Question

Write some of the characters of Cnidaria(Coelenterata) ​

Answer 1

ᴄʜᴀʀᴀᴄᴛᴇʀɪsᴛɪᴄs ᴏғ ᴄɴɪᴅᴀʀɪᴀ:

• ʀᴀᴅɪᴀʟʟʏ sʏᴍᴍᴇᴛʀɪᴄᴀʟ.
• ʙᴏᴅʏ ᴍᴜʟᴛɪᴄᴇʟʟᴜʟᴀʀ, ғᴇᴡ ᴛɪssᴜᴇs, sᴏᴍᴇ ᴏʀɢᴀɴᴇʟʟᴇs.
• ʙᴏᴅʏ ᴄᴏɴᴛᴀɪɴs ᴀɴ ɪɴᴛᴇʀɴᴀʟ ᴄᴀᴠɪᴛʏ ᴀɴᴅ ᴀ ᴍᴏᴜᴛʜ.
• ᴛᴡᴏ ᴅɪғғᴇʀᴇɴᴛ ғᴏʀᴍs ᴇxɪsᴛ, ᴍᴇᴅᴜsᴀ ᴀɴᴅ ᴘᴏʟʏᴘ.
• ʀᴇᴘʀᴏᴅᴜᴄᴛɪᴏɴ ɪs ᴀsᴇxᴜᴀʟ ᴏʀ sᴇxᴜᴀʟ.
• ʜᴀs ᴀ sɪᴍᴘʟᴇ ɴᴇᴛ ʟɪᴋᴇ ɴᴇʀᴠᴏᴜs sʏsᴛᴇᴍ. ʜᴀs ᴀ ᴅɪsᴛɪɴᴄᴛ ʟᴀʀᴠᴀʟ sᴛᴀɢᴇ ᴡʜɪᴄʜ ɪs ᴘʟᴀɴᴋᴛᴏɴɪᴄ.
• ʟɪᴠᴇs ɪɴ ᴀǫᴜᴀᴛɪᴄ ᴇɴᴠɪʀᴏɴᴍᴇɴᴛs, ᴍᴏsᴛʟʏ ᴍᴀʀɪɴᴇ.
• ᴍᴏsᴛʟʏ ᴄᴀʀɴɪᴠᴏʀᴏᴜs ᴏᴛʜᴇʀᴡɪsᴇ ғɪʟᴛᴇʀ ғᴇᴇᴅᴇʀs.
• ᴍᴀʏ ʜᴀᴠᴇ ᴀ ᴍɪɴɪᴍᴀʟ sᴋᴇʟᴇᴛᴏɴ ᴏғ ᴄʜɪᴛᴏɴ ᴏʀ ᴄᴀʟᴄɪᴜᴍ ᴄᴀʀʙᴏɴᴀᴛᴇ.

Answer 2

AnSwer :

Coelenterates :-

$\bigstar$ Most of the coelenterates are marine but a few of them are fresh water. (eg :- Hydra)

$\bigstar$ They are sessile or free swimming radially symmetrical animals. (Anthozoans like Adamsia exhibit biradial symmetry)

$\bigstar$ Coelenterates are diploblastic, with two germn layers ectoderm and endoderm.

$\bigstar$ The animals have blind sac body plan. There is a single opening on hypostome which Serves both as mouth and anus. This aperture leads into a cavity called gastrovascular cavity or coelenteron.

$\bigstar$ Body wall is two layered, .i.e., outer epidermis (ectoderm) and inner gastrodermis (endodorm). In between these two layers is present a non-cellular, nonliving gelatinous matrix or layer called mesoglea . Nerve fibres may traverse mesoglea.

$\bigstar$ The name cnidaria is derived from the cnidoblasts or enidocytes (which contam the stinging capsules or nematocytes) present on the tentacles and the body. They contain hypnotoxin or mucus

$\bigstar$ cnidoblasts are used for anchorage, defense and for the capture of prey. Cridoblasts contam hypnotoxin or mucus.