Which of the following is generally regarded in basic general knowledge as the fastest swimming fish in the ocean?

Introduction:
Speed records in the animal world are popular general knowledge topics. In the oceans, some large predatory fishes are capable of remarkable burst speeds. This question asks which fish is generally cited in school level books and competitive exam material as the fastest swimming fish in the sea.

Given Data / Assumptions:
- Options include sailfish, swordfish, bluefin tuna and mako shark. - The question focuses on maximum swimming speed, not size or strength. - We rely on widely accepted general knowledge rather than minor scientific disagreements. - All listed fishes are fast pelagic predators.

Concept / Approach:
The concept is straightforward factual recall. Many general knowledge references and quiz books state that the sailfish is the fastest swimming fish, capable of very high burst speeds when hunting or escaping predators. While bluefin tuna, swordfish and mako sharks are also very fast, sailfish is most commonly given as the record holder in exam oriented material.

Step-by-Step Solution:
Step 1: Recall which fish is usually labelled the fastest swimmer in oceans in exam guides and general science notes. Step 2: Recognise that sailfish is often described as reaching speeds of more than 100 km per hour in short bursts. Step 3: Compare this with swordfish, bluefin tuna and mako shark, which are fast but typically given slightly lower speeds in popular sources. Step 4: Select sailfish as the best answer according to standard general knowledge conventions.

Verification / Alternative check:
Many school level science books, quiz collections and competitive exam guides use the statement that the sailfish is the fastest fish. Although some recent studies discuss close competitors like the black marlin, the traditional and exam oriented answer remains sailfish. Therefore, for general knowledge purposes, sailfish is the accepted choice.

Why Other Options Are Wrong:
Swordfish: Very fast and streamlined, but usually not given as the absolute fastest fish in basic GK sources. Bluefin tuna: Powerful long distance swimmer, known for endurance and speed, but not usually credited as the single fastest species. Mako shark: One of the fastest sharks, but general knowledge lists still more commonly name sailfish as the top speed holder.

Common Pitfalls:
Learners may be confused by scientific debates or by reading about black marlin or mako sharks in more advanced material. In the context of most objective tests, however, the expected answer is what appears in standard GK compilations. Remember that sailfish is the name that shows up most frequently as the fastest fish in common exam references.

Final Answer:
The fish generally regarded as the fastest swimmer in the ocean is the Sailfish.