eChapters

Common characters

Modification of mandiblate mouth parts into sucking-piercing or suctorial type.

Absence of anal lobe in hind wing.

Background

The demand for development of Integrated Pest Management (IPM) strategies is increasing, since many problems have appeared with the use of synthetic pesticides and semiochemicals – informative molecules used in insect-insect or plant-insect interaction – are being considered as an alternative or complementary approach within IPM strategies. (Heuskin et al., 2011). Indeed, such communication molecules like para-pheromones do not present any related adverse effects on beneficial organisms in the ecosystem.

For fruitflies management, several eco-friendly control options  have been developed and recommended across the globe which  include trapping, safe disposal of infested fruits, repulsion with botanical products and physical covering of the developing fruits, besides area-based control through mass trapping and sterile-insect technique. Nevertheless, the use of para-pheromones-based lures in trap systems appears to have greater potential to be among the more widely adopted practices (Verghese, 2009).

WHY, WHEN AND HOW FISH GET PARASITES

Parasites pose a real risk to fishes

All fish are potential hosts to many different species of parasites. Small numbers of parasites are common and probably do little harm. However, all parasites have tremendous reproductive potential and can, under ideal conditions, quickly overwhelm fish in the confines of a tank or pond.

Types of parasites

We can broadly class parasites into two groups. Ectoparasites are found on the external surfaces such as skin, fins and gills, while endoparasites are found in the internal tissues and organs.

Endoparasites are uncommon in ornamental fish. However, there is a wide diversity of blood parasites, worms that colonize the intestines and other parasites that can invade various organs and tissues. Many require an intermediate host, such as snails, birds or the introduction of an infected fish, and so are rare in pond/ aquarium fish. There are a variety of clinical signs which might indicate the presence of endoparasites. Lethargy accompanied by emaciation is a common sign, as are worms protruding from the anus. Identification of sporozoan and protozoan endoparasites often requires microscopic examination of tissues (Chanratchakool et al. 1994).

INTRODUCTION

A parasite is an organism which exploits another organism for the purpose of staying alive. Some parasitic relationships are harmless, while in other cases a parasite can damage or even kill its host. The word is borrowed from the Greek word ‘‘parasitos’’, meaning “one who eats at the table of someone else.” In case of exotic carps parasites causes a great loss by reducing economy. Some, cannot live once their host dies, while others can continue thriving on dead hosts until their nutrients are consumed. Parasites live inside a host are called endoparasites or internal parasites. Ectoparasites live outside the host, and are generally more capable of switching hosts. A parasite preys on other parasites, is called epiparasite (Anderson, 1974).

Silver Carp

The silver carp (Hypophthalmichthys molitrix) is a species of freshwater cyprinid fish, a variety of Asian carp native to north and northeast Asia. It is cultivated in China. Pound for pound, more silver carp are produced worldwide in aquaculture than any other species. Silver carp are usually farmed in polyculture with other Asian major carps, or sometimes Indian major carps or other species. It has been introduced to, or spread into via connected waterways, at least 88 countries around the world.Introduced in india in 1959 at the pond culture division of CIFRI. In India in 1963 breed sucessfully by hypophysation. The silver carp is a filter feeder, and possesses a remarkably specialized filtration apparatus capable of filtering particles as small as 4 µm. The gill rakers are fused into a sponge-like filter, and an epibranchial organ secretes mucus which assists in trapping small particles. A strong buccal pump forces water through this filter. Silver carp, like all Hypophthalmichthys species, have no stomachs; they are thought to feed more or less constantly. Silver carp are thought to feed largely on phytoplankton; they also consume zooplankton and detritus. It is used in controlling water quality, especially control of noxious cyanobacteria (blue-green algae), microcystis .

An extraordinary variety of viruses, bacteria, and organisms stand ready to attack us and feed off our bodies’ cells. Using microscopes of varying power, photographers show us a teeming microbial world that we could barely imagine without their help.

Natural areas in tropical and sub tropical climates are more likely to enhance development of parasitic loads because of the fact that there are variations in climates of these areas in addition to the variations in the type of vegetations and species of wild fauna.

Purpose of study An essential component of the diagnostic process in the evaluation of the disease process is the laboratory diagnosis of any parasitic infection. Sometimes, this confirms the presumptive clinical diagnosis, and other times, it provides evidence that the clinician may have ignored. A sufficient specimen must be used for the examination to achieve a satisfactory diagnosis. Internal parasite testing needs to be done often. Regular inspection typically enables early parasitism identification, preventing gross infection. The majority of the parasites can be accurately identified by doing a detailed examination of the faeces. Faecal sample collection and delivery for parasite identificatio

The domestic duck is an economically important domestic bird in rural areas. They are productive and are reared around the globe for their egg, meat, feather and fattened livers. The worldwide population of ducks (Anas spp.) is 1.15 billion in 2020 out of which 89 per cent were in Asia. China, Viet Nam, Bangladesh and Indonesia are the largest duck rearing countries in Asia (FAO 2020). Geographical location, subtropical climatic condition, water lodged and low areas of the country are suitable for duck habitat. The advantages of ducks over other poultry species are that they are hardy, have higher disease tolerance and are easy to herd.

An Overview of Parasitic Diseases in Asian Aquaculture

Parasitic induced diseases bring about significant economic losses in fish culture system. Estimated loss due to mortality and morbidity of fish due to parasitic infection is much more than that from microbial diseases. Protozoan ciliates (Ichthyopthirius, Trichodina) and flagellates (Ichthybodo, cryptobia) are some of the common ectoparasites of fish. Certain ectocommensal ciliates (Epistylis, Vorticella and Zoothamnium) attach to the external surface of fish leading to fouling. These protozoan ectoparasites are often associated with mortalities of younger stages of cultured fish. The situation becomes worst in water with low oxygen and high organic matter. Most extoparasitic protozoans have simple and short life cycle and reproduce by binary fission. Most protozoan ectoparasites are readily detected in direct microscopic examination of skin and gill scrapings. Histopathological changes in the integument following ectoparasitic protozoan infection are outcome of two counteracting cellular processes – hyperplasia of the epithelial cells, including mucus cells and chloride cells, versus a progressive cellular destruction. Cellular necrosis primarily occurs due to the feeding and attachment activity of the parasites. Generally, immersion therapy using suitable chemicals can control ectoparasitic protozoan infections

Disease caused by endoparasitic sporozoans are a serious threat to fish farms. These sporozoan spores present in the pond soil are normally ingested by the fish. The infective element of the spore (sporoplasm) is released in the gut. The sporoplasm reaches the target tissue using the vascular route. Once inside the target tissue, the vegetative trophozoites cause massive destruction of the target tissue and produce large spore containing cysts. There are two types of sporozoan infecting fish and shell fish namely myxosporidian and microsporidian. Myxosporidian occur in fish either as histozoic (intercellular tissue parasites) or as coelozoic (inside the lumen of various ducts and tubules) parasites. Microsporidians are intracellular obligatory parasites and lead to massive hypertrophy of infected cells (xenomas). There is no effective treatment for sporozoans. However, treating pond soil with chemicals and lime is the best option.

The livestock play a significant role in generating gainful employment in rural areas, particularly among the landless and marginal farmers. The Jammu region of state of Jammu and Kashmir possesses a huge livestock population which is maintained under different management systems. The region has a vast diversity in agro-climatic conditions (comprising low altitude, middle altitude and high altitude), and animal husbandry and pasture management practices. Despite having huge livestock, the production potentials are very low. There are various factors related with low production and among them parasitic diseases rank very high.

Clinical Symptoms

• Anchor worms can be seen with the naked eye

• Frequent rubbing or “flashing”

• Localised redness

• Inflammation on the body of the fish

• Tiny white-green or red worms in wounds

• Breathing difficulties

1 The causative agent of red water fever in cattle is

a) Babesia bigemina b) Leptospira interrogans

c) Theileria annulata d) Theileria parva

Parasitic weeds are a major constraint in tropical agriculture. These are plants that are adapted to live on other plants sharing their nutrients and water. They constitute 1% of flowering plants, approximately 3000 - 5000 species coming under 20 families. Parasitic weeds from five families viz. Orobanchaceae, Convolvulaceae, Santalaceae, Scrophulariaceae and Loranthaceae are considered troublesome weeds as they infest economically important crops in many parts of the world and are very difficult to control by normal weed management measures.

Introduction
Parasitism is a biological interaction in which one organism, the parasite, lives on or within another organism, the host, causing harm. In the context of plant pathology, parasitism is a crucial concept, as many plant diseases are caused by various parasitic organisms, including fungi, bacteria, viruses, nematodes, and protozoa. Understanding the mechanisms of parasitism and pathogenesis is essential for developing effective strategies to manage plant diseases.
Definition & Concept of Parasitism
Parasitism is defined as a symbiotic relationship where one organism benefits at the expense of another. In plant pathology, this interaction typically involves pathogenic organisms that exploit host plants for nutrients, ultimately leading to disease.
Types of Parasites
Plant pathogens are generally categorized based on their nutritional relationships with their host plants. These relationships determine how the
pathogens interact with the host and whether they can survive outside the host environment. There are two primary types of plant parasites:

INTRODUCTION

It can be added that physiological stress as well as the physical offences contribute as primary factor for disease occurrence and fish mortality. Many parasitic diseases due to fluctuation in water quality leads to deplition of stock, and some times total stock will go eg. yellow grub disease.

EFFECT OF TEMPERATURE ON PARASITES

Heterophyid Trematode

Cyprinodon variegatus, an estuarine fish, is heavily parasitized in the bulbus arteriosus by the heterophyid trematode Ascocotyle pachycystis. Parasitized fish ventricles were hypertrophied due to mechanical blockage of normal blood flow by metacercariae in the bulbus Swimming performance generally was reduced by the presence of parasites, which had their most significant negative effect at cold temperatures and low dissolved oxygen level ( Felicia C. Coleman , 1993)

Parasitism
The term parasitism refers to a parasite’s taking of food from its host. Without chlorophyll, fungi are unable to synthesis their own sources of food. Fungi are classified into three main biological groups according on the basis of mode of the nutrient uptake . Parasites, Saprophytes and Symbionts, The term saprophytes, or saprobes, refers to those fungi that feed on dead and decaying organic matter (Gr. sapros rotten + bios life). Some of them have evolved farther, but they are still unable to grow on other living things and can only exist as saprobes. We refer to them as obligate saprophytes(L. Obligare = to bind sapros) . On the other hand, some species live as saprophytes, but under certain circumstances, they can infect another living entity. We refer to them as facultative parasites (Greek parasitos + Latin facultas ability). Many fungus infect living hosts and deprive them of their food. They are called parasites (Greek: parasitos, which means to eat beside). Additionally, a few of them developed into facultative soprophytes (L. facultatas ability + Gr. sapros) after diverging as obligatory parasites (L. Obligar? to bind + Gr. parasitos table mate). Obligate parasites can only grow in culture on living media; in the wild, they can only feed on living protoplasm. On the other hand, facultative saprophytes are basically parasitic organisms but also capable of growing on dead organic matter under some conditions.

Parasitology is the branch of biological sciences that deals with the study of parasites and all the related aspects. This leads to a basic question who is a parasite ? In fact, this term is frequently used in our society for those persons who are doing nothing and depending on others for their survival. The term Parasite means the organism (parasite) which depends on other organism (host) for its nutritional requirements. By definition, it excludes the organisms which are free living and do not depend on other organism for their food requirements. There are other details in fulfilling its nutritional requirements and important one is that in doing so, it causes some harm to the host other wise it will not be a parasite but a commensal.

Corynebacteria are gram positive, non-acidfast, non-motile, non-capsulated, small pleomorphic rods. They frequently occur in rods, coccoid, club and filamentous shape. The term coryneform which refers to the pleomorphic club shape of these gram-positive bacteria. (From Coryne – meaning club). The major pathogen is Corynebacterium diptheria. Which causes diptheria in children. Corynebacteria associated with animals are called diphtheroids.

Morphology
They are gram-positive slender rod with a tendancy to clubbing at one or both ends; they are non-sporing, non-motile, non-capsulated and non-acidfast. They have granules composed of (high energy phosphate stores) – polymetaphosphate. The granules are more strongly gram positive than the rest of the bacterial cell. Stained with Loeffler’s methylene blue, the granules take up a reddish purple color and hence they are called metachromatic granules. They are called as volutinor Babes Ernst Granules. They are often situated at the poles of the bacilli and are called polar bodies. Special stains,
such as Albert’s, Neisser’s and Ponder’s have been devised for demonstrating the granules clearly. Stained smears from animal tissues often reveal groups of cells in parallel (Palisades) or cells at sharp angles to each other (Chinese letter or Cuneiform arrangement). This is due to the incomplete separation of the daughter cells after binary fission. Rhodococcus equi can appear as a gram-positive coccus or a rod or club shaped form arranged in clusters. It is capsulated and sometimes weakly acid fast.

Synonyms : Johne’s disease, Chronic  specific enteritis of cattle, Chronic bacillary dysentery
 
Paratuberculosis (Johne’s disease), an infectious disease caused by Mycobacterium avium subspecies paratuberculosis (MAP), has been recognized as a major disease of ruminants for over a century. It is primarily a disease of domestic and wild ruminants and causes heavy economic losses  in cattle, sheep and goat industry. It is spreading insidiously among animal population worldwide.  Recently it has been shown  that  the disease is not restricted to ruminants only and the host range is expanding to cause disease in other species including Crohn’s disease in humans. In India, the  disease has been occurring  since early 1930s in cattle, sheep and goats in almost every state. The disease in ruminants is clinically characterized by chronic intermittent profuse diarrhea, weight loss, emaciation and finally death.

Introduction

Disease caused by motile Salmonella species in birds is called “Paratyphoid infections”. Paratyphoid infections are present in all parts of the world.

Etiology

Salmonella enterica includes six subspecies. Only one of that subspecies; S. enteric subspecies enterica includes more than 2500 motile serotypes.