You searched for: “hematocyte
hemocyte, haemocyte, hematocyte
1. A cellular component of the blood, especially of an invertebrate.
2. Blood cell, associated with a haemocoel, particularly those of insects and crustacea.

Despite the name, they are more like a leucocyte, being phagocytic and involved in defence and clotting of haemolymph and not involved in the transport of oxygen.