Open circulatory system is present in

Annelida (e.g., Nereis, Pheretima) – closed circulatory systemArthropoda (e.g., Bombyx, Laccifer) – open circulatory systemMollusca (e.g. Pinctada, Aplysia) – open circulatory systemCephalopod molluscs (e.g., Sepia, Octopus) – closed circulatory systemEchinodermata (e.g. Echinus) – open circulatory systemHemichordata (e.g. Balanoglossus, Saccoglossus) – open circulatory systemUrochordata (e.g. Ascidia ) – open circulatory systemCephalochordata (e.g., Branchiostoma) – closed circulatory systemVertebrata (e.g., Petromyzon,Testudo) – closed circulatory system