biology

Lolliguncula brevis

Lolliguncula brevis 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 Lolliguncula brevis rather than just read about it. In short: Lolliguncula brevis, or the Atlantic brief squid, is a small species of squid in the Loliginidae family. They are found in shallow parts of the western Atlantic Ocean, through Rio de la Plata, Argentina, as far as the Bay of Fundy.

Key takeaways

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

Reference excerpt

Lolliguncula brevis, or the Atlantic brief squid, is a small species of squid in the Loliginidae family. They are found in shallow parts of the western Atlantic Ocean, through Rio de la Plata, Argentina, as far as the Bay of Fundy. The average female Atlantic brief squid is 11 cm long and the average male is 9 cm. The maximum mantle length ever recorded was 12 cm.

Biology The mantle is widest in the middle and tapers to a rounded point at the back. It has thick muscular walls and a large water-filled cavity and is separated from the head by a collar. The head has two large eyes, the structure of which is very similar to vertebrate eyes. There is a funnel (siphon) underneath the head which is used in locomotion. The fins are wider than they are long, rounded and about half the length of the mantle. There are five pairs of appendages. Numbers 1, 2, 3 and 5 are short tapering arms with two rows of suckers. The left 5th appendage of males is modified to form a hectocotylus arm. The other pair of appendages are contractile tentacles and are much longer than the arms. These have clubs with four rows of suckers at the distal end, and are used for capturing food which is then transferred to the arms. The basic color is dark reddish-brown to yellow-brown. The upper surface is covered in chromatophores, which allow the squid to change colors. In order to move, water inside the mantle cavity is expelled through the funnel (siphon) by muscular contraction of the mantle walls. To catch fast-moving prey, the contraction is vigorous, directing a jet of water backwards through the funnel. To escape a predator, the funnel is directed forward, and the squid shoots water backwards at great speeds. The siphon can also emit a cloud of ink, a melanin-rich mixture which is stored in an ink sac near their gut. The expulsion of this ink is used to distract and daze predators. The Atlantic Brief Squid is common in the nektonic community and assumed to be important prey for carnivorous fishes, as well as adult squid, which will occasionally exhibit cannibalistic tendencies toward juveniles. Feeding habits change as they mature. Small squid feed on benthic crustaceans, small fish or fry, and large squid feed on schooling species of fish, such as Bay Anchovies and Silversides. When in captivity, they can survive well on grass shrimp and small fishes such as killifish, livebearers, and Sheepshead Minnow.

Reproduction The hectocotylus arm is used to transfer spermatophores into the female reproductive organ. The posterior end of the female's mantle is occupied by a pair of white nidamental glands, which secrete the material from which the egg capsule is formed. Eggs are deposited in a gelatinous capsule and attached to the sea bed. The large-yolked eggs hatch into fully formed miniature versions of the parent squid.

Distribution and Habitat The Atlantic brief squid occurs most frequently in shallow waters along the eastern seaboard of the United States as far north as Delaware. They have also been found in Argentina, Brazil, the British Virgin Islands, Colombia, Mexico, Panama, Puerto Rico, Suriname, Trinidad and Tobago and Venezuela. They are more abundant in mud bottoms rather than sand bottoms within inlets, commonly at depths of 8.9 to 26.5 m. The Atlantic brief squid is unique among cephalopods as an osmoconformer, meaning that their body salinity matches that of ambient water salinity. They are known to tolerate low salinity levels, down to about half normal marine salinity (17.9‰), but only slightly lower salinities (16.5‰) kill it in about 48 hours. Their tolerance is regarded as exceptional among cephalopods.

References

Illustrations

Worked examples

Example 1 — a first encounter with Lolliguncula brevis

Start with the simplest possible case. Write down what Lolliguncula brevis 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 Lolliguncula brevis 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 Lolliguncula brevis 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 Lolliguncula brevis

In research: Lolliguncula brevis 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 Lolliguncula brevis 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: Lolliguncula brevis is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cephalopods described in 1823, IUCN Red List data deficient species, Loliginidae, so understanding it makes those chapters shorter.
In everyday life: Look for Lolliguncula brevis 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 Lolliguncula brevis in 20 minutes

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

Frequently asked questions

What is Lolliguncula brevis in simple terms?

Why does Lolliguncula brevis 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 Lolliguncula brevis?

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 Lolliguncula brevis.