Paramphistomum

Key takeaways

Paramphistomum belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Paramphistomum to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Paramphistomum from memory before moving on to harder problems.

Reference excerpt

Paramphistomum is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals. They are responsible for the serious disease called paramphistomiasis, also known as amphistomosis, especially in cattle and sheep. Its symptoms include profuse diarrhoea, anaemia, lethargy, and often result in death if untreated. They are found throughout the world, and most abundantly in livestock farming regions such as Australia, Asia, Africa, Eastern Europe, and Russia. The generic name was introduced by F. Fischoeder in 1901 for the replacement of the then existing genus Amphistoma (Rudolphi, 1809). Under the new genus he redescribed both Paramphistomum cervi and P. bothriophoron and designated the former as the type species.

Species Due to striking resemblance with each other and with other amphistomes, a number of described species are known to be synonymous. Some important species are:

Paramphistomum cervi Paramphistomum cotylophorum Paramphistomum cracile Paramphistomum gotoi Paramphistomum grande Paramphistomum hiberniae Paramphistomum ichikawai Paramphistomum epiclitum Paramphistomum explanatum Paramphistomum leydeni Paramphistomum liorchis Paramphistomum microbothrioides Paramphistomum phillerouxi

Description The generic name (Greek: para meaning "similar" [to Amphistoma], amphi meaning "on both sides", and stoma for "mouth") is given due to the presence of an anterior oral sucker and a posterior larger ventral sucker in adult worms. The body is minute, measuring less than a centimetre. The body is covered with a highly folded tegument, which in turn is provided with sensory papillae. Paramphistomum are all hermaphrodite, having both male and female reproductive systems in the posterior region of the body.

Life cycle Their life cycle is indirect, requiring a definitive host such as ruminants, an intermediate host such as snail, and a free-living of external phases in water and plants. The sexually mature monoecious self-fertilises in the mammalian rumen, and release the eggs along with faeces. Eggs hatch in water into ciliated miracidia. The miracidia then enters the body of an intermediate host, which are snails belonging to the genera Bulinus, Planorbis, Physa Stagnicola and Pseudosuccinea. Then the miracidia lost their cilia to become sporocysts. After a few days they develop up to 8 rediae, which are rapidly liberated. Each redia contains about 15-30 cercariae. Mature cercariae are possess by two eyespots and a long slender tail, by which they find aquatic plants or other suitable substrata, to which they get attached and encyst to become metacercariae. The mammalian hosts ingest the infective larvae. Once inside the duodenum and jejunum, their cysts are removed. They penetrate the intestinal wall by actively destroying the mucosa, and then migrate to the rumen, where they grow into adults.

Pathogenicity and pathology

Paramphistomiasis causes enteritis and anaemia in livestock mammals and result in substantial production and economic losses. Pathological symptoms are produced by immature flukes. When the young flukes start to gather in the intestine, there is a watery and fetid diarrhoea which is often associated with high mortality (even up to 80-90%) in ruminants. At a given time, as many as 30,000 flukes may accumulate, fervently attacking the duodenal mucosa to induce acute enteritis. Adult flukes are relatively harmless, but in buffaloes liver lesions have been reported. Liver tissue resulted damaged extensively, indicated by swelling, haemorrhage, discolouration, necrosis, bile duct hyperplasia, and fibrosis.

Diagnosis and treatment Symptoms are easily indicated by infected sheep and cattle as they become severely anorexic or inefficiently digest food, and become unthrifty. Fetid diarrhoea is an obvious indication so that fluid faeces are examined for immature flukes. Paramphistomiasis is considered a neglected tropical disease, with no prescription drug for treatment and control. Thus management of infection is based mainly on control of the snail population. Drugs shown to be effective are resorantel, oxyclozanide, clorsulon, ivermectin, niclosamide, bithional and levamisole. An in vitro demonstration shows that plumbagin exhibits high efficacy on adult flukes.

References

External links

Worked examples

Example 1 — a first encounter with Paramphistomum

Start with the simplest possible case. Write down what Paramphistomum claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Paramphistomum before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Paramphistomum ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Paramphistomum

In research: Paramphistomum appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Paramphistomum in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Paramphistomum is common in secondary-school and first-year university syllabi. It links to neighbouring topics Digenea genera, Parasites of mammals, so understanding it makes those chapters shorter.
In everyday life: Look for Paramphistomum outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

How to study Paramphistomum in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Paramphistomum means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Paramphistomum out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Paramphistomum in simple terms?

Paramphistomum is a genus of parasitic flatworms belonging to the digenetic trematodes. It includes flukes which are mostly parasitising livestock ruminants, as well as some wild mammals.

Why does Paramphistomum matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Paramphistomum?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Paramphistomum.