biology

Spined loach

Spined loach 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 Spined loach rather than just read about it. In short: The spined loach (Cobitis taenia) is a common freshwater fish in Europe. It is sometimes known as the spotted weather loach, not to be confused with the "typical" weather loaches of the genus Misgurnus.

Key takeaways

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

Reference excerpt

The spined loach (Cobitis taenia) is a common freshwater fish in Europe. It is sometimes known as the spotted weather loach, not to be confused with the "typical" weather loaches of the genus Misgurnus. This is the type species of the spiny loach genus (Cobitis) and the true loach family (Cobitidae).

Description The spined loach typically reaches an adult length of 8–10 cm (3.1–3.9 in), although females may grow up to 12 cm (4.7 in). Adults weigh between 20–60 g (0.7–2.1 oz). Their backs feature a yellow-brown colouring interspersed with many small grey or brown scales on the spinal ridge. The scales on the belly are pale yellow or orange. The body overall is long and thin. There are six barbels around the mouth. Under the eyes there is a two-pointed spike, with which the fish can inflict a painful sting.

Distribution and relationships It is found from the Volga River basin to France. Generally it occurs across much of temperate Europe north of the Alpide belt, with the exceptions of Ireland, Scotland, Wales and northern Scandinavia. Some populations are also found just south of the Alpides. In the UK, the spined loach appears to be restricted to five east-flowing river systems in eastern England – the Rivers Trent, Welland, Witham, Nene and Great Ouse. Populations of southwestern Europe were formerly included in this species, but actually represent distinct branches of Cobitis. A member of subgenus Cobitis, close relatives of the spined loach are C. elongatoides, C. fahirae, C. tanaitica or C. vardarensis, which replace it in northern Greece, much of Romania, and western Turkey.

Ecology and behaviour Clear oxygen-rich water is preferred by the spined loach, be it slowly flowing brooks, rivers or still water. They are found near flat and sandy or stony areas, frequently in large numbers. The spined loach is often kept as an ornamental fish in aquaria. During the day, they bury themselves in the bed of the body of water, leaving only the head and tail exposed. At night, when the loach is most active, sand on the riverbed is consumed, and with it small animals and other organic material. Sand, stripped of nutrients, is ejected through the gills. This process must continue all night for the fish to get enough calories to survive. Spined loaches can breathe intestinally. This stop-gap measure sustains the spined loach when the water around it is oxygen-poor. At the water's surface, swallowed air brings oxygen into the intestine. The expended air is expelled through the anus. The spawning season is from April to June. The females produce between 300 and 1,500 eggs close to the ground, on stones, roots or plants. The eggs are then fertilized by the males. The larvae hatch in 4 to 6 days. The spined loach's lifespan is between 3 and 5 years, with the maximum reached in captivity being 10 years.

Illustrations

Worked examples

Example 1 — a first encounter with Spined loach

Start with the simplest possible case. Write down what Spined loach 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 Spined loach 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 Spined loach 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 Spined loach

In research: Spined loach 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 Spined loach 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: Spined loach is common in secondary-school and first-year university syllabi. It links to neighbouring topics Animal taxa named by Carl Linnaeus, Cobitis, Fish described in 1758, so understanding it makes those chapters shorter.
In everyday life: Look for Spined loach 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 Spined loach in 20 minutes

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

Frequently asked questions

What is Spined loach in simple terms?

Why does Spined loach 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 Spined loach?

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 Spined loach.