Your Dexterity score increases by 2, and your Constitution score increases by 1.

young Zeridians learn quickly how to use magic and to sense the world around them

you are taller and a littler lighter than humans even if you look like them, they are the humans of their world

Your base walking speed and swimming speed is 30 feet.

As an reaction if an hostile creature attacks with an melee weapon and deals damage to you, you can let more blood out of the wound and sacrifice 1d4 of your hit points to deal 1d10+ your constitution modi poison damage to the attacker then he must succeed on a DC 10+ your constitution modifier Constitution saving throw or become poisoned for 1 hour. You can use this feature times your constitution modifier then you must take a long rest to get this feature back.

you are used to your poisones blood, while its more dangerous to other races

Zeridians can breath air and water, because additionally to their nose they have four shark like gills on their neck and the gills can be opened and closed by the Zeridian at will

You can speak, read, and write Common and abbysall, because you have gills and a mouth