The first one with the boxing crab and anemone is mutualism. 
The second one with the dog and flea is parasitism.
        
                    
             
        
        
        
Humans are the closest relative I think
        
             
        
        
        
I mean each Animal has a purpose in order to keep the food chain in line, for example sharks if they went extinct there would be more seals and more fish and less of this and that. Each animal plays a certain part on earth in order to keep everything normal.