Question

Tornaria Larva is found in 
1. Hemichordates
2. Urochordates
3. Vertebrates
4. Cephalochordates

Answer 1

Correct Answer - Option 1 : Hemichordates

Concept-

• The larva is a stage in the development of many animals, occurring after birth or hatching and before the adult form is reached. These immature, active forms are structurally different from the adults and are adapted to a different environment.
• There are different types of larvas like Tonaria larva, Muller's larva, Tadpole larva, etc.

Explanation-

• Tornaria Larva is found in Hemichordates
• Animals of this phylum are worm-like, brittle, and soft.
• The body is divided into three-part:
  • Proboscis
  • collar
  • trunk
• The true notochord is absent, a notochord like structure is found in their buccal cavity called "Buccal diverticulum" or "Stomochord" 
• Development is indirect.
• The animals have tornaria larva (planktonic larva)  just like bipinnaria larva of Echinodermata in their developmental stages.

 

Important Larval Stages:

Tadpole, also called polliwog, the aquatic larval stage of frogs and toads.

• Compared with the larvae of salamanders, tadpoles have short, oval bodies, with broad tails, small mouths, and no external gills.
• The internal gills are concealed by a covering known as an operculum.
• Tadpole larva shows retrogressive metamorphosis.

Muller's larva:

• A ciliated larva that resembles a modified ctenophore and is characteristic of various polyclad turbellarians (a subdivision of phylum Platyhelminthes).