Fishies Flashcards
what are the bilaterally paired anterior fins, typically located just behind the gill pouches
or operculum?
Pectoral fins
what are the bilaterally paired posterior fins, typically located in the posterior half of the body
along the ventral (lower) margin
Pelvic fins
what are the usually one or two fins located medially (along the midline) along the dorsal
(upper) margin of the body.
Dorsal fin(s)
what Present in some groups, the adipose fin is a small fleshy lobe located behind the
dorsal fin and anterior to the caudal fin
Adipose fin
a single median fin located on the ventral (lower) margin of the body named for its
proximity to the anal pore
Anal fin
a single median fin located at the posterior end of the vertebral column. Commonly
called the tail fin
Caudal fin
cylindrical or oval in cross section and tapered at both ends. Typical of fast moving
fishes in open water
terete
laterally (side to side) flattened shapes that are tall and narrow. Typical of slower moving fish that inhabit highly structured habitats like coral reefs or weed beds
compressed
dorso-ventrally (top to bottom) flattened shapes that are short and wide. Typical of
bottom dwelling or sedentary species
depressed
named for the genus Anguilla (eels) this type of swimming involves alternating contractions of longitudinal muscles along most of the length of the body. The resulting lateral undulations move from the head to tail, applying posterior and lateral force on the surrounding water, propelling the fish forward. Typical of long, thin fish that move relatively slowly.
Anguilliform
the lateral undulations are restricted to the posterior half of the body. Typical ofterete shaped fish with faster movement.
Carangiform
undulations are restricted to the caudal peduncle and fin due to an inflexible body. Limited to fishes with an extremely rigid body
Ostraciiform
movement through flapping motion of the pectoral fins. Typical of wrasses and other fish who rely on a lot of vertical movement in complex three-dimensional habitats like coral reefs.
Labriform
coordinated undulations of the dorsal and anal fins create forward and backward movement. Typical of triggerfish and others that rely on anterior-posterior movements in complex three-dimensional environments like coral reefs.
Balistiform
most fish maintain vertical
position in the water column passively through the regulation of a ______ organ
Buoyancy
gas filled ______ ______ of actinopterygians
Swim bladder
fish deal with ___ because density of water is greater than that of air
Drag
the friction created between the surface of the fish’s body and the water
surrounding it
viscous drag
pressure differences created by the displacement of water as a fish
moves
inertial drag
evolutionary trend in the
jaw mechanics of Actinopterygian (ray-finned) fishes
jaw protrusion
Carp and Perch skulls – more advanced actinopterygians develop varying degrees of increased
jaw mobility
premaxilla and maxilla
dentary
the mouth is located at the anterior tip of the fishes head. ______ mouth
are typical of fishes that move throughout the water column in search of food
terminal mouth
the mouth is located on the upper surface of the head. ______ mouths are
seen in fishes that specialize in swimming just below and take food from the water surface.
superior mouth
the mouth is located on the underside of the head. ______ mouths are typical
of bottom dwelling fish that either search the sediment for food (rays, sturgeon) or graze on food growing on the substrate (sucker, plecostomus).
inferior mouth
recurved, sharp and conical teeth arranged in rows. ________ teeth are found in predatory fishes and are used to pierce and hold prey.
Caniniform
mall needle-like teeth arranged in patches as opposed to rows. Typical of predatory fish, ________ teeth are used to provide added grip in specific areas of the mouth.
Villiform
even smaller than villiform teeth, forming sandpaper like patches. Also seen in
predatory fishes, cardiform teeth are too small to pierce but likely increase grip
Cardiform
Flat blade-like teeth arranged in rows. Triangular teeth are used for slicing tissue
triangular
teeth with flattened or globular surfaces. Molariform teeth are typical of fishes
that crush hard shelled animals like clams or snails
molariform
– teeth fused into incisor-like shapes sometimes forming a beak-like structure.
Coalesced teeth are usually found in fish which scrape food from hard surfaces
coaleced
different forms of teeth (pointed or molariform) form on the muscular gill
arch and are used in processing food.
pharyngeal teeth
projections on the inside of gill arches aid some fish in filter feeding or prevent
passage of food particles through gill slits
gill rakers
the ______ covering of most fishes provides a protective barrier against abrasion or
predation. dermally derived and usually include bone, dentine and
enamel
scales
sharks scales
placoid
gars scales
ganoid
most osteichthyans
cycloid and ctenoid
Armor-like enlarged scales overlap considerably (catfish) or form thick closely packed
plates (trunkfish)
plates
elongate scales projecting outward from the body (Spiny puffer, Sculpin, Plecostomus)
spines
Poisonous fishes (often aposematic in colour), have toxins in their flesh capable of
killing predators that bite or eat them (Puffer).
poison
Some fish employ projecting fin spines to delivery toxins into predators (Stonecat)
venom
can be used like colouration to obscure the silhouette or startle attackers.
Bioluminescence is also used in some species for communication and for luring prey.
bioluminescence
Fishes of the family Sciaenidae (known as drums or croakers) create drumming
sounds by beating abdominal muscles against their large swim bladders. This mode of sound
production is more common in males and is usually associated with breeding
drumming
– Sometimes caused by the grinding of pharyngeal teeth, but more commonly as
the result of contact between specialized bony processes at the base of the pectoral fin,
stridulation is usually used as a distress signal or as part of a territorial display
stridulation
– Found in members of the Superorder Ostariophysi – a Taxon you will observe
next week. Also known as ‘fear scents’, Schreckstoff is released from the fish’s flesh when
damaged. This in turn, warns conspecifics nearby that they should be on the ‘lookout’ for
potential danger.
schreckstoff
Many fish species are capable of generating weak electrical signals used for
navigation and communication among conspecifics (members of the same species). More
common are the examples of electrogenic fish which produce strong electric pulses in order to
stun prey or possible predators. Note the variety of electric fishes provided.
electrogenesis
makes a fish’s body, or part thereof, less visible to
predators or prey.
cryptic colouration
wavelengths in the red region of the light spectrum are the
first to be filtered out as light passes through water. Nocturnal fishes or fishes
that live at moderate depths are often coloured red and are thus concealed as
red light doesn’t reach them.
red colouration
camouflaged fishes have pigmentation that matches well with
their habitual environment so they blend in. Common in bottom dwelling
species, camouflage is found in both predators and prey. Many freshwater
fishes have Par marks (vertical bands) that blend well with aquatic plants
(especially common in juveniles).
camoflage
describing a colouration where the dorsal surface is dark and
the ventral surface is light. Countershading is very common in open water fishes
and serves to allow them to blend in with a uniform background when viewed
from above (surrounded by dark deep water) or below (surrounded by light
coming from surface)
countershading
disruptive colouration may make individuals stand out
against a neutral background, but helps to conceal individuals within large
groups or deflect a predator’s attention toward less vital parts of the body.
Many schooling fishes are striped, blending into one another, while others may
bear lines that obscure the eye or fake ‘eyespots’.
disruptive colouration
Warning or bright colouration is common to fishes with toxins in their
bodies. Would-be predators avoid specific patterns or colours associated with poisonous
species.
aposematic colouration
– Fishes that display colours related to sex or breeding status. Many fish
species display Sexual dimorphism (males and females coloured differently).
Social colouration
A plesiomorphic trait of all extant jawed fishes, the lateral line is a system
of canals in the skin, housing cells that sense changes in water pressure, movement and
vibration.
lateral line system
Possibly present in other groups, ampullae of Lorenzini are most
abundant and obvious in chondrichthyan fishes. The ampullae are conspicuous pores distributed
about the head region that house electro-sensory cells. Sharks and rays use these pores to
detect electrical signals produced by muscle activity of other fishes, allowing them to locate
cryptically coloured or buried prey.
ampullae of lorenzi
Found only in members of the Superorder Ostariophysi, Webberian
ossicles are small bones modified from anterior vertebral processes which form a connection
between the swim bladder and the canals of the inner ear, thus enhancing the sense of hearing.
webberian ossicles
Barbels are sensory, whisker-like appendages located near the mouth on many species
of fish. The fact this character appears scattered throughout the fish family tree, suggests that it
may have evolved separately several times, or that it may be a primitive feature which has been
repeatedly lost.
Barbels
Hagfishes (~75 species)
Hagfish are scaleless eel-shaped fish lacking jaws and paired
fins. They are exclusively marine (salt water) and typically
scavenge on carrion. Hagfish are able to produce copious
amounts of slime in response to potential predators making
them difficult to hold onto and sometimes causing the predator
to choke on the slime.
Look for – long slender body – no scales visible – no jaws – small
eyes covered with skin - sensory barbels (fleshy projections)
around mouth
Myxiniformes
Petromyzontiformes
Chondrichthyes
Holocephali
Elasmobranchii
Sarcopterygii
Osteichthyes
Actinopterygii
Polypteriformes
Acipenseriformes
Lepisosteiformes
Amiiformes
Osteoglossiformes
Anguilliformes
Clupeiformes
Ostariophysi
Cypriniformes
Characiformes
Siluriformes
Gymnotiformes
Esociformes
Salmoniformes
Anadromous
Salmo trutta – Brown trout
Oncorhynchus mykiss – Rainbow trout
Salvelinus confluentus – Bull trout
Salvelinus fontinalis – Brook trout
Prosopium williamsoni – Mountain whitefish
Coregonus clupeaformis – Lake whitefish
Percopsiformes
Gadiformes
Gasterosteiformes
Sygnathiformes
Scorpaeniformes
Perciformes
Pleuronectiformes
Tetraodontiformes
Actinistia
Dipnoi
