800’s

Extra Credit: +3% total grade

A Fish Caught in Time : The Search for the Coelacanthby Samantha Weinberg ($10.50 @ www.amazon.com)

         

Read the book, and write a 1 page essay, clearly expressing YOUR interpretation and opinions of it, as well as how the reading affected your opinion on ichthyology.

Class Sarcopterygii• Infraclass Dipnoi (lungfishes)

– Massive toothplates– Maxillae and Premaxillae bones missing– Functional Lung, choanae (internal nostrils)– Family Ceratodontidae (Australia, 1spp.)– Family Lepidosirenidae (S. America, 1spp.)– Family Protopteridae (Africa, 4 spp.)

Ceratodontidae Australian lungfishNeoceratus forsteri

LepidosirenidaeS. American lungfishLepidosiren paradoxa

ProtopteridaeAfrican lungfishesProtopterus sp.

Class Sarcopterygii• Infraclass Osteolepimorphi †

– Sister group of modern tetrapods– Similar fins to Devonian Amphibians limbs– Other morphological similarities

Teleostomi or Osteichthyes(Bony Fishes)

Sarc

op

tery

gi

Actin

op

tery

gi

Class Actinopterygii

Class Actinopterygii

TELEO

STEI

Class Actinopterygii

• Order Polypteriformes– Family Polypteridae (bichirs & reedfish)

• 10 spp. (African rivers)• Facultative airbreathers (spiracle exhalation)• Lobed fins, ganoid scales, heterocercal tail,

spiral intestine.• Flagfins (vertical spine with horizontal rays)

Class Actinopterygii

• Order Acipenseriformes (secondary cartilaginous skeleton, heterocercal tail, fin rays, spiral valve intestine). Sturgeons and Paddlefish

– Family Acipenseridae (sturgeons)• 24 spp. (northern hemisphere)• 5 rows bony scutes (modified ganoid scales)• 4 barbels in front of ventral mouth• Fresh water spawning (typically Anadromous)

• Order Acipenseriformes (secondary cartilaginous skeleton, heterocercal tail, fin rays, spiral valve intestine)

– Family Polyodontidae (paddlefishes)• 2 spp. (N. American and Chinese

paddlefishes)• No bony scutes, small scales, ossified

head plates• Freshwater open water plankton feeders• Paddle as electroreceptor?

Class Actinopterygii

Class Actinopterygii

• Order Semionotiformes– Family Lepisosteidae (garfish)

• 7spp. (North and Central America)• Ossified skeleton• Ganoid scales• Slightly heterocercal caudal fin• Backwaters in lakes and rivers, predatory fish• Toxic eggs

Class Actinopterygii

• Order Amiiformes– Family Amiidae (bowfin)

• 1 spp. (Amia calva, Eastern North America)• Ossified skeleton• Slightly heterocercal caudal fin• Cycloid scales• Swims through dorsal fin ondulations• Backwaters in lakes and rivers