Definition: Siphonophorans are a group of marine invertebrates that primarily inhabit the water column. They are characterized by their unique ability to suck up and absorb nutrients from the surface of water, allowing them to grow and thrive in these environments. Siphonophors are known for their ability to extract nutrients from the water by utilizing specialized structures called siphons, which allow them to transport these nutrients to their cells. This process is crucial for the survival of many marine organisms that require