Dwarf Sperm Whale

*For pygmy sperm whale click here*

## About

A submerged dwarf sperm whale.

Dwarf sperm whales ***(Kogia sima)*** is a small member of the Kogiidae family. Much like their relatives the pygmy sperm whale ***(Kogia breviceps)*** have a flattened body and a small dorsal fin found in their lower back. Each fin of the dwarf sperm whale will vary in size and shape. Dwarf sperm whales adopt a very petite and narrow head covering and underlying jaw much like a shark. They posses a blueish grey body that faded into a lighter whitish pink underbelly much like other whale species. Dwarf sperm whales can only reach an age of 22 reaching sexual maturity at ages 2.5 to 5 years old. Dwarf sperm whales will release a black ink much like a squid that will support them in their escape from predators. Because of this animals cryptic and hidden nature they are rarely seen by people and when they are poorly distinguished between them and the pygmy sperm whale. Dwarf sperm whales travel in pods of up to around sixteen though roles aren't distinguished by stress there is little known about their social organisation. NOAA FIsheries explains how They can dive up to 1,000 metres in search of food though usually staying in more shallow tropics in temperate climates. An adult male dwarf sperm can reach up to 2.2 metres (7.2 feet) and weighing in at only 180kg (396.8) making it the smallest whale species.

## Diet

The dwarf sperm whale will often dive up to 1,000 feet (304 metres) in search of food, this is a relatively small diving depth for whales. Though dwarf sperm whales generally feed in the shallow waters, most of the time more shallow than their closest relative the pygmy sperm whale. The main foods that they indulge in are cephalopods, crustaceans and small fish. Much like other toothed whales the dwarf sperm whale uses echolocation to locate its prey. This means that they use sound as a way of navigation and sight. This occurs from the sound of their foreheads reflecting of surrounding objects. Dwarf sperm whale circle from ocean to ocean to find food. It is stated by National Geograhic that the adult male sperm whales generally retire in the arctic though females with young will often stay in more warm temperate regions. It is also said that dwarf sperm whale may travel up to a million miles in a lifetime.

## Conservation Status

Because of the dwarf sperm whales wide range as it is an ocean dweller that can travel from ocean from ocean through pod migration. The IUCN has listed the dwarf sperm whale as least concern as their current conservation status. Because of the dwarf sperm whales wide range and hard efforts to distribute them from the pygmy sperm whale it is very hard to accurately judge their conservation needs and to make an impact. These animals are also deliberately hunted deliberately across many different regions in the Indian ocean. They also fall victims to fisheries in their habitat were they get caught in nets and often die or have damaged ecosystems. Like other cetaceans the dwarf sperm whales fall victim to acids and oil leaks into the water and also the consumption of plastics and debris in their habitats.

## Range and Population

The Dwarf sperm whale has a very wide global range being an adaptable ocean dweller meaning that the IUCN has been unable to identify the current population of the dwarf sperm whale. Though it has been assessed that this mammal has been able to spread from the Atlantic, pacific and Indian ocean usually not varying to high or below the equator staying in warm temperate regions. Dwarf sperm whales do not tend to migrate though will stay between tropic and sub tropic regions. There has even been reports of a dwarf sperm whale observed in the Mediterranean sea. These mammals generally will stay between islander regions like the Bahamas and Hawaiian regions, there has also been a large amount of dwarf sperm whales found in the Mozambique Chanel. Dwarf sperm whales adopt a favourable range limit stretching from 45°S to 45°N, they will generally only migrate from their adopted regions for essential reasons like food.

## Behaviour

As said before NOAA Fisheries states that the dwarf sperm whale performs the squid tactic, which means that they store dark reddish ink in their intestines in which they let out in their surrounding area when they feel threatened. Dwarf sperm whales dive up to 1,000 in search of food meaning they spend very little time at the waters surface meaning that they do not often disturb vessels and for that matter have much human contact. However, when they are seen taking in oxygen through their blowholes at the surface they are either moving very slowly or lying still before diving back under the waters surface.

### Relationship with Humans

As mentioned in the Behaviour section the dwarf sperm whale rarely approaches boats as they are not generally observed to live on the surface and primarily try to avoid them as much as possible. Because of the dwarf sperm whales shy nature ADW explains that dwarf sperm whales typically do not posses any support that could help humans. Though they are seen to have an economical value to aboriginal/artisanal fisheries.

## In Captivity

Most cetaceans die within a month in captivity so for that matter there is little to no recorded dwarf sperm whales currently in captivity.

## Sources

* Dwarf sperm whale - NOAA Fisheries | https://www.fisheries.noaa.gov/species/dwarf-sperm-whale
* Dwarf sperm whale - IUCN | https://www.iucnredlist.org/species/11048/50359330
* Dwarf sperm whale - National Geographic | https://www.nationalgeographic.com/
* Dwarf sperm whale - ADW | https://animaldiversity.org/accounts/Kogia\_sima/