Fish Adaptations Flashcards
Which class of fish are hypomolar?
Cephalaspidomorphi (petromyzon marinus) and some teleosti
What class of fish are isomolar?
Hyperotreti (myxine glutionsa)
What classes of fish are hypermolar?
Chondrichthyes & Sarcopterygi
What 3 fishes in teleosti are hypomolar?
Exocoetus obtusirotris, hippocampus erectus, and psuedopleuronectes americanus
What 3 fishes in teleosti are hypermolar?
Ameiurus nebulosus, Perfa flavescens, Gasterosteus aculeatus, salmon trutta
Monophyly
a group that included a common ancestor and all of its descendants
Paraphyly
A group that includes a common ancestor and all of its descendants minus a monophyletic
Polyphyly
a group whode members have two or more distant separate origins
What are the four distinctive characteristics that separate the chordates from all other phyla?
Notochord, dorsal hollow nerve cord, musculae post anal tail, pharyngeal slits/clefts
Urochordata
No vertebrate, sessile adults (non moving) but free swimming larva.. an example of this is the tunicate
Cephalochordata
Amphioxus, no cranium, no vertebrate, filter feeder, not sessile! They have a caudal fin and tail. An example of this is the lancelet
Which of the vertebrata dont have a vertebrate?
Hagfish
Myxine Glutinosa
-Only animal with skull but no vertebrate
-Single caudal fin
-Photosensitive receptors/no eyes
-Single nasal opening
Petromyzon marinus
- Small cartilaginous vertebral structures
- Anadromous: move to streams/rivers to breed
- Functional eyes
- One or two dorsal fins
Main difference between hagfish and lamprey?
Lamprey tend to stick to coastal seas while hagfish are found in colder and deeper waters
Characteristics of chondrichthyes
- Cartilaginous skeleton
- Heterocercal (extended) tail
- No operculum (must use ram ventiliation)
- Placoid scales that are directional and hydrodynamic to help reduce drag
What are claspers?
Claspers are on the pelvic fins ans theyre used to siphon sperm to female cloaca during shark (squaliformes) mating
What type of ventilation do sharks and dogfish use?
Ram ventilation because they dont have operculum to cover their gill slits.
How do skates reproduce?
Eggs hatch outside of the body so this is oviparous
How do rays reproduce?
Viviparous (live birth)
Between little skates and rays, who has a rostrum and who doesn’t?
Little skates have a rostrum, rays do not.
What are three major characteristics of osteichthyes?
- swim bladder
- operculum
- eyes as primary sensory unit
What two classes fall under Osteichthyes?
Sarcopterygii and actinopterygii
What structure allows the lungfish to get O2 from air?
Swim bladder, and their thick fleshy fins allow movement on land… this is why they were central in the transition from fish to land animals.
What scales does the lungfish have compared to the coelacanth?
Lungfish has cosmoid while coelcanth has ganoid.
How do acipensar oxyrhyncus reproduce?
- Anadromous (born in freshwater, live most of their lived in sea)
Characteristics of Chondrostei
- largely cartilaginous
- heterocercal tail
- ganoid scales
Characteristics of Neoptertgyii
- Have stronger/lighter bones
- Ossified skeleton
- Homocercal tail
Cycloid vs Ctenoid scales
Cycloid scales are circular and smooth but ctenoid are toothed and ragged scales.
Some species that have cycloid scales are
salmo trutta and alosa pseudoharengus
Some species that have ctenoid scales are
perca flavescens
What species has both cycloid and ctenoid scales?
Psuedopleuronectes americanus
What is a superior mouth and what species have it?
Upward pointing like an underbite, typically feeding near the surface
- Remora remora
- Fundulus heteroclitus
What is a inferior mouth and what species have it?
Mouth situated lower than midoiint and typically feed on the ground
- catostomus commensori
- ameiurus nebulosus
