Class Actinopterygii and Class Sarcopterygii
- 1. Biology 2 : Zoology Rey John B. Rebucas USeP (Tagum)-BEEd
- 3. General Description Characteristics Classification
- 5. GENERAL DESCRIPTION Ray-finned Fishes Greek: aktis=ray + pteryx =fin/wing Contain 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.
- 6. 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.
- 9. OUTER COVERING Mucus – reduces friction and prevents infection Scales – protective outer cover Overlap like roof shingles Can tell age of fish
- 10. TYPES OF OUTER COVERING Ganoid- diamond shaped Placoid- cartilaginous fishes Ctenoid- comb-like ridges Cycloid-light, thin, & flexible Myomeres-zigzag bands
- 11. CLASSIFICATION 1. CHONDROSTEANS have heterocercal tails and ganoid scales like the sturgeons.
- 12. CLASSIFICATION 2.NEOPTERYGIANS One lineage of early neopterygians led to the modern bony fishes (teleosts). Early type neopterygians include the bowfin and gars.
- 13. CLASSIFICATION 2.1 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
- 14. CLASSIFICATION • 2.3 TELEOSTS Fins diversified for a variety of functions: camouflage, communication, complex movements, streamlining, etc.
- 16. GENERAL DESCRIPTION This group was much more abundant during the Devonian period. Rhipidistians are an extinct group of sarcopterygians that led to tetrapods.
- 17. GENERAL DESCRIPTION Name means “fleshy finned fishes” First appeared 385 million years ago Ancestors of land vertebrates! Internal nostrils and cosmoid scales.
- 18. 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.
- 19. BASIC FISH ANATOMY Bony leg-like supports, external to body. Pectoral fin Pelvic fin
- 20. 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.
- 21. CLASSIFICATION
- 22. CLASSIFICATION 1.CROSSOPTERYGII/COELACANTHIMORPHA “Coelacanths” Cosmoid scale Two dorsal fins and fleshy paired fins with skeletal elements. Thought to be extinct till found Sometimes grouped with lungfish in Subclass Sarcopterygii.
- 23. 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”).
- 24. CLASSIFICATION 2. DIPNOI “Lungfish” Jaw fused to brain case Caudal, dorsal, and anal fin connected Pectoral fins long and tubular Air breathing organ attached to esophagus
- 25. CLASSIFICATION 3. OSTEOLEPIMORPHA - EXTINCT Sister group of modern tetrapods Similar fins to Devonian Amphibians limbs Other morphological similarities
- 26. Habitat Locomotion Mode of Nutrition Characteristics Reproduction
- 27. HABITAT SARCOPTERYGIANS are mostly found in river mouths near the oceans (estuaries) and also in the freshwater habitats like lakes. ACTINOPTERYGIANS inhabit a variety of extreme environ- ments. These include high altitude lakes and streams, desert springs, subterranean caves, ephemeral pools, polar seas, and the depths of the ocean, mudflat habitats, hill stream loaches and steep, torrential watercourses of Asiatic hillstreams (C. Patterson, 1981). Across these habitats water temperatures may range from - 1.8˚C to nearly 40˚C, pH levels from 4 to 10+, dissolved oxy- gen levels from zero to saturation, salinities from 0 to 90 parts per million and depths ranging from 0 to 7,000 m (Davenport and Sayer 1993 in Moyle and Cech 2004:1).
- 28. 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.
- 29. LOCOMOTION Nektonic – swimmers control movement against current Move to food Escape 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
- 30. 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.
- 31. 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.
- 32. BOUYANCY Gas 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.
- 33. 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.
- 34. 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.
- 35. CHARACTERISTICS HEARING 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.
- 36. CHARACTERISTICS VISION Obtain better vision Fish eyes focus by moving closer or farther away from subject Many have color vision
- 37. CHARACTERISTICS LATERAL LINE SYSTEM Line of pores and canals running down body. Detect vibrations, changes in current direction and water pressure.
- 38. CHARACTERISTICS RESPIRATION 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.
- 39. CHARACTERISTICS RESPIRATION 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.
- 40. CHARACTERISTICS PROTECTION Camouflage ex. sargassum fish Spines ex. blow fish Countershading ex. tuna fish Disappear ex. flying fish Deceptive markings ex. butterfly fish
- 41. CHARACTERISTICS SCHOOLING ¼ of all species at some point in life Looks like one large individual Confuses predator Hard to catch one fish Easier feeding Easier mating No leaders
- 43. 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.
- 44. 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
- 45. 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.
- 46. REPRODUCTION The four major types: monogamy, polygyny, polyandry and polygy- nandry or promiscuity - both males and females have multiple partners during the breeding 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.
- 47. REPRODUCTION Fertilized 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.
- 48. 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 eggs Male releases sperm on top
- 49. MIGRATION OCEANODROMOUS- fishes that stay within saltwater POTAMODROMOUS- fishes that stay in fresh water in their entire lives. DIADROMOUS- fishes that migrate between the salt and fresh water as part of their life cycle (to reproduce) or to feed. ANADROMOUS- growth occurs primarily in saltwater but move into freshwater to spawn like salmons. CATADROMOUS- growth occurs primarily in freshwater but move into saltwater to spawn like anguilid eels. AMPHIDROMOUS- migrate between salt and fresh water for spawning and feeding purposes like gobies and sleepers.
- 50. 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
- 51. 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. "Scientific Studies Move Fish Up the Intelligence Scale" (On- line). Accessed September 04, 2004 at http://www.leeds.ac.uk/media/current/fish.htm. Froese, R., D. Pauly. 2004. "FishBase" (On-line). FishBase World Wide Web electronic publication. Accessed August 16, 2004 at http://www.fishbase.org. IUCN, 2003. "2003 IUCN Red List of Threatened Species" (On-line). Ac- cessed August 16, 2004 at http://www.redlist.org.