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 zoology selection and evolution extinction extinctions environmental science

Which of the following fish led to the extinction of an ecologically unique assemblage of more than 200 species of cichlid fish in the take Victoria of E. Africa?

  1. Catla catla

  2. Dog fish

  3. Nile perch

  4. African catfish
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Nile perch, (species Lates niloticus), large food and game fish of the family Centropomidae (order Perciformes), found in the Nile and other rivers and lakes of Africa. A large-mouthed fish, the Nile perch is greenish or brownish above and silvery below and grows to about 1.8 m (6 feet) and 140 kg (300 pounds). It has an elongated body, a protruding lower jaw, a rounded tail, and two dorsal fins. In 1954, L. niloticus was introduced into Lake Victoria in Africa, home to hundreds of cichlid fishes. A powerful predator, the Nile perch has greatly reduced the cichlid numbers.
So the correct option is 'nile perch'.
Multiple choice biology life processes in living organisms- part 2 earthworm - reproductive system reproduction in earthworm introduction to reproduction

Fertilization is internal in 

  1. Toads

  2. Frogs

  3. Dogfish

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

Fertilization can be internal or external. When the fertilization occurs inside the female body, then it is internal fertilization (e.g., most reptiles, some birds, some fishes.)
Fertilization in dogfish, shark is internal. While in catfish, toads and some frogs, it is external fertilization.
Hence, the correct answer is option (C).

Multiple choice zoology animal diversity - ii (phylum: chordata) circulatory system in frog frog - digestive system, circulatory system, excretory system and reproductive system frog

Ureotelic vertebrates are?

  1. Fish

  2. Reptiles and cartilaginous fish

  3. Bony fish and mammals

  4. Amphibians; mammals, cartilaginous fish
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The excretion of urea is called ureotelism. Land animals, mainly amphibians mammals, convert ammonia into urea. These animals are called ureotelic. Urea is a less toxic compound than ammonia. Eg marine fishes, many amphibians etc.


So the correct option is "amphibian, mammals, cartilaginous fish".

Multiple choice evs wonderful world of bholu aquatic habitat life inside water animal and habitat

Animals that live in both land and water condition is called as

  1. Terrestrial

  2. Aquatic

  3. Amphibious

  4. All of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Amphibians spend their lives in water and on land. There are more than 4,000 different kinds of amphibians. Members of this animal class are frogs, toads, salamanders, newts, and caecilians or blindworms.
Before amphibians reach adulthood, they first experience a larval stage, where they breathe primarily through their gills. When they get older, they start to breathe through their lungs, which allows them to live on land. Hence, it is necessary for amphibians to live in both land and water.
So, the correct answer is Amphibious.
Multiple choice evs wonderful world of bholu aquatic habitat life inside water animal and habitat

Identify the odd one.

  1. Deer, fish, and salamander

  2. Deer, bear, cow, and elephant

  3. Prawns, whales, and shark,

  4. Frog, salamander, and toad,
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Option A is the odd one because it mixes terrestrial (deer) with aquatic/amphibious animals, whereas the other options group animals by habitat or class (e.g., mammals, amphibians).

Multiple choice biology respiration in organism breathing underwater respiration in other organisms respiration in living organisms

Gills in fish are projection of

  1. Skin

  2. Fins

  3. Norstrils

  4. Alimentary canal
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fish and some amphibians respire primarily with gills. Gills are projection of the skin. Gills are comprised of highly vascular structures, with their outer surfaces thrown into thin folds or narrow filaments to increase the surface area for the exchange of oxygen between the water and the blood. These gill structures develop entirely from the pharyngeal arch complex. Blood is supplied through the aortic arches that pass through each pharyngeal arch. The aortic arches branch to form the afferent branchial arteries and the capillary network in the gills. Oxygenated blood comes from the gills through efferent branchial arteries which supply the dorsal aorta, the vessel which is the primary supply of oxygenated blood to the body. Gills are not the projections of fins, alimentary canal and nostrils in fish. Thus, option A is correct.

Multiple choice biology respiration in living organisms breathing underwater respiration in other organisms respiration in organism

Which organ is used by fishes for their respiration?

  1. Gills

  2. Skin

  3. Fin

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

Gills are tissues which consist of cloth and fabric structures called filaments. These filaments have many functions including the transfer of ions and water, as well as the exchange of oxygen, carbon dioxide, acids and ammonia.

Multiple choice biology respiration in living organisms breathing underwater respiration in other organisms respiration in organism

Which of the following has no blood but respires? 

  1. Earthworm

  2. Hydra

  3. Cockroach

  4. Fish
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In animals, three main types of respiratory systems exist: respiration through the skin, respiration through the gills or respiration through internal air structures. Respiration through the skin, as in the hydra, involves the passing of molecules into and out of the body via diffusion. Aquatic animals use gills, which are structures composed of tissues and blood vessels that extend from the body, for their respiration needs. Most terrestrial animals use internal air structures, such as lungs or tracheae, to respire. 

Therefore, the correct answer is option B.

Multiple choice biology respiration in living organisms breathing underwater respiration in other organisms respiration in organism

A freshwater fish must continuously

  1. Acquire water and get rid of salt

  2. Get rid of both water and salt

  3. Acquire both water and salt

  4. Get rid of water and acquire salt
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Freshwater fish lives in rivers and lakes where the salinity levels are less than 0.05%. The freshwater species differ physiologically from salt water fish in that their gills are modified to diffuse dissolved gasses while retaining the salts present in the body fluids. Further, their scales reduce water diffusion through the skin and also have well developed kidneys that can reclaim salts from body fluids before excretion. Through this process, they get rid of water and acquire salt.

Multiple choice biology respiration in living organisms breathing underwater respiration in other organisms respiration in organism

A marine bony fish must continuously

  1. Acquire water and get rid of salt

  2. Get rid of both water and salt

  3. Get rid of water and acquire salt

  4. Acquire both water and salt
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Water naturally seeks a chemical balance, or equilibrium. That means water flows from areas of higher water concentration to areas of lower water concentration to equalize the system. Water concentration inside a fish is higher than in the ocean itself because the ocean is so salty. As a result, most saltwater fish constantly lose water through their gills and skin. Because the fish is losing water, it must drink a lot to stay hydrated-but salty seawater is the only water around. To get rid of excess salt, the fish's kidneys pump lots of salt into its urine.