Biology 2 : ZoologyRey John B.

RebucasUSeP (Tagum)-

BEEd

SARCOPTERYGII:

Lobe-finned fish

ACTINOPTERYGII: Ray-finned Fish

General Description

Characteristics

Classification

ACTINOPTERYGII: Ray-finned Fish

GENERAL DESCRIPTIONRay-finned Fishes

Greek: aktis=ray + pteryx =fin/wingContain all the familiar bony fishes –

more than 23,600 species.More than 50 % of known fishes.Teleosts make up 96% of all living fish.Swim bladder moved away from any

function for respiration, used only for buoyancy.

Fins are flexible, controlled by muscles in body, fins are supported by spines rather than bones.

GENERAL DESCRIPTION

Morphological Trends

Heavy dermal armor replaced by light, thin, flexible cycloid and ctenoid scales. Increased mobility helps fish avoid predators and in

food getting.Some eels, catfishes and others completely lost scales.

Fins changed to provide greater mobility and serve a variety of functions: braking, streamlining and social communication.

The homocercal tail allowed greater speed and buoyancy. The swim bladder shifted from primarily respiratory to

buoyancy in function.The jaw changed to increase suctioning and protrusion to

secure food.

BASIC FISH ANATOMYInternal

BASIC FISH ANATOMYExternal

OUTER COVERINGMucus – reduces friction and prevents

infectionScales – protective outer cover

Overlap like roof shinglesCan tell age of fish

TYPES OF OUTER COVERINGGanoid- diamond shapedPlacoid- cartilaginous fishesCtenoid- comb-like ridges Cycloid-light, thin, & flexibleMyomeres-zigzag bands

CLASSIFICATION1. CHONDROSTEANS have heterocercal tails and

ganoid scales like the sturgeons.

CLASSIFICATION2.NEOPTERYGIANS

One lineage of early neopterygians led to the modern bony fishes (teleosts).

Early type neopterygians include the bowfin and gars.

CLASSIFICATION2.1 SEMIONOTIFORMES (Lepisosteiformes) ganoid scales abbreviated heterocercal tail intestine with spiral valve lung-like gas bladder

2.2 AMIIFORMES(Amia calva) ganoid scales abbreviated heterocercal

tail intestine with spiral value

CLASSIFICATION• 2.3 TELEOSTSFins diversified for a variety of functions:

camouflage, communication, complex movements, streamlining, etc.

SARCOPTERYGII: Lobe-finned Fish

GENERAL DESCRIPTIONThis group was much more abundant during the

Devonian period.Rhipidistians are an extinct group of sarcopterygians

that led to tetrapods.

GENERAL DESCRIPTION Name means “fleshy finned fishes” First appeared 385 million years ago Ancestors of land vertebrates! Internal nostrils and cosmoid scales.

GENERAL DESCRIPTION Some lungfishes can live out of the water for long periods of

time.During long dry seasons, the African lungfish can burrow

down into the mud and secrete lots of slime forming a hard cocoon where they will estivate until the rains return.

BASIC FISH ANATOMY

Bony leg-like supports, external to body.

Pectoral fin

Pelvic fin

BASIC FISH ANATOMY All early sarcopterygians had lungs as well as gills and a

heterocercal tail.Later sarcopterygians have a continuous flexible fin

around the tail. They have fleshy, paired lobed fins that may have been

used like legs to scuttle along the bottom.

CLASSIFICATION

Coelaca

nthimorp

ha

Dipnoi

Osteolep

imorpha -

extin

ct

CLASSIFICATION1.CROSSOPTERYGII/COELACANTHIMORPHA “Coelacanths”Cosmoid scaleTwo dorsal fins and fleshy paired fins with skeletal

elements.Thought to be extinct till foundSometimes grouped with lungfish in Subclass

Sarcopterygii.

CLASSIFICATION First discovered by Marjorie Courtenay-Latimer year

1939 and she named it Latimeria chalumnae (“Old fourlegs”).

Secondly discovered by J. L. B. Smith the 2nd specie in 1952.

Comoro Islands (now Kenia, Madagascar, South Africa…)

Mark Erdmann conducted a genetic study through live observations in Indonesia (Sulawesi), 1998 after his successful discovery he named it Latimeria menadoensis (“King of the Sea”).

CLASSIFICATION2. DIPNOI “Lungfish” Jaw fused to brain case Caudal, dorsal, and anal fin connected Pectoral fins long and tubular Air breathing organ attached to esophagus

CLASSIFICATION3. OSTEOLEPIMORPHA - EXTINCT

Sister group of modern tetrapodsSimilar fins to Devonian Amphibians limbsOther morphological similarities

Habitat Locomotion

Mode of Nutrition Characteristics Reproduction

HABITAT SARCOPTERYGIANS are mostly found in river mouths near

the oceans (estuaries) and also in the freshwater habitats like lakes.

ACTINOPTERYGIANS in habit a va ri ety of ex treme en vi ron ments. These in clude high al ti tude lakes and streams, desert springs, sub ter ranean caves, ephemeral pools, polar seas, and the depths of the ocean, mud flat habi tats, hill stream loaches and steep, tor ren tial wa ter courses of Asi atic hill streams (C. Patterson, 1981).

Across these habi tats water tem per a tures may range from -1.8˚C to nearly 40˚C, pH lev els from 4 to 10+, dis solved oxy gen lev els from zero to sat u ra tion, salin i ties from 0 to 90 parts per mil lion and depths rang ing from 0 to 7,000 m (Dav en port and Sayer 1993 in Moyle and Cech 2004:1).

LOCOMOTION Speed

Most fishes swim maximally at ten body lengths per second; a larger fish therefore swims faster.

Fishes use trunk and tail musculature to propel them through the water.

Many fast swimmers are streamlined with grooves so their fins can lie flat.

LOCOMOTION Nektonic – swimmers control movement against current

Move to foodEscape predator

Streamlining to reduce drag = teardrop shape =fusiform Most fish swim by moving tail side to side Mucous reduces drag Homocercal tail – top and

bottom same size

BOUYANCY The energy cost per kilogram of body

weight for traveling one kilometer is 0.39 Kcal for swimming, 1.45 Kcal for flying and 5.43 for walking.

Flexible fishes like eels use a serpentine movement.Not very efficient for high speed.

Fast swimmers are less flexible.Body undulations limited to caudal

region.The heterocercal tail provides lift

as it moves from side to side.

BOUYANCY Gas-filled swim bladder – to maintain

position in water Control quantity of gas Not present in fast moving fish or sharks

A fish can control depth by adjusting the volume of gas in the swim bladder.

Due to pressure, as a fish descends, the bladder is compressed making the total density of the fish greater.

As a fish ascends, the bladder expands making the fish lighter and it will rise ever faster.

BOUYANCYGas may be removed in two ways: Physostomous and

Physoclistous. Physostomous fishes (more primitive, e.g. trout) have a

pneumatic duct that connects the swim bladder and the esophagus. Air can be expelled through the duct.Gas must be secreted into the swim bladder from the blood,

although some species can gulp air to fill the swim bladder.• Physoclistous fishes (more derived, e.g. advanced teleosts) the

pneumatic duct has been lost. Gas must be absorbed by blood from the highly vascularized ovale.– Gas is secreted into the swim bladder from the blood at the

gas gland.

OSMOTIC REGULATION Freshwater fishes

(hyperosmotic regulators) must have a way to get rid of water that enters their bodies by diffusion through the gills.Water enters the body, salts

are lost by diffusion.Water is pumped out by the

opisthonephric kidney which can form very dilute urine.

Salt absorbing cells in the gill actively move salt from the water into the blood.

OSMOTIC REGULATION Saltwater fishes (hypoosmotic

regulators) have a lower blood salt concentration than the seawater.Tend to lose water and gain

salts.Marine teleosts drink

seawater.Salts are carried by the blood

to the gills where they are secreted out by salt-secretory cells.

Other salts are voided with feces or excreted by the kidney.

CHARACTERISTICSHEARING

The bodies of fishes are nearly the same density as water.Makes hearing difficult.

Weberian ossicles, found in minnows, suckers, & catfish, improves hearing.

Sound detection starts in swim bladder (sound vibrates easily in air) and is transmitted to the inner ear by Weberian ossicles.

CHARACTERISTICS VISIONObtain better visionFish eyes focus by moving

closer or farther away from subject

Many have color vision

CHARACTERISTICS LATERAL LINE SYSTEM

Line of pores and canals running down body.Detect vibrations, changes in current direction and

water pressure.

CHARACTERISTICSRESPIRATION

Fish gills are composed of thin filaments covered with an epidermal membrane that is folded into lamellae.Richly supplied with blood vessels.Located inside the pharyngeal

cavity.Covered with an operculum in

bony fishes.

CHARACTERISTICSRESPIRATION

Water must be continuously pumped over the gills.

A countercurrent system is found where the flow of water is opposite to the flow of blood.Deoxygenated blood

encounters the freshest water with the highest oxygen content.

CHARACTERISTICSPROTECTION

Camouflage ex. sargassum fish Spines ex. blow fish Countershading ex. tuna fish Disappear ex. flying fish Deceptive markings ex. butterfly fish

CHARACTERISTICS SCHOOLING

¼ of all species at some point in life

Looks like one large individualConfuses predatorHard to catch one fishEasier feedingEasier matingNo leaders

MODE OF NUTRITION

MODE OF NUTRITION Most fishes are CARNIVORES and prey on everything from

zooplankton to large vertebrates.Some deep-sea fishes can eat victims twice their size – an

adaptation to scarce food.Most fishes can’t chew with their jaws (this would block

water flow over the gills), many have pharyngeal teeth in their throats.

Large-mouthed predators can suck prey in by suddenly opening their mouths.

MODE OF NUTRITION

HERBIVOROUS fishes eat plants and micro-algae.Most common on coral reefs –

parrotfishes, damselfishes and etc.

And tropical freshwater habitats – minnows, characins, catfishes.

Grazers – fish that feed primarily on seaweeds and other plants

Some develop beaks to help scrape off algae or pieces of coral

MODE OF NUTRITION Suspension feeders filter microorganisms

from the water using gill rakers.Herring-like fishes are common –

menhaden, herring, anchovies etc.Many larval fishes.

Most are pelagic fishes that travel in large schools.

Other groups are scavengers that eat dead and dying animals.

Detritivores that consume fine particulate organic matter.

Parasites that consume parts of other live fishes.

REPRODUCTION The four major types: monogamy,

polyg yny, polyandry and polyg y nandry or promis cu ity - both males and fe males have mul ti ple part ners dur ing the breed ing sea son.

Most fishes are dioecious with external fertilization and external development – oviparity.

Ovoviviparous species (guppies, mollies, surfperches) bear live young after development in the ovarian cavity of the female.

REPRODUCTIONFertilized eggs may be pelagic

and hatch into pelagic larvae.Large yolky benthic eggs are

often attached to vegetation or deposited in nests, buried, or even carried in the mouth.Many benthic spawners guard

their eggs.Usually the male.

REPRODUCTION In some species, males defend nest sites and

perform courtship rituals to entice females to lay their eggs in his nest. Sometimes, several females will lay eggs in a nest.The male will guard the eggs from

predators and will also fan them with his fins to aerate them.

Separate sexes External fertilization = spawning

Female releases eggsMale releases sperm on top

MIGRATION OCEAN ODRO MOUS- fishes that stay within salt wa ter POTA MOD RO MOUS- fishes that stay in fresh water in their

en tire lives. DI ADRO MOUS- fishes that mi grate be tween the salt and

fresh water as part of their life cycle (to re pro duce) or to feed. ANADRO MOUS- growth oc curs pri mar ily in salt wa ter but

move into fresh wa ter to spawn like salmons. CATADRO MOUS- growth oc curs pri mar ily in fresh wa ter but

move into salt wa ter to spawn like anguilid eels. AM PHIDRO MOUS- mi grate be tween salt and fresh water

for spawn ing and feed ing pur poses like go b ies and sleep ers.

REFERENCES Bond, C. E. Biology of Fishes. Philadelphia, W.B. Saunders Co., 1979. Burton, Maurice and Robert B. Encyclopedia of Fish. 1984. St. Louis: BPC Publishing,.  Evans, David,. The Physiology of Fishes. Boca Raton: CRC Press, 1993.  Fichter, George, S. and Edward, C. M. The Fresh & Saltwater Fishes of the World. New

York: Greenwich House, 1983.  Hauser, H. Book of Marine Fishes. Glen Cove, New York: Pisces Books/Tetra Press,

1984.  Jordan, D., S.  The Genera of Fishes, and a Classification of Fishes. Stanford: Stanford

University Press, 1983.  Nelson and Joseph S. Fishes of the World. New York: John Wiley & Sons, 1976.  Nikolsky, G.V. The Ecology of Fishes. New Jersey: TF.H. Publications, Inc. Ltd., 1978.  Ommanney, F. D. The Fishes. New York: Time, Inc., 1984.  Thompson, P. Thompson's Guide to Freshwater Fishes. Boston: Houghton Mifflin Co.,

1985. Moyle, P. B. and J. J. Cech.. Fishes: An Introduction to Ichthyology. 5th ed. Benjamin

Cummings. San Francisco, CA. 2003 Pough, F. H., C. M. Janis, and J. B. Heiser. Vertebrate Life. 8th ed. Benjamin Cummings.

New York. 2009.pp. 688

REFERENCES Clack, J. A. 2002. Gaining Ground: The Origin and Evolution of Tetrapods.

Bloomington, Ind: Indiana University Press. ISBN 0253340543. Nelson, J. S. 2006. Fishes of the World, 4th edition. Hoboken, NJ: John Wiley

& Sons. ISBN 0471250317. Rosen, D. E., P. I. Forey, B. G. Gardiner, and C. Patterson. 1981. Lungfishes,

tetrapods, paleontology, and plesiomorphy. Bull. Am. Mus. Nat. Hist. 167(4): 159-276.

Brown, C. 2003. "Sci en tific Stud ies Move Fish Up the In tel li gence Scale" (On-line). Ac cessed Sep tem ber 04, 2004 at http:// www. leeds. ac. uk/ media/ current/ fish. htm.

Froese, R., D. Pauly. 2004. "Fish Base" (On-line). Fish Base World Wide Web elec tronic pub li ca tion. Ac cessed Au gust 16, 2004 at http:// www. fishbase. org.

IUCN, 2003. "2003 IUCN Red List of Threat ened Species" (On-line). Ac cessed Au gust 16, 2004 at http:// www. redlist. org.

Thank YouAnd God Bless