Is there a discount for Veterans or Seniors?

Yes for both

Personally I think it should be free for veterans every day, everything should. May 26 - 28 FREE admission for U.S. Military veterans and active-duty service members plus dependent discounts. EVERY DAY United States Military Discount Special admission rate of $27.99 per adult, $22.99 per youth (13-17) and $20.99 per child (3-12) As a thank you to all United States military personnel (active, retired, or veteran) for their service to our country, Mystic Aquarium offers a special admission rate of $27.99 per adult, $22.99 per youth (13-17) and $20.99 per child (3-12) when each person shows their U.S. Military ID, Veteran’s Administration Card, or form DD214. Applicable to general admission only for military and their dependents. $10 discount on the purchase of a new membership also available. Cannot be combined with any other offer.

Yes, there is discount for seniors

How much is the price for seniors and children

Yes, for either.

I know they have a military discount, I dont know if there is a senior citizen discount.

yes

There is a discount for veterans. Also $4-5 off for AARP members. Details on web site.