Exam 1 Flashcards
What is a fish?
-an aquatic vertebrate with gills and with limbs in the shape of fins
There are _____ living species of fishes, ______ families, and _____ order
- 25,000
- 482
- 57
There are ___ jawless fish, _____ cartilaginous, and _______ bony fish
- 85
- 850
- 23,000
Bony fish make up about _____% of fish species
-90
____% of modern fishes are marine, ___% of fishes are freshwater, and ___% are both
- 58
- 41
- 1
What are some properties of water that influence fish functional design?
- Density
- Transparency
- Low compressibility
- Properties as a solvent
Water is _____ times denser than air
-800
Light rarely goes over ____ meters deep
-100
Evolutionary history of fish goes back ___ mya
-450
Apomorphy
derived character
Fishes are not a natural group unless ____ are included
tetrapods
What led to craniates?
-development of internal skeleton and bony external skeleton
____ is an early relative of amphioxis
Pikaia
Characteristics of ostracoderms
- Armored head
- Jawless
- body with narrow scales
- no internal skeleton
Dermal skeleton
-always bony and includes teeth
Endoskeleton
- sometimes cartilaginous
- bone is formed around or in cartilage
Why might a fish evolve bone
- maybe preventing leaks
- maybe for storage for calcium, phosphate, and carbonate
what is the optimal shape for a fish for the flow of water while swimming
-teardrop shape, max diameter 1/3 to 1/2 back from nose and length of 4-5
What is an important evolutionary trend among the jawed fishes
evolution of jaw protrusion
Characterisitcs of lampreys
- Jawless, with teeth arranged in radiating rows
- 2 dorsal fins
- no paired fins
Gnasthostomes
-jawed fishes
Evolution of jaws allowed for :
- better predation
- also required better predator avoidance
Important features of the gnasthosomes
- Evolved with paired fins and internal skeleton and muscles to allow movement
- Added 3rd semicircular canal in ear
Jawless fish have:
inner and outer gill arches
-Sharks jaw evolution:
- inner arches from jaws and hyoid arch
- outer arches form labial and extrabranchial cartilages
Bony fish jaws:
-ony inner arches present
Characteristics of placoderms
- powerful jaws and head encased in bones
- Most have a bony joint between head and body armor (unique)
Characteristics of sharks and relatives
- Placoid scales
- internal fertilization
- calcified skeleton
Sarcopterygians (lobe finned fishes)
- hinged intracranial joint
- single bone attached to shoulder/hip joint
- Living fish include lungfishes and tetrapods
Sarcopterygians includes ___ which is believed to be the transition from fish to terrestrial vertebrates
-tiktaalik
Acanthodians characteristics
- Highly developed fins with bristled spines
- have paired lamellae on each gill
- has 3 pairs of otoliths
Familes in the gnathostomes (jawed craniates)
- Placoderm
- Chondrichtiyass
- Sarcopterygiass
- Acanthodians
Actinopterygians (ray-finned fishes)
-fins are supported by rays rather than skeletal extensions
Actinopterygians include:
- Cladista (birches and reedfishes)
- Chondrostei (sturgeons and paddlefishes)
- Neopterygii (gars, bowfins, teleosts)
Some characteristics of rayfinned fishes (actinopterygians)
- Flexible rays
- Spines in advanced teleosts
What features are shared between cladista and chondrostei
- Spiracles
- Maxillary united to skull
What features are shared between cladista, chondrostei, AND sarcopterygii
- Spiral valve intestine
- Paired lung
- Heterocercal tail
Characterists/features of chondrostei (paddlefishes and sturgeons):
- heterocercal tail
- Spiracles
- broad-based fins
- scondary cartilaginous skeleton
Characteristics of sturgeon
- Marine anadromous and freshwater
- among the largest freshwater fish in the world
- Source of cavier which leads to overexploitation
Neopterygii
gars, bowfins, teleosts
Characteristics of gars (holostei)
- abbreviate heterocercal tail
- ganoid scales
- can breathe air
Characteristics of bowfin
- median gular plate
- greatly elongate dorsal
- elasmoid-like scales
Heterocercal tail
a tail in which the tip of the vertebral column turns upward, extending into the dorsal lobe of the tail fin
What is the main group of fish that dominate the word?
-Teleosti -> End Bone
Groups of fishes in the Teleosti–>End-Bone
- Osteoglossomorpha
- Elopomorpha
- Clupeomorpha
- Ostariophysi
Elopomorpha
- Eels, tarpons, bonefishes
- Diverse group, united by the presense of leptocephalus larvae
Characteristic of ostariophysi (catfish, minnows)
- Weberian apparatus
- 1/4th of all fish
- 2nd most important fish group
What is the weberian apparatus
-modified anterior vertebrae to enhance hearing sensitivity
Where do minnows occur?
Where do minnows not occur?
- The occur in North America, Africa, and Eurasia
- They are absent in South America, and Australia
What improvements make the teleosti group so successful?
- Respiration
- Feeding
- Buoyancy
- Swimming
General info on the siluriformes
- Catfish family
- Over 50 families, both freshwater and marine
- Only 2 familes in the US
What 2 catfish families are in the US
- Ictaluridae(FW)
- Aridae (marine)
Armoured catfish info
- OVer 70 genera
- 700 species
- Neotropics
Protacanthopterygii
- Salmon, trouts, white fishes, pikes
- “original spiny fishes”
Salmoniformes characteristics
- Salmons, trouts, whitefishes
- Many have adipose fin
- Pelvics abdominal
- cycloid scales
- swimbladder connected to gut
Paracanthopterygii
- troutperches, codfishes, frogfishes
- Mostly benthic and nocturnal
Key innovations in Acanthopterygii
- Jaw protrusion maximal
- Pharyngeal dentition advanced
Typical Percomorph body plan
- Ctenoid scales
- Protractile premaxilla
- Physoclistous swimbladder
- Pelvic fins thoracic
Percamorpha include:
bluegills to tuna
What are the fish zoogeographic regions
- African
- Neotropical
- Oriental
- Palaearctic
- Nearctic
- Australian
African zoogeographic region
- 95% of fish are FW dispersants
- Dominated by minnows, characoids, catfishes, cichlids
Lungfishes are an example of:
- Archaic fish distribution
- Dispersed in SA, Africa, and AUS
- Beleived to be due to the split up of Pangea
Neotropical zoogeographic region
- Dominated by characoids, catfishes, gymnotids, cichlids
- NO minnows
- 38% FW disp
Oriental zoogeographic region
-Dominated by minnows, catfishes
Palaearctic zoogeographic region
- 420 species
- Dominated by minnows and loaches
- Anadromous fish dominate the arctic drainages
Nearctic zoogeographic region
- 93% FW disp
- 6% anadromous
- dominated by minnows, perches, suckers, sunfishes
Example of holoarctic fish distributions
- Pikes salmons
- Fish that exist in nearctic and palaeactic
Australian zoogeographic region
-Dominated by anadromous and marine-derived form s
Physostomous swimbladder
- tubular connection to gut
- filled with gas by gulping air
- primitive teleosts
-Physoclistous wimbladder
-no connection to gut, use of internally generated and absorbed gases
What type of tail do teleosts have
- Homocercal
- tail base formed of urostyle
What makes coral reefs important
- They are diverse and productive
- global cycles of oxygen and carbon dioxide
- formed by calcium carbonate
- dominated by perch like fish
Characteristics of kelp forests
- support large carnivorus predators
- fast growth rates
- help reduce erosion
Benthic habitat
-habitat on the bottom of the ocean
Pelagic habitat
-habitats off the bottom (regardless of depth)
Ocean ecosystems from top to bottom
- Epipelagic
- Mesopelagic
- Bathypelagic
- Abyssal
- Hadal
How do mesopelagic fishes migrate?
- vertically
- Use fat-filled sim bladder to migrate vertically
