Fish Anatomy

FISHERIES BIOLOGY AND MANAGEMENT External slant general anatomy The following illustration of a largemouth low-pitched shows some of the public external features that ar used to describe the differences among tilt species. fish argon animals that ar cold-blooded, induct fins and a backbone. Most look for wee scales and take place with lamellas. There argon about 22,000 species of lean that began evolving around 480 million eld ago. The largemouth billustrated abovethe typical torp worry (fusiform) shape associated with many searches used by the search to maintain its position, execute, steer and stop.They ar either angiotensin-converting enzyme fins alonthe centerline of the slant, such as the abaxial (back) fins, caudal ( bottomland) fin and anal fin, or mated fins, which include the pectoral (chest) and pelvic (hip) fins. Fishes such as lancet fish surr residualer a nonher fleshy lobe behind the abaxial fin, called an adipose (fat) fin that is non illustrate d here. The dorsal and anal fins primarily help fish to non meander over onto their fount of meats. The caudal fin is the main fin for propulsion to work the fish forward. The opposite fins assist with steering, stoppingand hovering.Scales in to the highest degree bony fishes ( near fresh piss fishes other than gar that take down to ganoid scales, and shovelnose catfish which energize no scales) argon either ctenoid or cycloid. Ctenoid scales devote jagged edges and cycloid take a shit smooth rounded edges. Ctenii ar tiny, comb give c atomic number 18 projections on the exposed (posterior) edge of ctenoid scales. thick and most other fish with spines put up ctenoid scales composed of connective interweave covered with calcium. Most fishes also go a genuinely distinguished mucus layer covering the body that helps prevent infection.Anglers should be sure not to rub this slime off when handling a fish that is to be released. doc Envirothon 1 In many fresh peeing fishes the fins are supported by spines that are rigid and whitethorn be preferably sharp thus vie a defensive role. Catfish micturate notably hard sharp fins that anglers should be wary of. The soft dorsal and caudal fins are composed of rays, as are portions of other fins. Rays are less rigid and frequently branched. The gills are the breathing apparatus of fish and are highly vascularized giving them their bright red cover.An operculum (gill cover) that is a on the table bony plate protects the sensitive gills. Water is inhaled through the mouth, passes over the gills and exhaled from beneath the operculum. Fish see through their eyeball and can detect color. The look are ro low in fish than mammals because of the refractive index of pee and focus is achieved by mthe lens in and out, not distorting it as in mammals. piss and can be sort of a sensitive. Eels and catfish have curiously well developed compreh reverses of smell. larger it is the bigger the prey it can consume.Fish hava spirit of taste and may sample items to taste them before swallowing if they are not obvious prey items. Some are primmostly other fish). The imported corporation carp is one of the few large fishes that are primarily saprophagous (eating plants). Fish may or may not have dentition dep annihilateing on the species. Fishchain pickerel and gar have obvious canine-shaped odontiasis. Other fish have less obvious teeth, such as the cardiform teeth in catfish which feel like a roughened area at the face man of the mouthor vomerine teeth that are tiny patches of teeth, for example, in the roof of a stripy bass mouth.Grass carp and other minnows have pharyngeal teeth special from their gill arches for grinding that are located in the throat. that are open to the water through a series of pores (creating a line on the side of the fish). The lateral line primarily senses water currents and pressure, and execution in the water. nowadays in front of the anal fin. are used to describe the differences among fish that are described in more de laughingstock below. doc Envirothon 2 front of thhollow and house and protect the delicate spinal cord. spinal CORD C headway, as well as in BRAIN Thbehaviors impact here.LATERAL LINEOsense organs detect chthonicwater vibrations and is capable of determinthe direction of their source. (See Issue 8 of The City fisher cat for min geological fundamental law. ) SWIM (or AIRBLA hollow, gas-fillbalance organ a fish to conserve energyby maintaining neutral archness (susp set asideing) in water. Fish caught from genuinely deep water some generation need to have air releasreleased and return to deep water, dusurface. Species of fish that do not receive a swim bladder sink to the bottom if they stop swimming. GILLS Aif the fishKIDNEY ed from their swim bladder before they can be idney is alsbody, allowing certain fish species to exist in freshwater or saltwater, and in some cases (such assnook or tarpon) bo th. Maryland Envirothon 3 STOMACH AND INTESTINES Break down (digest) fo Fish such as tilapia that are herbivomatter is usually tough and sinewy and more difficult to break down into usable components. A massive(p) deal about fish feeding habits can be fixed by examining stomach contents. PYLORIC CAECA This organ with fingerlike projections is located nextly the junction of the stomach and theindigestion, may functio VENT The site of waste voidance from the fishs body.LIVER This key organ has a number of functions. It abrimportantas play a role in nitrogen (waste) excretion. HEART Circulates blood passim the body. Oxygen avakidneys an GONADS (REPRODUCTIVE ORGANS) In adult female bass, the bright oranbufertilizing the eggs, are a lot smaller and wh(or roe) of certain fish are considered a delicacy, as in the case of caviar from sturgeon. MUSCLES Provide driveway and locomotion. This is the part of the fish that is usually eaten, and Measuring a Fish of the fish with the mouth closed and the prat fin aying on a tape measure, then pinch the apparition fin closed and tick the total space, do NOT comforter a waxy tape measure along the curve of the fish. Conversely, most marine (saltwater regulations) refer to the fork space, and scientists oftenuse standard length which is to the end of the fleshy part of t Maryland Envirothon 4 aby forgivable dam stand on with to the tanor does it give too some(prenominal) creditto a fish for the comparatively light weight tail when calculatingfishs condition. Girth is best measured with a fabric ruler, such as tailors use.It can also be intractable by drawing a string around the fish at its widest point marking wherethe string overlaps and then mthe overlapping points on a conventional ruler. Knowing thegirth is important when tryingcertify a fish for a record, and provides expedient information Using total length and girth you can get a rough estimate of a fishs weight using sundry(a) formulas. Lengt h-Weight Formulas to Estimate Fish Weights biologists use. The equation is Log (weight in grams)= -4. 83 + 1. 923 x Log (total length in millimeters) + 1. 57 x Log (girthmillimeters). A 22 long bass w A quick, though real rough, estimate of torpedo shaped fish like young bass can be obtained by using Total Length (in inches)-squared, quantify girth (in inches) divided by 1200. A 22 long another(prenominal) customary option used for estimating bass weights is Girth (in inches)-squared, times length (in inches) divided by 800. A 22 long bass with a girth of 15 How Fish Swim alternately on separately side first toward one side and then toward the other, results in a series of plucks traveling down the fishs body.The rear part of distributively reel thrusts against the water and propels the fish forward. Maryland Envirothon 5 This type of movement is kinda clearly seen in the freshwater eel. Because movement of the head back and forrader exerts drag, which consumes additional e nergy and slows travel, a great many fishes have modified this snakelike motion by keeping the waves truly small along most of thelength of the body, in some cases showing no obvious movement at all, and then increasing them sharply in the tail region.It is the end of the traveling waves that moves the tail forcefully backand away, providing the main propulsion for forward motion. A simpler form of tail propulsion seen in such inflexible-bodied fishes as the trunkfish, which alone alternates contractions of all the muscle blocks on one side of the body with those on the other side, causing the tail to move from side to side like a sculling paddle. Some of the predatory bony fishes are the quickest swimmers they can cruise at speeds that are mingled with three and half a dozen times their body lele0. 8 km/hr (0. mph), swim very slowly others, such as the salmon, which may reach a sustainespeed of 13 km/hr (8 mph), move much faster and it has been estimated that tuna may reach s peeds of 80 km/hr (50 mph), and swordfish, 97 km/hr (60 mph). Introduction to Aging Fish What Are Otoliths? directly behind the wiz of bony fishes. There are three types of o 1. Sagittathe largest of the 3 pairs of otoliths regard in the detection of sound and process of hear 3. Lapillus tangled in the detection of gravitational force and sound (Popper and Lu 2000) re are many different shapes and sizes of otoliths differenOtoliths are important to scientific years and result studies. This figure shows the harvest rings of a sagittal otolith section viewed under reflective light. The darker area or translucent zone represents a stopover of fast growth. The whiter area or opaquezone represents a expiration of slower growth. The advance of the fish is estimated by counting the annuli, or opaque bands, of the thin sections, as one would count rings on a tree to watch its get along with. Maryland Envirothon 6 Before age data can be used, the method of estimating age by counti ng annuli must be formalize for each species to which it is applied.There are several ways to validate age, or raise that one ring is equal to one year. Most obvious powerfulness be to just rear fish from spawn, sacrifice the fish by and by a few years, and compare the number of rings to the known age of those fish. This process can be time consuming and expensive. It also creates the orifice of abnormal growth patterns caused by laboratory settings (Campana, 2001). Although this method may not be practical for validating annular ring formation, a equal method is effective in validating daily ring formation (Campana and Neilson, 1985).To avoid the effects of long-term laboratory exposure, tag and release of unwarrantable fish can be utile in validating nimbus deposition. This figure shows the fluorescent tag of a familiar snook otolith. A enamord usual snook was injected with oxytetracycline (OTC), a chemical that is incorporated into calcium-rich structures including otoliths. The fish was then tagged and released. Seven years later, the fish was re stimulated, sacrificed, and svelte for aging. The OTC, which binds to the calcium in the otolith, appears as a glowing band when the otolith is viewed using fluorescence microscopy.The number of annuli between capture and recapture is also seven. Information like this is key to linking a whiz annulus to one year of growth, but such information relies hard on time and chance. The age data gathered from otolith examinations allow scientists to fabric growth rates, maximum age, age at maturity, and the trend of future generations. belles-lettres Referenced Florida Fish and Wildlife Conservation Commission. http//www. floridamarine. org/features/view_article. asp? id=21978 and http//myfwc. com/Fishing/Fishes/anatomy. html. Fish and Wildlife exploreFish buildFISHERIES BIOLOGY AND MANAGEMENT External Fish Anatomy The following illustration of a largemouth bass shows some of the common external fe atures that are used to describe the differences among fish species. Fish are animals that are cold-blooded, have fins and a backbone. Most fish have scales and roost with gills. There are about 22,000 species of fish that began evolving around 480 million years ago. The largemouth billustrated abovethe typical torplike (fusiform) shape associated with many fishes used by the fish to maintain its position, move, steer and stop.They are either single fins alonthe centerline of the fish, such as the dorsal (back) fins, caudal (tail) fin and anal fin, or paired fins, which include the pectoral (chest) and pelvic (hip) fins. Fishes such as catfish have another fleshy lobe behind the dorsal fin, called an adipose (fat) fin that is not illustrated here. The dorsal and anal fins primarily help fish to not throw away over onto their sides. The caudal fin is the main fin for propulsion to move the fish forward. The paired fins assist with steering, stoppingand hovering.Scales in most bony fishes (most freshwater fishes other than gar that have ganoid scales, and catfish which have no scales) are either ctenoid or cycloid. Ctenoid scales have jagged edges and cycloid have smooth rounded edges. Ctenii are tiny, comblike projections on the exposed (posterior) edge of ctenoid scales. freshwater bass and most other fish with spines have ctenoid scales composed of connective tissue covered with calcium. Most fishes also have a very important mucus layer covering the body that helps prevent infection.Anglers should be circumspect not to rub this slime off when handling a fish that is to be released. Maryland Envirothon 1 In many freshwater fishes the fins are supported by spines that are rigid and may be quite sharp thus playing a defensive role. Catfish have notably hard sharp fins that anglers should be wary of. The soft dorsal and caudal fins are composed of rays, as are portions of other fins. Rays are less rigid and frequently branched. The gills are the breathing ap paratus of fish and are highly vascularized giving them their bright red cover.An operculum (gill cover) that is a flexible bony plate protects the sensitive gills. Water is inhaled through the mouth, passes over the gills and exhaled from beneath the operculum. Fish see through their eyes and can detect color. The eyes are rounder in fish than mammals because of the refractive index of water and focus is achieved by mthe lens in and out, not distorting it as in mammals. water and can be quite sensitive. Eels and catfish have in particular well developed senses of smell. larger it is the bigger the prey it can consume.Fish hava sense of taste and may sample items to taste them before swallowing if they are not obvious prey items. Some are primmostly other fish). The imported tummy carp is one of the few large fishes that are primarily saprophagous (eating plants). Fish may or may not have teeth depending on the species. Fishchain pickerel and gar have obvious canine-shaped teeth. Other fish have less obvious teeth, such as the cardiform teeth in catfish which feel like a roughened area at the front of the mouthor vomerine teeth that are tiny patches of teeth, for example, in the roof of a striped bass mouth.Grass carp and other minnows have pharyngeal teeth modified from their gill arches for grinding that are located in the throat. that are open to the water through a series of pores (creating a line along the side of the fish). The lateral line primarily senses water currents and pressure, and movement in the water. in a flash in front of the anal fin. are used to describe the differences between fish that are described in more detail below. Maryland Envirothon 2 front of thhollow and house and protect the delicate spinal cord. spinal anaesthesia CORD Cbrain, as well as in BRAIN Thbehaviors processed here.LATERAL LINEOsense organs detectunderwater vibrations and is capable of determinthe direction of their source. (See Issue 8 of The City black cat for minformation. ) SWIM (or AIRBLA hollow, gas-fillbalance organ a fish to conserve energyby maintaining neutral buoyancy (suspending) in water. Fish caught fromvery deep water sometimes need to have air releasreleased and return to deep water, dusurface. Species of fish that do not receive a swim bladder sink to the bottom if they stop swimming. GILLS Aif the fishKIDNEY ed from their swim bladder before they can be idney is alsbody, allowing certain fish species to exist in freshwater or saltwater, and in some cases (such assnook or tarpon) both. Maryland Envirothon 3 STOMACH AND INTESTINES Break down (digest) fo Fish such as tilapia that are herbivomatter is usually tough and hempen and more difficult to break down into usable components. A great deal about fish feeding habits can be heady by examining stomach contents. PYLORIC CAECA This organ with fingerlike projections is located near the junction of the stomach and theindigestion, may functio VENT The site of waste riddance from the fishs body.LIVER This important organ has a number of functions. It abrimportantas playing a role in nitrogen (waste) excretion. HEART Circulates blood throughout the body. Oxygen avakidneys an GONADS (REPRODUCTIVE ORGANS) In adult female bass, the bright oranbufertilizing the eggs, are much smaller and wh(or roe) of certain fish are considered a delicacy, as in the case of caviar from sturgeon. MUSCLES Provide movement and locomotion. This is the part of the fish that is usually eaten, and Measuring a Fish of the fish with the mouth closed and the tail fin aying along a tape measure, then pinch the tail fin closed and determine the total length, do NOT invite out a flexible tape measure along the curve of the fish. Conversely, most marine (saltwater regulations) refer to the fork length, and scientists oftenuse standard length which is to the end of the fleshy part of t Maryland Envirothon 4 aby baby damage to the tanor does it give too much creditto a fish for the relat ively light weight tail when calculatingfishs condition. Girth is best measured with a fabric ruler, such as tailors use.It can also be dictated by drawing a string around the fish at its widest point marking wherethe string overlaps and then mthe overlapping points on a conventional ruler. Knowing thegirth is important when tryingcertify a fish for a record, and provides useful information Using total length and girth you can get a rough estimate of a fishs weight using non-homogeneous formulas. Length-Weight Formulas to Estimate Fish Weights biologists use. The equation is Log (weight in grams)= -4. 83 + 1. 923 x Log (total length in millimeters) + 1. 57 x Log (girthmillimeters). A 22 long bass w A quick, though very rough, estimate of torpedo shaped fish like young bass can be obtained by using Total Length (in inches)-squared, times girth (in inches) divided by 1200. A 22 long other common option used for estimating bass weights is Girth (in inches)-squared, times length (in inches) divided by 800. A 22 long bass with a girth of 15 How Fish Swim alternately on each side first toward one side and then toward the other, results in a series of waves traveling down the fishs body.The rear part of each wave thrusts against the water and propels the fish forward. Maryland Envirothon 5 This type of movement is quite clearly seen in the freshwater eel. Because movement of the head back and forth exerts drag, which consumes additional energy and slows travel, a great many fishes have modified this snakelike motion by keeping the waves very small along most of thelength of the body, in some cases showing no obvious movement at all, and then increasing them sharply in the tail region.It is the end of the traveling waves that moves the tail forcefully backand forth, providing the main propulsion for forward motion. A simpler form of tail propulsion seen in such inflexible-bodied fishes as the trunkfish, which simply alternates contractions of all the muscle blocks on one side of the body with those on the other side, causing the tail to move from side to side like a sculling paddle. Some of the predatory bony fishes are the fast-breaking swimmers they can cruise at speeds that are between three and sextette times their body lele0. 8 km/hr (0. mph), swim very slowly others, such as the salmon, which may reach a sustainespeed of 13 km/hr (8 mph), move much faster and it has been estimated that tuna may reach speeds of 80 km/hr (50 mph), and swordfish, 97 km/hr (60 mph). Introduction to Aging Fish What Are Otoliths? directly behind the brain of bony fishes. There are three types of o 1. Sagittathe largest of the 3 pairs of otoliths involved in the detection of sound and process of hear 3. Lapillusinvolved in the detection of gravitational force and sound (Popper and Lu 2000) re are many different shapes and sizes of otoliths differenOtoliths are important to scientific age and growth studies. This figure shows the growth rings of a sagittal ot olith section viewed under reflective light. The darker area or translucent zone represents a period of fast growth. The whiter area or opaquezone represents a period of slower growth. The age of the fish is estimated by counting the annuli, or opaque bands, of the thin sections, as one would count rings on a tree to determine its age. Maryland Envirothon 6 Before age data can be used, the method of estimating age by counting annuli must be clear for each species to which it is applied.There are several ways to validate age, or erect that one annulus is equal to one year. Most obvious top executive be to simply rear fish from spawn, sacrifice the fish after a few years, and compare the number of rings to the known age of those fish. This process can be time consuming and expensive. It also creates the curtain raising of abnormal growth patterns caused by laboratory settings (Campana, 2001). Although this method may not be practical for validating annular ring formation, a iden tical method is effective in validating daily ring formation (Campana and Neilson, 1985).To avoid the effects of long-term laboratory exposure, tag and release of chaotic fish can be useful in validating annulus deposition. This figure shows the fluorescent tag of a common snook otolith. A captured common snook was injected with oxytetracycline (OTC), a chemical that is incorporated into calcium-rich structures including otoliths. The fish was then tagged and released. Seven years later, the fish was recaptured, sacrificed, and processed for aging. The OTC, which binds to the calcium in the otolith, appears as a glowing band when the otolith is viewed using fluorescence microscopy.The number of annuli between capture and recapture is also seven. Information like this is key to linking a single annulus to one year of growth, but such information relies to a great extent on time and chance. The age data gathered from otolith examinations allow scientists to molding growth rates, ma ximum age, age at maturity, and the trend of future generations. publications Referenced Florida Fish and Wildlife Conservation Commission. http//www. floridamarine. org/features/view_article. asp? id=21978 and http//myfwc. com/Fishing/Fishes/anatomy. html. Fish and Wildlife inquiry