Copyright Pearson Prentice Hall Biology CHAPTER 24 Fish Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ch.24 Fish Interesting Fish Facts: Gills are efficient at extracting oxygen from water that has 1/20 the oxygen of air Lateral line system detects water currents and vibrations, a sense of “distant touch” Adapted to live in medium 800 times denser than air Can adjust to the salt and water balance of their environment “Fish” refers to one or more individuals of one species “Fishes” refers to more than one species Photo Credit: © Art Wolfe/Stone Copyright Pearson Prentice Hall

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Copyright Pearson Prentice Hall History of Fish Descended from an unknown free-swimming protochordate (tunicates) ancestor about 550 million years ago Earliest fish-like vertebrates: Group of agnathan fishes Agnathans (Jawless) Include extinct ostracoderms and living hagfishes and lampreys Hagfishes lack vertebrae Lampreys have primitive vertebrae Gnathostomes (Jawed) Appear after Agnathans in fossil record with fully formed jaws Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ch. 24 Types of Fish Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ch. 24 What Is a Fish? What are the basic characteristics of fishes? Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall What Is a Fish? What Is a Fish? Fishes are aquatic vertebrates. Most fishes have paired fins, scales, and gills. Caudal fin Dorsal fin Lateral line Scales Eye Fishes come in many shapes and sizes. Like most fishes, this African cichlid has paired fins, scales, and gills. Photo Credit: ©Labat-Lanceau/AUSCAPE International Mouth Operculum (gill cover- bony fish) Anal fin Pelvic fin Pectoral fin Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Evolution of Fishes Evolution of Fishes What were the important developments during the evolution of fishes? Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Evolution of Fishes Evolution of Fishes Evolution of Fishes The evolution of jaws and the evolution of paired fins were important developments during the rise of fishes. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Evolution of Fishes Evolution of Fishes The First Fishes The earliest fishes to appear in the fossil record lived about 510 million years ago. These fishes were jawless and had bodies covered with bony plates. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Evolution of Fishes Evolution of Fishes The Arrival of Jaws and Paired Fins The evolution of jaws in fish was extremely useful. Jaws with muscles and teeth made it possible for fish to eat a wider variety of foods. Animals with jaws can also defend themselves by biting. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Evolution of Fishes Evolution of Fishes Fishes evolved paired pectoral and pelvic fins. These fins were attached to girdles—structures of cartilage or bone that support the fins. Cartilage is a strong tissue that supports the body and is softer and more flexible than bone. Paired fins gave fishes more control of body movement. Tail fins and powerful muscles gave fishes greater thrust when swimming. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Evolution of Fishes Evolution of Fishes Hagfish - only caudal fin Shark - many single and paired fins Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Evolution of Fishes The Rise of Modern Fishes Early jawed fishes soon disappeared, but left behind two major groups that continued to evolve and still survive today. One group—the ancestors of modern sharks and rays—evolved a skeleton made of strong, resilient cartilage. Chondrichthyes The other group evolved skeletons made of true bone. Osteichthyes Copyright Pearson Prentice Hall

Form and Function in Fishes How are fishes adapted for life in water? Copyright Pearson Prentice Hall

Form and Function in Fishes Adaptations to aquatic life include various modes of feeding, specialized structures for gas exchange, and paired fins for locomotion. Copyright Pearson Prentice Hall

Form and Function in Fishes Feeding Every mode of feeding is seen in fishes. A single fish may exhibit several modes of feeding, depending on the type of food available. Copyright Pearson Prentice Hall

Form and Function in Fishes Food passes through the mouth and esophagus, into the stomach. In the stomach, the food is partially broken down. Esophagus Stomach The internal organs of a typical bony fish are shown here. Mouth Copyright Pearson Prentice Hall

Form and Function in Fishes In many fishes, the food is further processed in fingerlike pouches called pyloric ceca. The pyloric ceca secretes digestive enzymes and absorbs nutrients from the digested food. Pyloric cecum The internal organs of a typical bony fish are shown here.  Copyright Pearson Prentice Hall

Form and Function in Fishes The liver and pancreas add enzymes and other digestive chemicals to the food as it moves through the digestive tract. Liver Pancreas Copyright Pearson Prentice Hall

Form and Function in Fishes The intestine completes the process of digestion and nutrient absorption. Intestine Only show “Intestine” label on this slide. Copyright Pearson Prentice Hall

Form and Function in Fishes Undigested material is eliminated through the anus. Anus Copyright Pearson Prentice Hall

Form and Function in Fishes Respiration Most fishes exchange gases using gills located on either side of the pharynx. Gills Copyright Pearson Prentice Hall

Form and Function in Fishes Fishes use their gills to exchange gases by pulling oxygen-rich water in through their mouths, pumping it over their gill filaments, and pushing oxygen-poor water out through openings in the sides of the pharynx. Gills Copyright Pearson Prentice Hall

Form and Function in Fishes Circulation Fishes have closed circulatory systems with a heart that pumps blood around the body in a single loop from the heart to the gills, from the gills to the rest of the body, and then back to the heart. Copyright Pearson Prentice Hall

Form and Function in Fishes In most fishes, the heart has four parts: the sinus venosus - chamber that receives bloods and forces into atrium the atrium - received oxygen deprived blood the ventricle - pumps to force blood to gills/lungs the bulbus arteriosis - chamber that receives blood from ventricle before heading throughout body thru aorta. Blood flows from heart to gills to body and back Bulbus Arteriosis Copyright Pearson Prentice Hall

Form and Function in Fishes Circulation in a Fish Gills Brain and head circulation Body muscle circulation Blood circulates through a fish’s body in a single loop—from the heart to the gills to the rest of the body, and then back to the heart again. Digestive system circulation Heart Copyright Pearson Prentice Hall

Form and Function in Fishes Excretion Fishes eliminate nitrogenous wastes in the form of ammonia. Some wastes diffuse through the gills into the surrounding water. Copyright Pearson Prentice Hall

Form and Function in Fishes Others wastes are removed by kidneys. The kidneys of marine fishes concentrate wastes and return water to the body. Kidney The internal organs of a typical bony fish are shown here.  Copyright Pearson Prentice Hall

Form and Function in Fishes The kidneys of freshwater fishes pump out dilute urine. (High water content, low salt) The kidneys of saltwater fish, pump out concentrated urine.(Low water content, high salt) Kidney Copyright Pearson Prentice Hall

Form and Function in Fishes Response  Fishes have well-developed nervous systems organized around a brain. Brain The brain of a fish, like all vertebrate brains, is situated at the anterior end of the spinal cord and has several different parts.  Copyright Pearson Prentice Hall

Form and Function in Fishes The olfactory bulbs are involved with the sense of smell, or olfaction. Olfactory bulb Copyright Pearson Prentice Hall

Form and Function in Fishes In most vertebrates, the cerebrum is responsible for all the voluntary activities of the body. In fishes, however, the cerebrum primarily processes the sense of smell. Cerebrum Copyright Pearson Prentice Hall

Form and Function in Fishes The optic lobes process information from the eyes. Optic lobe Copyright Pearson Prentice Hall

Form and Function in Fishes The cerebellum coordinates body movements. Cerebellum Copyright Pearson Prentice Hall

Form and Function in Fishes The medulla oblongata controls the functioning of many internal organs. Medulla oblongata Copyright Pearson Prentice Hall

Form and Function in Fishes Almost all fishes that are active in daylight have well-developed eyes and color vision. Many fishes have extraordinary senses of taste and smell. Most fishes have ears but may not hear sounds well. Fishes use the lateral line system to sense the motion of other fishes or prey swimming nearby. Some fishes can detect low levels of electric current. Copyright Pearson Prentice Hall

Form and Function in Fishes Lateral Line in Scales Lateral Line in a shark Copyright Pearson Prentice Hall

Form and Function in Fishes Many bony fishes have an internal, gas-filled organ called a swim bladder (or air-bladder) that adjusts their buoyancy. Gases are pulled out of circulatory system and into the bladder to increase buoyancy. Controlled by pressure of water Swim bladder The internal organs of a typical bony fish are shown here.  Copyright Pearson Prentice Hall

Form and Function in Fishes Movement  Most fishes move by contracting paired sets of muscles on either side of the backbone. A series of S-shaped curves move down the fish’s body. The force and the action of the fins propels the fish forward. The fins of fishes are used to keep on course and adjust direction. Copyright Pearson Prentice Hall

Form and Function in Fishes Reproduction   The eggs of fishes are fertilized either externally or internally, depending on the species. Fishes whose embryos in the eggs develop and hatch outside the mother's body are oviparous. The embryos of oviparous fishes obtain food from the yolk in the egg. Male banded jawfish: Retrieves famales eggs and incubates until they hatch. Copyright Pearson Prentice Hall

Form and Function in Fishes In ovoviviparous species, the eggs stay in the mother's body after internal fertilization. Each embryo develops inside its egg, using the yolk for nourishment. The young are “born alive” like most mammals. Rainbow surfperch: Giving birth Copyright Pearson Prentice Hall

Form and Function in Fishes In viviparous animals, the embryos stay in the mother's body after internal fertilization. These embryos obtain the substances they need from the mother's body (not from material in an egg). The young of viviparous species are “born alive.” Bull shark give live birth to up to 13 young. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Groups of Fishes What are the three main groups of fishes? Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Groups of Fishes Groups of Fishes All living fishes can be classified into three groups: jawless fishes (agnathan), and Chondrichthyes fish and Osteichthyes fishe (gnathostomes). Chondrichthyes = cartilage skeleton (sharks) Osteichthyes = bony fish- ray-finned (most) or lobe-finned (gave rise to tetrapods) Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Groups of Fishes Groups of Fishes Jawless Fishes- Agnathan  Jawless fishes have no true teeth or jaws. Their skeletons are made of fibers and cartilage. They lack vertebrae, and keep their notochords as adults. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Groups of Fishes Groups of Fishes Modern jawless fishes are divided into two classes: lampreys and hagfishes. Photo Credit: Animals Animals/©Zig Leszczynski Lamprey Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Groups of Fishes Groups of Fishes Lampreys are typically filter feeders as larvae and parasites as adults. Adult lampreys attach themselves to fishes, whales, and dolphins. They scrape away at the skin with small toothlike structures. The lamprey sucks up the tissues and body fluids of its host. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Groups of Fishes Groups of Fishes Hagfishes have pinkish gray, wormlike bodies and four or six short tentacles around their mouths. They lack eyes, but have light-detecting sensors scattered around their bodies. They feed on dead and dying fish by using a toothed tongue to scrape a hole into the fish’s side. Copyright Pearson Prentice Hall

Hagfishes - Jawless fish Hagfish use teeth to grasp food Hagfish knotting, to help tear flesh from prey Copyright Pearson Prentice Hall

Lamprey - Jawless fish - feeding on fish Copyright Pearson Prentice Hall

Lamprey - Jawless fish - Life Cycle Copyright Pearson Prentice Hall

Sharks (Chondrichthyes): Groups of Fishes Sharks and Their Relatives - Chondrichthyes   The class Chondrichthyes contains sharks, rays, skates, sawfishes, and chimaeras. The skeletons of these fishes are built entirely of cartilage. Many sharks have thousands of teeth arranged in several rows, new teeth develop internally, and those on the external rows are shed. Most species of sharks do not attack people. Sharks do not have a swim bladder, instead they rely on their liver which produces oil (less dense). Copyright Pearson Prentice Hall

Sharks (Chondrichthyes): Groups of Fishes Male Spiny Dogfish Shark Copyright Pearson Prentice Hall

Sharks (Chondrichthyes): Groups of Fishes In males, the medial part of the pelvic fin is modified to form a clasper used in copulation Lateral eyes are lidless Behind each eye is a spiracle Remnant of the first gill slit Tough, leathery skin with placoid scales Reduce water turbulence Paired nostrils are anterior to mouth Detect prey at a distance by large olfactory organs sensitive to one part per 10 billion Prey may also be located from long distances sensing low frequency vibrations in the lateral line Electroreceptors, the ampullae of Lorenzini, are located on the shark’s head - allow shark to find bioelectric field of prey Copyright Pearson Prentice Hall

Sharks (Chondrichthyes): Groups of Fishes Sensory Canals and Receptors Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Rays (Chondrichthyes): Groups of Fishes Groups of Fishes Some skates and rays feed on bottom-dwelling invertebrates. The largest rays eat floating plankton. Skates and rays glide through the sea with their large, winglike pectoral fins. Many skates and rays cover themselves with sand and rest on the ocean floor. Some “Electric” Rays produce a high-amp current from electric organs. Voltage = 50 , Output = 1 kilowatt During Egyptian times Rays were used to treat arthritis. Feed on mollusks, crustaceans, small fish Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Rays (Chondrichthyes): Groups of Fishes Groups of Fishes Contain cells called electrocytes: When discharged simultaneously, a high amperage current flows into the surrounding water to stun prey or discourage predators. This is controlled by the Cerebellum. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Groups of Fishes Groups of Fishes Bony Fishes - Osteichthyes   Bony fishes make up the class Osteichthyes. Their skeletons are made of bone. Almost all living bony fishes are ray-finned fishes. “Ray-finned” refers to the slender bony spines, or rays, that are connected by a thin layer of skin to form the fins. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Groups of Fishes Groups of Fishes Ray-Finned Fish Class Actinopterygii Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Groups of Fishes Groups of Fishes Only seven living species of bony fishes are not classified as ray-finned fishes. These are the lobe-finned fishes, a subclass that includes lungfishes. The fleshy fins of lobe-finned fishes have support bones. Some of these bones are jointed. Copyright Pearson Prentice Hall

Ancestors to the tetrapods: Groups of Fishes Groups of Fishes Lobe-Finned fish - Class Sarcopterygii Ancestors to the tetrapods: have lungs and gills Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ecology of Fishes Some fishes spend most of their lives in the ocean but migrate to fresh water to breed. These fish are called anadromous. Salmon are anadromous. Photo credit: ©Ralph A. Clevenger/CORBIS Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ecology of Fishes Spawning Salmon Photo credit: ©Ralph A. Clevenger/CORBIS Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall Ecology of Fishes Some eels spend most of their lives in freshwater but migrate to the sea to breed. These fish are called catadromous. The American Eel is catadromous. Photo credit: ©Ralph A. Clevenger/CORBIS Copyright Pearson Prentice Hall

Ecology of Fishes - Eel Migration Photo credit: ©Ralph A. Clevenger/CORBIS Young travel up stream to develop, adults swim to oceans to breed and die. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 30-2 Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 30-2 A characteristic of almost all fish is (not catfish and eel) a notocord as an adult. the presence of scales. a skeleton made of cartilage. the lack of jaws. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 30-2 Fishes whose eggs hatch outside the mother’s body are ovoviviparous. oviparous. viviparous. parous. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 30-2 Salmon are anadromous fishes that spend their lives in the sea. spend their lives in rivers or streams. migrate to the sea in order to spawn. migrate to rivers and streams to spawn. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 30-2 An example of a fish that is a filter feeder as a larva and a parasite as an adult is a shark. skate. lamprey. lungfish. Copyright Pearson Prentice Hall

Copyright Pearson Prentice Hall 30-2 Most members of the class containing sharks and rays are characterized by a cartilaginous skeleton. a bony skeleton. a single operculum over the gills. swim bladder. Copyright Pearson Prentice Hall

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