biology

Piscivore

Piscivore 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 Piscivore rather than just read about it. In short: A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted reptiles and synapsids evolved herbivory.

Key takeaways

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

Reference excerpt

A piscivore () is a carnivorous animal that primarily eats fish. Fish were the diet of early tetrapod evolution (via water-bound amphibians during the Devonian period); insectivory came next; then in time, the more terrestrially adapted reptiles and synapsids evolved herbivory. Almost all predatory fish (most sharks, tuna, billfishes, pikes etc.) are obligated piscivores. Some non-piscine aquatic animals, such as whales, sea lions, and crocodilians, are not completely piscivorous; often also preying on invertebrates, marine mammals, waterbirds and even wading land animals in addition to fish, while others, such as the bulldog bat and gharial, are strictly dependent on fish for food. Some creatures, including cnidarians, octopuses, squid, cetaceans, spiders, grizzly bears, jaguars, wolves, snakes, turtles and sea gulls, may have fish as significant if not dominant portions of their diets. Humans can live on fish-based diets, as can their carnivorous domesticated pets such as dogs and cats.

Etymology The name piscivore is derived from Latin piscis 'fish' and vorō 'to devour'. Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater".

Discussion The ecological effects of piscivores can extend to other food chains. In a study of cutthroat trout stocking, researchers found that the addition of this piscivore can have noticeable effects on non-aquatic organisms, in this case bats feeding on insects emerging from the water with the trout. Another study done on lionfish removal to maintain low densities used piscivore densities as a biological indicator for coral reef success. There exist classifications of primary and secondary piscivores. Primary piscivores, also known as "specialists", shift to this habit in the first few months of their lives. Secondary piscivores will move to eating primarily fish later in their lifetime. It is hypothesized that the secondary piscivores' diet change is due to an adaptation to maintain efficiency in their use of energy while growing.

Examples of extant piscivores

Arachnids Fishing spider

Birds Bald eagle Merganser Osprey Penguin

Fish African tigerfish Alligator gar Arapaima Barracuda Bluefish Giant trevally Kidako moray Lemon shark Lionfish Piranha Silver arowana

Mammals Amazon river dolphin American mink Aquatic genet Bottlenose dolphin Bulldog bat Eurasian otter Fish-eating bat Fishing cat Flat-headed cat Fur seal Giant otter Harbor seal North American river otter Orca Otter shrew Sea lion Tiger

Reptiles Asian water monitor Gharial Green anaconda Komodo dragon Yellow anaconda Yellow-bellied sea snake

Extinct and prehistoric piscivores Numerous extinct and prehistoric animals are hypothesized to have been primarily piscivorous due to anatomy and/or ecology. Furthermore, some have been confirmed to be piscivorous through fossil evidence. This list includes specialist piscivores, such as Laganosuchus, as well as generalist predators, such as Baryonyx and Spinosaurus, found to have or assumed to have eaten fish:

Fish Diplomystus (a small relative of the herring, numerous fossils of individuals that died while trying to swallow other fishes, including smaller individuals of the same species, are known) Thyrsocles (fossil specimen found with the stomach stuffed with the extinct herring Xyne grex) Xiphactinus (a 4-meter-long specimen was found with a perfectly preserved skeleton of its relative, Gillicus, in its stomach)

Reptiles Baryonyx (an opportunistic predator that had a crocodile-like skull, and scales of the lepidotid fish Scheenstia have been found in a skeleton where the stomach should be) Elasmosaurus (long neck, stereoscopically positioned eyes, and long teeth are thought to be adaptations for stalking and trapping fish and other schooling animals) Laganosuchus (flattened head suggests that it passively waited for fish to swim near its mouth in order to engulf them) Ornithocheirus (hypothesized to be piscivorous due to anatomy of its jaws and dentition) Pteranodon (remains of fish found in the beaks and stomach cavities of some specimens) Spinosaurus (close relative of Baryonyx, is hypothesized to have preyed on fish because of giant coelacanthids found in the same environment, and due to anatomical features, including a pressure-sensitive snout that could have detected movements of swimming prey) Titanoboa (multiple cranial and biochemical characteristics suggest that it was primarily piscivorous)

References

Illustrations

Worked examples

Example 1 — a first encounter with Piscivore

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

In research: Piscivore 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 Piscivore 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: Piscivore is common in secondary-school and first-year university syllabi. It links to neighbouring topics Animals by eating behaviors, Carnivory, Ecology stubs, so understanding it makes those chapters shorter.
In everyday life: Look for Piscivore 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 Piscivore in 20 minutes

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

Frequently asked questions

What is Piscivore in simple terms?

Why does Piscivore 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 Piscivore?

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 Piscivore.