Bony FishBony Fish

Class OsteichthyesClass Osteichthyes

Includes all bony fishesIncludes all bony fishes Cold-blooded vertebratesCold-blooded vertebrates Largest class of all vertebratesLargest class of all vertebrates Accounts for 96% of all fish species.Accounts for 96% of all fish species. Freshwater and MarineFreshwater and Marine

Distinguishing FeaturesDistinguishing Features

Skeleton of boneSkeleton of bone ScalesScales Paired finsPaired fins Single pair of gill openingsSingle pair of gill openings JawsJaws Paired nostrilsPaired nostrils

Body ShapeBody Shape

Primarily Fusiform shapePrimarily Fusiform shape Deviate in 3 waysDeviate in 3 ways

Laterally compressed: common for fish who Laterally compressed: common for fish who live in dense cover or coral reefs. live in dense cover or coral reefs. Example: ButterflyfishExample: Butterflyfish

Depressed: common in bottom dwelling fishDepressed: common in bottom dwelling fishExample: Sea MothExample: Sea Moth

Elongated: common in open ocean fish and Elongated: common in open ocean fish and eels. Example: Barracuda eels. Example: Barracuda

Laterally CompressedLaterally Compressed

Butterfly fishButterfly fish

Depressed body shapeDepressed body shape

Sea MothSea Moth

ElongatedElongated

BarracudaBarracuda

ColorationColoration

Most fish species have pigmentation Most fish species have pigmentation called chromatophores.called chromatophores.

Chromatophores can contract and Chromatophores can contract and expand to change colors.expand to change colors.

Iridescent- Reflective scalesIridescent- Reflective scales Cave dwelling fish lack pigmentation. Cave dwelling fish lack pigmentation.

ChromatophoreChromatophore

Fish using chromatophores to match Fish using chromatophores to match backgroundbackground

IridescentIridescent

Fish reflects light and matches Fish reflects light and matches backgroundbackground

Purpose of ColorationPurpose of Coloration CamouflageCamouflage

CountershadingCountershading Disruptive coloration- breaks up animals shapeDisruptive coloration- breaks up animals shape Change color to match surroundingsChange color to match surroundings

Advertisement to other fishesAdvertisement to other fishes Mate attraction and recognitionMate attraction and recognition Territorial behaviorTerritorial behavior Warning signsWarning signs

Disruptive ColorationDisruptive Coloration

Moorish IdolsMoorish Idols

BioluminescenceBioluminescence

Some species produce light through a Some species produce light through a chemical reaction process.chemical reaction process.

Used to attract mates, confuse or deter Used to attract mates, confuse or deter predators, or attract preypredators, or attract prey

Light production occurs inLight production occurs in Photophores- light producing cellsPhotophores- light producing cells Light-producing bacteria- live in or on the Light-producing bacteria- live in or on the

fish in a symbiotic relationshipfish in a symbiotic relationship

Attract PreyAttract Prey

Angler FishAngler Fish

FinsFins Two kinds of fins-Two kinds of fins-

Paired fins- Pectoral and PelvicPaired fins- Pectoral and Pelvic Median fins- Dorsal, Caudal, and analMedian fins- Dorsal, Caudal, and anal

Most fins are supported by rays (soft or rigid)Most fins are supported by rays (soft or rigid) Some species have spiny rays associated Some species have spiny rays associated

with venom glands.with venom glands. Example: Stonefish, Lionfish, ScorpionfishExample: Stonefish, Lionfish, Scorpionfish

Venomous SpinesVenomous Spines

Lionfish, warning colorsLionfish, warning colors

Head StructureHead Structure

Mouth- located on anterior endMouth- located on anterior end Nostrils- used for smell, no connection to Nostrils- used for smell, no connection to

mouthmouth Gills- Single pair of openings, covered by Gills- Single pair of openings, covered by

a flexible plate called Operculum.a flexible plate called Operculum. Teeth- fused to the jaw boneTeeth- fused to the jaw bone Eyes- size and position vary by habitat Eyes- size and position vary by habitat

and behavior. Deeper = bigger eyesand behavior. Deeper = bigger eyes

OperculumOperculum

ScalesScales

Scales are thin and flexibleScales are thin and flexible Develop from bone tissueDevelop from bone tissue Scales overlap from head to toe to Scales overlap from head to toe to

reduce drag.reduce drag. Covered by a thin layer of tissue as well Covered by a thin layer of tissue as well

as mucus.as mucus. Some bony fishes only have scales on Some bony fishes only have scales on

portion of body, or none at allportion of body, or none at all

4 Types of Scales4 Types of Scales

Cosmoid (primitive)Cosmoid (primitive)

GanoidGanoid

CycloidCycloid

CtenoidCtenoid

Purpose of MucusPurpose of Mucus

Helps to protect fish from infectionHelps to protect fish from infection Covers body to conceal scent from Covers body to conceal scent from

predatorspredators Example: Parrotfish enclose their bodies in Example: Parrotfish enclose their bodies in

a mucus bubble at night so predators cannot a mucus bubble at night so predators cannot detect themdetect them

Some juvenile fish feed on the mucus of Some juvenile fish feed on the mucus of parentsparents

Parrotfish enclosed in Parrotfish enclosed in MucusMucus

BuoyancyBuoyancy

Buoyancy provided by gas-filled swim Buoyancy provided by gas-filled swim bladder.bladder.

Gas volume changes as the fish changes Gas volume changes as the fish changes depths.depths.

Swim BladderSwim Bladder

LifespanLifespan

Average lifespan of fish is 12-20 years.Average lifespan of fish is 12-20 years. Larger species typically live longer than Larger species typically live longer than

smaller species.smaller species. Infections and parasites are common Infections and parasites are common

causes of death in fish. causes of death in fish.

3 Types of fish Movement3 Types of fish Movement

1) Most fish swim with a rhythmic side to side 1) Most fish swim with a rhythmic side to side motion of the body or caudal finmotion of the body or caudal fin

2) Elongated fish like eels swim using a 2) Elongated fish like eels swim using a serpentine motion. They undulate their body in serpentine motion. They undulate their body in lateral waves that travel from head to tail.lateral waves that travel from head to tail.

3) Other fish, like tuna, have shorter bodies 3) Other fish, like tuna, have shorter bodies and swim by moving only powerful and rigid and swim by moving only powerful and rigid caudal tail. (fastest)caudal tail. (fastest)

ReproductionReproduction Most fish reproduce externally by spawningMost fish reproduce externally by spawning Females lay eggs and males release spermFemales lay eggs and males release sperm Eggs willEggs will

1. Drift in water column1. Drift in water column 2. sink and remain on bottom2. sink and remain on bottom 3. Eggs may be sticky and attach to plants etc.3. Eggs may be sticky and attach to plants etc. 4. Some fish brood eggs in mouth4. Some fish brood eggs in mouth 5. Some bury eggs5. Some bury eggs

ReproductionReproduction

Some fish have internal fertilization and are Some fish have internal fertilization and are ovoviviparous.ovoviviparous. Seahorse: Females deposit eggs in a pouch on the male’s Seahorse: Females deposit eggs in a pouch on the male’s

abdomen.abdomen. The male then releases sperm and the eggs develop inside The male then releases sperm and the eggs develop inside

the male.the male. The male then gives birthThe male then gives birth

Some fish are hermaphrodites.Some fish are hermaphrodites. Sequential - Born one sex but change at some point during life Sequential - Born one sex but change at some point during life

due to social hierarchy/behaviordue to social hierarchy/behavior Synchronous- Have both sperm and egg producing organs at Synchronous- Have both sperm and egg producing organs at

the same time.the same time.

EggsEggs

The number of offspring is inversely The number of offspring is inversely related to the chances of the eggs related to the chances of the eggs reaching maturity.reaching maturity.

The larger number of eggs laid means The larger number of eggs laid means there is a lower chance of surviving. there is a lower chance of surviving. The Common Mola lays 28 million eggs in a The Common Mola lays 28 million eggs in a

single season.single season. The Atlantic Tarpon releases over 100 The Atlantic Tarpon releases over 100

million every time it spawns.million every time it spawns.

Breeding BehaviorBreeding Behavior

Various factors may influence breeding Various factors may influence breeding behavior.behavior. 1. Change in duration of sunlight1. Change in duration of sunlight 2. Temperature change of the water2. Temperature change of the water 3. Presence of the opposite sex3. Presence of the opposite sex 4. Change in currents, tide, or stages of the 4. Change in currents, tide, or stages of the

moon.moon.

Breeding CyclesBreeding Cycles Reproduction is generally cyclic in bony fish.Reproduction is generally cyclic in bony fish. Some spawn many times a year, while Some spawn many times a year, while

others spawn only once a lifetime and then others spawn only once a lifetime and then die soon after. Ex: Pacific Salmondie soon after. Ex: Pacific Salmon

Anadromous- Fish that spend most of their Anadromous- Fish that spend most of their time in the sea, but breed in rivers.time in the sea, but breed in rivers.

Catadromous- FW fish that migrate to the Catadromous- FW fish that migrate to the sea to breed.sea to breed.

SensesSenses

Hearing- No external opening; inner ear for Hearing- No external opening; inner ear for equilibrium, detecting acceleration, and equilibrium, detecting acceleration, and hearing.hearing.

Eyesight- Well developed for some species.Eyesight- Well developed for some species. Taste- taste buds inside mouth, responsible for Taste- taste buds inside mouth, responsible for

accepting or rejecting preyaccepting or rejecting prey Smell- well developedSmell- well developed Lateral Line- VibrationsLateral Line- Vibrations

Human InteractionHuman Interaction

1. Commercial Fishing1. Commercial Fishing 2. Recreational fishing2. Recreational fishing 3. Habitat destruction- building dams, 3. Habitat destruction- building dams,

stream diversion, destroy coastal stream diversion, destroy coastal wetlandswetlands

4. Pollution4. Pollution 5. Introduced species5. Introduced species 6. Aquarium Collection6. Aquarium Collection