REVIEW OF LITERATURE

Hippocrates (460-340 BC) who is considered as the Father of Medicine was

the first person who pointed out the role of water for human health. He suggested that

water should be boiled before its use; otherwise it would be harmful (Borchart and

Walton, 1971). However aquatic pollution was recognized as an environmental

problem in the 13th

century when laws were made to prohibit the washing of Charcoal

in the downstream part of the rivers in Britain (Sweeting, 1994). Public awareness on

the deterioration of water quality began to be voiced in the 19th

century when many

rivers of Europe (Elbe, Rhine, Danube, etc.) and USA (Ohio, Connecticut, Hudson

etc.) experienced marked pollution and full-time river keepers were employed at the

end of sanctuary to remove the remains of dead animals from the river Cambridge

(Haslam , 1981).

First Royal Commission on sewage disposal was set up in 1898 (Haslam,

1991). This commission submitted ten reports emphasizing the modern attitude for

river pollution in Britain. In this regard, a survey of river was conducted to

differentiate the rivers into the following five categories and the modified forms of

these standards were also followed by many other countries- (i) Very clean, (ii)

Clean, (iii) Fairly clean, (iv) Doubtful and (v) Bad.

Since the beginning of 20th

century, a lot of efforts have been made to

describe the effects of pollution on physico-chemical aspects of water and biota.

However it is difficult to quote the work of all the scientists, therefore, most

significantly relevant references are being reported here. Initially, no significant work

was carried out on the analysis of pollutants and the most of the work was concerned

with the effects of pollution on aquatic organisms. Marsh (1907), John (1952) and

Hughes (1976) observed the effects of pollution on fish population. Greenfield (1925)

made a comparative study of chemicals and bacteriological aspects of Illinois River.

Carpenter (1924, and 1926) investigated toxic effects of lead salts on the water

quality and biota of rivers. Alexander et al. (1935) recorded chemical constituents of

Tees River. Jones (1940) and Lloyd (1960, 1965) worked on the tolerance of different

heavy metals particularly zinc by fishes. Ganapati and Chako (1951) determined the

effect of paper mill effluents on physico- chemical aspects of Godavari River in India.

John (1952) observed the effects of water pollution on human beings. In 1963, US

Senate constituted a committee which submitted various reports on the effects of

pollution. Gorham and Gordon (1963) determined the effect of smelter pollution on

aquatic vegetation. Velz and Gannon (1964) have reported advances in aquatic

pollution.

European Inland fisheries Advisory commission (EIFAC) in 1964 gave the

water quality criteria for European freshwater fisheries (as referred by Muller and

Lloyd, 1994). Eisler (1965) studied the effects of synthetic detergents on estuarine

fisheries while Brown et al. (1968), Abel (1974) and Abel and Skidmora (1975)

worked on the chronic exposure to zinc and other detergents on fishes and aquatic

invertebrate fauna. Ball (1967a, b, and c) worked on the relative susceptibilities of

fresh water fishes to poisons like ammonia, cadmium and zinc. Brown et al. (1967,

1968, 1974), Brown (1969) analysed the acute toxic ranges of four different

pollutants for rainbow trout. Irukayama (1967) has observed that arsenic compounds

immediately kill the fish and other animals while mercury cause a fatal disease

Minimata in fishes. Sprague (1969, 1970 and 1971), Alabaster (1972) and Alabaster

et al. (1972), Adelman and Smith (1972) found the toxic effect of hydrogen sulphide

to goldfish. Thorp and Lake (1973), Tylar and Buckney (1973), Brown (1977),

Armitage (1980), Norris et al. (1982), Abel and Papoutsoglou (1986) recorded the

influence of mine influents and various heavy metals like cadmium, copper, iron, lead

and zinc on the water quality and fauna of various fresh water bodies. Scullion and

Edwards (1980) observed the effect of coal industry pollutant on macroinvertibrate

fauna of a small river in the South Wales Coal field. Warren (1971), William (1975)

and Kosmala et al. (1999) discussed the biological indicators of pollution. Bryan

(1976) and Abo-Rady (1980) observed the effect of heavy metal pollution on aquatic

inhibitors.

CAUSES AND TYPE OF POLLUTION

Besides recognizing the effect of pollution on aquatic environment and human

being, efforts were also made to determine the causes of pollution. Carpenter (1924,

1926) found lead mining as a cause of river pollution. Ellis (1937) listed 114

pollutants in his document on detection and measurement of stream pollution. He also

noted the lethal limits of these substances of previous studies. Klein (1957, 1962)

published a lot on the causes of river pollution.

After the mid of 20th

century, many attempt have been made to find out the

causes of pollution in the water resources of various part of the world. Different types

of pollutants have been discovered which not only differ on account of nature of

contents but also differ due to their intensity, quantity (gross or negligible) and

persistency. Several efforts have also been made to classify various types of

pollutants but none of the classification can be thought perfect. Wilber (1969),

however, proposed a better classification and roughly classified the pollutant in the

following three categories:

1. Organic pollutants (carbonaceous pollutants containing carbon as the main

constituent).

2. Inorganic pollutants (pollutant of elements, other than carbon and some may

even be insoluble).

3. Miscellaneous pollutants (pollutant related to physical and radioactive

substances).

Haslam (1987) and Ali (1992) further distinguished the organic pollutants into

(a) domestic and agricultural run-off and (b) commercial organic wastage which

include all type of pollutants from beverages, bakeries, milk dairies, chemical

factories, fertilizer and poultry feed manufacturing plants, oil refineries, tanneries,

paper, sugar and textile mills etc. Both type of wastage cause serious pollution in

river as observed by Curtis and Harrington (1970), Newbold (1975) and Goel and

Trivedy (1984).

Organic pollution in water bodies occurs either due to the allochthonous

matters or due to the autochthonous matters. The autochthonous matters are formed

by the decaying of excessive growth of aquatic weeds, algae and aquatic animals. The

allochthonous matters include decaying of leaves, other parts of terrestrial plants and

animals blown into the water by the wind action.

Thieneman (1954) and Pinter and Backhaus (1984) have observed that organic

wastage serve as a fertilizer in small quantity to enhance the productivity of water

body. These, however, become injurious when present in a huge quantity due to the

oxidation by bacteria resulting in the depletion of oxygen level of the water. The high

BOD level, therefore, causes anoxic condition which in turn produces toxic gases like

hydrogen sulphide and methane. These toxic substances destroy most of the aquatic

organisms as reported by Klien (1962).

Similar to organic pollutants, inorganic pollutants are also differentiated into

two major categories: (a) toxic materials and (b) suspended materials. Toxic materials

include agrochemicals (like fertilizers, biocide), detergents, heavy metals and wastes

from oil refineries (Singh and Sinha, 1996). These materials either get into the

inflowing water through their use in agriculture or through the wastage of different

industries such as petrochemicals, oil refineries, textiles paper and sugar mill,

tanneries etc. These industries use synthetic chemical in the manufacture of their

product like fiber, plastic, rubber but release their influents in natural water. These

wastes cause serious pollution due to the presence of the heavy metals salts of copper,

cadmium, lead, nickel, mercury and chromium. These chemicals are highly injurious

to aquatic animals (Bryan, 1976; Abo-rady, 1980; Abel and green, 1981).

It has been observed that the wastes of oil refineries remain on the surface of a

water body after discharging into it and prevent the dissolution of oxygen. It creates,

in turn, obnoxious odors in water and makes it unhygienic for drinking and other

purposes (Ali et al., 1993).

Pollution occurs also due to the discharge of mine wastes in water because

these wastes contain acids. The acidic effluents suddenly change the pH of the

receiving water body and affect the whole ecosystem causing serious pollution

(Carpenter, 1924, 1926; Newton, 1944; Patterson and Whitton, 1981; Chandra and

Krishna, 1983). In addition to the toxic substances, suspended solids like soil and

sand also causes water pollution (Cairns et al., 1972) on entering the natural water

sources due to the erosion or floods.

Like previous two types, miscellaneous pollution is also distinguished into

two types i.e. physical pollution and radioactive pollution. Physical pollution is also

known as thermal pollution. Sometimes, inclusion of hot waters from the thermal

power plants and hot effluents of industries causes sudden environmental changes in

rivers and lakes (Kamath, 1983; Trivedi and Raj, 1992) and affects the natural

ecosystems and biota adversely as reported by Brock and Yoder (1970).

Radioactive pollution occurs mainly in the oceans by dumping the drums of

radioisotope wastes in the deeper part of the oceans or by discharging the wastes from

atomic reactors and the fuel processing units. These wastes include variety of isotopes

as Sr90, Cs117, Po219, Co60 and C14. They are highly injurious to the aquatic life

(Ali et al., 1993; Singh and Sinha, 1996). They enter into the rivers from the seas

during floods and cause pollution.

LITERATURE SURVEY

This chapter reviews the literature relevant to the objective of the study, i.e.,

status of water quality. Significant amount of work has been reported on the quality

of water. A discussion on the current thinking about the water quality has also been

incorporated. The most common and wide spread threat associated with water is

contamination, either directly or indirectly, by sewage, by other wastes or by human

or animal excrement. If such contamination is recent, and if among the contributors,

these are carriers of communicable enteric diseases, some of the living casual agents

may be present. The drinking water so contaminated or its use in the preparation of

certain foods may result in further cases of infection. An appreciable number of

reports are available on hydrobiological studies of water pollution and their

abatement. However, no detail report on quality of water of river Varuna in relation to

urbanization and industrialization is available. Studies on different physico-chemical

parameters of river Varuna at different sites yielded useful data for the understanding

of the nature of the water environment and it throws a flood of light on the changes

which have been brought about by human interference.

Pollutional effects due to discharge of domestic sewage and industrial

effluents into the Indian rivers have been studied by many workers viz., Bhimachar

and David (1946) studied the effect of factory effluents on the Bhadra river fisheries

at Bhadravati. Ganapati and Alikunhi (1950) studied factory effluents of Mettur

chemical and Industrial Corporation Ltd, Mettur Dam, Madras (Chennai) alongwith

their pollutional effects on the fisheries of Cauvery River. Ganapati and Chacko

(1951) reported about the effects of pollution on Godavari River due to wastes of

paper mills at Rajahmundry. Motwani et.al, (1956) studied the pollution of river Sone

by factory effluents of the Rohtas Industries at Dalmianagar. Bhaskaran (1959)

studied the effect of industrial waste on river pollution in Bihar and Uttar Pradesh.

Quasim and Siddique (1960) made some preliminary observations of river Kali

effected by effluents of industrial wastes. Saxena et al., (1966) studied the water

quality of river Ganga at Kanpur and concluded that the tanneries significantly

increases the pollution load of river as they discharge huge amount of effluents

containing organic wastes and heavy metals.

Venkateswarlu (1970) studied ecology of algal flora of the Moosi River,

Hyderabad with special reference to the water pollution. He studied the phyico-

chemical characteristics affecting the distribution and periodicity of algae. Pollution

studies of Chambal River and its tributaries at Kota were made by Olaniya et al.,

(1976). Aggarwal et al., (1976) studied physico-chemical characteristics of the river

Ganga at Varanasi. Govindan and Sundaresan (1979) carried out the pollutional

aspects of the Adyar River in Madras (Chennai) and its effect on aquatic life with

special reference to algae and their seasonal succession over a period of one year.

Effects of industrial effluents on phytoplankton communities of the river Ganga at

Barauni was studied by Bilgrami and Siddiqui (1980). Shrinivasan et al., (1980)

studied pollution effect of industrial and urban wastes on river Cauvery. Prasad and

Saxena (1980) extended their study on the blue green algae in relation to industrial

pollution of the river Gomati at Lucknow. The change in algal flora in Cauvery river

due to industrial and domestic pollution was studied by Parmasivum and Sreenivasan

(1981). Gunale and Balakrishnan (1981) studied eutrophication on the river Pavana,

Mula and Mutha flowing through the Pune city. These rivers, unpolluted at the point

where they enter the city, get progressively polluted due to waste from industries and

city sewage. Effects of sewage and fertilizers on phytoplanktons of the Doodhganga

river (Kashmir) was studied by Rishi and Kachroo (1981). Boralkor et al., (1982)

studied the soil pollution of the Krishna River in Maharastra. Nandan and Patel

(1985) studied the eutrophication in Viswamitri River flowing through Baroda city.

According to Mehrotra (1990), the various sources responsible for pollution of

the river Ganga in Varanasi are domestic sewage, effluents of the industries, burning

of dead bodies at the ghats, use of detergents, insecticides and pesticides used in

agriculture. Ghatak and Konar (1992) studied the effect of various industrial effluents

on Damodar River Ecosystem, West Bengal. The Physico-Chemical and Biological

characteristics of Damodar River water (West Bengal, India) was found gradually

changed due to toxic effects of various industrial effluents. The concentrations of DO,

Alkalinity, Phosphate and Hardness of river water were significantly decreased but

CO2, was found significantly increased (P<0.05) at various sampling stations. This

also resulted in reduction of plankton Population (both zooplankton and

Phytoplankton) and also bottom organisms significantly. Bhaskar et al., (2003) have

studied the Physico-chemical and bacteriological parameters on certain locations of

the river Torsa and reported that the water was highly alkaline with high

concentration of free ammonia.

Gupta and Pankaj (2006) reported organic pollution of River Gomati due to

anthropogenic activities. Magudeswaran and Ramachandran (2007) reported that

sewage from many parts of Tripur and discharged from the surrounding areas, gets

into Noyyal River, which are responsible for the decreased in water quality. Okendro

et al. (2007) described chloride; bicarbonate alkalinity and pH are indicators of three

significant component viz., animal waste, sewage, and industrial discharges in to the

Narmada River. Verma and Khan (2007) reported that rapid urbanization and

increased anthropogenic activities have been deteriorated the water quality parameter

of Arpa river water of Bilaspur in Chattisgarh.

Verma and Saksena (2010) studied the water quality and the pollution status

of river Kalpi at Gwalior (Madhya Pradesh) and concluded that the main cause of

pollution is the organic pollution due to anthropogenic activities. Sujitha et al. (2011)

studied the water quality of river Karamana at Trivendrum (Kerala) and concluded

that the main causes of low DO and High BOD in the river was due to organic

detritus, weed growth and biomass degradation in the benthic layer. Srivastava and

Srivastava (2011) reported that majority of water characteristics of River Gomati

(Uttar Pradesh) were found to exceed the permissible limits due to sewage discharge

and posed problems for the survival of the aquatic life and human beings. The river

also continuously receives daily sewage, domestic and municipal and industrial waste

water from the city. Due to presence of such huge amount of pollutants in to surface

water, river lost their self purifying nature, resulting high level of pathogenic bacteria.

WORK DONE OUTSIDE INDIA

Various aspects of physico-chemical characteristics of river water were

discussed by several workers. Water chemistry of river Tees (Alexander et al., 1935),

river Nile (Abdin, 1948), river Tugela (Oliff, 1960), Jukskei crocodile river system of

South Africa (Keller, 1960), river Lark (Owens and Edwards, 1963), Columbia river

basin (Gunnerson, 1967), river Redcedar ( Ball et al., 1969), river Thames (Lack,

1971), river Amazon (Gibbs, 1972), river Gaudalupe (Young et al., 1972), river

Nida, Poland (Starzecka, 1979), Montreal river (Cushing, 1984), Rhine and Rone

river (Golterman and Meyers, 1985), Rous river, Australia (Eyre et al., 1999), Osun

river (Olajire and Impekperia, 2000), Warri river, Nigeria (Ikomi and Emuh, 2000),

Odzi river, Zimbabwe (Jonnalagadda and Mhere, 2001), Keiskamma river (Morrison

et al., 2001), Coastline of Mauritius (Daby et al. 2002), Yesilirmak river, Turkey

(Tuzen et al., 2002) Bow river watershed (Little et al., 2003), Burlington and

Hamilton sewage (Rao et al., 2003), Sagami river, Japan (Iwashita and Shimamura,

2003), Keiskamma river (Fatoki et al., 2003), Odiel River, South West Spain (Olias et

al., 2004), River Soan, Pakistan (Iqbal et al., 2004), Alaro river, Nigeria (Fakayode,

2005), Asa river, Nigeria (Eletta and Adekola, 2005), Mouri river, Bangladesh

(Kamal et al., 2007), Cekerek steam, Turkey (Duran and Suicmez, 2007), Ogun river,

Nigeria (Jaji et al., 2007) Haraz river (Keramat, 2008), Calaber river, Nigeria ((Abu

and Egenonu, 2008), Ethiope river, Nigeria (Agbaire and Obi, 2009), Buriganga,

Bangladesh (Saha et al., 2009) Landzu river, Nigeria (Yisa and Jimoh, 2010), Chenab

river, Pakistan (Iqbal et al., 2010), Ona river and Alaro river, Nigeria (Osibanjo et al.,

2011) have been extensively studied outside India.

WORK DONE IN INDIA

In India, pioneering studies on physicochemical characteristics of river were

carried out by Chacko and Ganapati (1949) on river Adyar, Chakrabarty et al. (1959)

on river Yamuna, David (1963) on river Gandak, Ray et al. (1966) on river Ganga

and Yamuna, Pahwa and Mehrotra (1966) on river Ganga, Vyas (1968) on Pichhola

lake, Udaipur, David et al. (1969) on Tungabhadra reservoir, Verma and Dalela,

(1975) on river Kalinadi near Mansurpur, John (1978) on the river Kallayi, Kerala,

Zingde et al., (1980) on river Damanganga (Gujarat), Chandra and Krishna (1983) on

river Ganges at Kanpur, Raina et al. (1984) on river Jhelum, Tiwari et al. (1986) on

river Jhelum, Tiwari and Ali (1988) on river Subarnarekha, Rana and Palaria (1988)

on river Ayad at Udaipur, Tripathi et al. (1991) on river Ganga at Varanasi, Haniffa et

al. (1993) on river Thabaraparani, Qadri et al. (1993) on river Ganga, Das and Sinha

(1994) on river Ganga, Hosetti et al. (1994) on Jayanthi nalla and river Panchaganga

at Kolhapur, Murugesan et al. (1994) on river Tampraparani, Chaurasia and Kanran

(1994) on river Mondakini, Mishra et al. (1994) on river Subarnarekha, Sinha et al.,

(1994) on river Sai at Rae Bareli, Mitra et al. (1995) on river Mahanadi, Choubey

(1995) on river Tawa , Desai (1995) on river Dudhsagar, Desai et al. (1995) on river

Khandepar, Kataria et al. (1995) on river Kubza, Chandra et al. (1996) on river

Ramaganga, Banerjee et al. (1999) on river Tikara and Brahmani, Koshy and Nayar

(1999 and 2000) on river Pamba, Bhuvaneswaran et al. (1999) on river Adyar,

Sharma (1999) on river Yamuna, Singh et al. (1999) on River Damodar,

Dhanapakium et al. (1999) on river Cauvery, Pande and Sharma (1999) on river

Ramganga at Moradabad, Nanda and Tiwari (1999) on river Brahmani at Rourkela,

Singh et al. (1999) on river Ghaghra, Gyananath et al. (2000) on river Godavari,

Kaushik et al. (2000) on river Ghaggar, Musaddiq (2000) on river Morna at Akola,

Chatterjee and Raziuddin (2001) on river Nunia in Asansol, West Bengal, Kaur et al.

(2001) on river Satluj, Tripathi and Mishra (2001) on river Ganga, Shrivastava and

Patil (2002) on river Tapti, Garg et al. (2002) on western Yamuna canal from

Tajewala (Haryana) to Haiderpur treatment plant (Delhi), Abbasi et al. (2002) on

Buckinghhum canal, Sinha (2002) on river Sai at Rae Bareli, Fokmare and Musaddiq

(2002) on river Purna at Akola, Maharashtra, Garg (2002) on river Mandakini at

Chitrakoot, Martin and Haniffa (2003) on river Tamiraparani, Srivastava and

Srivastava (2003) on river Gaur at Jabalpur, Bhadra et al. (2003) on river Torsa,

North Bengal, Rajurkar et al. (2003) on river Umshyrpi, Shillong, Sinha et al. (2004)

on river Ram Ganga, Singh et al. (2004) on river Yamuna, Guru Prasad and Satya

Narayan (2004) on Sarada river basin, Tiwari et al. (2005) on river Ganga in Bihar,

Chavan et al. (2005) on Thane creek water, Kumar et al. (2006) on river Tunga,

Karnataka, Singh and Singh (2007) on river Gomati, Kosygin et al. (2007) on river

Moirang river, Manipur, Raju et al. (2008) on river Kaveri, Tamil Nadu, Sinha and

Kumar (2008) on river Gagan at Moradabad, Tripathi et al. (2008) on river Rapti at

Balrampur, Saksena et al., (2008) on river Chambal, Prasad and Patil (2008) on river

Krishna, Begum and Vishwaranjan (2009) on river Cauvery, Joshi et al. (2009) on

river Ganga at Haridwar, Thitame and Pondhe (2010) on river Pravara, Maharashtra,

Singh et al., (2010) on Manipur river system, Verma and Saksena (2010) on river

Kalpi at Gwalior, Kumar et al. (2010) on river Behgul at Bareilly, Agarwal and

Saxena (2011) on river Gagan at Moradabad, Sujitha et al.(2011) on river Karamana

at Trivendrum, Kerala, Yadav and Srivastava (2011) on river Ganga at Ghazipur and

Annalakshmi and Amsath (2012) on river Cauvary at Tanjore, Tamil Nadu.

AREA UNDER STUDY

Varuna is the main tributary of river Ganga at Varanasi. It maintains the

groundwater level of trans-Varuna area and is also helpful for irrigation, washing, bathing

and fishing. Various toxic matter and liquid effluents daily enter into the river Varuna.

Thus it is important to estimate the extent to which the water consumed by the

residents of Varanasi city and the periphery areas has been polluted. They are not

aware of the pollution and its effect. It was found from the survey of literature; hardly

any systematic work had been done in this area. As Varuna is the most important

river of Varanasi, it directly or indirectly affects the social, economical, cultural and

other activities of the people on and around living on its periphery and are also

dependent on it. River Varuna and its periphery are selected as the study area because

it has a high potential for the study of environmental pollution due to various

industrial and anthropological activities. Depending on the magnitude of the

dependency, water samples have been collected from various locations of the river

Varuna. So the area under study has the potentiality to investigate the status of water

pollution.

HAEMATOLOGY OF FISHES

Fishes live in very intimate contact with their environment and are therefore

very susceptible to physical and chemical changes in it, which may be reflected in

their blood components. Blood is, therefore, recognized as a potential index of fish

response to water quality, and can be used to ascertain the effects of pollutants in the

environment. Hesser (1960) framed out methods for routine fish haematology. Larson

and Snieszko (1961) compared various methods of determination of haemoglobin in

trout blood. Bouck and Ball (1966) stated that haematology may be useful tool in

monitoring stress levels of aquatic pollution on fish. Gelineo (1969) studied

concentration of haemoglobin in 53 species of fresh water and marine fish. Blaxhall

and Daisely (1973) described routine haematological methods for examining fish

blood which included haemoglobin estimation, PCV, erythrocyte counts, ESR, TLC

and DLC’s and cytochemical staining. They gave description of stained blood cells as

well as the range and mean value for these tests on brown trout Salmo trutta (L).

Hussein et al. (1974) made a haematological study of Anguilla vulgaris and Mugil

cephalus. They observed seasonal variations for both species in erythrocyte count,

haematocrit values and haemoglobin content which were found to be higher in

summer and lower in winter. Denten and Yousuf (1975) observed seasonal changes in

the haematology of Salmo gairdneri.

Pandey et al., (1976) studied the effect of an organo-phosphate, melathion on

the blood of Channa punctatus and found significant decrease in RBC counts, Hb

concentration, haematocrite and MCHC whereas there was increase in WBC counts.

Panigrahi and Mishra (1978) observed reductions in haemoglobin percentage and

RBC count of the fish Anabas scandens treated with mercury. Clark et al. (1979)

studied physiological stress resulting from environmental influences in largemouth

bass, Micropterus salmonids, and reported that Haematocrit (Ht), haemoglobin (Hb)

and total plasma protein were positively correlated with fish length; Hb and Ht were

positively correlated with fish age, while Mean corpuscular haemoglobin negatively

correlated with fish age. Both haemoglobin and packed cell volume were related to

erythrocyte counts. Siddiqui and Nasim (1979) made haematological observation on

Cirrhina mrigala and recorded higher haemoglobin and erythrocyte concentration in

males than in females. Sastry and Sharma (1980) observed a decline in Haemoglobin

and Haematocrit value in Channa punctatus exposed to mercury. Shrivastava and

Sriwastva (1980) observed cellular and nuclear hypertrophy, change in shape,

agglutination and bursting of erythrocytes in Cirrhinus mrigala fingerlings treated

with urea. Wedemeyer et al. (1983) studied physiological stress response in

Oncorhynchus kisutch and found that leucocrit was a sensitive indicator of the

physiological stress resulting from crowding population densities and to stress of

handling and to temperature changes. Sharma and Gupta (1984) found reduction in

neutrophil population in Clarias batrachus exposed to carbon tetrachloride. Kumar et

al. (1984) studied the haematological changes in cold water fish, Schizothorax

plagiostomus (Heckel) and that naturally infected fish with metacercarae of

Diplostomium tertare had decreased total erythrocyte count, PCV, Hb, TLC relative

to uninfected controls indicative of pollution. Murray (1984) related haematological

characteristics with the sex of fish and season of the year. Ralio et al. (1985) reported

that fish blood parameters of diagnostic importance like erythrocyte and leucocyte

count, haemoglobin, haematocrit and leucocyte differential counts readily respond to

incidental factors such as physical stress and environmental stress due to water

contaminants.

Rao, et al. (1989) observed that active, fast-moving fish (Scomberomorous

guttatus and Rastrelliger kanagurata) had higher values of erythrocyte parameters to

meet the high metabolic rate than the sluggish, predacious fish (Arius maculates) and

bottom detritus feeder (Liza parsia). The leukocyte parameters were not related to

activity and the habitat of the fish. Thakur and Pandey (1990) studied the effect of

BHC on Clarias batrachus and concluded that lymphocytosis, neutropenia and

eosinopenia were linked to BHC intoxication. Hoglund et al. (1992) studied the

haematological variations in population of Anguilla anguilla naturally infected with

Anguillicola crassus off the Swedish Baltic coast in an area receiving heated cooling

water from a nuclear power station. Infection resulted in reduced lymphocyte

numbers and increased granulocyte numbers which were considered indicative of a

humoral and cellular immune response. Allen (1993) determined the haematological

parameters of Oreochromis aurens. The results revealed that O. aurens parameters

appear to be similar to those of O. niloticus and O. mossambicus. Haemoglobin

concentration was higher in O. aurens than latter species.

Rauthan and Grover (1994) observed that blood parameters are altered by

intrinsic as well as extrinsic factors. Studies on blood parameters of Barilius

bendelisis during different seasons of year showed that total erythrocyte count,

haemoglobin, packed cell volume, blood glucose values raised during summer

months, whereas lowest values of all parameters were observed in winter months,

when ambient temperature was quite low. Hrubec et al. (1997) investigated the effect

of water temperature on haematological and serum biochemical analysis in hybrid

stripped brass. Collazos et al. (1998) worked on seasonal variation in male and

female tench, Tinca tinca and found significant changes in red blood cell count and

haematocrit in males comparing spring and summer with autumn and winter, whereas

in females the RBC remained constant for all four seasons but the haematocrit

decreased in autumn and winter compared to spring and summer. The results

indicated marked seasonal variation in the blood of male and female Tinca tinca.

Sahoo and Mukherjee (1999) worked out normal ranges for diagnostically important

haematological parameters of laboratory reared Rohu (Labeo rohita) fingerlings.

There were wide variations in haematocrit and MCV of individual healthy fish.

Fagbenro et al. (2000) studied haematological profile, food composition and

enzyme assay in the gut of the African bony-tongue fish, Heterotis niloticus. Hrubec

et al. (2001) worked out age-related changes in haematology and plasma chemistry

values of hybrid stripped Bass (Morone chrysops and Morone sexatilis). The results

showed that values for packed cell volume and red blood cell indices were

significantly lower, and plasma protein concentration was significantly higher in

younger fish. Total white blood cell and lymphocyte counts were significantly higher

in fish of six and nine month’s age. Orun et al. (2001) conducted a study to determine

and compare blood parameter levels of Alburnoides bipunctatus, Chalcalburnus

mossulensis and Cyprinion macrostomus. The number of total leukocyte, neutrophil

and monocyte levels was found to be higher in female fish, especially in reproductive

season than in male fish. Levels of haemoglobin, haematocrit, and erythrocyte were

high in male fish in an annual period.

Adham et al. (2002) studied the blood chemistry of Nile tilapia, Oreochromis

niloticus under the impact of water pollution. Homatowska et al. (2002) studied

haematological indices and cytomorphometry of circulating blood in the sun bleak,

Leucaspius delineates. Red cell indices were found to be higher, and made it possible

for the species to function normally even in less comfortable oxygen conditions of its

natural habitat. The lymphocyte and monocyte count was lower. Svetina et al. (2002)

studied haematology and some blood chemical parameters of young carp till the age

of three years, The results suggested that the investigated haematological and

biochemical variables could be successfully utilized in monitoring the metabolic

balance and health status of fish. Sowunmi (2003) studied the haematology of the

African catfish, Clarias gariepinus from Eleyele Reservoir, Ibadan.

Gabriel et al. (2004) studied the influence of sex, source (pond and wild)

acclimation and health status on some blood parameters of Clarias gariepinus.

Results from this study suggest that sex, source of fish and period of acclimation have

some degrees of influence on the blood parameters of C. gariepinus. Jawad et al.

(2004) analyzed the relationship between haematocrit and body length, sex and

reproductive state in the Indian Tenalosa ilisha, Male fish showed a higher

haematocrit value than females. Rehulka and Adamec (2004) studied female rainbow

trout to calculate reference haematology values for red cell counts, haematocrit values

and haemoglobin concentration. Tierney et al. (2004) studied the differential

leucocytes count of four teleost species, Coho salmon (Oncorhynchus kisutch),

pacific herring (Clupea pallasi), brook stickle back (Clupae inconstans) and feathered

minnow (Pimephales promelas), and reported that relative leucocyte number

responds significantly to changes in water quality.

Arnold (2005) established standardized haematological methods and reference

intervals for cartilaginous fishes (sharks, skates, and rays). De-Pedro et al. (2005)

studied daily and seasonal variations in haematology and blood biochemical

parameters in tench, Tinca tinca. Elahee and Bhagwant (2005) studied gill

histopathology and haematological indices, in three tropical marine fish species,

Scarus ghobban, Epinephelus merra, and Siganus sutor, from the presumably

contaminated lagoon of Bain des Dames, Mauritius. Gbore et al. (2006) studied the

effects of stress due to handling and transportation on haematology and plasma

biochemistry in the fingerlings of two species of fish (Tilapia zilli and C. gariepinus).

It was concluded from the study that fingerlings generally are susceptible to stress but

those of T. zilli are more susceptible to physical stresses than those of C. garipinus.

Tavares-dias and Moraes (2006) worked out the reference intervals for biochemical

variables and red blood cell indices of healthy intensively bred channel catfish

Ictalurus punctatus. Trumble et al., (2006) studied dietary and seasonal influences on

blood chemistry and haematology in seals. Vetansnik et al. (2006) carried out

haematological analysis on Carassius auratus irrespective of sex.

Gabriel et al. (2007) presented the haematological characteristics of

Sarotherodon melanotheron from the brackish water creek of Buguma. The highest

range of parameters was recorded in thrombocytes, while the lowest was observed in

RBC. Significant differences between males and females were observed in

haemoglobin, haematocrit, red blood cells and thrombocytes. Sahan et al. (2007)

carried out a study in agricultural, industrial, domestic, and slaughter house

discharging region of Ceyhan River and found that leukocyte values and neutrophil

proportion in fish blood were found increased by means of environmental stressors.

Zexia et al. (2007) carried out morphological studies on peripheral blood cells of

Chinese sturgeon, Acipenser sinensis. The erythrocyte and four main types of

leucocyte viz., thrombocytes, lymphocytes, granulocytes (including neutrophils and

eosinophils) and monocytes were identified in the peripheral blood. In addition to

normal erythrocytes, reticulocytes and division of erythrocytes were observed.

Adam and Agab (2008) investigated the reference values for haematological

and biochemical ranges for Clarias gariepinus. Red blood cell count was positively

correlated with haemoglobin and negatively correlated with MCV and MCH. Bastami

et al. (2008) carried out a study to obtain a basic knowledge of the haematology and

the influence of sex on some blood parameters of wild carp (Cyprinus carpio)

spawners. The highest haematocrit, haemoglobin concentration, RBC, MCH and

MCHC were found for males. The highest leucocyte differential counts were found

for females. Latifi et al. (2008) studied cytomorphometric evaluation of Koran

(Salmo letnica) erythrocytes under natural conditions.

Mastan et al., (2009) studied the haematology of Clarias batrachus exposed

to lead nitrate, observed significant decrease in RBC and haemoglobin percentage.

The increase was observed in the number of lymphocytes and eosinophils while

decrease was noticed in the number of monocytes and neutrophils. Adeyeno et al.

(2009) conducted a study for the induction of acute handling and transport stress that

could reproducibly affect haematological changes in African catfish, Clarias

gariepinus. Significant differences were observed in the values of the neutrophil and

lymphocyte of the stressed fish relative to the baseline data. Singh and Tandon (2009)

studied the effect of river water pollution on haematological parameters of fish,

Wallago attu from river Suheli and river Gomti. The haemoglobin, red blood cells,

total leucocyte count and packed cell volume values were higher in Suheli river fish

whereas white blood cells and erythrocyte sedimentation rate were found higher in

Gomti river fish. The study revealed that blood parameters are sensitive indicators of

stress on fishes exposed to water pollutants. Zhou et al. (2009) compared of

haematology and serum biochemistry between cultured and wild ecotypes of dojo

loach, Misgurnus anguillicaudatus. The results revealed that haemoglobin in the two

ecotypes were significantly different whereas red blood cells were significantly

higher in cultured individuals than in wild counterparts. In contrast, the white blood

cell level in cultured fish was significantly lower than that in the wild one. Sabri et al.

(2009) studied the impact of Henneguyosis infestation on haematology of Clarias

gariepinus. They observed reduction in RBC count, Hb value and packed cell volume

whereas WBC count elevated in the infected fish.

Nikolov and Boyadzieva-Doichinova (2010) examined the red blood cell

count in three carp species: Carassius gibelio (L.), Alburnus alburnus (L.) and

Scardinius erythrophthalmus (L.). The results were compared for individual species,

as well as with data for other freshwater fishes. Akinrotimi et al. (2010) investigated

the haematological characteristics of Tilapia guineensis from Bunguma creek Nigeria.

Dove et al. (2010) studied blood cells and serum chemistry in whale shark Rhincodon

typus. Ikechukwa and Obinnaya (2010) carried out haematological studies of African

lungfish, Protopterus annectens in order to establish a normal range of blood

parameters. Abdul et al. (2010) studied the impact of triazophos on haematology of

Channa punctatus. The haematological analysis showed significant reduction in RBC

count, Hb value, PCV, MCH, MCHC and MCV while there was a significant increase

in total WBC count. Zarejabad et al. (2010) studied the effect of environmental

temperature changes on haematological and biochemical parameters of Hoso hoso

juveniles. The results showed that haematocrit, calcium and eosinophil were affected

by different temperature. Increasing temperature led to significant increase in

haematocrit, calcium and eosonophil but WBC lymphocyte, cortisol and glucose

concentration decreased slightly.

Gabriel et al. (2011) studied the effect of acclimation on blood composition of

Oreochromis niloticus. After acclimation to captivity, there was significant reduction

(p<0.05) in the values of haemoglobin (Hb), packed cell volume (PCV), red blood

cell (RBC), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin

concentration (MCHC), lymphocytes and thrombocyte, while the values of mean

corpuscular volume (MCV), WBC, neutrophils and monocytes increased significantly

(p < 0.05). Kori-Siakpere and Oboh, (2011) studied the effects of tobacco leaf dust on

the haematology of African catfish Clarias gariepinus. The result obtained revealed

significant difference (P<0.01) in the haematological parameters examined

(haematocrit, haemoglobin, total erythrocytes count and mean erythrocyte

haemoglobin concentration) depicting a proportional decrease with an increase in the

toxicant concentration during the exposure period. Haematological examination

showed that there was destruction of the erythrocytes production and the

concentration of haemoglobin in the RBC was much lower in the exposed fish

compared to the control depicting an anaemic condition. Malathi et al. (2012) studied

the comparative haematology of Channa punctatus and Channa striatus (Bloch)

collected from freshwater bodies of Cauvery delta. Data shows that the

haematological parameters showed slight fluctuation between the two species. The

RBC count, haemoglobin, packed cell volume, mean corpuscular volume and mean

corpuscular haemoglobin concentration showed higher value in C. punctatus and

lower value in C. striatus while WBC count and mean corpuscular haemoglobin

showed higher value in C. striatus than C. punctatus. Saroch et al. (2012) studied the

effect of mercuric chloride on the haematology of Clarias gariepinus. The treatment

with mercuric chloride was found to inflict a drastic reduction in the total count of

RBCs. Exposed fishes showed a significant increase in W.B.C count while there was

a significant decrease in haemoglobin content and haematocrit level when compared

to the control.

The study of morphological and quantitative variations in blood parameters

induced by pollutants and other environmental factors has been studied by many

workers. Heavy metals are serious pollutants of the aquatic environment because of

their environmental persistence and to be accumulated by aquatic organisms. A

survey of literature on heavy metals toxicity clearly shows heavy metals cause several

haematological and biochemical disorders in aquatic organisms. The toxicity of heavy

metals such as lead, copper, zinc, mercury and other metals have been studied in

Oncorhynchus kisutch (McLeay, 1975; Buckley et al., 1976), in Mystus vittatus

(Dalela et al., 1981), in Oreochromis niloticus (Omoregie and Oyebanji, 2002; El-

Sayed et al., 2007; Younis et al., 2012), in Oreochromis mossambicus (James et al.,

1993; Nussey et al., 1995), in Anabas testudineus (Nair et al., 1984; Kumari and

Banerjee, 1986; Banerjee and Kumari, 1988; Kumar et al., 1999a, 1999b, 2004), in

Tinca tinca (Shah and Altindag, 2004; Shah, 2006), in Heteropneustes fossilis

(Sharma et al., 1982; Agrawal et al., 1982, 1983; Banerjee, 1986; Banerjee and

Banerjee, 1988; Garg et al., 1989; Srivastava et al., 1995; Nanda, 1997), in Anabas

scandens (Panigrahi and Mishra, 1978), in Puntius conchonius (Gill and Pant, 1981,

1985), in Catla catla (Rai and Qayyum, 1981, 1984), in Tilapia mossambica (Naidu

et al., 1984; Dhanekar et al., 1985), in Cyprinus carpio (Beena and Vishwaranjan,

1987; Masud et al., 2005), in Clarias gariepinus (Adeyemo, 2007; Adeyemo et

al.,2008), in Clarias batrachus (Joshi et al., 2002; Maheswaran et al., 2008, Mastan

et al., 2009) and in Channa punctatus (Sastry and Sharma, 1980; Juneja and Mahajan,

1983; Agrawal et al., 1983; Chekrabarthy and Banerjee 1988; Garg et al., 1989a;

Misra and Behera, 1992; Bala et al.,1994; Singh, 1995; Singh et al., 2008).

Haematological parameters studied in response to seasonal variations in

Anguilla anguilla (Andersen et al., 1985) and in Mugil cephalus (Cech and

Wohlschlag, 1982). Some investigators have studied effects of stressors, like

infections, drugs etc., on haematological parameters such as in Tilapia guineensis

(Akinrotimi et al., 2009), in Salmo gairdneri (Barnhart, 1969; McCarthy et al.,

1973), in Goldfish (Burton and Murray, 1979), in Oncorhynchus mykiss (Li et al.,

2010b; Rehulka, 2000, 2002a & 2002b; Rehulka and Adamec 2004; Talas et al.,

2009), in Oreochromis niloticus ( Sebastiao et al., 2011), in Heteropneustes fossilis

(Borah and Yadav, 1996), in Clarias gariepinus (Ogbulie and Okpokwasili, 1999;

Gabriel et al., 2001; Gabriel et al., 2004; Sabri et al., 2009), in Clarias batrachus

(Joshi et al., 1980; Ruhela et al., 2006; Srivatava and Choudhary, 2010) and in

Channa punctatus (Mahajan and Dheer, 1983; Dheer et al., 1986).

Alternations in haematological parameters due to insecticide/ pesticide

toxicosis in various freshwater teleosts have been reported by several workers such as

in Labeo rohita (Bansal et al., 1979; Adhikari et al., 2004), in Oncorhynchus mykiss

(Velisek et al., 2007), in Sarotherodon mossambica (Koundinya and Ramamurthi,

1979a), in Puntius ticto (Chauhan et al., 1983), in Barbus conchonius (Gill et al.,

1991), in Trichogaster fasciatus (Raizada and Gupta, 1982), in Cyprinus carpio

(Chandrasekara and Pathiratne; 2005, Dobsikova et al., 2006; Ramesh and Saravanan,

2008), in Labeo umbratus (Van Vuren,1986), in Heteropneustes fossilis (Joshi et al.,

1979; Dabral and Chaturvedi, 1983; Mishra and Srivastava, 1983; Mustafa and

Murad, 1984; Ghosh and Banerjee, 1989; Nath and Banerjee, 1995), in Oreochromis

niloticus (Gaafar et al., 2010), in Clarias gariepinus (Musa and Omoregie, 1999;

Adedeji et al., 2009; Ovie et al., 2009; Yakeen and Fawole, 2011; Akinrotimi et al.,

2012), in Clarias batrachus (Qayyum et al., 1982; Shammi and Qayyum, 1982; Joshi,

1982; Goel and Maya, 1986; Thakur and Pandey, 1990; Patnaik and Patra, 2006), in

Channa striatus (Natrajan, 1981, 1984; Thakur and Sahai, 1994; Sasikala et al.,

2011), in Channa punctatus (Pandey et al., 1976, 1979, 1984; Pandey et al., 1981;

Thakur and Sahai, 1994; Saxena and Seth, 2002; Devi et al., 2008; Malla et al., 2009;

Abdul et al., 2010; Parveen and Shadab, 2011).

Effect of fertilizers and sewage/ effluents on the haematological values of

fishes have been observed in Oncorhynchus kisutch (McLeay, 1975), in

Heteropneustes fossilis (Narain and Srivastava, 1979; Murad and Mustafa, 1989), in

Rasbora daniconius ( Nayak and Madhyastha, 1977; Madhyastha and Nayak, 1979),

in Anabas testudineus (Verma and Banerjee, 1989), in Labeo rohita (Balaji and

Chockalingam, 1989) in Clarias gariepinus (Adeyemo, 2005; Anjani et al., 2007) and

in Channa punctatus (Pandey et al., 1979, Poddar and Mishra, 2011).

There are many reports related to toxicity of metals, pesticides and pollutants

on haematology of different fish species. But there is no information on the effect of

pollution of river Varuna on the haematological parameters of Clarias batrachus and

Channa punctatus.

CALCIUM METABOLISM IN FISHES

In freshwater fish, blood electrolyte concentration is regulated by many

interacting processes -- absorption of electrolytes from surrounding medium through

active mechanisms, predominantly at the gill; control of water permeability; and

selective reabsorption of electrolytes from urine. Any alteration in one or more of the

above mentioned processes would result in a change in the plasma electrolyte

composition. The endocrine glands involved in the calcium homeostasis in fishes are-

pituitary, ultimobranchial gland and corpuscles of stannius. Prolactin secreted by

pituitary releases hypercalcemic factor in fishes. The hypocalcemic factors are

released conjointly from ultimobranchial gland (UBG) and the corpuscles of Stannius

(CS), which is found only in this group.

CORPUSCLES OF STANNIUS:

Corpuscles of Stannius (CS) were first described by Stannius (1839) on the

kidneys of teleostean and holostean fishes. Huot (1898) studied the embryological

origin of CS and described that in Symbranchus these glands originate as evaginations

of the pronephric duct. Garrett (1942), Bauchot (1953) and Kaneko et.al., (1992) have

also reported similar origin of CS. However, Krishnamurthy (1967) and Belsare

(1973a) have mentioned the origin of CS from the mesonephric duct. Giacomini

(1933), ford (1959) and de Smet (1962) have, however, reported that the CS

originates from the pro- and mesonephric ducts. The CS originating from the

pronephric duct is called ‘duct corpuscles’ and that originating from the mesonephric

duct is called the ‘tubule corpuscles’ (de Smet, 1962). The number of CS differ from

species to species, there are up to 10 CS may be present in Clarias batrachus, up to 8

in Heteropneustes fossilis, 1-2 in Channa punctatus and between 2 to 4 in Mystus

vittatus (Belsare, 1973b; Krishnamurthy, 1976; Subhedar and Prasad Rao, 1976;

Ahmad and Swarup, 1979; Srivastav et.al., 1985; Singh, 1990; Singh and Srivastav,

1996). Moreover within one species individual variations may occur which are related

to sex or age (Wendelaar Bonga and Pang, 1986, 1991).

Earlier investigators, on the basis of histochemical and fine structural

observations, have suggested that CS is involved in protein synthesis and secretions

(Ogawa, 1967; Tomasulo et al., 1970; Wendelaar Bonga et al., 1977, 1980;

Bhattacharya and Butlar, 1978; Aida et al., 1980a, b). Pang et al. (1974) named the

substance secreted by the CS as hypocalcin. Later, a glycoprotein with molecular

weight 3000 was isolated from salmon CS by Ma and Copp (1978) and they termed it

as teleocalcin. Lafebar et al. (1988a, b) have isolated and purified a glycoprotein with

molecular weight of 54 K Da from trout CS and considered it as hypocalcin. During

in vitro incubation the principal substances which are produced and released by trout

CS are glycoproteins of molecular weight 10,000 and 28,000 which are capable of

inducing hypocalcemia in eels (Lafeber et al., 1984). The substance secreted by the

CS and named earlier as hypocalcin, teleocalcin or stannous corpuscles products has

been now renamed as stanniocalcin (Milliken et al., 1990) and is widely accepted.

Involvement of CS in fish calcium was reported first by Fontaine (1964). The

findings of Fontaine (1964) was later confirmed by some workers who have observed

hypercalcemia after stanniectomy (Chester Jones and Henderson, 1965; Chan et al.,

1967, 1969; Fontaine, 1967; Rankin et al., 1967; Ogawa, 1968; Pang, 1971a; Pang et

al., 1973; Fenwick, 1974, 1976; Wendelaar Bonga and Greven, 1978; Kenyon et al.,

1980; Hanssen et al., 1989; Fenwick and Gilles Braseur, 1991; Butler, 1999).

Corpuscles of Stannius have also been suggested to be involved in phosphate

regulation (Fontaine, 1967; Chan, 1970; Pang, 1971a; Kenyon et al., 1980; Butler,

1999). These workers have reported a fall in the serum phosphate level after

stanniectomy.

ULTIMOBRANCHIAL GLAND:

Van Bemmelen (1886) was first to describe the gland in the elasmobranches.

He termed this gland as suprabranchial bodies considering its position in relation to

the pericardium. Nusbaum-Hilarowicz named it as sub-eosiphageal gland as he found

that it lies under the digestive tract in some deep-sea fishes. The term ultimobranchial

body was first coined by Greil (1905) and since then it has been widely used as it

describes the embryonic origin and the anatomical position of the gland in some

vertebrates.

In elasmobranches during embryonic development the ultimobranchial gland

appears as outpockets from the pharyngeal wall slightly caudal to the sixth gill pouch

(Pang, 1971b). In adults the left gland persists but the right one sometimes fails to

develop or degenerates (Camp, 1917). In bony fish, the glands may be single or

paired located ventral to the oesophagus and lie in the transverse septum of the adult

(Pang, 1971b, Robertson, 1986). Pang (1971b) describes that a single gland

sometimes may be subdivided into a left and right position by a connective tissue

septum.

The ultimobranchial gland of fish has been reported to contain calcitonin

(Copp et al., 1967, 1968; Niall et al., 1969; Orima et al., 1972; Otani et al., 1975,

1976; Noda and Narita, 1976; Fenwick, 1978; Robertson, 1986; Takei et al., 1991).

Rasquin and Rosenbloom (1954) were first to correlate the ultimobranchial gland

with the calcium homeostasis. Administration of ultimobranchial gland extract (Pang,

1971b) and calcitonin (Louw et.al., 1967; Chan 1970; Peignoux-Deville et al., 1975;

Lopez et al., 1976; Mathur, 1979; Wales and Barrett, 1983; Glowacki et al., 1985;

Fouchereau-Peron et al., 1987; Srivastav et al., 1998a) have provoked hypocalcemia.

Thus, these investigators have ascribed a hypocalcemic function to the fish

ultimobranchial gland. The calcium-lowering effects in fish can be further supported

by observations obtained after the removal of the UBG. Partial

ultimobranchialectomy in European and American eels evoked transient but moderate

hypercalcemia, which became more pronounced when the fish were exposed to high-

calcium water (Lopez et al., 1976; Fenwick, 1978).

PITUITARY GLAND (PROLACTIN CELLS):

Several workers have reviewed the structural and functional aspects of the

teleostean pituitary (Wingstrand, 1966; Van Oordt, 1968; Barr, 1968; Jorgensen,

1968; Lofts, 1968; Hoar, 1969; Ball and Baker, 1969; Yamamoto, 1969; Yamazaki,

1969; Sage and Bern, 1971; Reinboth, 1972; Schreibman et al., 1973; Holmes and

Ball, 1974; Fontaine and Olivereau, 1975; Follenius et al., 1978; Van Oordt and

Peute, 1983; Schreibman, 1986). Among vertebrates the pituitary gland exhibits a

common basic structural pattern. But the teleostean pituitary has some peculiar

features. The most peculiar feature of teleost pituitary is that the adenohypophysis is

clearly divided into three regions, which is essential due to a restriction of hormone

producing cells of a peculiar type to specific regions of the adenohypophysis. Except

agnatha, a prolactin cell type has been identified in all vertebrates (Aler et al., 1971;

Holmes and Ball, 1974; Nicoll, 1974; Schreibman, 1986). There is a striking

similarity in the distribution of prolactin cells in non-mammalian vertebrates. The

prolactin cells are restricted to the rostral zone in teleosts. The rostral pars distalis

(RPD) has a preponderance of prolactin cells (Schreibman, 1986).

In freshwater fish a decline in the serum/ plasma calcium level has been

observed after removal of pituitary gland (Fontaine, 1956; Olivereau and Chartier-

Baraduc, 1965; Chan and Chester Jones, 1968; Chan et al., 1968b; Wendelaar Bonga

and Pang, 1989; Srivastav et al., 1998). Hypocalcemia has been observed in

hypophysectomized killifish kept in calcium-deficient seawater (Pang et al., 1971).

This clearly suggests that killifish pituitary possess a hypercalcemic factor. It has

been observed that a prolactin free part of carp pituitary did not provoke

hypercalcemia in test fish (Pang et al., 1978). Moreover, the grafts of the part of the

pituitary gland containing the prolactin cells induced hypercalcemia in the American

eel, Anguilla rostrata (Flik et al., 1989a). In killifish kept in low-calcium freshwater

the removal of pituitary gland caused hypocalcemia which could be corrected by

pituitary homogenates or mammalian prolactin (Pang, 1981). There exist several

studies which clearly indicate that prolactin is hypercalcemic factor in fishes

(Olivereau and Olivereau, 1978; Pang, 1981; Wandelaar Bonga and Flik, 1982;

Wandelaar Bonga et al., 1985; Srivastav and Swarup, 1985; Flik et al., 1986b, 1989a,

b; Fargher and McKeown, 1989; Srivastav et al., 1995). Fish prolactin has also been

suggested to play a role in reproduction. Salmon prolactin potentiated gonadotropin

hormone stimulation of estradiol production by incubated ovarian follicles from

rainbow trout (Fostier and Prunet cited by Prunet et al., 1990).

Phosphorus is an important constituent of nucleic acids and cell membranes,

and is directly involved in all energy-producing cellular reactions. The role of

phosphorus in carbohydrate, lipid, and amino acid metabolism, as well as in various

metabolic processes involving buffers in body fluids, is also well established. Feed is

the main source of phosphate for fish because the concentration of phosphate is low

in natural waters. The dietary supply of phosphate is more critical than that of

calcium because fish must effectively absorb, store, mobilize, and conserve phosphate

in both freshwater and sea water environments.

In most fish, the main phosphorus deficiency signs include poor growth, feed

efficiency, and bone mineralization. Other signs of deficiency in carp include increase

in the activity of certain gluconeogenic enzymes in liver, increase in carcass fat with

decrease in carcass water content, reduced blood phosphate levels, deformed head,

and deformed vertebrae (Ogino and Takeda, 1976; Onishi et al., 1981; Takeuchi and

Nakazoe, 1981). A reduction in hematocrit level of catfish may also occur (Andrews

et al., 1973). A low-phosphorus intake by red sea bream also causes curved, enlarged

vertebrae; increased serum alkaline phosphatase activity; higher lipid deposition in

muscle, liver, and vertebrae; and reduction in liver glycogen content (Sakamoto and

Yone, 1980).