Toxins produced by some red-tide organisms have produced massive invertebrate and fish kills and can be deadly to humans as well. Some cause malaria. They lack contractile vacuoles because their rigid cell walls do not allow excess water in. Almost all are heterotrophic but few are photosynthetic endosymbionts. They also have two nuclei.
Cilia are for locomotion.
Pseudopods are used to engulf food. They are also used for locomotion on the bottom of lakes, ponds, and other bodies of water. They eat other organisms or are parasites. Actinopod means ray foot . Besides being used for feeding and locomotion, actinpods are also used to float.