Write salient features of phylum hemichordata.

1.	Write salient features of phylum hemichordata.
Answer» Solitory/colonial, marine, tubiculous, free living & free swimming. Bilateral symmetrical, triploblastic, enterocoelic true coelomate. The body is divisible into proboscis, collar and trunk. The proboscis bears an endoskeleton called buccal diverticulum which is not homologous to the notochord. Alimentary canal is straight or U-shaped. Excretion by glomerulus found in the proboscis. Presence of gill slits. Unisexual, external fertilization and indirect development. The larva is called as tornaria. It is divided into two classes – 1. Class – Enteropheusta Examples : Balanoglossus (Tongue worm), Saccoglossus, Protoglossus etc. 2. Class – Pterobrauchii Examples – Rhabdopleura, Cephalodiscus

Answer»

Solitory/colonial, marine, tubiculous, free living & free swimming.
Bilateral symmetrical, triploblastic, enterocoelic true coelomate.
The body is divisible into proboscis, collar and trunk.
The proboscis bears an endoskeleton called buccal diverticulum which is not homologous to the notochord.
Alimentary canal is straight or U-shaped.
Excretion by glomerulus found in the proboscis.
Presence of gill slits.
Unisexual, external fertilization and indirect development.
The larva is called as tornaria.
It is divided into two classes –

1. Class – Enteropheusta

Examples : Balanoglossus (Tongue worm), Saccoglossus, Protoglossus etc.

2. Class – Pterobrauchii

Examples – Rhabdopleura, Cephalodiscus

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