unaab, aq&fm, fis201 dr. ikenweiwe introduction to fish management fis201

UNAAB, AQ&FM, FIS201UNAAB, AQ&FM, FIS201 DR. IKENWEIWEDR. IKENWEIWE

INTRODUCTION TO FISH INTRODUCTION TO FISH MANAGEMENTMANAGEMENT

FIS201FIS201

IKENWEIWE Bolatito NafisatIKENWEIWE Bolatito Nafisat

SENIOR LECTURERSENIOR LECTURER

DEPARTMENT OF AQUACULTURE AND DEPARTMENT OF AQUACULTURE AND FISHERIES MANAGEMENTFISHERIES MANAGEMENT

UNIVERSITY OF AGRICULTURE, UNIVERSITY OF AGRICULTURE, ABEOKUTAABEOKUTA



INTRODUCTIONINTRODUCTION

Fish are poikilothermic cold Fish are poikilothermic cold blooded animals that live in blooded animals that live in aquatic environmentaquatic environment


Most fish , especially the Most fish , especially the recent species, have scales on recent species, have scales on their body and survive in their body and survive in aquatic environment by the aquatic environment by the use of gills for respiration. use of gills for respiration.


Another major characteristic Another major characteristic of a typical fish is the of a typical fish is the presence of gill slits which presence of gill slits which cover the gills on the cover the gills on the posterior.posterior.


ICTHYOLOGYICTHYOLOGY


Icthyology is the scientific Icthyology is the scientific study of fish. study of fish.

Fish, because of the Fish, because of the possession of notochord possession of notochord belong to the phylum belong to the phylum chordatachordata


Fish are the most numerous Fish are the most numerous vertebrates. About 20,000 vertebrates. About 20,000 species are known to species are known to sciencescience


FISH TAXONOMYFISH TAXONOMY


Taxonomy is the Taxonomy is the scientific classification scientific classification of organismsof organisms


WHY WHY TAXONOMY?TAXONOMY?


To know/identify the To know/identify the different components in a different components in a fish population. fish population.


To study the population To study the population dynamics in a population. dynamics in a population. (Number of each species in (Number of each species in a population.)a population.)


Important in fish culture Important in fish culture propagation – to know the propagation – to know the species of fish that is most species of fish that is most suitable for culture.suitable for culture.


HOW TO IDENTIFY FISHHOW TO IDENTIFY FISH


NAMESNAMES

Confusion can be avoided only Confusion can be avoided only by using the Latin scientific by using the Latin scientific names for they are the same names for they are the same throughout the world, while throughout the world, while vernacular names are often vernacular names are often different in locations only fifty different in locations only fifty miles apart. miles apart.


SpeciesSpecies

Any group of fish, or of any other Any group of fish, or of any other animal for that matter, whose animal for that matter, whose members are similar in structure members are similar in structure and appearance and are capable and appearance and are capable of breeding among themselves of breeding among themselves belong to the same species.belong to the same species.


GenusGenus

A genus encompasses a group A genus encompasses a group of species, which are closely of species, which are closely related to one another and are related to one another and are therefore usually similar in therefore usually similar in appearance. appearance.


Generic names begin Generic names begin with a with a capital lettercapital letter, and , and both generic and specific both generic and specific names are names are italizeditalized. .


MERISTIC FEATURESMERISTIC FEATURES

The most vital external The most vital external characteristic for identifying characteristic for identifying fish is the fin ray counts, fish is the fin ray counts, especially those of the dorsal especially those of the dorsal and anal fins. and anal fins.


Head pore pattern in Head pore pattern in Ophthalmolycus macropsOphthalmolycus macrops

a) Nasal, b) Suborbital, c) Postorbital, d) a) Nasal, b) Suborbital, c) Postorbital, d) Mandibular, and e) PreopercularMandibular, and e) Preopercular


The number of spines and or The number of spines and or rays in the dorsal and anal fins rays in the dorsal and anal fins is generally the most is generally the most consistent character in a consistent character in a species and seldom the same species and seldom the same in different species. in different species.

Spinespines


RaysRays

Each fin is made up of a Each fin is made up of a number of rays, which are number of rays, which are usually bony and flexible, and usually bony and flexible, and may be either simple or may be either simple or branchedbranched


Dorsal FinsDorsal Fins

Some West African species have Some West African species have two dorsal fins, the posterior of two dorsal fins, the posterior of which is often soft, fleshy tissue which is often soft, fleshy tissue and are thus termed an adipose and are thus termed an adipose fin. The size and shape of the fin. The size and shape of the adipose fin is sometimes given as adipose fin is sometimes given as a clue to the identity of a species. a clue to the identity of a species.


Caudal FinCaudal Fin

The caudal fin (or tail fin) of The caudal fin (or tail fin) of most fish is lobed; i.e. it is most fish is lobed; i.e. it is forked and has the upper and forked and has the upper and lower lobes attenuated to lower lobes attenuated to points. It can also be rounded points. It can also be rounded or truncate. or truncate.


MouthMouth

The position of the mouth is The position of the mouth is sometimes given when sometimes given when describing a species. describing a species.

A mouth is said to be A mouth is said to be terminal when it is at the terminal when it is at the extreme tip of the snout. extreme tip of the snout.


It is a general rule that fish It is a general rule that fish with mouths in an inferior with mouths in an inferior position, like most catfish and position, like most catfish and carps feed on detritus, worms, carps feed on detritus, worms, algae and bottom dwelling algae and bottom dwelling organismsorganisms


Fish with terminal Fish with terminal mouths, such as perch mouths, such as perch and tiger fish, are usually and tiger fish, are usually predators or plankton predators or plankton feeders. feeders.


Cyprinodonts and others Cyprinodonts and others with oblique mouths usually with oblique mouths usually feed on insects or their feed on insects or their larvae which they take from larvae which they take from the surface of the water.the surface of the water.


TeethTeeth

The position and The position and character of teeth are character of teeth are sometimes important in sometimes important in the classification of fish. the classification of fish.


PremaxillaryPremaxillary- - teeth in the front margin of the teeth in the front margin of the upper jaw, upper jaw,

MaxillaryMaxillary- - teeth on the sides of the upper jaw on a teeth on the sides of the upper jaw on a separate bone;separate bone;

MandibularMandibular- - teeth on the margin of the lower jaw; teeth on the margin of the lower jaw; VomerineVomerine- teeth on the front part of the roof of - teeth on the front part of the roof of

the buccal cavity, the buccal cavity, PalatinePalatine - when further back on the palate and - when further back on the palate and PharyngealPharyngeal - - when they are situated in the throat.when they are situated in the throat.

The The termsterms used to describe used to describe positions of teethpositions of teeth are: are:


NostrilNostril

Most fish have two nostrils Most fish have two nostrils on each side of the head in on each side of the head in front of the eyes. Cichlids front of the eyes. Cichlids are exceptions, with only are exceptions, with only one on each side. one on each side.


GillsGills

The function of the gills is to extract The function of the gills is to extract oxygen from water, where it is usually oxygen from water, where it is usually abundant in a dissolved form, and to rid abundant in a dissolved form, and to rid the blood of carbon dioxide. the blood of carbon dioxide.

The large surface area of gill filaments and The large surface area of gill filaments and their thin membranous covering allows an their thin membranous covering allows an interchange of gases to take place as the interchange of gases to take place as the oxygenated water passes over them. oxygenated water passes over them.


Lateral LineLateral Line

This is the visible part of the This is the visible part of the extraordinary sensory system of extraordinary sensory system of fishes, fishes,

lateral line consists of a series of lateral line consists of a series of marks or pits, usually one on each marks or pits, usually one on each scale, running along about the scale, running along about the midline of each side of the body and midline of each side of the body and also at times on the head. also at times on the head.


ScalesScales

Scales are protective coat of Scales are protective coat of flexible armour that cover flexible armour that cover the body of some bony fish the body of some bony fish which are embedded which are embedded below the skinbelow the skin


The different types of scales The different types of scales possessed by various fish are possessed by various fish are important for identification important for identification purposes. purposes.

Polypterus alone among local Polypterus alone among local fishes have fishes have ganoid scalesganoid scales. .


Scales are termed Scales are termed CtenoidCtenoid when the when the exposed edges are ciliated or toothed. exposed edges are ciliated or toothed. The surface of fish with ctenoid scales, The surface of fish with ctenoid scales, such as climbing perches, is always such as climbing perches, is always rough. rough.

Most fish have Most fish have Cycloid scalesCycloid scales; that is, ; that is, with the exposed margin evenly with the exposed margin evenly rounded, giving the skin a smooth rounded, giving the skin a smooth surface. surface.


ColourColour

Identification on the basis of colour Identification on the basis of colour can be quite misleading as these can be quite misleading as these often differ strikingly according to often differ strikingly according to the habitat, sex, breeding activity or the habitat, sex, breeding activity or other factors. Many members of the other factors. Many members of the cichlid family have ability to change cichlid family have ability to change colour. colour.


Male Male Hemichromis fasciatusHemichromis fasciatus, for , for example, when in clear water example, when in clear water during breeding activity, are during breeding activity, are canary yellow and have vivid canary yellow and have vivid black bands on the sides. At other black bands on the sides. At other times they are usually silvery on times they are usually silvery on the sides and the bands are the sides and the bands are reduced to smaller black patches. reduced to smaller black patches.


SexualSexual DifferencesDifferences

The sex of a fish can very The sex of a fish can very seldom be determined from its seldom be determined from its external characters, but the external characters, but the anal fins of males and females anal fins of males and females of some species do differ in of some species do differ in shape. shape.


FISH FISH CLASSIFICATIONCLASSIFICATION


A system of classification A system of classification provides the means for resolving provides the means for resolving the problem of the origin and the problem of the origin and evolution of life.evolution of life.

Classification involves scientific Classification involves scientific philosophy that uses inductive philosophy that uses inductive procedures.procedures.


“Family tree” of the Nile tilapia”

Phylum Chordata – Notochord group of animals

Subphylum Vertebrate – Animals with a backbone

Class Osteichthyes – Bony fishes Order Perciformes – Perch-like fishes Family Cichlidae – Cichlid fishes Genus Oreochromis – Mountain cichlid group Species niloticus – Nile tilapia


Name AuthorityName Authority

Thus “ Thus “ Clarotes Clarotes macrocephalusmacrocephalus Daget 1954” Daget 1954” indicates that this species indicates that this species was first described by Daget was first described by Daget in his publicationin his publication


REASONS REASONS FOR FOR

CLASSIFICATIONCLASSIFICATION


To create order out of To create order out of confusion by making confusion by making accurate identification accurate identification of every organism.of every organism.


To serve as guide To serve as guide on relationship on relationship between between organisms.organisms.


MEHODS OF MEHODS OF STUDYING STUDYING TAXONOMY TAXONOMY OF FISHESOF FISHES


MORPHOMETRIC MORPHOMETRIC CHARACTERSCHARACTERS

They are characters that They are characters that represent the morphology. represent the morphology. They are always measurable They are always measurable characters e.g. body depth, characters e.g. body depth, fork length, standard length, fork length, standard length, total length, front length etc.total length, front length etc.


In using these morphometric In using these morphometric characters for identification, the ratio characters for identification, the ratio of these lengths are used which are of these lengths are used which are peculiar to a certain species within a peculiar to a certain species within a certain range. E.g. certain range. E.g.

BD BD 0.4 –0.6 0.4 –0.6

TLTL


ELECTROPHORETIC ELECTROPHORETIC METHODMETHOD

This involves the This involves the analysis of component analysis of component proteins in the blood proteins in the blood or tissue in identifying or tissue in identifying fish. fish.


RACIAL STUDYRACIAL STUDY

It involves separation into It involves separation into different racial stocks. This different racial stocks. This is only relevant to a is only relevant to a particular species of fish. particular species of fish. The third name of a fish The third name of a fish reflects its race. reflects its race.


METHODS METHODS OF OF

CLASSFICATIONCLASSFICATION


Generally, seven standard Generally, seven standard categories forms the categories forms the internationally accepted internationally accepted groups of classification for groups of classification for all living organisms. all living organisms.


These standard categories These standard categories are:are:

KingdomKingdom Phylum (phyla)Phylum (phyla) ClassClass OrderOrder FamilyFamily Genus ( Genera)Genus ( Genera) Species (species)Species (species)


The complexity and diversity The complexity and diversity increase downward; from increase downward; from kingdom to specie. kingdom to specie. Therefore, we find fish Therefore, we find fish names existing in the names existing in the genera and species levels. genera and species levels.


Sub-Sub-divisionsdivisions

In a attempt to make the In a attempt to make the classification table more classification table more meaningful and to give room for meaningful and to give room for major dissimilarities we have major dissimilarities we have within the seven major divisions within the seven major divisions sub-divisions e.g. subphylum, sub-divisions e.g. subphylum, super class, sub order etc. super class, sub order etc.


RULESRULES OF OF

CLASSFICATIONCLASSFICATION


In genera, generic name In genera, generic name must always begin with must always begin with capital letter while the capital letter while the specific name must begin specific name must begin with small letter. E.g. with small letter. E.g. Lates Lates niloticusniloticus note “ note “LL” and “” and “nn” ”


The generic and specific The generic and specific name must always be name must always be underlinedunderlined e.g. e.g. ClariasClarias gariepinusgariepinus,, Oreochromis Oreochromis niloticusniloticus or or italicizeditalicized


The naming system The naming system comprising of specific and comprising of specific and generic name is called generic name is called BINOMIAL SYSTEMBINOMIAL SYSTEM OF OF CLASSIFICATION.CLASSIFICATION.


CHARACTERTISTICCHARACTERTISTICS OFS OF

CHORDATES CHORDATES


The presence of The presence of notochord which runs notochord which runs longitudinally, from the longitudinally, from the anterior to the posterior anterior to the posterior end of the body.end of the body.


The possession of a The possession of a nerve cord which is nerve cord which is dorsally oriented except dorsally oriented except in the primitive fishes.in the primitive fishes.


The possession of The possession of holes in the pharynge holes in the pharynge (throat) called silts or (throat) called silts or clefts.clefts.


CHARACTERTISTICCHARACTERTISTICS OF S OF

VERTEBRATESVERTEBRATES


They possess some They possess some form of cranium.form of cranium.

They possess some They possess some trace of vertebraltrace of vertebral


The front end of the nervous system The front end of the nervous system is differentiated into an elaborate is differentiated into an elaborate brain, associated with special brain, associated with special receptors like eyes, nose etc.receptors like eyes, nose etc.

The meter organisation of the body The meter organisation of the body allows the performance of delicate allows the performance of delicate movements to suit the situations that movements to suit the situations that the receptors reveal.the receptors reveal.


Presence of heart, at least 3 Presence of heart, at least 3 chambers, assisting in chambers, assisting in circulation of blood.circulation of blood.

The presence of haemoglobin The presence of haemoglobin in the red corpuscles as an act in the red corpuscles as an act of carrying oxygen in the of carrying oxygen in the blood.blood.


The excretory system The excretory system consists of meso-dermal consists of meso-dermal funnel (kidney) which funnel (kidney) which functions as osmo-regulatorfunctions as osmo-regulator


CHARACTERISTICHARACTERISTICSCS OF OF

ELASMOBRANCHELASMOBRANCH

IIII


They are cartilaginous.They are cartilaginous.They possess 5-7 gill They possess 5-7 gill slitsslits

They have spiracles.They have spiracles.


CHARACTERISTICS CHARACTERISTICS OF OF

CHONDRICHTHYESCHONDRICHTHYES


They possess constricted They possess constricted notochord notochord

They all have jawsThey all have jawsThe skeletons are The skeletons are

cartilaginous cartilaginous


They have the paired and They have the paired and unpaired finsunpaired fins

Nostrils are in pairsNostrils are in pairsThey have three semi-They have three semi-

circular canals in the ear circular canals in the ear


The cranium is not totally The cranium is not totally fussed to the arch (not joined fussed to the arch (not joined by connective tissues).by connective tissues).

They possess placoid scales They possess placoid scales Mouths are inferiorMouths are inferior


CHARACTERISTICHARACTERISTICSCS OF OF

OSTEICHTHYES OSTEICHTHYES


They have bony jaws, skull and They have bony jaws, skull and skeletonskeleton

Gills are usually 4 pairs, in Gills are usually 4 pairs, in number number

They possess operculum They possess operculum The scales are bony either The scales are bony either

cycloid ctenoid or ganoidcycloid ctenoid or ganoid


The external features The external features of a scaleless fish.of a scaleless fish.


1. Operculum1. Operculum 10. Lateral line10. Lateral line 2. Cephalo- muchal shield 2. Cephalo- muchal shield 11. 11. Pelvic finPelvic fin 3 Dorsal spine 3 Dorsal spine 12. Pectoral spine 12. Pectoral spine 4. Dorsal filament4. Dorsal filament 13 pectoral fin13 pectoral fin 5. Dorsal fin5. Dorsal fin 14 Humeral process14 Humeral process 6. Adipose fin 6. Adipose fin 15 maxillary barbel15 maxillary barbel 7. Caudal pedunle7. Caudal pedunle 16 Outer mandibular 16 Outer mandibular

barbelbarbel 8. Caudal fin 8. Caudal fin 17 Inner mandibular 17 Inner mandibular

barbelbarbel 9. Anal fin9. Anal fin


The external feature of a scaly The external feature of a scaly fish.fish.

1. Dorsal fin 1. Dorsal fin 6. Lateral line6. Lateral line2. Adipose fi2. Adipose fi 7. Pelvic fin7. Pelvic fin3. Dorsal spine3. Dorsal spine 8.Pectorial fin8.Pectorial fin4. Caudal peduncle4. Caudal peduncle 9.Operculum9.Operculum5. Anal fin5. Anal fin


FISH ANATOMYFISH ANATOMY


The Basic Structure of a FishThe Basic Structure of a Fish

Like most animals, the fish Like most animals, the fish has a body which includes has a body which includes the head, the trunk and the the head, the trunk and the limbs. The body has limbs. The body has generally an elongated generally an elongated shape. shape.


The head, the trunk and the tail The head, the trunk and the tail follow each other without any follow each other without any separation, which enables the fish separation, which enables the fish to wriggle easily in the water. to wriggle easily in the water. Limbs are fins. The body is Limbs are fins. The body is covered with the skin. covered with the skin.


The HeadThe Head

In the front part of the In the front part of the head is the mouth, of head is the mouth, of which the shape and which the shape and features differ according features differ according to the feeding habits of to the feeding habits of the fish. the fish.


Some fish have large mouths Some fish have large mouths with sharp teeth for seizing with sharp teeth for seizing prey while others have small prey while others have small mouths on the under surface mouths on the under surface of the head, suitable for of the head, suitable for scrapping up algae from the scrapping up algae from the bottom. bottom.

MOUTH


The shape of the teeth The shape of the teeth depends also on the feeding depends also on the feeding habits of the fish. Predatory habits of the fish. Predatory fish, such as the fish, such as the Hydrocynus are well Hydrocynus are well supplied with sharp teeth. supplied with sharp teeth.

TEETH


Vegetation eating fish may Vegetation eating fish may have teeth, each one with have teeth, each one with many more or less rounded many more or less rounded points, arranged in bands points, arranged in bands along the side of the jaws along the side of the jaws (Tilapia rendalli). (Tilapia rendalli).


The teeth of some omnivorous The teeth of some omnivorous fish (Alestes) are quite similar to fish (Alestes) are quite similar to the molars of man. In many the molars of man. In many fishes, there is, in addition, a bony fishes, there is, in addition, a bony plate bearing teeth in the back of plate bearing teeth in the back of the throat which are called the throat which are called pharyngeal teeth (Tilapia, Carp). pharyngeal teeth (Tilapia, Carp).


NostrilNostril

On the snout, above the On the snout, above the mouth, are the nostrils. The mouth, are the nostrils. The nostrils are not used for nostrils are not used for breathing but only for breathing but only for smelling. smelling.


BarbelBarbel

Some fish have filaments along the Some fish have filaments along the side of their mouth which can be side of their mouth which can be longer, than the head itself (catfish) longer, than the head itself (catfish) which are called barbels. Their which are called barbels. Their number can vary within the range of number can vary within the range of 2 to 8. They are sensory organs 2 to 8. They are sensory organs which help the fish to find its food. which help the fish to find its food.


OperculaOpercula

At the hind end of the head At the hind end of the head are two bony flaps called are two bony flaps called opercula or gills covers, opercula or gills covers, which can be lifted; which can be lifted; underneath are the gills. underneath are the gills.


GillsGills

Every gill is made of a bony Every gill is made of a bony arch carrying long red arch carrying long red filamentsfilaments on one side called on one side called the gill filaments and short the gill filaments and short teeth like, or longer comb like teeth like, or longer comb like projections on the other side projections on the other side called called gill rakersgill rakers. .


The gill filaments are the The gill filaments are the breathing organs of the fish, breathing organs of the fish, the gill rakers are used as a the gill rakers are used as a strainer to sieve out food strainer to sieve out food particles from the water particles from the water


The trunkThe trunk

The trunk is the part of the body The trunk is the part of the body in which are located a number of in which are located a number of organs: the air bladder, the organs: the air bladder, the stomach, the intestine, the liver, stomach, the intestine, the liver, the kidneys, the ovaries, the the kidneys, the ovaries, the testicles. It starts from the head testicles. It starts from the head and includes the ventral cavity.and includes the ventral cavity.


The tail – caudal finThe tail – caudal fin

It is located behind the anus It is located behind the anus and ends with the caudal and ends with the caudal fin. An anal fin and fin. An anal fin and sometimes a part of the sometimes a part of the dorsal fin can be found on dorsal fin can be found on the tail.the tail.


The finsThe fins

When identifying a fish, the When identifying a fish, the fins are the first things, which fins are the first things, which should be examined. The should be examined. The number of fins, their types, number of fins, their types, sizes, situtation on the body sizes, situtation on the body and position in relation to each and position in relation to each other, are most important.other, are most important.


The fins are similar to paddles The fins are similar to paddles made out of rays which would made out of rays which would be joined together by a web. be joined together by a web. The rays can be either spiny or The rays can be either spiny or soft, ramified into a paint-brush soft, ramified into a paint-brush and are then called soft rays. and are then called soft rays.


Types of Caudal FinsTypes of Caudal Fins

The caudal fin or tail of most The caudal fin or tail of most fish is fish is lobedlobed, which means that , which means that it is it is forkedforked and has the upper and has the upper and lower lobes attenuated to and lower lobes attenuated to points. But in some fish, it is points. But in some fish, it is roundround, , pointedpointed or or truncatedtruncated. .


Adipose FinAdipose Fin

Some species of fish have two Some species of fish have two dorsal fins, the second of dorsal fins, the second of which is often an adipose fin, which is often an adipose fin, composed only of soft, fleshy composed only of soft, fleshy tissue and usually without rays tissue and usually without rays of any kind. of any kind.


Body Body FormsForms

Commonly, the fish body is torpedo-Commonly, the fish body is torpedo-shaped (shaped (fusiformfusiform), and most often ), and most often slightly to strongly slightly to strongly ovoid in cross ovoid in cross sectionsection. In free swimming species, . In free swimming species, the body approximates the the body approximates the theoretically perfect theoretically perfect streamline formstreamline form in which the greatest cross section is in which the greatest cross section is located close to 36 percent of the located close to 36 percent of the length back from the anterior tip length back from the anterior tip


globe shapes (globe shapes (globiformglobiform – e.g. – e.g. puffers, tetraodontidae) puffers, tetraodontidae)

serpentine (serpentine (anguilliformanguilliform – e.g. – e.g. eels, eels, anguillidaeanguillidae), ),

threadlike in outline (threadlike in outline (filliformfilliform e.g. e.g. snipe eels, Nemichthyidae). snipe eels, Nemichthyidae).


CompressedCompressed: flattened but : flattened but greatly elongated greatly elongated

TrachipteriformTrachipteriform: flattened from : flattened from top to bottom top to bottom

DepressedDepressed – the skates, – the skates, rajidae, and the batfishesrajidae, and the batfishes


FISH FISH ADAPTATION ADAPTATION

TOTO AQUATIC LIFE AQUATIC LIFE


ShapeShape - streamlined, fusiform- streamlined, fusiform

rounding edge of such rounding edge of such shapes shapes reduces resistancereduces resistance

taperingtapering of posterior part of posterior part minimizes dragminimizes drag

mucus covermucus cover further reduce further reduce drag, drag, smoothenssmoothens


Laterally compressedLaterally compressed body body prevails in quiet water body of prevails in quiet water body of relatively dense cover.relatively dense cover.

Depressed bodyDepressed body prevail among prevail among bottom dwellersbottom dwellers

Dorso-ventral flatteningDorso-ventral flattening body body characterized stream fishes.characterized stream fishes.


FinsFins

Used by fishes to achieve all Used by fishes to achieve all forms of locomotion, forms of locomotion, stabilization, balancing, stabilization, balancing, change of direction and change of direction and breaking in their aquatic breaking in their aquatic environmentenvironment


Used as Used as gliding organgliding organ in some in some flying fishesflying fishes

Used for terrestrial Used for terrestrial locomotionlocomotion in in some catfishessome catfishes

As As crawlingcrawling organisation use of organisation use of some modified fins e.g. paired like some modified fins e.g. paired like pectoral, pelvic finspectoral, pelvic fins


FISH FISH DIVERSITY DIVERSITY

OFOF NIGERIA NIGERIA


Nigeria has diversity of Nigeria has diversity of fin and shell fish fauna fin and shell fish fauna consisting of over 250 consisting of over 250 species in Inland watersspecies in Inland waters


There are about There are about 101 species101 species (22 (22 families) in families) in Kainji lakeKainji lake alone (Ita alone (Ita 1993) 1993)

8686 in in lake Chadlake Chad (Hopson 1967), (Hopson 1967), 2525 species (10 families) in species (10 families) in Tiga lakeTiga lake

(Ita 1985)(Ita 1985)2121 species (10 families) in species (10 families) in BakoloriBakolori

(Ita 1993)(Ita 1993)


3232 species (11 families) in species (11 families) in Oyan lakeOyan lake (Ikenweiwe 2005) (Ikenweiwe 2005) and and

199 species from 78 families 199 species from 78 families in the brackish and marine in the brackish and marine waters (Tobor and Ajayi 1978). waters (Tobor and Ajayi 1978).


OPPORTUNITIEOPPORTUNITIES IN S IN

ICHTHYOLOGYICHTHYOLOGY


Research and Teaching Research and Teaching

Research opportunities are Research opportunities are boundless in all of the aspects boundless in all of the aspects of ichthoyology; much more is of ichthoyology; much more is unknown than is known. There unknown than is known. There is teaching position, which is is teaching position, which is not yet occupied. not yet occupied.


As at present, fewest are As at present, fewest are those in which the those in which the primary responsibility is primary responsibility is to study and to teach to study and to teach ichthyology. ichthyology.


MuseumMuseumss

There are curatorial There are curatorial opportunities of opportunities of developing, canning and developing, canning and studying of collections in studying of collections in museumsmuseums


ManagementManagement

The great commercial fisheries – The great commercial fisheries – e.g. professional fisheries, farm e.g. professional fisheries, farm management aquaculture, sales management aquaculture, sales of fish products as in cold rooms, of fish products as in cold rooms, fish game, ornamental fish fish game, ornamental fish production bait fishes are production bait fishes are available for people who have available for people who have training on ichthyology. training on ichthyology.


Trained personnel are needed Trained personnel are needed in managing the fisheries of in managing the fisheries of marine and inland waters and marine and inland waters and also those of reservoirs and also those of reservoirs and hatcheries – fingerling hatcheries – fingerling production.production.


Employment Employment opportunityopportunity

The expanding nature of the The expanding nature of the fisheries field affords many fisheries field affords many opportunities for employment in opportunities for employment in areas not previously investigated. areas not previously investigated. Opportunities are also opened in Opportunities are also opened in area of environmental impact area of environmental impact assessment, hobbies of recreational assessment, hobbies of recreational fishing and aquarium care. fishing and aquarium care.


Direct fishing, fishing gear making Direct fishing, fishing gear making selling or repair, boat making or selling or repair, boat making or repair, fresh fish selling, sale of repair, fresh fish selling, sale of processed/preserved fish, canned processed/preserved fish, canned fish selling, shrimp selling, ice fish selling, shrimp selling, ice block making, making of different block making, making of different types of fish processing machines, types of fish processing machines, ovens, fish pond construction etcovens, fish pond construction etc

Other job opportunitiesOther job opportunities


REFERENCESREFERENCES

Dublin – Green, C.O and Tobor, J.G. (1992) Marine Dublin – Green, C.O and Tobor, J.G. (1992) Marine resources and Activities in Nigeria. NIOMR Technical resources and Activities in Nigeria. NIOMR Technical paper No 84 An invited paper presented at the maritime paper No 84 An invited paper presented at the maritime Orientation Course for managers and Journalists. Orientation Course for managers and Journalists. Organized by the maritime Academy of Nigeria. ORON Organized by the maritime Academy of Nigeria. ORON 26th – 30th Oct. 1992. 26th – 30th Oct. 1992.

Ikenweiwe, N.B (2005) Limnology Plankton abundance Ikenweiwe, N.B (2005) Limnology Plankton abundance in relation to fish production in Oyan lake, South Western in relation to fish production in Oyan lake, South Western Nigeria. A. PNigeria. A. Ph.D Thesish.D Thesis in the Department of in the Department of Aquaculture and fisheries management, university of Aquaculture and fisheries management, university of Agriculture, Abeokuta, Nigeria. 230pp.Agriculture, Abeokuta, Nigeria. 230pp.


Ita, E.O (1993) Inland fishery Resources of Ita, E.O (1993) Inland fishery Resources of Nigeria. Nigeria. CIFA Occasional paper No, 22 Rome, CIFA Occasional paper No, 22 Rome, FAO 120pp. FAO 120pp.

Ita, E.O. Sado, E.K, Balogun, J.K, Pandogari, A. Ita, E.O. Sado, E.K, Balogun, J.K, Pandogari, A. and Ibitoye, B (1985) Inventory survey of Nigeria and Ibitoye, B (1985) Inventory survey of Nigeria inland waters and their fishery Resources: A inland waters and their fishery Resources: A preliminary checklist of inland water bodies in preliminary checklist of inland water bodies in Nigeria with special reference to ponds, lakes, Nigeria with special reference to ponds, lakes, reservoirs and major rivers. Kanji lake Research reservoirs and major rivers. Kanji lake Research institute Technical Report series No 14, KLRI, institute Technical Report series No 14, KLRI, New Bussa, 51pp. New Bussa, 51pp.


NIFFR (1998) Commercially important NIFFR (1998) Commercially important freshwater fishes of Nigeria. A fishery chart freshwater fishes of Nigeria. A fishery chart catalogue prepared by National Institute catalogue prepared by National Institute For Freshwater Fisheries Research P.M.B. For Freshwater Fisheries Research P.M.B. 6006, New – Bussa.6006, New – Bussa.

Odulate, D.O. (198-) Introduction to Odulate, D.O. (198-) Introduction to Ichthyology. A. Laboratory Manual for Ichthyology. A. Laboratory Manual for undergraduate students.undergraduate students.


THANK YOUTHANK YOU

Further ReadingsFurther Readings

The Fresh Water Fishes And Fisheries of Nigeria by D.H.J Sydenham

Fish and Fisheries of Northern Nigeria Ikenweiwe, N.B, D. Odulate, B. Adigun (2011)

Ichthyology and Limnology: Tools In Fisheries Management Fisheries Management. United Kingdom. Lap Lambert Academic Publishing. ISBN: 978-3-8433-9364-5. Available online at http://dnb.b-nb.de 127 pages

http://www.fishbase.org/summary/species


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