Cyclostomata, like lamprey eels and hagfish,
a. feed on other fish or invertebrates
b. have cartilage skeletons
c. reproduce by internal fertilization

b. have cartilage skeletons

Cyclostomata is a group of Agnatha class. It comprises of jawless fish species like lampreys and hagfishes. They have jawless mouth, epidermal structure that function as teeth. The name Cyclostomata suggests round mouth. The fertilization and development in these fishes is external to the body and the offspring do not get the parental care. These animals are cold blooded and exhibit a cartilaginous skeleton. They have two chamber heart. They feed on other fishes and mammals.  

the food storage products of chrysophytes are oils or the polysaccharide laminarin.   formerly classified as plants, the chrysophytes contain the photosynthetic pigments chlorophyll a and c all but the yellow-green algae also contain the carotenoid pigment fucoxanthin.