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Genus : Corylus 
Species : avellana L.
Family : Betulaceae
Chromosome No. : 2n=2x=28

European filbert Corylus avellana L, is known by several names common being Cob, cobnut, hazel, Spanish or Lambert nut, which has been due to its origin, fruit shape, husk and the general appearance. ‘Filbert’ has also come from name ‘full beard’ as the nut of commerce is fully enclosed by the long husk. It is this husk or involucres which very often has been used to distinguish between various species and cultivars. Corylus the genus has been derived from korys which indicate bonnet, hood or helmet and there are several other views of its name being derived after the name of some renowned places. The word ‘hazelnut’ is from anglosaxon haesel meaning hood. Further the term hazelnut is used in European and Filbert in Asian countries for and its other species. However in America, the term is used to refer to three native species C. archericana, C. californica and C. cornuta. Filbert is an important member of birch family, Betulaceae which has a long history of cultivation (8000 to 5500 B.C.). 

Hazelnut is also known as a cob nut or filbert nut according to species. The hazelnut was native to the Black Sea coast long before our era, where it was found growing wild. Turkey is one of the few countries in the world having a favourable climate for hazelnut production. Hazelnuts are extensively used in confectionery to make praline and also used in combination with chocolate for chocolate truffles and products such as Nutella. Hazelnut oil recovered from hazelnuts is strongly flavoured and used as cooking oil. Hazelnuts are a good source of energy with 60.5 per cent fat content. Hazelnuts have been ranked as one of the most nutritious nuts because they supply significant amounts of protein and fiber, vitamin E and B, minerals like iron, zinc, calcium, magnesium and potassium. 

• Turkish hazelnut production of 625,000 tons accounts for approximately 75% of world productions.
• The common hazel (Corylus avellana) is native to Europe and Western Asia.
• In H P, it is found growing wild in Pangi region of Chamba district and locally known as Thangi.
• Hazelnut is also known as cobnut and filbert.
• Hazelnuts are extensively used in confectionery to make praline and also used in combination with chocolate truffles.
• The temperature of minus 10°C is critical, especially if accompanied by wind, which may kill both pistillate and staminate flavours.
• Hazelnuts are more shallow-rooted, most fruit and nut trees do not tolerate wet soils, the tree cannot tolerate excessive dry summer heat and hot winds.
• Hazel will grow in pH ranging from 4.5-8.5 but around pH 7 is ideal.

Skull: The skull of domestic animals has two sets of bones i.e facial and cranial bones. The facial bones are placed in front and cranial bones are placed caudally.

Facial bones: The paired facial bones are premaxilla, maxilla, nasal, pterygoid, lacrimal, turbinates, malar and palatine bones. The unpaired facial bones are mandible, hyoid and vomer.

Headache is the most common of all nervous complaints. The causes are varied and so also its mode of onset, duration, intensity and other conditions associated with it.

Structures of the head, which are sensitive to pain, are:

Tissue – Proliferating Potential of Cell Types
1. Labile Cells
• Continuously dividing cells
• e.g. epidermis, epithelial cells, bone marrow cells
2. Stable Cells - Quiescent cells
• Undergoes division occasionally
• Liver, kidney    pancreas, fibroblasts,
• Endothelial cells
3. Permanent Cells - Non–dividing cells: Neurons, muscle cells (cardiac, skeletal)

Health and disease management is a crucial component of hatchery operations in aquaculture. Hatcheries, which rear aquatic organisms like fish, crustaceans, and mollusks during their early life stages, are particularly vulnerable to disease outbreaks due to high stocking densities, variable water quality, and the fragile nature of eggs, larvae, and fry. These outbreaks can result in significant mortality, reduced seed quality, and substantial economic losses.
To prevent such outcomes, a comprehensive health management strategy is essential. This includes maintaining optimal water quality, implementing proper feeding practices, and minimizing stress on the organisms. Regular monitoring and early diagnosis help in identifying diseases promptly, allowing for targeted and effective treatments.
Robust biosecurity protocols are also vital. These measures aim to prevent the introduction and spread of pathogens through controlled access, disinfection procedures, and quarantine practices. Together, these steps help create a stable, disease-free environment that supports the healthy growth and survival of hatchery-reared aquatic species.
COMMON PATHOGENS
India’s aquaculture industry faces significant challenges from various pathogens that affect fish and shellfish health. These include bacteria, fungi (particularly oomycetes), viruses, and parasites, all of which can lead to disease outbreaks, poor growth, and mortality.
1. Bacterial Pathogens:
• Bacterial infections are among the most frequently reported health issues in aquaculture:
• Aeromonas spp.: Aeromonas hydrophila is a common pathogen in carp and other freshwater fish, causing ulcerative and hemorrhagic diseases.

(I)  Deficiency Diseases

Mineral and vitamins, in adequate quantities, are essential in the diet of all animals. Many diseases occur due to deficiency of mineral and vitamins. Mineral and vitamins are more necessary in pigs due to their higher growth rate. It is normally seen that when pigs are reared on self made rations, they suffer more with the deficiency of one or more mineral and vitamins. Thus, it is necessary to introduce extra mineral and vitamins in the pig ration. If it is not done, its growth rate and body weight do not increase in proper ratio. The excess and deficiency of one mineral depends on quantities of other minerals present in the ration. It is frequently seen that pigs suffer from deficiency of more than one mineral and vitamin but some time pigs suffer from deficiency of one substance and excess of the other substance, so a balanced ration- with appropriate proportions of various mineral and vitamins- is necessary. Many times it is seen that some infectious diseases increase the necessity of mineral and vitamins in the body. This may cause deficiency of mineral and vitamins in the body and the animal may not recoup.

Following are the description of these symptoms and their prevention.

General Signs of Healthy and Ill Animals

Health

It is a state of freedom from disease. It may also be stated as a condition of an animal in which all the body organs are normal and are functioning to their optimum capacity in relation to animal’s age, sex, work, and production with optimum pulse, temperature and respiration rates appropriate to the species, sex and environment.

Disease

Disease may be any deterioration from normal health or normal functioning of any or all the tissues or organs of animal body. Thus, it shuns animal to perform its normal physiological functions though the nutritional and environmental parameters are maintained normal.

Abstract

Tea is the most consumed, rejuvenating and thirst-quenching beverage. It is bestowed with ‘miraculous’ health benefits which includes promotion of cardio-vascular health, skin protection, antioxidant activity, defence against microbial infection, prevention from cancer, obesity, and many more. Among the four types of tea, green tea has attained much attention of tea consumers due to its magical health potentials.Owing to increased knowledge and marketing of its health benefits, there has been astonishing changes in its consumption pattern and increase in its production. The tea industry drives economies of the tea growing regions and contributes greatly to the country’s GDP growth as well as foreign exchange earnings. However, in recent years, tea farming has become subject to environmental deterioration because of exploitation in cultivation practices.

Common Poultry Diseases

Infectious diseases

Bacteria

Commonly known as “germs”, bacteria are very small living microorganisms. Only a few bacteria cause diseases. In birds these include Salmonella, Clostridia, Pasteurella, Vibrio, Staphylococci, Streptococci, Mycoplasma, Hemophilus, and Mycobacterium etc.

Abstract

Health-conscious consumers are increasingly seeking functional foods in an effort to control their own health and well-being. The field of functional foods, however, is in its infancy. Claims about health benefits of functional foods must be based on sound scientific criteria. A number of factors complicate the establishment of a strong scientific foundation. These factors include the complexity of the food substance, effects on the food, compensatory metabolic changes that may occur with dietary changes, and, lack of surrogate markers of disease development. Additional research is necessary to substantiate the potential health benefits of those foods for which the diet-health relationships are not sufficiently scientifically validated. Research into functional foods will not advance public health unless the benefits of the foods are effectively communicated to the consumer. Finally, those foods whose health benefits are supported by sufficient scientific substantiation have the potential to be an increasingly important component of a healthy lifestyle and to be beneficial to the public and the food industry. Mounting evidence supports the observation that functional foods containing physiologically-active components, either from plant or animal sources, may enhance health. It should be stressed, however, that functional foods are not a magic bullet or universal panacea for poor health habits. There are no “good” or “bad” foods, but there are good or bad diets. Emphasis must be placed on over-all dietary pattern, which follows the current Dietary Guidelines, and is plant-based, high in fiber, low in animal fat, and contains 5-9 servings of fruits and vegetables per day.

Introduction

The study of fish health is crucial for understanding aquatic ecosystems and ensuring the well-being of aquatic species. This report provides a detailed account of a hands-on activity involving necropsy and health examination of fish. Through this practical experience, we aimed to gain insights into the common ailments affecting fish populations and develop skills in identifying pathological conditions.

The necropsy process involves the post-mortem examination of fish specimens, enabling us to observe and analyze internal organs, tissues, and external features. By combining practical techniques with theoretical knowledge, we seek to contribute to the broader understanding of fish health and disease.

We performed a detailed hands-on practical on ‘Shrimp Health Examination’ at the Pathology Necroscopy room on 29th September 2023. Several activities regarding the health examination of shrimp were performed. It included, the collection of blood from an in-between portion of pereiopods and pleopods, also making blood smears on a glass slide, staining, and observation of blood cells under a microscope. Collection of samples from hepatopancreas for microbial culture to know the presence of any pathogen present. Collection of body part samples like gill, pleopods, and telson to observe the presence of external parasites. The species used health examination Whiteleg shrimp (Litopennaenus vannamei).

The aquaculture sector showed an overwhelming growth of 468% during the last two decades and is presently playing a key role in the changing Indian economic growth. The contribution from aquaculture is 21.6% by volume and 49.3% by value to the total fisheries exports. Inland fisheries sector had shown consistent growth of over 5% per annum over the period of 1999-2005. High demand of aquaculture products in the world has forced the aquaculturist to change the culture system from extensive to intensive. This has led aquaculturist to lose millions of dollars due to fish mortalities associated with fish disease and related conditions. Out break of disease has been considered as a major stumbling block in intensive aquaculture practices.

Disease is a very complex interaction between three important factors, namely the susceptible fish, the disease causing agents (pathogen) and the environment. These three factors are most important and must be considered in any fish disease outbreak. The environment in which the causative agent of diseases and their host fish interacts, may favour one or the other. Changes in the environment, whether natural or artificial, may shift the balance from one side to the other and will often determine whether the host will survive or succumb. Understanding and managing the stress and their causative factors are thus the key factors for successful aquaculture.

Herd management practices in the handling, nutrition, milking techniques, sanitation, and housing of dairy animals play key roles in predisposing the individual animal as well as herds to diseases. The key factor influencing the reduction of health issues are the decisions made by herd managers or animal owners.In order to maximize output and profitability through disease control, herd management approaches in conjunction with a veterinarian programme can be most beneficial.

Being a Health Extension Practitioner, one should have a clear idea regarding some fundamental aspects like the nature of health, health education, health promotion and some related concepts. This will help them to understand the social, psychological and physical components of health and enable them to be a better health educator by considering these basic ideas while planning and carrying out a health education session.

Definition & concepts of health

As a Health Extension Practitioner, one’s main target will be to prevent health problems in a community rather than to treat them. Malaria, diarrheal diseases, tuberculosis, pneumonia, HIV/AIDS, substance abuse and many harmful traditional practices are among the different health problems we generally see within our community setting.

Heart

The heart is a cone shaped thick walled and four chambered muscular organ. It lies obliquely craniocaudal in the middle mediastinum in between the left and right lungs and is covered by pericardium inside the thoracic cavity. The major part of heart (about 60 per cent) lies to the left of the middle mediastinum. The broad upper end is the base of the heart. It lies at the junction of the dorsal and middle third of the dorsoventral diameter of thorax at the level of about third to sixth rib and it faces craniodorsally. The narrow lower end is the apex. It lies just dorsal to the sternum at the level of about sixth rib and it faces caudoventrally. The surfaces, right and left are convex. They meet cranially at the right ventricular border and caudally at the left ventricular border. The right (cranial) border is strongly convex. It runs ventrally and caudally. The greater part of this border lies parallel to the sternum. The left (caudal) border is much shorter and nearly vertical. The surfaces of the heart are marked by grooves which indicate the division of the heart into four chambers the two atria dorsally and the two ventricles ventrally. The atria are separated internally by the interatrial septum. The ventricles are separated by interventricular septum. The circular coronary groove indicates the division of the heart in to atria dorsally and ventricles ventrally. It encircles the heart in its upper third part except at the level of the origin of pulmonary artery. The coronary groove is quite deep and wide. It provides passage for the coronary artery and vein. Apart from these, it is deeply filled with fat. The right (subsinuosal) interventricular groove and left (paraconal) interventricular groove indicates the line of separation between the two (right and left) ventricles by the interventricular septum. Both of these grooves run downward from the coronary groove towards the apex parallel to the respective borders and terminate just above the apex. The right and left ventricular grooves are occupied by the respective coronary vessels along with the fat.

Heart failure in canine is being recognized with an increasing frequency throughout the world. It is the end stage pathological event progressively occurring in heart diseases. Heart failure is the condition in which heart is unable to meet the metabolic and nutritional demands of the tissues of the body due to insufficient cardiac output. Heart failure has also been observed with normal cardiac output in conditions like hyperthyroidism or anemia where tissue metabolic needs are increased.

Heart failure is not a disease but it is the end stage of heart diseases. Heart failure in horses is not very common as in dogs and cats. In horses it is characterized by the signs of forward failure, backward failure and fall in blood pressure.

Heart diseases in feline are silent killer as cats are able to hide their symptoms in early stage. Cats are brought to clinics only when disease is more advanced. Heart diseases are different from heart failure. Heart failure is the end stage of heart diseases.

The ferret is a domestic species of small mustelid. Congestive heart failure is most common form of heart disease seen in aged ferrets. Heart failure in ferrets is due to heart diseases and clinical presentation varies from no clinical signs in initial stage to many signs of fulminant heart failure.

With an increase in domestication of rabbits, a leporine, as pet in urban dwellings and their increased life span, risk of cardiac diseases has also increased. Heart diseases are being diagnosed in rabbits with an increasing frequency. The development of clinical signs of heart failure is gradual in rabbits causing late recognition of the heart disease.

Heart failure is a common progressive and complex clinical syndrome with high morbidity and mortality in humans. It is mostly due to cardiac involvement. Clinical signs and symptoms developed in heart failure cases are the manifestations of body’s compensatory efforts to meet chronic inadequate cardiac output as seen in other species of animals also.

Heart failure is the end stage of cardiac diseases. It occurs in pet birds when cardiac output is insufficient and unable to maintain arterial blood pressure. In birds right side heart failure is more common as compared to left heart failure.

Heart failure is the terminal outcome of heart diseases. It is defined as ventricular dysfunction (pump failure) leading to cardiac inability to maintain an adequate cardiac output. Heart failure is the outcome of filling defect, cardiac muscle abnormality, conduction defect, an excessive work load or a combination of these abnormalities.

Cardiomyopathies in acts can be classified broadly as Hypertrophic cardiomyopathy and non-hypertrophic cardiomyopathies. Usually, no alarming clinical signs are detected during routine examination in the preclinical stage except cardiac murmurs in some cats with HCM. This is because, that the cats are sedentary and excellent in hiding the signs of illness from the pet parents. Hence the onset is often acute with the sudden appearance of the clinical signs linked to congestive heart failure like severe dyspnoea, cardiogenic shock, aortic thromboembolism, arrhythmias and even syncope and death

Cats with CHF will be presented with severe dyspnoea, due to fulminant pulmonary oedema and or pleural effusion. The pleural effusion associated with CHF is usually a modified transudate, some cases it may be chylous .In echocardiography ,the size of the left atrium should be determined .If the LA size is normal ,then the dyspnoea may not be of cardiac origin .The presence of B-lines in the lung area in association with LA enlargement confirms cardiogenic pulmonary oedema. Stress, anaesthesia, I/V fluids and steroids leads to decompensation and fulminant pulmonary oedema. Thoracocentesis is will be helpful if there is dyspnoea due to significant pleural effusion. At least 300ml of effusion can be usually removed. The dyspnoeic cat is very fragile and should be handled carefully. Butorphanol may be given for anxiolytic effect. Oxygen administration is beneficial. Furosemide when given intravenously has an initial venodilator effect and should be repeated as required monitoring the sleeping respiratory rate (SRR). Addition of nitro-glycerine (vasodilator) reduces preload, decreases left atrial pressure and help in reducing pulmonary oedema. If the clinical signs are suggestive of cardiogenic shock or myocardial failure, Pimobendan I/V or Dobutamine CRI should be considered.

The heart, composed primarily of specialized muscle tissue known as cardiac muscle, is responsible for maintaining the circulatory system’s function by pumping blood throughout the body. The unique characteristics of heart muscle allow it to respond dynamically to various physiological demands. Among these adaptive responses, hypertrophy, atrophy, and the process of pacemaking are fundamental to heart function and health. Understanding these processes is crucial for comprehending how the heart responds to different stressors, such as physical activity, disease, or aging, and how its electrical and mechanical functions are integrated.
Nature of cardiac muscle
Cardiac muscle is a specialized type of muscle tissue found only in the heart. It is unique because it combines features of both skeletal and smooth muscle, providing both strength and rhythm in its contractions. Cardiac muscle fibres are striated and connected by intercalated discs, which allow rapid transmission of electrical impulses between cells, ensuring synchronized contraction. Unlike skeletal muscle, cardiac muscle has a relatively high density of mitochondria, providing the energy necessary for continuous activity.

The heart is a muscular structure that contracts in a rhythmic pattern to pump blood. The heart functions as a pump to provide a continuous circulation of blood throughout the body.The blood vessels that take blood from the heart to the various tissues are called arteries.Arterioles open into a network of capillaries which constitute the microcirculation. Circulation of blood in the body is important for the transport of nutrients to all parts of the body and for the transport of gases and waste products. The primary function of the heart is to transfer sufficient blood from the venous system to the arterial side of the circulation under sufficient pressure to maintain the circulatory needs of the body.

Heat desiccated products represent khoa and khoa-based sweets, rabri, basundi, etc. These are important traditional dairy products. Traditional dairy products and a great assortment of sweets is an integral part of Indian heritage. These products are endowed with enormous value and enjoy tremendous mass appeal. Of great social, religious, cultural and economic importance these products have been developed over a long period of culinary skills and carry with them, the age-old wisdom and experience. Traditional dairy products have always played a pivotal role in preservation of precious milk nutrients and promotion of its consumption among masses. The increased availability of milk during the flush season coupled with lack of facilities to keep liquid milk fresh during transit from rural production areas to urban market has led to the conversion of milk into variety of traditional products. In addition to preservation of milk solids for longer duration, manufacture of traditional dairy products adds value to milk and also provides tremendous employment opportunity. It is estimated that about 50% of milk produced in India is converted into a variety of traditional products.

Traditional dairy products represent the most prolific segment of Indian dairy industry. These products not only have an established market in India but also have a great export potential because of strong presence of Indian diaspora in many parts of the world. In view of the growing awareness towards the safety aspects of milk-based sweets in India, the consumer shall prefer to buy these products from the organized sector. Despite the widespread popularity and acceptability of traditional milk products in the Indian market, the organized sector has so far not been able to tap into this market potential for many reasons such as lack of published literature on their technology, inadequacy of appropriate technologies for their commercial exploitation, inadequacy of appropriate packaging materials and labeling to take care of new pattern in consumer demand, low keeping quality and a lack of quality assurance systems.

Abstract

The objective of this chapter is to provide an overview of heat pump dryer (HPD) and recent developments in its applications for drying of agricultural and food products. The basics of heat pump dryer, classification, operating principle, configuration and control system have been presented for better understanding. Many researchers have concluded that HPDs use energy more efficiently than electrical dryers. The heat pump dryer is best suited for drying high value commodities such as fruits, vegetables, spices, condiments, herbs, medicinal and aromatic plants at near ambient temperature for producing better quality dehydrated product.

Introduction

Stress represents the reaction of body to stimuli that disturb normal physiological equilibrium or homeostasis, often with detrimental effects (Khansari et al., 1990). Domestic animals undergo various kinds of stress such as physical, nutritional, chemical, psychological and thermal stress (Marai et al., 2007; Nardone et al., 2010). Figure 1 summarises the different types of stressors and their effects on animals.

Introduction

A huge increase in the demand of animal production is expected in the next decades. Food and water security will be one of the other priorities for humankind in the 21st century. Over the same period the World will experience a change in the global climate that will cause shifts in local climate that will impact on local and global agriculture (Nardone et al. 2010). Global climate change is expected to alter temperature, precipitation, atmospheric carbon dioxide levels and water availability in ways that will affect the productivity of crop and livestock systems (Hatfield et al. 2008). For livestock systems, climate change could affect the costs and returns of production by altering the thermal environment of animals thereby affecting animal health, reproduction, and the efficiency by which livestock convert feed into retained products (especially meat and milk).

Stress is described as the cumulative detrimental effect of a variety of factors on the health and performance of living beings (Rosales, 1994). Heat stress arises when there is an imbalance between heat production within the body and its dissipation. Homeotherms can maintain their body temperature within a relatively narrow range and both physiological and behavioural responses help in thermoregulation. Stress occurs when an animal suddenly faces a change in its environment. Heat stress during summer and post summer months in tropical countries is a problem of great concern among farmers and livestock producers as it costs both production and reproduction of animals.

Rearing poultry industrially is a necessity in the present condition where the demand is high and the land holdings for extensive rearing is diminishing. All over the world the poultry industry is growing rapidly. The poultry industry in India is growing at around 8 per cent per annum. The poultry population of the country mainly consists of chicken, ducks, quails, ornamental birds and ratites. Chicken form is the major component of the industry. They are mainly reared as broilers for meat purpose and as layers for eggs. The climatic variations and their effects on profitable poultry rearing are an important topic of study in the current situation, where intensive rearing and global warming are being discussed with equal importance. The welfare aspects of the birds are also a matter of concern all over the world. Thus the knowledge of normal physiology of poultry, the effects of the tropical climate on them and the measures to alleviate detrimental effects produced by adverse climatic conditions have been discussed in detail here.

5.1. INTRODUCTION

Temperature is the one of the most important environmental element influencing the plant growth and development limiting the productivity and adaptation of crops, especially when it coincides with critical ranges (Chen et al., 1982; Paulsen, 1994). Nearly all commercial crops in the arid and semi-arid tropics often suffer from heat stress. Every plant has an optimal temperature for its normal growth, deviation from this may cause stress to plants. The adverse effects on plant of temperatures higher than the optimal considered as heat stress. Crops are exposed to periods of heat stress during their life-cycle. The optimum temperature for the most species ranges from 25 to 35 0C. Above this value, a decline in the photosynthesis rate is observed (Berry and Bjorkman, 1980; Pimentel, 1998). Even brief periods of heat-shock between temperature ranges of 45-50 0C induce marked change in plant growth processes.

3.1 Introduction

The subject of heat transfer is firmly grounded in the sciences of thermodynamics and fluid mechanics. It has become exceedingly important for engineers to possess a clear understanding of the principles of heat transfer and its application to a large number of problems. In view of process engineering, the knowledge of heat transfer and its application is most important, because heat transfer is one of the basic unit operations in the agricultural processing activities. The design of process equipments, refrigerators, boilers or type of heat exchangers, thermal treatment of food grains, cooling of perishables, pasteurizations, sterilizations, freezing of milk and fruit juices and a large number of similar applications involve consideration of heat transfer rates. There may be other situations where heat is being generated during a certain operation, and may be detrimental to the equipment and the food product. In such cases we are often faced with the task of removing the undesirable amount of heat as far as possible.

Q. 1 Psychrometric chart is a graphical representation of which properties
of air
(A) Chemical        (B) Aerodynamic
(C) Hygroscopic   (D) Thermodynamic

4.1 Introduction

Heat is energy which flows due to difference in temperature. Whereas energy is stored heat. Therefore, when the heat energy transfer is completed. It is stored in the form of potential or kinetic energy, in general as internal energy. Heat as energy is measured in terms of observed changes in other forms of energy & other physical properties. A heat transfer analysis is required for estimating the size, the efficiency and cost of the equipment necessary to transfer a specified amount of heat in a given time. It is well known fact that the size of a solar collector or a heat exchanger depends not so much on the amount of heat to be transmitted but rather on the rate at which heat is to be transferred under given conditions.

4.2 Modes of Heat Transfer

Heat is transferred from one body to another in three possible ways, conduction, convection, and radiation.

1.    Heat transfer by conduction is given by

(a) Boyle’s law

(b) Stefan’s law

(c) Fourier’s law

(d) Charles’ law

2.    Heat flow per hour is proportional to change in

(a) Area

(b) Vapour pressure

(c) Mass

(d) Temperature

Whenever the daily maximum temperature exceeds more than average values during summer season the heat wave will occur. Similarly, whenever the daily minimum temperature falls below the average values cold wave will occur. The India Meteorological department has developed the criteria to identify the occurrence the heat waves and cold waves.

11.1 Heat Waves

Heat wave is defined as the condition when the daily maximum temperature is 45ºC or more. Based on departure from normal daily maximum temperature of 40ºC onwards the heat waves are defined as follows:

6.1 Introduction

Greenhouses play an essential role in modern agriculture and horticulture by providing a regulated environment for plant development. To ensure optimal growing conditions and maximum yields, it’s crucial to maintain the temperature inside these structures effectively. This leads us to the fascinating subject of “Heating and Cooling of Greenhouses,” where we investigate the delicate balance between temperature, humidity, and ventilation to promote plant health and production. With greenhouses, growing seasons can be extended, a broader range of crops can be grown, and even plants that would not do well in the local environment can thrive.

Abstract
Aquatic ecosystems are seriously threatened by heavy metal pollution from urban, agricultural, and industrial processes. Aquatic animals can accumulate toxic metals like mercury, lead, cadmium, arsenic and chromium, which can have detrimental physiological, ecological, and toxicological impacts. Oxidative stress, organ damage, poor reproduction, and disruption of ecosystem functioning, including loss of biodiversity and changes in food web dynamics, can all result from exposure to these contaminants. Human health is also at risk from heavy metals moving via aquatic food networks. The effects of heavy metal pollution on aquatic life are examined in this chapter, along with mitigation strategies.
Keywords: Heavy metals, pollution, toxicity, aquatic ecosystems and mitigation strategies

Introduction
The aquatic ecosystem is full with harmful contaminants like heavy metals. Due to farming, mining, geochemical composition, and anthropogenic wastes, their concentration has dramatically increased. Heavy metals contaminate aquatic ecosystems through multiple pathways, such as industrial effluents, agricultural runoff, and atmospheric deposition. Once released heavy metals into water bodies, these metals undergo bioaccumulation, wherein they accumulate in aquatic organism’s tissue, including fish, gradually over time over time. Toxicity of heavy metals due to their long persistence in the environment and non-biodegradable nature. Additionally, heavy metals undergo biomagnification, leading to increasing concentrations as they ascend the food chain, posing greater risks to higher trophic level organisms, including fish. Fish serve as crucial bioindicators for evaluating the potential risks of pollution (Lakra & Nagpure, 2009). Exposure to pollutants, particularly heavy metals like cadmium (Cd), iron (Fe), lead (Pb), and copper (Cu), can lead to both acute and chronic toxicity, disrupting various physiological functions, including reproduction. A  ealthy reproductive system in fish signifies their ability to maintain population sustainability. Fish are widely consumed due to their desirable taste and affordability, making them a vital and cost- effective source of animal protein.
Fish are more susceptible to heavy metal pollution than other aquatic species, despite being one of the most widely distributed species. Some heavy metals like cadmium, mercury, arsenic, and lead have no biological significance, while some like iron, copper, and zinc are vital to the metabolism of fish. Heavy metals concentration in the water bodies has increased significantly as a result of farming, mining, geochemical composition, anthropogenic wastes, and other factors. Heavy metals are among the most hazardous and widely distributed contaminants, naturally occurring as trace elements in the hydrosphere (Sankhla & Kumar, 2019). Fish, however, breed in environments that are naturally contaminated with heavy metals. Fish reproduction is essential to the natural ecosystem and is required for the development of aquaculture. Several studies show that heavy metals interfere with fish reproduction by preventing the induction of vitellogenin, postponing oogenesis, increasing the secretion of luteinizing hormone, and lowering the parameters of the gonadal somatic index and ovulation.

Arsenic
General Information
    1.    Exists in elemental form (-3), trivalent As⁺³ and pentavalent As⁺⁵ oxidation states
    2.    Arsenic is an essential element for rats, chicks, mini-pigs and goats
    3.    The second most important pollutant for livestock. 

Source
    1.    Inorganic form is used in paints.
    2.    Pasture near smelters may be contaminated. 
    3.    Industrial effluents released into nearby water body
    4.    Insecticides (Arsenic trioxide, lead arsenate).
    5.    Herbicides (Sodium arsenite, lead arsenate)

Arsenic
General Information

    1.    Exists in elemental form (-3), trivalent As+3 and pentavalent As+5 oxidation states
    2.    Arsenic is an essential element for rats, chicks, mini-pigs and goats
    3.    The second most important pollutant for livestock. 

Source

Inorganic form is used in paints.
Pasture near smelters may be contaminated. 
Industrial effluents released into nearby water body.
Insecticides (arsenic trioxide, lead arsenate).
 

Metals

Metals are ubiquitous in the modern industrialized environment. Heavy metals like cadmium, iron, molybdenum, lead, nickel, tin and zinc are present in the environment in trace concentrations. These metals are universally present in soil, water, air and biota (Freedman, 1995). Global anthropogenic heavy metal inputs to ecosystem through air, water and soil have increased substantially world wide over last century (Nriagu, 1996).