Polycheles typhlops 
Pom-pom crab 
Porcellanella triloba 
Porcellio echinatus 
Porcellionides cingendus 
Portly spider crab 
Portunus gladiator 
Portunus pelagicus 
Potamon potamios 
Pott's Crinoid Shrimp 
Powder Blue Isopod 
Pronghorn Spiny Lobster 
Pseudocryptochirus viridis 
Purple Climber Crab 
Purple Crab 
Purple shore crab 
Purple Urchin Shrimp 
Pygmy locust lobster 
Quadrella boopsis 
Racilius compressus 
Randall's Pistol Shrimp 
Rathke's Woodlouse 
Red Coral Crab 
Red Hermit Crab