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Smooth handfish

Smooth handfish 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 Smooth handfish rather than just read about it. In short: The smooth handfish (Sympterichthys unipennis) is a possibly extinct species of handfish in the genus Sympterichthys. It was likely endemic to waters off the coast of Tasmania, mainly the D'Entrecasteaux Channel.

Smooth handfish — main illustration
Smooth handfish — illustration

Key takeaways

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

Reference excerpt

The smooth handfish (Sympterichthys unipennis) is a possibly extinct species of handfish in the genus Sympterichthys. It was likely endemic to waters off the coast of Tasmania, mainly the D'Entrecasteaux Channel. It was declared extinct by the IUCN Red List in 2020, marking the first entirely marine fish classified as such. However, in 2021 its status was changed to Data Deficient due to uncertainties over the exhaustiveness of the unsuccessful surveys to find this species. It is known only from its holotype collected by French explorers in 1802. The smooth handfish was first formally described as Lophius laevis in 1804 by the French naturalist Bernard Germain de Lacépède; this name however was preoccupied by Lophius laevis described by Pierre André Latreille, also in 1804. The next available name was Chironectes unipennis which was coined by Georges Cuvier in 1817. In 1878 the American biologist Theodore Gill classified Lacépède's L. laevis in the new genus Sympterichthys. The genus Sympterichthys is classified within the family Brachionichthyidae which the 5th edition of Fishes of the World classifies the family Brachionichthyidae within the suborder Antennarioidei within the order Lophiiformes, the anglerfishes. In the past, it was likely reasonably common, as it was one of the first fish described on François Péron's 1802 survey of Australia and an individual was caught with a simple dipnet; this is the only known specimen of the species. When and how the species went extinct is relatively unclear, but it likely had to do with the intensive scallop and oyster harvesting that went on in the area between the 19th and mid-20th centuries which dredged every part of the channel, resulting in the destruction of critical habitat that the benthic handfish required. In March 2020, the smooth handfish was the first modern-day marine fish to be officially declared extinct in the IUCN Red List. However, this was reversed in September 2021, as there is not sufficient data to confirm this status.

References

Illustrations

Smooth handfish illustration
Smooth handfish illustration

Worked examples

Example 1 — a first encounter with Smooth handfish

Start with the simplest possible case. Write down what Smooth handfish 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 Smooth handfish 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 Smooth handfish 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 Smooth handfish

In research
Smooth handfish 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 Smooth handfish 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
Smooth handfish is common in secondary-school and first-year university syllabi. It links to neighbouring topics Endemic fauna of Tasmania, Fish described in 1817, Fish extinctions since 1500, so understanding it makes those chapters shorter.
In everyday life
Look for Smooth handfish 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 Smooth handfish in 20 minutes

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

Frequently asked questions

What is Smooth handfish in simple terms?

The smooth handfish (Sympterichthys unipennis) is a possibly extinct species of handfish in the genus Sympterichthys. It was likely endemic to waters off the coast of Tasmania, mainly the D'Entrecasteaux Channel.

Why does Smooth handfish 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 Smooth handfish?

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 Smooth handfish.

Tags

  • Endemic fauna of Tasmania
  • Fish described in 1817
  • Fish extinctions since 1500
  • IUCN Red List data deficient species
  • Species known from a single specimen
  • Sympterichthys
  • Taxa named by Georges Cuvier

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