Biology · General Awareness

Aquatic and Marine Biology

1,834 Questions

This hub covers key concepts in aquatic and marine biology, including fish anatomy, marine animal behavior, and commercial fisheries. These topics are essential for general science sections in various competitive exams. Use these resources to test your knowledge of diverse aquatic ecosystems.

Marine animal adaptationsCommercial fisheriesFish anatomyAquatic ecosystems

Aquatic and Marine Biology Questions

Multiple choice

What is a young eel known as?

  1. Eelk

  2. Worm fish

  3. Elver

  4. Eelkid
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An elver is the specific term for a young eel that has developed from the larval stage (leptocephalus) but is not yet fully mature. They migrate from the ocean back into freshwater rivers where they grow into adult eels.

Multiple choice

What is salmonella?

  1. A fish

  2. A medical instrument

  3. A bacterium

  4. A reptile
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Salmonella is a genus of rod-shaped gram-negative bacteria that causes one of the most common foodborne illnesses worldwide. It typically spreads through contaminated food products like eggs, poultry, meat, and unpasteurized milk. Symptoms include diarrhea, fever, and abdominal cramps, usually appearing 6-72 hours after infection.

Multiple choice

Organisms living inside a frozen lake survive because

  1. These organisms are cold blooded

  2. Water near the bottom does not freeze

  3. These organisms hibernate in ice

  4. None of the above
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Organisms survive at the bottom of frozen lakes because water at the bottom remains liquid due to water's unique density properties. Water is densest at 4°C, so the coldest water sinks and freezes at the surface, creating an insulating ice layer while warmer water (around 4°C) stays at the bottom, allowing aquatic life to survive.

Multiple choice

Fresh water edible fishes are ______.

  1. catla catla

  2. labeo rohita

  3. cirrhina mrigala

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Catla catla (catla), Labeo rohita (rohu), and Cirrhina mrigala (mrigal) are collectively known as Indian major carps and are all freshwater fish widely cultivated in aquaculture for food. All three are important edible fish species in South Asia.

Multiple choice

The most important pelagic fish found in the North Sea adjacent to U.K. is

  1. cod

  2. halibut

  3. herring

  4. mackerel
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Herring is the dominant pelagic fish in the North Sea ecosystem. The North Sea herring fishery has been commercially crucial for centuries, supporting the UK's fishing industry. Cod, halibut, and mackerel are also present, but herring biomass has historically been highest. Pelagic fish live in the water column (not near bottom), and herring form massive schools.