Form versus Function in Form versus Function in FishesFishes

Megan EnnesMegan Ennes

In conjunction with the North In conjunction with the North Carolina Aquarium at Fort Carolina Aquarium at Fort

FisherFisher

Form versus FunctionForm versus Function

• Body shape fits the needs of the Body shape fits the needs of the animalanimal

• Outside (environmental) factors can Outside (environmental) factors can influence the development of an influence the development of an animalanimal

Anatomical DirectionsAnatomical Directions

• DorsalDorsal

• VentralVentral

• CranialCranial

• CaudalCaudal

• Anterior Anterior

• PosteriorPosterior

Fish PartsFish Parts

Mouth ShapeMouth Shape

• A fish’s mouth tells A fish’s mouth tells you where in the you where in the water column it water column it feedsfeeds

• You can also tell You can also tell how it feedshow it feeds

Superior MouthSuperior Mouth

• Points upPoints up

• Feeds at the Feeds at the surfacesurface

• Often paired with a Often paired with a flat backflat back

Tarpon Tarpon Megalops atlanticusMegalops atlanticus

Terminal MouthTerminal Mouth

• Located at the end Located at the end of the bodyof the body

• Usually feeds Usually feeds midwatermidwater

• ““Normal” mouthNormal” mouth

• Eat things in front Eat things in front of themof them

Yellow Tail Snapper Yellow Tail Snapper Ocyurus chrysurusOcyurus chrysurus

Inferior MouthInferior Mouth

• Located ventrallyLocated ventrally

• Usually bottom Usually bottom feedersfeeders

• Often accompanied Often accompanied by barbelsby barbels

• Used for locating Used for locating foodfood

Atlantic SturgeonAtlantic SturgeonAcipenser oxyrhinchusAcipenser oxyrhinchus

ElongatedElongated

• Greater surface Greater surface area to catch food area to catch food withwith

Long Nose GarLong Nose GarLepisosteus osseus Lepisosteus osseus

http://rol.freenet.columbus.oh.us/aquatic_long.gif

Blue Ribbon EelBlue Ribbon EelRhinomuraena quaesitaRhinomuraena quaesita

Tubular Mouth Tubular Mouth

• Terminal mouthTerminal mouth

• Often fusedOften fused

• Suction feedingSuction feeding

• StrawStraw

Lined Seahorse Lined Seahorse Hippocamus erectusHippocamus erectus

Body ShapeBody Shape

• By looking at the By looking at the overall shape of a overall shape of a fish, you can get fish, you can get an idea of where an idea of where they live within the they live within the aquatic aquatic environment. environment.

Body ShapesBody Shapes

• Fish that live at the surface usually have Fish that live at the surface usually have a flattened back and an upturned mouth. a flattened back and an upturned mouth.

• Fish that live in slow-moving waters Fish that live in slow-moving waters usually have tall bodies and are laterally usually have tall bodies and are laterally compressed.compressed.

• Bottom-dwelling fish have flattened Bottom-dwelling fish have flattened bellies and inferior or down turned bellies and inferior or down turned mouths mouths

Surface swimmersSurface swimmers

• Fish that live at the surface usually Fish that live at the surface usually have a flattened back and an have a flattened back and an upturned mouth. upturned mouth.

• Flat NeedlefishFlat Needlefish

Slow Moving WatersSlow Moving Waters

• Fish that live in Fish that live in slow-moving slow-moving waters usually waters usually have tall bodies have tall bodies and are laterally and are laterally compressed. compressed.

• LookdownsLookdowns

• Selene vomerSelene vomer

Bottom FeedersBottom Feeders

• Bottom-dwelling fish often have Bottom-dwelling fish often have flattened bellies and inferior or down flattened bellies and inferior or down turned mouthsturned mouths

Southern Stingray Southern Stingray Dasyatis americanaDasyatis americana

Fast Moving WaterFast Moving Water

• In fast moving In fast moving waters a slender, waters a slender, torpedo shape is torpedo shape is better better

• This body shape is This body shape is also good for fish also good for fish who live far from who live far from the reef: speedthe reef: speed

Atlantic Mackerel Atlantic Mackerel Scomber scombrusScomber scombrus

Fat and Wide BodiesFat and Wide Bodies

• Good Good maneuverabilitymaneuverability

• Better for close to Better for close to the reefthe reef

• Easier to move Easier to move around coralsaround corals

French Angelfish French Angelfish Pomacanthus paruPomacanthus paru

Eel-like bodyEel-like body

• This long body This long body shape is perfect for shape is perfect for moving through moving through small spaces: small spaces: especially holes and especially holes and cavescaves

• The trunk is The trunk is undulated to undulated to provide the provide the propulsive forcepropulsive force

Green Moray Eel Green Moray Eel Gymnothorax prasinusGymnothorax prasinus

Caudal Fin: TailCaudal Fin: Tail

• The caudal fin, or tail, is used for The caudal fin, or tail, is used for propulsion, or movement, in most propulsion, or movement, in most fish species.fish species.

Lunate TailsLunate Tails

• Fishes with lunate Fishes with lunate are strong, fast are strong, fast swimmers.swimmers.

• They are capable They are capable of swimming for of swimming for long periods of long periods of timetime

Yellowfin Tuna Yellowfin Tuna Thunnus Thunnus albacaresalbacares

Forked TailsForked Tails

• Fish that spend a Fish that spend a lot of time lot of time swimming often swimming often have forked tailshave forked tails

Channel Catfish Channel Catfish  Ictalurus punctatusIctalurus punctatus

Truncate and Rounded TailsTruncate and Rounded Tails

• Fishes with Fishes with truncate or truncate or rounded caudal fins rounded caudal fins are usually strong, are usually strong, slow swimmers.slow swimmers.

• Fishes that live Fishes that live near the reef often near the reef often have this type of have this type of tail because it aids tail because it aids in maneuverability.in maneuverability.

Truncate

Rounded

Majestic Angelfish Majestic Angelfish Pomacanthus navarchusPomacanthus navarchus

Heterocercal TailHeterocercal Tail

• A tail with a long A tail with a long upper lobe and a upper lobe and a shorter lower lobeshorter lower lobe

• Common in SharksCommon in Sharks

Juvenile Tiger Shark Juvenile Tiger Shark Galeocerdo cuvierGaleocerdo cuvier

http://www.flmnh.ufl.edu/fish/gallery/descript/TigerShark/juvenile.JPG

Eel-like TailEel-like Tail

• The propulsive force The propulsive force for a fish with this for a fish with this type of tail begins in type of tail begins in the trunk of the body the trunk of the body and moves as a and moves as a wave down through wave down through the tail.the tail.

• This shape is great This shape is great for fitting into holes for fitting into holes and tunnels. and tunnels.

Ocellated Moray EelOcellated Moray EelGymnothorax saxicolaGymnothorax saxicola

Create your own fishCreate your own fish

• Use the second worksheet we gave youUse the second worksheet we gave you• Cut out the different fish shapesCut out the different fish shapes• Choose one of each and glue them to a Choose one of each and glue them to a

sheet of papersheet of paper• Color your fish and give it a designColor your fish and give it a design• Name your fishName your fish• Write a paragraph telling the function Write a paragraph telling the function

of each part, where it lives, ect. of each part, where it lives, ect.

Examples of colorationExamples of coloration

What’s next?What’s next?

• Choose a tankChoose a tank

• Choose 3 fishes to sketch in your Choose 3 fishes to sketch in your notebooknotebook

• Find the name of your fishesFind the name of your fishes

• Label that parts of your fish using the Label that parts of your fish using the worksheet we just madeworksheet we just made

For each fish answer the For each fish answer the following questions:following questions:1. Where do you think this fish lives on the reef? 1. Where do you think this fish lives on the reef?

What about this fish leads you to that decision?What about this fish leads you to that decision?2. Where do you think the fish eats? What mouth 2. Where do you think the fish eats? What mouth

shape does it have?shape does it have?3. Is it a schooling fish or does it appear to be 3. Is it a schooling fish or does it appear to be

solitary?solitary?4. Is your fish territorial? How can you tell?4. Is your fish territorial? How can you tell?5. How does your fish swim? Is it built for speed? 5. How does your fish swim? Is it built for speed?

Maneuverability? How can you tell?Maneuverability? How can you tell?6. Does your fish live close to the reef or far away? 6. Does your fish live close to the reef or far away?

What body shape does it have?What body shape does it have?7. Is your fish well adapted to its environment? Why 7. Is your fish well adapted to its environment? Why

or why not?or why not?

After your observations:After your observations:

• We’ll come back to the room and talk We’ll come back to the room and talk about what fish we chose.about what fish we chose.

• We’ll discuss as a group what we We’ll discuss as a group what we decided for each fish.decided for each fish.

• We do not expect you to be right, We do not expect you to be right, just be able to explain why you made just be able to explain why you made the decision you did.the decision you did.