8. సమృద్ధి అంటేఏమిటి?
జ. అవసరానికి మించి బౌతిక సౌకర్యాలు కలిగి ఉండుటను సమృద్ధి అనవచ్చును. దాదాపుగా మనమందరము ధనము మాత్రమే సమృద్ధి అని బావిస్తాము. ఇది సగం మాత్రమే నిజము. మనమందరము బౌతిక సౌకర్యాల వినియోగం ద్వారా, ఆనందం మరియు సమృద్ధి సాధించటానికి ప్రయత్నిస్తున్నాము. ఇది పర్యావరణ వ్యతిరేకము మరియు ప్రజా వ్యతిరేకము. ఇది మానవమనుగడకు కూడా ప్రమాదకరము
సమృద్ది కోసం రెండు విషయాలు అవసరం
ఎ. మనకు ఏ స్థాయిలో భౌతిక సౌకర్యాలు అవసరమనే విషయాన్ని గుర్తించటం
బి. అవసరమైన భౌతిక సౌకర్యాల కంటే ఎక్కువ ఉత్పత్తి
భౌతిక సౌకర్యాలకు ఒక పరిమితి ఉంటే మనకు శ్రేయస్కరము. భౌతిక అవసరాలయొక్క అంచనా ఒక్కటి మాత్రమే సరిపోదు. మనకు అవసరమైన దానికంటే ఎక్కువగా ఉత్పత్తి చేసే సామర్ధ్యం కూడా ఉండేలా చూసుకోవాలి. ఉదా: మన అవసరాలకు నెలకు పది వేల రూపాయలు చాలనుకొంటే, దానికంటే కొంచెం ఎక్కువగా మన సంపాదన ఉండేలా చూసుకోవాలి.
9. ప్రణాలిక, అవగాహనల మధ్య సామరస్యాన్ని (అన్నిస్థాయిలలో) వివరించుము?
జ. మనం ఆనందాన్ని పొందుతూ దాన్ని నిరంతరం ఉండేటట్లు గా చేసుకోవాలంటే మనం జీవించే నాలుగు స్థాయిలలోనూ (నేను, నా కుటుంబం, సమాజం మరియు ప్రకృతి) సామరస్యాన్ని కలిగి ఉండాలి. మనం వీటిలో దేనిని విస్మరించినా ఆస్థాయిలో మనకు ఆనందం కలుగదు.
ఈ నాలుగు స్థాయిలలోను సామరస్యంతో జీవించటానికి ఆయా స్థాయిలలో మన పాత్ర పట్ల అవగాహన అవసరం
ఎ. నాతో నేను: మనం ఎక్కువసేపు మనతోనే గడుపుతాము. మనం మన ఆశయాలు, కోరికలు, మన ప్రవర్తనల గురించి పరిశీలించుకోవాలి. తద్వారా మనకేం కావాలి, మనమెలా ఉండాలి అన్న వాటిమీద అవగాహన ఏర్పడుతుంది
బి. మన కుటుంబం మన సంబంధాలను నిర్మిస్తుంది. నన్ను నేను ఎలా చూసుకుంటాను అన్నదాని మీదనే నేను ఇతరులను ఎలా చూస్తాను అన్నది ఆధారపడి ఉంటుంది. ఇదే మన సంబంధాలకు కుటుంబసభ్యులతో సఖ్యత కు ఆధారమౌతుంది.
సి. సమాజంలో ఉండే అనేక కుటుంబాలు ఆహారం, దుస్తులు, సేవలు, విద్య, న్యాయం అనే వాటి వలన ఒకదానిపై ఒకటి ఆధార పడి ఉంటాయి. ఇదే మన సమాజం. మన కుటుంబాన్ని అర్ధం చేసుకున్నప్పుడు సమాజంలో ఉండే అనేక కుటుంబాలను కూడా అర్ధం చేసుకోగలం.
డి. ప్రకృతితో: మనం ఈ భూమిపై, చెట్లు, పక్షులు, జంతువులు వంటి అనేక జీవరాశితో కలిసి సహజీవనం చేస్తున్నాము. భూమి, సూర్యమండలం, పాలపుంతలు, విశ్వం అనే వ్యవస్థల మధ్య మన ఉనికి ని అవగాహన చేసుకొన్నప్పుడు మన జీవితంలో ప్రకృతి పట్ల మనకుండాల్సిన బాధ్యత తెలుస్తుంది.
చివరగా
ఆనందం సంపదలు నిరంతరం ఉండాలన్న మన కోరిక నెరవేరాలంటే
అన్ని స్థాయిలలోను(నేను, నా కుటుంబం, సమాజం, ప్రకృతి) సామరస్యాన్ని కలిగి ఉన్నప్పుడు మాత్రమే సాధ్యమౌతుంది. అదే మన ప్రణాళిక గా ఉండాలి.
10. జంతు అస్థిత్వానికి, మానవ అస్థిత్వానికి గల తేడాను పట సహాయమున వివరించుము
జ. కేవలం భౌతికమైన సౌకర్యాలతోనే జీవనం గడపటాన్ని జంతు అస్తిత్వమ్ అంటారు.
సరైన అవగాహన, మంచి సంబంధాలు మరియు భౌతిక అవసరాలు వంటి మూడు అంశాలతో జీవనాన్ని కొనసాగించటాన్ని మానవ అస్తిత్వం అంటారు. మానవ అస్త్తిత్వం లో నిరంతరానందం, పరస్పరాభివృద్ధి ఉంటాయి.
ఉదాహరణకు ఒక మేకను కాని ఆవుని గాని తీసుకొన్నప్పుడు అవి నిరంతరం ప్రకృతినుండి ఆహారాన్ని తీసుకోవటంలోనే నిమగ్నమై ఉంటాయి. మనల్ని మనం పరిశీలించుకొన్నప్పుడు మనమూ దాదాపు అదే పనిలో ఉంటాము. కానీ ఆస్థాయిని దాటి ఇతర అవసరాలను కూడా తీర్చుకొంటాము. అవి సరైన అవగాహన, మంచి సంబంధాలు. ఇవి మానసికమైన ఆనందాన్ని ఇస్తాయి. తద్వారా మానవులు నిరంతరంగా ఆనందాన్నిపొందుతూ, ఒకరికొకరు సహాయపడుతూ జీవనాన్ని సాగిస్తారు
Second Module
11. మూడు రకాల మనుషులను గురించి తెలుపుము
జ. మను ష్యులు మూడు రకాలు
ఎ. భౌతికమైన వస్తు సంపదలు లేక నిత్యం బాధపడుతూ నీరసించి పోయినవారు. వీరిని సాధన విహీన దుఖీః దరిద్ర అనవచ్చు (సావిదుద)
బి. వస్తుసంపదలు ఉండి కూడా సంతోషం కరువై నిరాశలో ఉన్నవారు. వీరిని సాధన సంపన్న దుఖీః దరిద్ర అనవచ్చు (సాసదుద)
సి. వస్తుసంపదలుండి ఆనందంలో సంపన్నులుగా ఉన్నవారు
వీరిని సాధన సంపన్న సుఖీః సమృధ్ అనవచ్చును (సాససుస)
మూడవ రకంగా ఉండటం వాంచనీయము. అలా ఉండాలంటే సరైన అవగాహన, సత్సంబంధాలు మరియు భౌతిక సౌకర్యాలు ఉండాలి.
Zoology in the Classroom - is a blog for teachers and students of zoology. I have been teaching as Zoology teacher for the last 30 years. I post the notes or handouts that I supply to my students in my classroom. Hope this will benefit Zoology fraternity
Friday, April 21, 2017
Monday, April 17, 2017
HVPE MATERIAL
1. What is value education? Why there is a need of value education?
ANS. Character oriented education that instills basic values and ethnic values in one’s psyche is called ‘Value Based Education’.
The subject that enables us to understand ‘what is valuable’ for human happiness is called value education. Once, one has understood his/ her values in life he/she can examine and control the various choices he/she makes in his/ her life.
Value education enables us to understand our needs and visualize our goals correctly and also helps to remove our confusions and contradictions and bring harmony at all levels.
It also helps remove our confusions and contradictions and enables us to rightly utilize the technological innovations.
Values form the basis for all our thoughts, behaviors’ and actions. Once we know what is valuable to us, these values becomes the basis, the anchor for our actions.
We also need to understand the universality of various human values, because only then we can have a definite and common program for value education.
Then only we can be assured of a happy and harmonious human society.
Q 2. What are the basic guidelines for value education?
ANS. The subject that enables us to understand ‘what is valuable’ for human happiness is called value education. In order to qualify for any course on value education, the following guidelines for the content of the course are important:
• Universal: It needs to be applicable to all the human beings irrespective of cast, creed, nationalities, religion, etc., for all times and regions.
• Rational: It has to appeal to human reasoning. It has to be amenable to reasoning and not based on dogmas or blind beliefs.
• Natural and verifiable: It has to be naturally acceptable to the human being who goes through the
course and when we live on the basis of such values it leads to our happiness. It needs to be experientially verifiable, and not based on dogmas, beliefs or assumptions.
• All encompassing: Value education is aimed at transforming our consciousness and living. Hence, it needs to cover all the dimensions (thought, behaviour, work and realization) and levels (individual, family, society, nature and existence) of human life and profession.
• Leading to harmony: The value education ultimately is targeted to promote harmony within the individual, among human beings and with nature.
Q 3. What is the need for value education in technical and other professional institutions?
ANS. The subject that enables us to understand ‘what is valuable’ for human happiness is called value education.
The present education system has become largely skill-based. The prime emphasis is on science and technology. However, science and technology can only help to provide the means to achieve what is considered valuable. It is not within the scope of science and technology to provide the competence of deciding what really is valuable. Value Education is a crucial missing link in the present education system.
Because of this deficiency, most of our efforts may prove to be counterproductive and serious crises at the individual, societal and environmental level are manifesting.
Q 4. Define self exploration. What is the content of self – exploration?
ANS. Self exploration is the process to find out what is valuable to me by investigating within myself, what is right for me, true for me, has to be judged within myself.
Through self exploration we get the value of ourself. We live with different entirety (family, friends, air, soil, water, trees, etc.) and we want to understand our relationship with all these. For this we need to start observing inside.
The main focus of self-exploration is myself - the human being.
Self exploration is the process to find out what is valuable to me by investigating within myself, what is right for me, true for me, has to be judged within myself. Through self exploration we get the value of ourself. The process of self exploration is a follows:
First of all we have to keep in mind that, Whatever is being presented is a PROPOSAL.
This process is not complete. It will be completed when on verification on the basis of natural acceptance and testing in our living ultimately results in ‘realization’ and ‘understanding’ in us.
• Verify on the basis of your natural acceptance
• Live accordingly to validate it experientially
• If the proposal is true in behaviour with human leads to mutual happiness
• If the proposal is true in work with rest of the nature leads to mutual prosperity
• Results in realization and understanding
• On having realization and understanding we get
• Assurance
• Satisfaction
5. What do you understand by the terms svatva, swatantrata and swarajya?
ANS. This process of self exploration helps us to identify our swatva and through that acquiring swantantrata and swarajya. Swatva means innateness of self – the natural acceptance of harmony.
Swatantrata means being self- organized – being in harmony with oneself
Swarajya means self-expression, self- extension – living in harmony with others
The swatva is already there, intact in each one of us. By being in dialogue with it, we attain swantantrata enabling us to work for swarajya.
Living in contradiction, means we are not self-organized and living with pre-conditionings where we have assumed certain things, have accumulated desires without having first evaluated them, then it means we are partantra.
On the other hand, when we identify our innateness, what we really want to be and establish a dialogue with it, it enables us to start living with this harmony, it starts expressing itself through our harmonious behaviour and work, and it naturally extends to our participation with the surroundings. This is working towards swarajya.
Q 6. What is the meaning of prosperity? How can you say that you are prosperous?
ANS. The feeling of having or making available more than required physical facilities is prosperity. Almost all of us feel that wealth alone means prosperity and try to explain this phenomenon on this nonexistent or half fact.
We are trying to achieve happiness and prosperity by maximizing accumulation and consumption of physical facilities. It is becoming anti-ecological and anti-people, and threatening the human survival itself. For prosperity, two things are required-
1. Identification of the required quantity of physical facilities, and
2. Ensuring availability / production of more than required physical facilities.
We can be prosperous only if there is a limit to the need for physical facilities. If there is no limit what so ever be the availability the feeling of prosperity cannot be assured.
Secondly, just assessing the need is not enough. We need to be able to produce or make available more than the perceived need.
ANS. Character oriented education that instills basic values and ethnic values in one’s psyche is called ‘Value Based Education’.
The subject that enables us to understand ‘what is valuable’ for human happiness is called value education. Once, one has understood his/ her values in life he/she can examine and control the various choices he/she makes in his/ her life.
Value education enables us to understand our needs and visualize our goals correctly and also helps to remove our confusions and contradictions and bring harmony at all levels.
It also helps remove our confusions and contradictions and enables us to rightly utilize the technological innovations.
Values form the basis for all our thoughts, behaviors’ and actions. Once we know what is valuable to us, these values becomes the basis, the anchor for our actions.
We also need to understand the universality of various human values, because only then we can have a definite and common program for value education.
Then only we can be assured of a happy and harmonious human society.
Q 2. What are the basic guidelines for value education?
ANS. The subject that enables us to understand ‘what is valuable’ for human happiness is called value education. In order to qualify for any course on value education, the following guidelines for the content of the course are important:
• Universal: It needs to be applicable to all the human beings irrespective of cast, creed, nationalities, religion, etc., for all times and regions.
• Rational: It has to appeal to human reasoning. It has to be amenable to reasoning and not based on dogmas or blind beliefs.
• Natural and verifiable: It has to be naturally acceptable to the human being who goes through the
course and when we live on the basis of such values it leads to our happiness. It needs to be experientially verifiable, and not based on dogmas, beliefs or assumptions.
• All encompassing: Value education is aimed at transforming our consciousness and living. Hence, it needs to cover all the dimensions (thought, behaviour, work and realization) and levels (individual, family, society, nature and existence) of human life and profession.
• Leading to harmony: The value education ultimately is targeted to promote harmony within the individual, among human beings and with nature.
Q 3. What is the need for value education in technical and other professional institutions?
ANS. The subject that enables us to understand ‘what is valuable’ for human happiness is called value education.
The present education system has become largely skill-based. The prime emphasis is on science and technology. However, science and technology can only help to provide the means to achieve what is considered valuable. It is not within the scope of science and technology to provide the competence of deciding what really is valuable. Value Education is a crucial missing link in the present education system.
Because of this deficiency, most of our efforts may prove to be counterproductive and serious crises at the individual, societal and environmental level are manifesting.
Q 4. Define self exploration. What is the content of self – exploration?
ANS. Self exploration is the process to find out what is valuable to me by investigating within myself, what is right for me, true for me, has to be judged within myself.
Through self exploration we get the value of ourself. We live with different entirety (family, friends, air, soil, water, trees, etc.) and we want to understand our relationship with all these. For this we need to start observing inside.
The main focus of self-exploration is myself - the human being.
Self exploration is the process to find out what is valuable to me by investigating within myself, what is right for me, true for me, has to be judged within myself. Through self exploration we get the value of ourself. The process of self exploration is a follows:
First of all we have to keep in mind that, Whatever is being presented is a PROPOSAL.
This process is not complete. It will be completed when on verification on the basis of natural acceptance and testing in our living ultimately results in ‘realization’ and ‘understanding’ in us.
• Verify on the basis of your natural acceptance
• Live accordingly to validate it experientially
• If the proposal is true in behaviour with human leads to mutual happiness
• If the proposal is true in work with rest of the nature leads to mutual prosperity
• Results in realization and understanding
• On having realization and understanding we get
• Assurance
• Satisfaction
5. What do you understand by the terms svatva, swatantrata and swarajya?
ANS. This process of self exploration helps us to identify our swatva and through that acquiring swantantrata and swarajya. Swatva means innateness of self – the natural acceptance of harmony.
Swatantrata means being self- organized – being in harmony with oneself
Swarajya means self-expression, self- extension – living in harmony with others
The swatva is already there, intact in each one of us. By being in dialogue with it, we attain swantantrata enabling us to work for swarajya.
Living in contradiction, means we are not self-organized and living with pre-conditionings where we have assumed certain things, have accumulated desires without having first evaluated them, then it means we are partantra.
On the other hand, when we identify our innateness, what we really want to be and establish a dialogue with it, it enables us to start living with this harmony, it starts expressing itself through our harmonious behaviour and work, and it naturally extends to our participation with the surroundings. This is working towards swarajya.
Q 6. What is the meaning of prosperity? How can you say that you are prosperous?
ANS. The feeling of having or making available more than required physical facilities is prosperity. Almost all of us feel that wealth alone means prosperity and try to explain this phenomenon on this nonexistent or half fact.
We are trying to achieve happiness and prosperity by maximizing accumulation and consumption of physical facilities. It is becoming anti-ecological and anti-people, and threatening the human survival itself. For prosperity, two things are required-
1. Identification of the required quantity of physical facilities, and
2. Ensuring availability / production of more than required physical facilities.
We can be prosperous only if there is a limit to the need for physical facilities. If there is no limit what so ever be the availability the feeling of prosperity cannot be assured.
Secondly, just assessing the need is not enough. We need to be able to produce or make available more than the perceived need.
Thursday, April 13, 2017
FISHERY RESOURCES OF INDIA
. What are the different fishery resources?
A. Fishes are primarily aquatic organisms living in different types of water bodies. Fish living in freshwater bodies like rivers, streams, reservoirs, lakes, ponds and tanks constitute inland fish. Those organisms that live in estuarine regions (the region where river meets the sea)are called brackish water organisms. Those live in seas are referred as marine. The commercially important organisms like fish, crustaceans, molluscs that live in these three types of water bodies constitute Inland/Freshwater Fisheries, Brackish water Fisheries and marine fisheries.
Inland/Freshwater Fishery resources of India
Inland Fishery Resources in India are very rich. About 30% of total fish production of India is contributed by Inland Fishery. India's fresh water resources consist of 195,210 kilometers of rivers and canals, 2.9 million hectares of minor and major reservoirs, 2.4 million hectares of ponds and lakes
The major Fresh water inland water bodies are the Ganges System, Brahmaputra System of Northern part of India - Mahanadi, Krishna, Godavari, Cauvery, Narmada, Tapti river systems of southern part.
River Ganga: Ganga originates in Himalayan region and extends over 12500 km length and with an estimated 97.6 million hectars area suitable for fishing. The fishes like Labeo rohita, Catla catla, Cirrhinus mrigila, Hilsa ilisha, Wallago attu, Notopterus chitala are some important species that are harvested from Ganga
River Brahmaputra: It is about 4,023km in length with 51 million hectares catchment area. It has rich fish fauna. Wallago attu, Labeo rohita, Mystus rita, Puntius sarana, Notopterus chitala, Cirrhinus mrigila are some of the fish that are found in Brahmaputra
River Narmada: The length of the river is 1280 km, The effective catchments area of this river system is 94235 sq. km and 6330 sq. km of its all tributaries.
The carp fish groups are Labeo frimbriatus, L.calabasu, L.bata,Cirrhinus reba, Puntius sarana etc, cat fish groups such as Mystus senghala, M. cavasius, Wallago attu, Clupisomagarua, otherfish groups like Tor tor; Channaspp, Mastacembalus spp; Notopterus notopterus etc.
River Cauvery : This river has a length of 800 km with catchment area of 4,70000 sq km.
The fishes like Tor. Putitora, Barbus dubius, Labeo kontius,Cirrhinus cirhosa, Mystus seenghala, Pangasius pangasius,Wallago attu, carps such as Catla catla; Labeo rohita; Cirrhinus mrigala and the exoticspecies Cyprinus carpio and Osphronemus goramy& game fish like Tor khudri and Tmussullahare also found in Cauvery.
Tapti River:This river is with a total length of 720 km and a total catchments area of 48,000 sq.km.
The main fisheries of this river system are Tor tor, Mystusseenghala, Wallago attu, Labeo calabasu, Labeo fimbriata, Cirrhinus mrigala, Channa spp etc
Inland resources of Andhra Pradesh
River Godavari: Its length is 1465 km and has a total catchments area of over 315,980 sqkm. The fishes available are – Labeo rohita, L. calabasu, L. fimbriatus, Catla catla, Cirhinus mirigala, Mystes singhaal, Wallago attu, Hilsa ilaisha, Bangarius bagarius, Macrobrachium rosenbergii etc. During monsoon months Hilsa fishery contributes much to the economy of this region.
River Krishna: It has a length of 1401km with a total catchment area of 2,33,229 sq km. The Fish fauna of Krishna river resembels the Godavari river systems.
River Penna: Its length is 600 km. In summer it dries up. Some carp and other cat fishes are found in it.
Brackish water fisheries
The region where the rivers meet the seas is called estuary. The salinity of these waters is highly variable from 5ppt to 30ppt depending on season and tides of the sea. The organisms which can tolerate rapid salinity fluctuations only can survive in these waters. Such organisms are called euryhaline organisms. The brackish water is rich in nutrients.
The important estuaries in India include the Hoooghly estuary where Ganga join bay of Bengal, Mahanadi estuary in Gujarath, Krishna-Godavari estuary in Andhra Pradesh, Cauvery Estuary in Tamilnadu. Important brackish water lakes are Chilka lake in orissa, pulicat lake in Tamilnadu, kolleru lake in andhra pradesh.
Types of Estuaries: The estuaries can be categorised as Open estuary and Enbanked estuary. In open estuaries the river directly is connected to the sea. In enbanked estuary the estuary is surrounded by land. It is connected to the sea during hightides and heavy rains only. Eg. Lagoons.
Characters of Estuary
a. The water is mixure of freshwater and marine water
b. The pH value of water is between 7.5-8.5
c. The water is rich in nutrents
d. The Oxygen content will be less
e. It forms a good breeding ground for many fishes
f. Estuary harbours many Anadromous and catadromous fishes.
There are about 1.2 million hectares brackishwater area available in India suitable for farming. Out of it only 13% only is being utilised.
A. Fishes are primarily aquatic organisms living in different types of water bodies. Fish living in freshwater bodies like rivers, streams, reservoirs, lakes, ponds and tanks constitute inland fish. Those organisms that live in estuarine regions (the region where river meets the sea)are called brackish water organisms. Those live in seas are referred as marine. The commercially important organisms like fish, crustaceans, molluscs that live in these three types of water bodies constitute Inland/Freshwater Fisheries, Brackish water Fisheries and marine fisheries.
Inland/Freshwater Fishery resources of India
Inland Fishery Resources in India are very rich. About 30% of total fish production of India is contributed by Inland Fishery. India's fresh water resources consist of 195,210 kilometers of rivers and canals, 2.9 million hectares of minor and major reservoirs, 2.4 million hectares of ponds and lakes
The major Fresh water inland water bodies are the Ganges System, Brahmaputra System of Northern part of India - Mahanadi, Krishna, Godavari, Cauvery, Narmada, Tapti river systems of southern part.
River Ganga: Ganga originates in Himalayan region and extends over 12500 km length and with an estimated 97.6 million hectars area suitable for fishing. The fishes like Labeo rohita, Catla catla, Cirrhinus mrigila, Hilsa ilisha, Wallago attu, Notopterus chitala are some important species that are harvested from Ganga
River Brahmaputra: It is about 4,023km in length with 51 million hectares catchment area. It has rich fish fauna. Wallago attu, Labeo rohita, Mystus rita, Puntius sarana, Notopterus chitala, Cirrhinus mrigila are some of the fish that are found in Brahmaputra
River Narmada: The length of the river is 1280 km, The effective catchments area of this river system is 94235 sq. km and 6330 sq. km of its all tributaries.
The carp fish groups are Labeo frimbriatus, L.calabasu, L.bata,Cirrhinus reba, Puntius sarana etc, cat fish groups such as Mystus senghala, M. cavasius, Wallago attu, Clupisomagarua, otherfish groups like Tor tor; Channaspp, Mastacembalus spp; Notopterus notopterus etc.
River Cauvery : This river has a length of 800 km with catchment area of 4,70000 sq km.
The fishes like Tor. Putitora, Barbus dubius, Labeo kontius,Cirrhinus cirhosa, Mystus seenghala, Pangasius pangasius,Wallago attu, carps such as Catla catla; Labeo rohita; Cirrhinus mrigala and the exoticspecies Cyprinus carpio and Osphronemus goramy& game fish like Tor khudri and Tmussullahare also found in Cauvery.
Tapti River:This river is with a total length of 720 km and a total catchments area of 48,000 sq.km.
The main fisheries of this river system are Tor tor, Mystusseenghala, Wallago attu, Labeo calabasu, Labeo fimbriata, Cirrhinus mrigala, Channa spp etc
Inland resources of Andhra Pradesh
River Godavari: Its length is 1465 km and has a total catchments area of over 315,980 sqkm. The fishes available are – Labeo rohita, L. calabasu, L. fimbriatus, Catla catla, Cirhinus mirigala, Mystes singhaal, Wallago attu, Hilsa ilaisha, Bangarius bagarius, Macrobrachium rosenbergii etc. During monsoon months Hilsa fishery contributes much to the economy of this region.
River Krishna: It has a length of 1401km with a total catchment area of 2,33,229 sq km. The Fish fauna of Krishna river resembels the Godavari river systems.
River Penna: Its length is 600 km. In summer it dries up. Some carp and other cat fishes are found in it.
Brackish water fisheries
The region where the rivers meet the seas is called estuary. The salinity of these waters is highly variable from 5ppt to 30ppt depending on season and tides of the sea. The organisms which can tolerate rapid salinity fluctuations only can survive in these waters. Such organisms are called euryhaline organisms. The brackish water is rich in nutrients.
The important estuaries in India include the Hoooghly estuary where Ganga join bay of Bengal, Mahanadi estuary in Gujarath, Krishna-Godavari estuary in Andhra Pradesh, Cauvery Estuary in Tamilnadu. Important brackish water lakes are Chilka lake in orissa, pulicat lake in Tamilnadu, kolleru lake in andhra pradesh.
Types of Estuaries: The estuaries can be categorised as Open estuary and Enbanked estuary. In open estuaries the river directly is connected to the sea. In enbanked estuary the estuary is surrounded by land. It is connected to the sea during hightides and heavy rains only. Eg. Lagoons.
Characters of Estuary
a. The water is mixure of freshwater and marine water
b. The pH value of water is between 7.5-8.5
c. The water is rich in nutrents
d. The Oxygen content will be less
e. It forms a good breeding ground for many fishes
f. Estuary harbours many Anadromous and catadromous fishes.
There are about 1.2 million hectares brackishwater area available in India suitable for farming. Out of it only 13% only is being utilised.
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