Physeter macrocephalus has very few interactions with other species because the majority of them can't cope with the extreme pressure changes the sperm whale undergoes while diving deep down for food. Some interactions that do occur within the species are the females will stay in pods of about ten with their young in tropical waters. Since the young whales can't dive down as deep in search of food and they are still vulnerable to predators, the female whales will vary their dive times so that they younger whales are always left at the surface with protection. Remora catching a ride on a Sperm Whale.

One organism that does have some interaction with Physeter macrocephalus is a Remora or a "suckerfish." They will often times be found on the underside of sperm whales and are provided with transport, protection as well as food. This relationiship has little to no effect on the sperm whale so it is seen as commensalism.

Predators:  Sperm whales have very few predators. The main predator which is only a serious threat to younger whales are orcas. These creatures feed on the young whales if they are left a lone at the surface and that is the reason females will vary their diving times.
Male Physeter macrocephalus however have far fewer interactions because they live a much more solitary life. As they age and mature, they slowly grow more independent and most eventually end up completely solitary.

Human Interactions:  Humans would hunt these whales in the past to harvest their blubber as well as the spermaceti (not sperm). Spermaceti is fluid stored in the head of the sperm whale and scientist are not sure what it does exactly, some theories believe it to be a focusing mechanism for the whales echolocation, others believe that it helps to control the whales bouyance. This fluid was used for many things such as candles, waxes, and different high end oils.
Humans have had a great impact on the sperm whale population and have greatly deminished it over time. The only country that still allows the hunting of sperm whales is Japan.

Continue on to learn some fun facts about sperm whales, or head back to the homepage.