biology

Legendrea

Legendrea is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Legendrea rather than just read about it. In short: Legendrea is a genus of extremely rare ciliates first described by French biologist Emmanuel Fauré-Fremiet in 1908, rediscovered and re-examined in 2022. Classification The genus has 5 species including the type species, Legendrea loyezae, described in 1908.

Key takeaways

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

Reference excerpt

Legendrea is a genus of extremely rare ciliates first described by French biologist Emmanuel Fauré-Fremiet in 1908, rediscovered and re-examined in 2022.

Classification The genus has 5 species including the type species, Legendrea loyezae, described in 1908. Other genera (e.g. Lacerus and Thysanomorpha) were only distinguished from Legendrea by their physical appearance, not affinities. These genera were misidentifications and were synonymised with Legendrea along with their respective species. First true taxonomic assignment of the cilliate was made in December 2022. The current 5 species are:

Legendrea bellerophon Penard, 1914 [=Thysanomorpha bellerophon (Penard, 1914) Jankowski, 1967] Legendrea crassa Penard, 1922 [=Penardiella crassa (Penard, 1922) Kahl, 1930] Legendrea interrupta Penard, 1922 Legendrea loyezae Faure-Fremiet, 1908 Legendrea pespelicani Penard, 1922 [=Lacerus pespelicani (Penard, 1922) Jankowski, 1967]

Taxonomic affinities The genus (and species) are distinguishable from one another by the length of their finger-like tentacles. These tentacles are located at the rear end of the cell. Varied descriptions of these tentacles have been attributed to their different morphologies when swimming versus at rest, such as in the case of L. loyezae. Phylogenetic analysis of the 18S rRNA gene within L. loyezae placed the genus within the family Spathidiidae taxonomically ranked under the order of Haptorida. A shorter gene of 18S rRNA was used to classify the species and so its affinity should be carefully interpreted with there being the likelihood of it changing to a new affinity. The sequence used to determine the identity of L. loyezae implies that it forms a sister group with the sequences from the re-identified Epispathidium papilliferum as well as an undescribed species of the same genus. The Epispathidium possessed protruding papillae that are analogous to those found on L. loyezae, although the papillae on Epispathidium were only present on its oral region.

Genus divisions Although A. Jankowski did not directly observe any members of Legendrea, Jankowski published a revision of the genus that divided Legendrea into two genera based on morphological differences: Lacerus and Thysanomorpha. Legendrea bellerophon was reclassified to the genus Thysanomorpha and was renamed Thysanomorpha bellerophon, re-described as having a serrated body edge/surface with an uneven series of outgrowths with trichomes. These names of the species and genera were in use by subsequent publications, but were challenged by Weiss et al. in 2022 as misidentifications of Legendrea species.

References

Illustrations

Worked examples

Example 1 — a first encounter with Legendrea

Start with the simplest possible case. Write down what Legendrea 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 Legendrea 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 Legendrea 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 Legendrea

In research: Legendrea 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 Legendrea 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: Legendrea is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ciliate genera, Litostomatea, Microscopic eukaryotes, so understanding it makes those chapters shorter.
In everyday life: Look for Legendrea 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.

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How to study Legendrea in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Legendrea 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 Legendrea out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Legendrea in simple terms?

Legendrea is a genus of extremely rare ciliates first described by French biologist Emmanuel Fauré-Fremiet in 1908, rediscovered and re-examined in 2022. Classification The genus has 5 species including the type species, Legendrea loyezae, described in 1908.

Why does Legendrea 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 Legendrea?

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 Legendrea.