A panamic green moray (Gymnothorax castaneus) gazes into a school of mysid shrimp (Mysida). Mysid shrimp live in salt and fresh water throughout the world, at all temperatures. These were in the Sea of Cortez, in the Bahia de los Angeles, in water at 87F. The females carry their larvae offspring in pouches, giving them the name "opossum shrimp". Like their second cousins, krill, they are filter feeders on even smaller creatures, and are an important food source for larger, b