Bony Fishes - Introduction Flashcards
aka bony fishes
osteichthyes
skeleton of osteichthyes
primarily composed of bone
osteichthyes is from the word
Greek
- osteon (bone)
- ikhthus (fish)
when does osteichthyes date back to
Late Silurian period
Silurian period
time of major evolutionary advancements in both marine and terrestrial life
where did bony fishes evolve from
early jawed fish
oldest known bony fish
Guiyu oneiros
general skeletal structure of bony fishes:
endoskeleton
true bone (ossified tissue0
general skeletal structure of bony fishes:
skul
- composed of multiple fused bone
- well-defined jaw with tooth (some have tooth plates)
general skeletal structure of bony fishes:
vertebral column
- provides structural support and flexibility
- notochord replaced by vertebrae
general skeletal structure of bony fishes:
fins and limb structure
- supported by bony fin rays
- lobed fins have internal bones homologous to tetrapods
bony fin rays
lepidotrichia
general skeletal structure of bony fishes:
ribs and girdles
- ribs protect internal organs
- girdles support fin attachment
general skeletal structure of bony fishes:
operculum
- bony plate covering gills
- aid in respiration
gas-filled organ found in most bony fish that helps them contrl buoyancy in water
swim bladder
two types of swim bladder
- physostomous swim bladder
- physoclistous swim bladder
- found in more primitive fish
- connected to the esophagus via a duct, allowing the fish to gulp air at the surface to fill the bladder or release ari
physostomous swim bladder
- found in more advanced fish
- not connected to the esophagus
- gas exchange happens throught he rete mirabile, a network of blood vesselst that transfers gas into or out of the bladder
physoclistous swim bladder
network of blood vessels that transfers gas into or out of the bladder
rete mirabile
three main types of scales in bony fishes
- cycloid
- ctenoid
- ganoid
shape of cycloid
round, smooth, without spines or ridges
location of cycloid scales
found in fish like salmon, trout, and carp
function of cycloid scales
greated flexibility and speed while reducing friction
structure of cycloid
comopsed of thin layers of bone
appearance of cycloid scales
smooth, shiny, streamlined appearance
shape of ctenoid scales
similar to cyclid but with tiny comb-like structures on the outer edges
location of ctenoid
common in perch, bass, and other modern fish
function of ctenoid scales
reduce drag even further than cycloid scales
structure of ctenoid scales
- made up of bone
- have more textured surface
appearance of ctenoid scales
fine, comb-like teeth along the edges, contributing to their rough texture
shape of ganoid scales
diamond-shapes or rhomboid, with a hard, glossy, and thick outer layer
location of ganoid scales
more primitive bony fish like gars, sturgeons, and bichirs
function of ganoid scales
provide extra protection and ahve a more rigid structure making them less flexible
structure of ganoid scales
- made of bone
- enamel-like outer layer
- heavy and durable
appearance of ganoid scales
- shiny, armor-like look
- more rigid
- supports the gills
- provide a framework for the gill filaments
- typically four on each side of the head
gill arches
how many arches are typically on each side of the head
4
- covers gill arch
- made of thin, flat layers called lamellae
- where gas exchange occurs
gill filaments
thin, flat layers that make up gill filaments
lamellae
- bony plate that covers the gills
- protects the gill filaments and help control the flow of water
operculum
- comb-like structures on the gill arches
- filter out debris and food particles before it passes over the gill filaments
gill rakers
where does the water exit through after oxygen has been absored
operculum
when is the origin and early evolution of bony fish
silurian-devonian period (~420-360 mya)
earliest bony fish likely evolved from what
placoderms (armored jawed fish)
when did bony fish diversify into two major groups
Devionian period (age of fishes)
two major group of bony fish
- Class Sarcopterygii
- Class Actinopterygii
class that are ancestors of amphibians, reptiles, birds, and mammals
Class Sarcopterygii (lobe-finned fish)
dominant group of fish today
Class Actinopterygii (Ray-finned fish)
when did the rise of ray-finned fish happen
carboniferous-permian period (~360-250 mya)
where did early actinopterygians live
freshwater
key adaptations for succes of Actinopterygians
- ray-supported fins
- swim bladder
- efficient jaw and skull structures
ray-supported fins of actinopterygians
provided better maneuverability than fleshy fins
swim bladder of actinopterygians
imporved buoyancy control with minimal energy
efficient jaw and skull structures of actinopterygians
enables to adapt to various feeding strategies
became less common, but some adapted to land, leading to the evolution of tetrapods
Sarcopterygians (lobe-finned fish)
began adapting to shallow water and land environments
- Tiktaalik and other
- tetrapodomorphs
when did “The Great Dying” happen
end of Permian Period
- was the most severe mass extinction in Earth’s history
- wiped out about 90-96% of marine species and 70-75% of terrestrial species
- caused by massive volcanic eruptions, which released huge amounts of CO2, triggering severe global warming, ocean acidication, and habit destruction
- ray-finned fish survived and thrived, eventrually becoming the most dominant fish group in both freshwater and marine ecosystems
The Great Dying (~250 mya)
how many marine species and terrestrial species were wiped out in the great dying
- 90-96% marine species
- 70-75% terrestrial species
cause of the great dying
massive volcanic eruptions
survived the great dying and thrived in the post-extinction world
ray-finned fish
when did telesot appear
mesozoic era (~250-66mya)
- highly advanced group of ray-finned fish
- appeared and quickly became dominant
teleosts
key adaptations for success of teleosts
- advanced jaw structure and feeding adaptations
- flexible fins for better swimming
- ligher and more adaptable skeleton
when did bony fish continued to diversify, adapting oto marine and freshwater environments worldwide
cenozoic era (66mya-present)
how many species ostechthyes exist today
30,000 species
