biology

Nomorhamphus

Nomorhamphus 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 Nomorhamphus rather than just read about it. In short: Nomorhamphus is a southeast Asian genus of viviparous halfbeaks from streams, rivers and lakes in Sulawesi (Indonesia) and the Philippines. They are all viviparous, producing small clutches of around a dozen fry about 10 to 15 mm (0.39 to 0.59 in) long at birth.

Key takeaways

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

Reference excerpt

Nomorhamphus is a southeast Asian genus of viviparous halfbeaks from streams, rivers and lakes in Sulawesi (Indonesia) and the Philippines. They are all viviparous, producing small clutches of around a dozen fry about 10 to 15 mm (0.39 to 0.59 in) long at birth. Females are generally larger than the males. In the largest species, such as Nomorhamphus liemi, the females typically reach about 10 centimetres (3.9 in) in length, whereas the males reach about 6–7 cm (2.4–2.8 in) in length. Males are also more brightly coloured than the females (often having red, black, or blue patches on their fins). Compared with many other halfbeaks, the lower mandible, or beak, is relatively short, on females in particular barely protruding beyond the length of the upper mandible. The males of some species (e.g., N. ebrardtii) have short, straight beaks, but those of others (e.g., N. liemi) have short beaks that curve downwards forming a shape often compared to a goatee beard by aquarists. N. aenigma is unique within Nomorhamphus because of its lack of lower jaw elongation. Nomorhamphus feed extensively on small insects, either in the form of aquatic larvae or as flying insects that have fallen onto the surface of the water. They are important predators on insects such as mosquitoes, so play a role in controlling malaria. Nomorhamphus are too small to be of value as food, but they do have some value as aquarium fish.

Reproduction

Nomorhamphus species are livebearing fish that practise internal fertilisation. The male is equipped with a gonopodium-like anal fin known as a gonopodium that delivers sperm into the female. The gestation period is about six weeks. The exact mode of reproduction ranges from ovoviviparity through to viviparity, and in some species, oophagy is known, as well. Only around ten to twenty embryos are developed at a time, but at birth these are fairly large (around 13 millimetres or 0.5 inches) and well developed, able to take small prey, such as Daphnia, immediately after birth.

Species There are currently 22 recognized species in this genus:

Nomorhamphus aenigma Kobayashi, Masengi & Yamahira, 2020 Nomorhamphus bakeri Fowler & Bean, 1922 Nomorhamphus brembachi Vogt, 1978 Nomorhamphus celebensis Weber & de Beaufort, 1922 (Poso halfbeak) Nomorhamphus ebrardtii Popta, 1912 Nomorhamphus hageni Popta, 1912 Nomorhamphus kolonodalensis Meisner & Louie, 2000 Nomorhamphus lanceolatus Huylebrouck, Hadiaty & Herder, 2014 Nomorhamphus liemi Vogt, 1978 Nomorhamphus manifesta Meisner, 2001 Nomorhamphus megarrhamphus Brembach, 1982 Nomorhamphus pectoralis Fowler, 1934 Nomorhamphus philippinus Ladiges, 1972 Nomorhamphus pinnimaculatus Meisner, 2001 Nomorhamphus ravnaki Brembach, 1991 Nomorhamphus rex Huylebrouck, Hadiaty & Herder, 2012 Nomorhamphus rossi Meisner, 2001 Nomorhamphus sagittarius Huylebrouck, Hadiaty & Herder, 2014 Nomorhamphus sanussii Brembach, 1991 Nomorhamphus towoetii Ladiges, 1972 Nomorhamphus versicolor Kraemer, Hadiaty & Herder, 2019 Nomorhamphus vivipara Peters, 1865 Nomorhamphus weberi Boulenger, 1897

References

Further reading Scott, Peter (1997): Livebearing Fishes, Tetra Press, ISBN 1-56465-193-2

Illustrations

Worked examples

Example 1 — a first encounter with Nomorhamphus

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

In research: Nomorhamphus 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 Nomorhamphus 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: Nomorhamphus is common in secondary-school and first-year university syllabi. It links to neighbouring topics Actinopterygii genera, Fishkeeping, Nomorhamphus, so understanding it makes those chapters shorter.
In everyday life: Look for Nomorhamphus 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 Nomorhamphus in 20 minutes

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

Frequently asked questions

What is Nomorhamphus in simple terms?

Why does Nomorhamphus 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 Nomorhamphus?

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 Nomorhamphus.