Manual Parasitology - A High Yield Study Chart On Non-athropods Protozoans (PART 1)

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The highest rate of sample with protozoan infection was at Kamal District There were six species of protozoa that infected gastrointestinal tract; those are Eimeria spp. The highest number of protozoa found in this research was Eimeria In this study, we found that samples In addition, there were Cattle aged 6 months-2 years old The present study revealed that protozoan infection of cattle is common in Bangkalan Regency. Studies focused on determining that the prevalence of protozoan, risk factors for the parasitism, and the geographic distribution are needed and will be effective guide for prevention and control measures.

Madura cattle is one of the Indonesian local cattle that are widely developed in East Java, especially in Madura Island. Madura cattle have great potentials to be developed because they are genetically tolerant to hot climates and marginal environments, resistant to tick infestations, and highly adaptable to low feed quality, as well as require less food compared to imported cattle. Besides, Madura cattle are easy to maintain, easy to breed, and resistant to various diseases [ 1 ].

The population of Madura cattle in Bangkalan Regency in was , and predicted to increase every year parallel to the promotion of crossbreed artificial insemination program between Madura cattle and Limousine cattle Madrasin [ 2 ]. Beef cattle as a potential commodity in the development of rural farming must be supported by an adequate maintenance system. The business of animal husbandry is faced with problems of reproductive disorders and chronic parasitic diseases, especially protozoan infections.

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Gastrointestinal disease needs special attention because it can be an obstacle that affects the acceleration of livestock development in the countryside so that it can cause economic losses due to decreased livestock productivity, decreased weight, quality of meat, skin, and internal organs, growth retardation in young animals, and danger of zoonoses. Based on the examination results of fecal samples gathered from Madura cattle butchered at slaughterhouse at Surabaya, it was found that those cattle were infected by several kinds of protozoa species, such as Eimeria spp.

However, there has been no research published about protozoan infections in the gastrointestinal tract of Madura cattle in Bangkalan Regency, Madura, Indonesia. The present study was based on the laboratory examination of cattle feces without treatment.

Efficacy of eleven antimicrobials against a gregarine parasite (Apicomplexa: Protozoa)

The samples were collected as per standard sample collection procedure, directly from the rectum without disturbing the animals, and were accompanied by a responsible veterinarian. This research was conducted at 10 districts located in coastal areas each district was represented by one village in Bangkalan Regency with high livestock population.

Fecal sampling was conducted at sites with different altitudes. A total of fecal samples were collected for this research. Fecal sampling was conducted from April to May During fecal sampling process, questionnaire and interview with the farmer were also conducted to obtain certain information about farmer name, age, gender, education, and breeding experience and cattle breed and quantity, gender, age, type of maintenance, treatment that has ever given, the other reared cattle, type or material of the enclosure, environmental condition, or livestock care.

The samples were collected directly from the rectum and brought to the laboratory in mini zip locked polythene bags and added with 2. Each plastic bag was labeled with registered sample number and then stored in a container with ice. To determine the existence of protozoa, identification key methods were carried out [ 6 ].

The positive result of protozoan-infected cattle could be determined when protozoa were found during examination using one of those methods. The prevalence of the protozoan infections was expressed in percentage value using the following formula:. The data obtained will be analyzed descriptively and presented in the form of the prevalence of protozoan infections based on district, kind of protozoa, sex, and age. Based on this research, it was found that there were from samples The highest prevalence of protozoan infections was found in Kamal district, in which The prevalence of protozoan infection in the gastrointestinal of Madura cattle in each district in Bangkalan Regency.

The high prevalence in this study was in accordance with the study of Volpato et al. Those ten districts are located in coastal areas and are well known as livestock meeting points from several locations as well as temporary shelters for cattle that will be traded out of the island or for Idul Adha. On the other hand, the results of this research indicate that the prevalence of protozoan infections in Madura cattle from those 10 districts was high. Therefore, routine monitoring for protozoan infections should be preceded by performing fecal examination so that the infections can be completely controlled to improve the health and productivity of the cattle.

Research result showed that, from positive samples, there were District with the highest infection of two species protozoan was Sepuluh district with At Kamal district, there were 9. At Labang district, Arosbaya district and Socah district were 7. The prevalence of protozoan species in the gastrointestinal tract of Madura cattle in Bangkalan Regency.

The results showed that there were six species of protozoa infecting the gastrointestinal tract of Madura cattle, i. Eimeria is the most common species of protozoan-infected Madura cattle in 10 districts, whether it was single or mixed infections. The second common species of protozoan-infected Madura cattle in Bangkalan district, both single and mixed infections, was Blastocystis. However, Blastocystis was not found infecting cattle in Arosbaya, Klampis, and Burneh districts. Some types of protozoa found in this research showed to have zoonotic potentials, such as Balantidium spp.

Cryptosporidium parvum oocyte is usually found in exoskeleton and gastrointestinal tract of Musca domestica on dairy farms. Flies as mechanical vectors have the ability to spread diarrheal diseases caused by protozoa as they can travel up to 20 miles [ 8 ]. Cryptosporidium bovis oocyte can infect six species of livestock and poultry in Tunisia [ 9 ]. The prevalence of Cryptosporidium infection in cattle in Northern Nigeria reported to be The high prevalence of Blastocystis spp.

The prevalence of protozoan infections in the gastrointestinal tract of dogs in France was Both can potentially trigger infections to their hosts [ 15 ]. The number of samples with single infection caused by Eimeria spp. Single infection caused by Blastocystis spp. Samples with single infection caused by Balantidium spp.

Single infection caused by Entamoeba spp. Samples infected by two species of protozoan, such as Eimeria and Blastocystis , were found in 34 at six districts. Sepuluh district with 11 samples was the highest. There were five samples infected with three species of protozoa Eimeria spp. Based on sex, the prevalence of protozoan infections in bulls The comparison of the prevalence of protozoan infections based on sex in each district is shown in Table The prevalence of protozoan infections in the gastrointestinal tract of Madura cattle in Bangkalan Regency based on sex.

Furthermore, the prevalence of protozoan infections in cattle aged from 6 months to 2 years was The highest prevalence was found in Arosbaya district The prevalence of protozoan infections in the gastrointestinal tract of Madura cattle in Bangkalan Regency based on age. Another research in India showed that Similarly, the prevalence of protozoan infections in cows in this research was also higher than in bulls due to predisposing genetic factor, hormonal factor, stress-reducing immune factor to infection, parturition factor, and lactation factor, resulting in weakness and malnutrition.

Hence, the prevalence of the infections in calf is always lower, since they were less exposed to larger areas contaminated with protozoa and it is also because the calf is still suckling. Madura cattle are reared in cages or not, vulnerable to protozoan infection that contaminate the grass they eat. If one of the cattle was infected by protozoa, the area then would be considered as a good place for various types of protozoa to develop.

Medusae Craspedacusta, for exam- secrete calcium carbonate exoskeletons within their soft polyps ple usually swim free, the Frisbee-, umbrella-, or box-shaped shelter. Medusae lack a calcium carbonate skeleton. The tentacles of medusae resemble the snaky locks of mals, which are usually caught with the tentacles. Coelenterates the mythical Medusa. Cnidoblasts trig- with placozoans, which lack epithelial tissues.

This mesogleal Figure E. A reef consisting of herbivorous soft coral Dendro- layer contains translucent secretions and often loose cells but is nephthya , which lacks symbiotic algae and has poorly devel- not organized as a tissue. The gastrodermis lines the gastrovas- oped nematocysts, feeds almost exclusively on photoplankton, cular cavity or stomach. Coelenterates have nerve nets but have no central nervous Coelenterates digest food with their saclike gastrovascular cavity, system.

The pacemaker of the nerve net maintains the swimming or stomach, which opens through the mouth. The mouth squirts Figure A Craspedacusta sowerbii, the living medusa of a freshwater coelenterate. Contraction of the bell expels water, thereby propelling the medusa. Class Hydrozoa. Bar 5 10 mm. Flaten and C. The mouth of the medusa opens at the external end of the manubrium; the stomach is at the internal end. Meszoly; information from C. The tentacles are at the top of the upright sessile form, two spermaries are located below the tentacles, a large swollen ovary is shown at the lower left in this picture, and bud is at the right.

These green hydra are normally about 3 mm long when extended, but this one shrank by about 1 mm when it was prepared for photography. These green hydras harbor Chlorella Pr in their endoderm gastroderm cells. The photo symbionts are maternally inherited on the external surface of the egg after it is released from the ovary.

P W N Kanyari, J M Kagira* and R J Mhoma**

SEM, bar 5 1 mm. Planula larvae metamorphose into the stomach to the periphery of the medusa. Within the cells of many corals, and a few medusae, algae are All or so species of Scyphozoa are marine—most have symbiotic partners. The algae sustain the animal partner with a benthic polyp stage and all have free-swimming medusae.

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Symbionts are not common in scy- Medusae of Scyphozoa and Hydrozoa are frequently called jel- phozoans, with the notable exception of the upside down jelly- lyfish because their mesoglea is thick relative to that of other fish, Cassiopea. Scyphozoan medusae do not have velums. They pro- Anthozoans, as solitary or colonial marine polyps, include duce zygotes that grow into planulae.

Though some open-ocean about species—sea anemones, sea pens, sea fans, sea pan- species develop directly into medusae, most settle and grow into sies, stony true or hard corals, and soft corals. Anthozoans sessile polyps. At their oral ends, polyps produce distinctive form polyps exclusively, never medusae. Some anthozoan species juvenile medusae ephyrae serially in a process called strobila- are hermaphroditic, whereas others have separate genders.

Fer- tion.


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The adult form is sessile, by secretions of their pedal disk. Some anemones are vivipa- usually living on red, brown, or green algae. Adults produce gametes which nes may also reproduce uniparentally by growth into two, by are shed into the water. Fertilization produces creeping noncili- budding, or by pedal laceration—splitting off part of the pedal ated planulae which grow into polyps. Polyps metamorphose. Without their photosymbionts, most anthozoans survive, The tentacles are resorbed into the adult.

As is the case with coel- but they grow more rapidly in sunlight and corals deposit lime- enterate groups, relatively a few life histories are known in detail. Anthozoans possess a ciliated grove along one side Coral reefs—underwater limestone ridges in shallow tropical of their mouths, essentially making their symmetry bilateral. Soft corals causing some to hypothesize that coelenterates may be ances- predominate in Atlantic reefs; a soft coral does not lay down an trally bilateral. Hard corals are more impor- Cubozoa, or box jellies and sea wasps, bear one or a group tant in the Pacific.

Below a depth of 60 m, corals tend not form of tentacles at each of the four corners of their translucent bells. Most symbionts of anthozoans are dinomastig- active swimmers in tropical and subtropical seas. Nematocysts otes Pr-5 ; for example, Symbiodinium microadriaticum also of cubotoans usually cause nasty stings for humans, some are called zooxanthellae are yellow in color.

Zooxanthellae inhabit even fatal. Corals, cubozoan eyes among the most complex among animals. The live to a depth of m. Reefs provide a sea haven for protoc- cubozoan planula gives rise to a polyp then metamorphoses into tists, fish and other marine animals. Increasing carbon dioxide a single medusa, which reproduce sexually.

This pH change Hydrozoans, with about described species, include creates condition less favorable for skeletal production than the colonial hydroids and siphonophores such as the Portuguese more alkaline one. Jewelry jellyfish. A velum—characteristic of most hydrozoan medusae— has been carved from the internal limestone skeletons of the forms a rim around the umbrella margin. Overcollect- through which they move using cilia.

Hydras are named for the ing of corals prompted the United States to forbid the importa- nine-headed dragon slain by Hercules in Greek myths. Hydro- tion of coral. Biocoral, a biomaterial derived from natural coral, zoan life cycles are diverse; many have small or ephemeral is being used for jaw and face bone grafts in Europe and the medusae, or lack medusae altogether. Hydrozoan polyps usually United States; the porous structure of coral facilitates movement reproduce by laterally budding offspring polyps to form polyp into the substitute bone graft by cells that form bone osteob- colonies and medusae, whereas hydrozoan medusae reproduce lasts.

The biocoral graft is partly replaced by normal bone when sexually by release of eggs and sperm from gonads along the the graft is resorbed. Most hydrozoans Many of the newly discovered deep-sea medusae biolumi- produce either eggs or sperm, but some species are hermaph- nesce sparkling blue green. One species sheds its bioluminescent rodites. The zygote develops from a fertilized egg into a micro- tentacles on attackers; the bell then pulses off into the wine dark scopic blastula and then into a free-swimming, ciliated, solid sea and eventually regenerates tentacles.

Toxin is injected through the poison tube. This is a giant seafloor- not permit us to suggest any more about their taxonomic and deposit feeder. The tiniest coelenterates, such as Cryptohydra, are Perhaps they represent early macroscopic Eukarya, maybe numerous and diverse polyps and medusae smaller than 2 mm in undisturbed sunbathing protoctists in a prePhanerozoic world their longest dimension. Cambrian rocks Although Ediacaria, and many others mainly phosphate-embed- million years old include fossils interpreted as anthozoans, ded and sandstone imprinted pre-Phanerozoic fossils touted as hydrozoans, and scyphozoans.

This enigmatic well-pre- Although it is clear that Coelenterates diverged relatively served, visible and varied fossil biota, has been found world- early in the history of animals, their precise position on the tree wide in rocks million years in age. Ediacaran assemblages of Animalia remains unknown. Some molecular data indicate persisted until the base of the Cambrian Period mya, per- that sponges and ctenophores branched from protoctist ances- haps some slightly beyond. Now reported from some two dozen tors prior to the divergence of coelenterates, placozoans, and the localities they are entirely extinct.

Nearly fifty distinct Ediacaran metazoans.


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Within Coelenterata, a primary divergence separated genera and species e. Scyphozoa appear to have a close relationship. These two taxa Their indeterminate growth, three-fold and larger symmetries, appear to be the sister group of Hydrozoa. Staurozoa may be the lazy beach-dwelling lifestyles and often quilt-like structures do sister group of all other Medusozoa. Orientation depends on the ability of an more comb jellies are placed in the phylum Ctenophora. Each ctene supports thousands of cilia with balancers consisting of — sensory hairs of fused cilia.

Ele- lengths as great as 2 mm—the longest cilia known—and their vated bundles of long, thin, microtubule-filled processes origi- rapid, coordinated rowing away from the mouth results in con- nate from each side of the apical organ, run through parallel tinuous, smooth movement and reliable, mouth up orientation. Balancers may induce rapid or slow beats ctenophores are the largest animals propelled by cilia. While weak swimmers, ctenophores are carried ies that may also secrete a poisonous or anesthetic mucus.

Some ctenophores absorbing the shock and tug of struggling prey. Colloblasts and, employ muscular flapping while escaping from predators. Oth- indeed, tentacles are continuously regenerated Figure C. A, Crustacea , fish, eggs, or larvae. Creeping ctenophores The coherent packing of cilia in ctenes diffracts light and pro- extend their tentacles as rafts, picking up sea currents, while duces iridescence, giving rise to a rainbow of colors as the cilia pelagic ctenophores, such as members of the genus Bolinopsis beat.

Otherwise, most ctenophores are translucent. Those living Figure A , extend tentacles into sinuous nets as much as near the surface may be virtually transparent, whereas deep- times the length of the body. Prey is unloaded with a wipe of living species may be highly pigmented. Tropical ctenophores tentacles across the mouth or through the action of currents may be tinted violet, rose, yellow, or brown by symbiotic algae, produced by cilia.

Many ctenophores are also bioluminescent, Pleurobrachia , typically 3 cm or fewer, have long tentacles with emitting a faint blue-green light when disturbed. The source of branches known as tentalia or tentilla , while members of the ctenophoran bioluminescence is a luciferin chromophore identi- order Lobata Bolinopsis and Mnemiopsis are larger but have cal to that found in Coelenterates A One species of ctenopho- reduced tentacles that may remain within expandable oral lobes rans releases a red cloud that glows with a luminous blue.

Ctenophores are compact, carnivorous marine animals Lobates also have a pair of ciliated flaps or ribbonlike projec- with biradial symmetry—like an American football—and tions called auricles Figure A that participate in feeding. Benthic members of the order storing reserves, a home of ameboid cells, a nerve net, smooth Platyctenida are unusual in lacking ctenes as adults.

Ingestion occurs through the action of apical mouth and pharynx or gullet. Macrocilia plates. Digestion is extracellular in the stomach, via the action of are attached by bundles of microfilaments to underlying smooth enzymes secreted by the gastrodermis. Dissolved and suspended muscle. The indigestible refuse is expelled muscle and epithelial adhesive cells. The efficiency of predatory behavior by comb jellies was Ctenophora is divided into two classes: Tentaculata and strikingly illustrated by the consequences of the unintended Nuda. Tentaculata is the larger class, consists of animals with two introduction of the tentaculate Mnemiopsis leidyi into the opposing tentacles that emerge about midway on the body Fig- northern Black Sea.

Within a decade, and coupled to other ure A. Members of the smaller class, Nuda, lack tentacles entirely anthropogenic effects, such as consequences of intense over- in both larvae and adults Figure B. A planktonic species of class Tentaculata, Bolinopsis, swims vertically with its mouth end forward at the bottom of this figure and enmeshes prey in mucus on its extended ciliated oral lobes. Tentacles are short in this adult but long in the young. Bar 5 1 cm. Laverack; drawing by I.

Atema; information from M. Similar collapses now threaten the Caspian Sea and Ctenophores have extraordinary powers of regeneration even the Mediterranean. Canni- omeres determined in advance or as they were cleaved from the balism may also account for the bioamplification of arsenic in egg or other blastomeres. The ferti- The discovery of fossils with spheroidal morphology and eight lized eggs of tentaculates typically develop into cydippid larvae comb rows in the lower Cambrian suggests an ancient origin for bearing long feeding tentacles.

At metamorphosis into an adult, ctenophores. Indeed, the parazoan ctenophores have been placed members of the order Cydippida retain the tentacles, while at the base of animal evolution as a sister group to metazoa. It engulfs prey with muscular lips visible here at the bottom of the animal. The large SOX family of transcription the bilateria. Moreover, ctenophores exhibit the same resembling a gene active in mesoderm development a putative telomere sequences found in vertebrates, indicative of extreme member of the Tlx family was seen to be expressed in ctenopho- conservation of a motif.

Ctenophore ectoderm and endoderm ran epidermis and possibly gastrodermis but not in the mesoglea. These worms graze on fungi, bacteria, and protoctists among grains of sea sand. Like platyhelminths, jaw worms are bilaterally symmetrical, acoelo- mate eumetazoans. As triploblastic animals they have three body layers, the middle layer of mesodermally derived muscle is exte- rior to the digestive cavity and interior to the epidermis. About 80 species in 20 genera of gnathostomulids have been described. Probably, more than a thousand species of these worms live today in shallow oceans down to a depth of several hun- dred meters throughout the world.

Jaw worms adhere to sand particles or live on leaves of marine plants, such as the eel grass Zostera, turtle grass Thallassia, and marsh grass Spartina Pl- 12 , and on thalli leafy parts of algae. Because they are recog- nizable only when living, the natural history of gnathostomulids remained unknown for a long time, until sophisticated tech- niques were devised to pull jaw worms off the surfaces on which they live. In California, jaw worms live near the roots of surf grass, Phyllospadix, in anoxic sand. Some inhabit sulfureta, com- munities in black, sulfide-rich fine-grained sediments.

Often deep and underneath the white oxidized layer of marine sand bottoms, sulfureta smell like rotten eggs. The odor emanates from hydrogen sulfide, a gas produced by marine bacteria under anoxic conditions in absence of molecular oxygen. Gnathostom- ulids in sulfureta tolerate low levels of O2 and high quantities of Figure A An adult sulfide.

In certain sediments, gnathostomulids may outnumber Problognathia minima. It even nematodes A Population densities of more than glides between sand grains gnathostomulids per liter of sediment have been reported. The single ovary pro- shallow waters off Bermuda. Posterior to the ovary LM phase contrast , are paired testes Figure A.

Male organs in the different species bar 5 0. Sperm may be undulipodiated, mushroom shaped, or dwar- courtesy of W. Sterrer, ful spheres. During copulation, one worm injects hundreds of Transactions of the American sperm within a mucus ball beneath the skin of a second worm.

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Microscopical Society A female genital pore is present in certain species. The penis of —; ; drawing by some species, like the Problognathia shown here, is stiffened with L. Meszoly; information from a stylet, facilitating hypodermic impregnation. Sperm in the preb- W.

They fertilize the head bears tactile organs collectively called the sensorium: the most mature egg. Afterward, the fertilized egg ruptures the stiff bundles of sensory bristles and pits lined with cilia. On the body wall and is released. Because development is from egg to ventral portion of the head a cuticular comblike based plate that adult with no larval stage, we say that development is direct. In can be protruded through the mouth and a pair of toothed lat- at least some species, a nonsexual feeding stage alternates with a eral jaws comprise the feeding structures Figure B.

Contrac- distinct nonfeeding sexual stage year that is required to complete tion of the muscular pharynx snaps the jaws open and closed the cycle to the mature adult. Food particles are passed into the diges- The gnathostomulid body lacks an external cuticle; its tive cavity with its single opening. Undigested solid waste leaves average length is 1.

Dissolved waste in some; in others, an elongate rostrum forms the anterior end. Gas exchange occurs across Gnathostomulids move by cilia undulipodia. The modest their heads from side to side, swim, glide, and twist. Under the nervous system is made up of longitudinal nerve fibers and epidermis lie weak circular muscle fibers, with three or four ganglia frontal, buccal, caudal, and penile. In some species, paired longitudinal muscles underneath.

They have protonephridia and are hermaph- roditic. Sperm tails of flatworms different in their arrangement of microtubules. The jaw structure may relate gnathostomulids to do not take part in locomotion but do shorten the body. Polyg- rotifers A ; however, monociliated epithelium is found only in onal cells of the external epithelium bear only one cilium each, gastrotrichs A and gnathostomulids. These sive cells are not homologous to the dual adhesive glands of platy- traits distinguish gnathostomulids from turbellarian flatworms helminth or gastrotrichs.

A-7 , which gnathostomulids otherwise resemble. Anterior Fossil conodonts were once thought to be remains of the bristles and less flattened bodies of gnathostomulids distinguish tough parts of ancient gnathostomulids found in rocks that them from the flatworms. Gnathostomulids have been recognized as an independent phy- However, the basal plates of modern gnathostomulids differ lum since , and were initially grouped with Platyhelminthes from those of conodonts in that gnathostomulid toothlike feed- Phylum A-7 because of broad similarities in organization.

How- ing structures are made of acellular rather than cellular organic ever, the architecture of the cuticular mouth parts suggests a close material. Conodonts, are made of cells that, like bone, precipi- relationship with rotifers Phylum A , possibly within a taxon tate calcium phosphate. Since conodonts are now assigned a fos- called Gnathifera which also includes Micrognathozoa and Acan- sil phylogenetic position in the Craniata A gnathostomulid thocephala.

Both jaw worms and flatworms are externally ciliated, fossil history remains to be discovered. Most free-living aquatic species are The soft body of the flatworm is bilaterally symmetrical. Struc- benthic, a few swim with undulations or loop along substrate tures for capturing and consuming prey are localized in the like caterpillars, and some live among the plankton.

Flatworm organs are composed of tissues and scavengers. They eat insects or crustaceans A , tunicates A- are organized into systems. Flatworms are the simplest metazo- 35 , bivalve molluscs A , other worms, bacteria, mastigotes ans to possess an embryonic intermediate tissue layer, the meso- Phylum Pr , ciliates Phylum Pr-8 , and diatoms Phylum derm.

The platyhelminth worm, like the cnidarian, lacks an Pr Most free-living flat worms are marine; some inhabit anus. The flatworm middle tissue layer, a loose mesoderm called the digestive tract of sipunculans A and echinoderms parenchyma, never splits into a cavity coelom in which inter- A ; a few are terrestrial in damp habitats or are freshwater nal organs are suspended.

Flatworms and other animals without species. Digestive systems of free-living flatworms range from a a coelom are called acoelomates. Flatworms, having three tissue straight or branched gut to absence of a gut; food moves from layers, are triploblastic, have spiral cleavage in their eggs, and the pharynx of acoel lacking a gut free-living flatworms into yet are among the least complex of bilaterally symmetrical true loose digestive cells.

Some jab food by using a proboscis separate metazoans. The symbiotrophic forms, which undergo a transforma- the mouth on the ventral side. Digestive enzymes secreted into tion of the epidermis to a cuticle-like neodermis during devel- the gut begin digestion; intestinal cells continue digestion by opment, are generally placed among two or three traditional engulfing food in food vacuoles. Two established classes Necrotrophic flatworms undergo a phenomenon in which contain the Trematoda, or flukes, and the single to multi-host the epidermis is replaced by a new skin, the neodermis, during Cestoda, the tapeworms.

Some workers divide the Trematoda maturation. Thus, all cilia are lost and movement within the into the Digenea, or multi-host trematodes, which are internal host is carried out by detaching and reattaching the sucker or necrotrophs, and Monogenea, which typically have a single host variations of the sucker.

The free-living flatworms All flukes digenean and monogenean trematodes are inter- make up a number clusters or clades using cladistic method- nal or external necrotrophs, usually of vertebrates. The digenean ologies , the relationships of each remain unresolved. The most trematodes have a life cycle that includes several types of larvae distinctly primitive group, the Acoela Acoelomorpha , may not and sometimes an intermediate host or hosts.

Trematode larvae be a platyhelminth group at all. There are about 20, species of flatworm altogether. Some Schistosomiasis bilharziasis , caused by several species of the species are richly colored. Others harbor symbiotic algae called blood fluke Schistosoma, is currently the second most prevalent zoochlorellae producing a green color. Most necrotrophic forms infectious disease worldwide malaria is first. Cercariae, which and those free-living forms that inhabit caves and underground are distinctive swimming larvae with a tail and sucker, are car- water are colorless.

Tapeworms are the largest platyhelminths; ried by snails that spread schistosomiasis. Snails release cer- some reach a length of more than 30 m. The smallest are less cariae; the cercariae swim, attach to and penetrate human skin than 1 mm in length. Some live in bat guano, others in the of the human host. Members of many animal phyla, certainly an enormous tract and bowel blockage also can result. Monogenean trema- number of vertebrates, play host to ubiquitous flatworm symbi- todes typically have only one larval type, the onchomiracidium, otrophs.

In sediments low in molecular oxygen, a few flatworms which is released alive. Larvae move about the host or locate utilize energy by oxidizing hydrogen sulfide. A survey of the other hosts and attach. The larva matures, a neodermis replaces phylum reveals that flatworms tolerate an immense temperature the ciliated epidermis, and the cycle repeats itself. Trematodes range from minus 50 degrees to plus 47 degrees. Soil flatworms Tapeworms cestodes are exclusively internal necrotrophs are mainly tropical whereas aquatic forms are more abundant in that usually attach inside the gut of vertebrates by means of a temperate than in tropical waters.

Free-living and non-neoder- specialized structure, the scolex. The scolex may contain exclu- matid necrotrophic forms have several undulipodia per cell. By sively suckers or a combination of suckers and other structures simultaneously sweeping ventral cilia through secreted mucus enabling a firm grasp of the host tissue. Tapeworms lack a gut. On the ventral surface of acids and sugars from the hosts exploited by tapeworms. Protonephridia are the organs of excretion and osmoregulation in flatworms, except in free-living flatworms that lack a gut.

Protonephridia regulate water and ions by wafting liquid through ducts that exit to the outside through pores. The simplest flatworm nervous system consists of light-sen- sitive pigment-cup eyespots either single or in groups con- nected to a cluster of nerve cells brain in the head and ventral, Intestinal longitudinal nerve cords.

The nervous system of flatworms branches ranges in complexity from this simple system to the more prim- itive nerve net of acoel free-living flat worms resembling that of cnidarians and ctenophores. Free-living flatworms detect chem- icals, food, objects, and currents with sensory pits or tentacles on the sides of the head. When flatworms wander away from a Pharynx scent source, they turn from side to side more frequently and so eventually home in on the source.

Triclad free-living flatworms and cestodes have prodigious powers of regeneration and reproduce sexually or asexually. Slices of Dugesia, a triclad, regenerate to form entire worms. Outline of Planarians freshwater species of triclad free-living flatworms, copulatory an order of free-living flatworms characterized by a gut having organs three branches and taeniid cestodes reproduce asexually as well as sexually.

Almost all flatworm species are simultaneous her- maphrodites. Each individual flatworm bears ovaries and testes. Self-fertilization is rare in free-living flat worms and common in cestodes. In mating pairs of hermaphrodites a copulatory bursa receives sperm or, in some free-living flatworms, a hypodermic- Figure A Dorsal view of gliding Procotyla fluviatilis, like penis injects sperm through the body wall into the body a live freshwater turbellarian flatworm from Great Falls, of the mate. Some flatworm sperm have no tails; others have a Virginia.

Ribbons of fertilized free-living flatworm eggs are laid in [Photograph courtesy of R. Kenk; drawing by cocoons. Eggs of L. Many reproductive cycles, with a succession of larval stages. Schisto- tapeworms, however, lack segments. Like flukes, most tape- soma, a fluke, is dioecious. Bothrioplana, a free-living flat worm, worms have intricate life cycles with several distinctive larval exhibits parthenogenesis—females asexually produce females. Others, typically without segments, have simpler life The origin of this phylum is uncertain because flatworms cycles, and may represent progenetic forms of more typical seg- fossilize poorly.

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Prevailing theory maintains that the bilaterally mented tapeworms. Arguments worms relative to their volume has physiological implications. Like cnidarians and ctenophores, flatworms are ies suggests they are spiralian protostomes; their coelom, anus, blood-, lung-, and heartless. In symbiotrophic flatworms, gases and multicellular excretory organs having been lost. Free-living and nutrients diffuse into tissues of the flatworm from the host flatworms logically preceded parasitic forms, but the relation- digestive system or from water.

Free-living flatworms ingest ship between platyhelminth worms and other metazoan phyla food. Platyhelminth worms that have a gut discharge solid waste remains unclear.

When cultured, dicyemids consume glucose in cul- multicellular organisms that live in the nephridia of cephalopod ture media; thus, they are aerobes. Dicyemids contribute to the Mollusca A Except for placozoans A-1 , rhombozoans are acidification of urine, facilitating ammonia excretion by the the least morphologically complex animals.

The name of the mollusc; the dicyemid—cephalopod relation is thus a metabolic former phylum Mesozoa indicates that they were at one time symbiosis. Rhom- nonsexually reproductive stage, and rhombogen, the sexually bozoans are small wormlike bilaterally symmetrical animals. Rhombogens develop from nematogens and Although they are multicellular and contain metazoan cell junc- are sexual adults. All rhombozoans have a hermaphroditic gonad. When a population of adult dicyemid rhombogens becomes Moreover, the inner cell layer of rhombozoans does not cor- dense, the rhombogens develop nonciliated, sexual infusorigens respond to endoderm.

Rhombozoans lack body cavity and cir- nested within the axial cells. Aga- digestive systems. Like Platyhelminthes A-7 , rhombozoans are ciliated. During development, specific cell lineages give rise to The ciliated cells form a jacket enclosing one or several long, specific regions of the larva. Immature vermiform wormlike cylindrical axial cells. Within the axial cell or cells are from 1 larvae are released into the urine of the young mollusc. Vermi- to about cells called axoblasts, each containing a polyploid form larvae attach to the kidney—urine interface and grow into nucleus.

The function of the large specialized axial cell is solely nematogen adults. As long as the cephalopod is immature, new to surround the axoblast cells also called agametes. The axo- generations of nematogens are uniparentally produced this way. Pseudicyema and heterocyemids Conocyema, Microcyema. The sexual phase rhombogen involves the singe-celled Stages in the rhombozoan life history include rhombogen, hermaphroditic gonad, the infusorigen. Within the gonad, both nematogen, vermiform larvae, and infusoriform larvae.

The eggs and ameboid sperm are produced, but do not emerge from nematogen of heterocyemids has a syncytial, unciliated outer the enclosing rhombogen. Self-fertilization takes place within cell layer, whereas the nematogen of dicyemids Figure A has a the axial cells of the rhombogen parent. Oocytes do not com- cellular outer layer. Rhombozoans have both uniparental and plete the first meiotic nuclear division until after fertilization.

The resulting zygotes develop into infusoriform larvae. About 65 species of rhombozoan have been described. The sexually produced larva is the infusori- All rhombozoans are symbiotrophs that live in the bodies of ben- form. These larvae are the dispersal stage of the dicyemid. The thic seafloor-dwelling cephalopods mainly in temperate waters, spherical or top-shaped dicyemid infusoriform larva is about especially cuttlefish and octopods. It consists of 28 cells—each of the four interior cells more complex free-living ancestors.

Because they frequently contains another cell. Like sets of Chinese boxes and Paramyxa inhabit cephalopods that are widespread in shallow seas, rhombo- protoctists Pr , one cell is packed inside the other. The larva zoans are common. Dicyemids live in the kidneys of octopus and grows by differentiation and enlargement of its existing cells other benthic cephalopod molluscs A but not pelagic open rather than by mitotic cell division. The dicyemid microhabitat is the interface Newly hatched, free-swimming infusoriform larvae between urine and mucus-covered epithelial kidney tissue of the Figures A and C are soon weighted to the sea bottom by two mollusc host.

The dicyemid attaches loosely by its anterior end cells filled with a high-density substance, magnesium inositol to the kidney. The rest of the dicyemid body hangs free in urine. The larvae are acquired somehow by young These minute symbiotrophs absorb nutrients directly from the bottom-dwelling cephalopods. The dotted arrow in Figure urine of their host.

A indicates a possible intermediate host. The dashed arrow indicates the unknown mode by which infusoriform larvae enter their cephalopod habitat. Meszoly; information from E. Infusoriform larvae develop into nematogens mediate hosts transfer rhombozoans to other cephalopods. Infusoriform larvae have been found in cephalopods younger It has been theorized that rhombozoans are simplified than 3 weeks old. Larvae seem not to infect older cephalopods. Platyhelminthes A Symbiotic lifestyles often result in mor- The entry route of the larva into the cephalopod is obscure, phological simplification.

Like most platyhelminths, rhombo- although experimental infection in laboratory aquaria has been zoans are symbionts integrated at the metabolic level. Evidence achieved. The larvae enter the kidneys of their host and attach that rhombozoans are not degenerate platyhelminths includes lightly by their anterior cells. Free-swimming larvae disperse the dicyemids. In other percent. Additionally, kinetid ultrastructure appears distinct respects, though, what is known of rhombozoan biology sug- from other metazoans.

The issue is not resolved by recent stud- gests that rhombozoans and orthonectids have originated inde- ies on similar sequences of rDNA in Dicyema spp. Because of the differences mediate stage between sponges or Porifera A-3 and all other between orthonectids and platyhelminths A-7 , such a relation- metazoans.

The orthonectids, however, display many character- ship is unlikely. The body plan, with its unique musculature, is istics that are clearly unlike those of rhombozoans. Adults from within a plasmodium is distinct from any of the near phyla have one or two cell layers and are clearly multicellular but lack including the Platyhelminthes.

However, growing evidence, tissues and organs. Although there may be two layers of cells, including the presence of a distinct muscle layer in some ani- there is no indication of true ectoderm or endoderm. Exter- mals, structure of the kinetids, and analysis of rDNA sequences nally, the adult wormlike body consists of as many as 40 rings suggest that orthonectids in fact descend from a triploblastic of jacket cells.

For a given species, cell arrangement and number ancestor, but probably not the Platyhelminthes. The jacket cells are multiciliated and when the animal is free living, it freely swims about. In adults of the genus Intoshia, thin bands of smooth muscle lie between outer jacket cells and an inner cell mass. The muscle forms a continu- ous band in immature individuals; it develops to more reduced, separate strips during maturity. The muscle extends the length of the animal; the muscle band uniquely connects with the jacket, cell kinetids cilia rootlets. Furthermore, poor genetic potential due to lack of selection and predation are also potential threats to productivity [ 12 ].

Parasitism ranks high among factors that threaten village chicken production [ 13 ]. The authors reported that mortality due to parasitic diseases was higher than those attributed to Newcastle disease, an acknowledged most endemic and mortality causing viral infection of poultry. Common poultry parasites range from lice, mites, fleas, ticks, and helminths to gnats and coccidia [ 14 ]. Parasitism causes reduced growth, egg production, emaciation, and anaemia as well as mortality [ 15 — 19 ]. Moreover, some of the ectoparasites, especially tick and mites, are vectors of other poultry diseases such as pastuerellosis, Fowl pox, Newcastle disease, and possibly chlamydia [ 17 , 20 , 21 ].

In addition, the roles of poultry worms such as Heterakis gallinarum has been associated with the transmission of Histomonas meleagridis in turkeys and chicks [ 20 , 21 ]. Moreover, it has been reported that parasitic infection or their concurrent infections result in immunosuppression, especially in response to vaccines against some poultry diseases.

In Zambia, [ 23 ] reported helminth prevalence at Reports also exist on the prevalence of coccidiosis of village chicken [ 26 ]. Currently, there is a paucity of information regarding the prevalence of ecto- and endoparasites of local chickens in the study area. There is also the need to constantly assess the status of village chicken production constraints and the dynamic of their interactions. In addition, as cofactors in other poultry diseases, the knowledge of their prevalence is essential in understanding the epidemiology of such diseases and the design of their appropriate control measures.

The current study was designed to investigate the prevalence of ecto- and endoparasites of village chickens in the subhumid tropics of South Eastern Nigeria. Three villages lacking in contiguous boundaries were selected within each local council with an average of eight villages. Within each village comprising of about households, 10 were randomly selected for sampling. A minimum of ten birds were again randomly sampled per household without consideration for age or sex.

A total of one thousand and thirty eight chickens were involved in the survey. The sampling was done between the months of April and July Within the survey period, presurvey visits were made to the selected households for an agreement on the sampling dates and to provide them with a locally made basket for the restraint of the birds over night. During our interaction with the village chicken keepers, enquiries pertaining to mortality patterns among the various age groups, and the distribution of observable parasites were made.

Information regarding the dynamics of flock size, number of eggs laid before incubation, percentage hatch, number successfully brooded, and number that attain adulthood were orally obtained from the poultry keepers. Screening for ectoparasites involved a thorough examination of the body of the birds including the head, cloacal, brachial, ventral, and femoral areas. Those with parasites were identified and recorded. They were cleared with lactophenol and fixed on a microscopic slide using a little quantity of polyvinyl alcohol and lactophenol solution before detailed morphological examination and identification using a compound microscope [ 27 , 28 ].

Following this, birds that were positive for ectoparasites were liberally dusted with an insecticide powder, Piff Paff R permetrine powder. Also, thorough examination of cracks and crevices within the sleeping areas of the chickens was carried out to ensure that those parasites with nocturnal activities are identified. For each of the birds, after thorough examination for ectoparasites, faecal samples were collected per cloaca where possible or with a spatula for freshly voided faeces. As it was not possible to collect faecal samples from all the birds examined for ectoparasites, where it was possible the sample was matched with the record of ectoparasitism.

The faecal sample were put into sample bottles and identified appropriately. The samples were later processed in the laboratory using the salt floatation technique with saturated sodium chloride solution as the floating medium [ 29 ]. Identification of helminth eggs and coccidia oocysts was done using a standard microscope under 10 objective magnification. This was a qualitative assessment. Thorough examination was made to separate strongyle eggs from those of cestodes. In some cases proglotides or whole worms were collected harvested with the faecal samples.

Moreover, from each village, ten birds were selected randomly and paid for the purposes worm recovery and identification after necropsy in our laboratory. These were humanely slaughtered, eviscerated and the content of the gastrointestinal tract harvested, washed thoroughly for possible worm recovery and identification according to [ 28 ]. Information from the village poultry keepers reveal that most hens lay between 6—18 eggs prior to natural incubation out of which hatchability varies between hens.

Due to the undefined production objective, chicks are sold at any age and used for various purposes. The result of this study showed that based on age strata the adults chickens were the most infested with ectoparasites Table 1. They were followed by the growers and lastly the chicks. Also of the three common ectoparasites encountered, lice infestation was significantly higher than flea and mites while lice was higher than mites. Generally, of the chicken population sampled, representing Table 2 below shows the prevalence of the various ectoparasite species.

The result of the faecal analyses showed that of the faecal samples collected, Moreover, it was observed that the two enteric parasites had equal prevalence of Comparisons between endo- and ectoparasite prevalence indicated a statistically significant higher prevalence in favour of the former. Moreover, among those positive for gastrointestinal helminthes, there were variations in the prevalence of the various helminth types in the population especially between the nematodes and cestodes as shown in the Table 3.

Table 3 below shows the prevalence of the various helminth species in the sample population. Furthermore, our study showed that parasitic infestations are usually conjoint. Thus, apart from the conjoint infections among the enteric parasites, helminth and coccidia, helminths lice, helminth and fleas, lice and fleas, lice and mites, lice and coccidia, fleas and mites, and fleas and coccidia had prevalent rates of The result of this study showed a wide range of parasitic infestations among village chickens in the study area.

The prevalence of ectoparasites was high out of which lice infestation was outstanding. This result is in agreement with earlier studies [ 13 , 14 , 30 — 33 ] in America, South Africa and Nigeria. Following lice is flea with Echinophaga gallinacea as the most predominant species. The fact that fleas leave their host between meals [ 28 ] accounts for the predominance of stick Echinophaga gallinacae as the commonest flea type.

Moreover, it is expected that the prevalence may have been higher as other flea types may have left the host after feeding and during overnight caging of the chicks. Fleas have been reported as the dominant ectoparasites by [ 14 ] while [ 33 ] showed that they were the least occurring of the ectoparasites.

Moreover, [ 13 ] encountered no flea in their survey of blood and ectoparasites of domestic fowls in Ibadan, Western Nigeria. We speculate that these variations in result could be attributed to the season, time of the day, and the study location with respect to urban, periurban or pure village setting. With respect to mites, our results agreed with those of [ 13 , 33 ] who listed mites as one of the common ectoparasites of village chicken.

Ticks were apparently absent in our sample population. Earlier studies had demonstrated Haemophysallis hoodi hoodi as the only tick species among village chicken population in Nsukka area [ 13 , 14 , 34 ]. They however stated that tick infestation was not widespread.

Our thorough examination of cracks and crevices within the sleeping areas of the chicks did not yielded any positive result showing the rarity of this parasite among this class of chicken. Ectoparasites, fleas, lice, and mites cause anaemia and depending on the degree of infestation may lead to egg abandonment in brooding hens. They also cause chick mortality attributed to starvation and immune depression under heavy infestation.

This highlights the economic importance of ectoparasites in village chickens in the study area and Nigeria in general.