Biology · General Awareness

Aquatic and Marine Biology

1,905 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 biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

A jawless fish which lays eggs in fresh water and whose ammocoete larvae after metamorphosis return to ocean is _____________.

  1. Entatretus

  2. Myxine

  3. Neomyxine

  4. Petromyzon
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Petromyzon (lamprey) is an anadromous fish that migrates from the ocean to fresh water to spawn, and its larvae are called ammocoetes.

Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Choose the correct statement.

  1. All pisces have gills covered by an operculum

  2. All mammals are viviparous

  3. All cyclostomata do not possess jaw and paired fins

  4. All reptiles have a three chambered heart
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Cyclostomes are characterized by the absence of jaws and paired fins. Other options are false because not all pisces have an operculum (e.g., sharks), not all mammals are viviparous (e.g., monotremes), and not all reptiles have a three-chambered heart (crocodiles have four).

Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Choose the correct statement

  1. All mammals are viviparous

  2. All cyclostomes do not possess; jaws and paired fins

  3. All reptiles have a three-chambered heart

  4. All Pisces have gills covered by an operculum
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  1. All mammals are not Viviparous. Four species of Echidna and the Platypus are oviparous.
    2. All cyclostomes are jawless and lack paired fins.
    3. Crocodile is a reptile but has a four chambered heart unlike all other reptiles.
    4. Only the member of osteichthyes have gills covered by operculum while members of chondrichthyes lack operculum.
    So, the correct option is 'All cyclostomes do not possess; jaws and paired fins'.
Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

How many animals in the following are Gnathostomates?
Myxine, Laligo, Pristis, Salamander, Calotes, Laxelets.

  1. 2

  2. 1

  3. 5

  4. 3
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Gnathostomata consists of species of fishes which have jaws (jawed vertebrates).
  • Myxine is a genus of hagfishes which are jawless (superclass- Agnatha).
  • Loligo is a genus of squids belonging to the phylum Mollusca.
  • Pristis is a genus of sawfish which is cartilaginous and belongs to the superclass Gnathostomata.
  • Salamanders are animals having a slender body, blunt snout and short limbs which belong to the class- Amphibia.
  • Calotes is a genus of lizards belonging to the class- Amphibia.
  • Lancelets are fish-like marine chordate animals which are also known as amphioxi.
  • So, the correct answer is 1.
Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Internal nares are absent in

  1. Agnatha

  2. Chondrichthyes and Osteichthyes

  3. Chindrichthyes

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

Agnatha is a class of Chordata phylum. These are the jawless vertebrates. They have two nostrils but nares are absent. Chondrichthyes are the class of cartilaginous fishes. They are jawed vertebrates. In this, external nares are present whereas internal nares are absent. Osteichthyes are the class of bony fishes. They are jawed vertebrates. In this, external nares are present whereas internal nares are absent. 

Thus, the correct answer is option B.

Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Jawless fishes are included in

  1. Chondricthyes

  2. Osteichthyes

  3. Cyclostomata

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

Cyclostomata is characterized by round mouths. It is a group of chordates that comprises the living jawless fishes, examples are lampreys and hagfishes. They lack jaws which are replaced by retractable horny teeth. Their mouths cannot close due to the lack of a jaw, so they have to constantly cycle water through the mouth.

So, the correct answer is option C.

Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Only one semicircular canal is present in

  1. Bony fish

  2. Cartilaginous fish

  3. Hagfish

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

The jawed animals have three semicircular canals which are mainly statoreceptors which help to maintain the balance. Hagfish has a single semicircular canal which contains both stereocilia and the second class of hair cells, whereas other vertebrates have stereocilia only. Because the inner ear of hagfish has two forms of sensory ampullae, their single semicircular canal is assumed to be a result of two semicircular canals, that have merged into just one.

So, the correct answer is option C.

Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Petromyzon is ectoparasite on

  1. Rat and squirrel

  2. Fishes and turtles

  3. Cattles

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

Petromyzon (lampreys) are all carnivorous and are true predators. The method of attack is very peculiar. It attack fishes, turtles etc and it attach themselves by suctorial mouth which is circular in shape. Mouth acts a sucker, it rasps the flesh of the prey with its tongue. Teeth which are situated around the mouth sink into the flesh of the prey and serve it to hold properly. 

So, the correct answer is option B.

Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Fishes which are parasite as well as scavanger are

  1. Ostracoderm

  2. Cyclostomata

  3. Tetrapoda

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

Cyclostomata is a group of chordates that comprises the living jawless fishes: lampreys and hagfishes. Both groups have round mouths that lack jaws but have retractable horny teeth. The name Cyclostomata means "round mouths". These fishes are parasites and as well as scavengers. They feed off dead and wounded organisms in the ocean. 

Therefore, the correct answer is option B.

Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Hag fish is another name for

  1. Petromyzon

  2. Lamprey

  3. Myxine

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

Myxine is scientific name of hagfish. They are eel-shaped, slime-producing marine fish. They are the only known living animals that have a skull but no vertebral column. Classification of Myxine is

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Superclass: Cyclostomata
Class: Myxini
Order: Myxiniformes
Therefore, the correct answer is option C.

Multiple choice biology diversity in living world characteristics of vertebrates classification of vertebrata classifications of chordata

Lamprey (Petromyzon) belongs to

  1. Chondrichthyes

  2. Osteichythes

  3. Agnatha

  4. Amphibia
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
A. Class Chondrichthyes comes under the superclass Pisces. Most fishes are marine and a few live in the tropical rivers.
B. Class Osteichthyes comes under the superclass Pisces and includes lungfishes, lobbed finned fishes and ray-finned fishes.
C. Agnatha is a paraphyletic superclass of jawless fish and includes two class, Cyclostomata, and an extinct class Ostracodermi.
D. Class Amphibia comprises the animals that inhabit both land and water.
Lamprey (Petromyzon) belongs to class Cyclostomata under superclass Agnatha.
So, the correct answer is 'Agnatha'.
Multiple choice evs - i busy at work - our internal organs human lymphatic system lymph and its function lymph and tissue fluid experiments on digestive enzymes role of receptors in the mouth types of teeth introduction to human digestive system circulatory system and organs

Teeth not found in

  1. Primitive jawless fishes

  2. Lampreys

  3. Sharks

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

Teeth appear to have first evolved in sharks, and are not found in the more primitive jawless fish. Lampreys do have tooth-like structures on the tongue, these are in fact, composed of keratin, not of dentine or enamel, and bear no relationship to true teeth.