True whale
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True whale ( Mesoplodon mirus ) |
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| Mesoplodon mirus | ||||||||||||
| True , 1913 |
The true whale ( Mesoplodon mirus ), also known as the true two-toothed whale , is a species of whale that belongs to the genus of the two-toothed whale ( Mesoplodon ) within the beaked whale family (Ziphiidae). It got its name from its first describer, the American zoologist Frederick William True .
Distribution area
True whales have a two-part range, they are found in the northern Atlantic and southern Indian oceans . The population in the North Atlantic occurs in the west between the peninsulas Labrador and Florida , in the east the British Isles and the Canary Islands are the limits of the range. The population in the Indian Ocean was only discovered in 1959, strandings are known from South Africa and Australia . This whale species may be found in other regions of the world where it has not yet been discovered.
description
With a maximum length of 5.3 meters and a weight of up to 1.5 tons, the true whale is one of the larger representatives of the two-toothed whale. Males grow slightly larger than females. The true whale is slender and greyish in color, the underside is lighter, specimens of the Indian Ocean are characterized by a marbled underside. A dark ring around the eyes is striking in all animals. They have a long snout, from which the two teeth of the lower jaw protrude in males, and a slightly arched forehead with a flat melon . The flippers are small, rounded and sit low on the body, the fluke is wide and not notched in the middle. Scars on the back and on the flanks indicate rival fights between the males.
Way of life
True whales predominantly inhabit the open sea and rarely come to the coast. It was not until 1993 that clearly identified specimens were first observed on the open sea, east of North Carolina . This school consisted of three animals and was located in a sea region around 1000 meters deep. Like all beaked whales, true whales are likely to make long and deep dives, consuming squid , their preferred food. Nothing is known about social behavior and reproduction. In 2018, a group of young researchers was able to identify a true whale along with other beaked whales, the sowerby.
observation
In 2013, an international youth research team filmed true whales underwater for the first time off the Azores island of Pico , and the underwater photos and films were presented in early 2017, including a picture of a young animal. In 2018, the true whale was first observed and filmed while spy hopping.
threat
True whales have never been hunted commercially, but they get caught in fishing nets and drown (-> " ghost nets "). Due to the infrequent sightings and strandings, they are not believed to be particularly common, however exact data are not available.
literature
- Rüdiger Wandrey: The whales and seals of the world . Franckh-Kosmos Verlags GmbH, Stuttgart 1997, ISBN 3-440-07047-6 .
Web links
- Mesoplodon mirus in the endangered Red List species the IUCN 2006. Posted by: Cetacean Specialist Group, 1996. Retrieved on 12 May, 2006.
Individual evidence
- ↑ Natacha Aguilar de Soto, Vidal Martín, Monica Silva, Roland Edler, Cristel Reyes, Manuel Carrillo, Agustina Schiavi, Talia Morales, Belen García-Ovide, Anna Sanchez-Mora, Nerea Garcia-Tavero, Lisa Steiner, Michael Scheer , Roland Gockel , Dylan Walker, Enrico Villa, Petra Szlama, Ida K. Eriksson, Marisa Tejedor, Monica Perez-Gil, João Quaresma, Wojtek Bachara, Emma Carroll: True's beaked whale ( Mesoplodon mirus ) in Macaronesia. PeerJ March 2017, DOI: 10.7717 / peerj.3059 (scientific article with drawings, photos and video recordings of true whales)
- ↑ badische-zeitung.de , Panorama , March 8, 2017: Phantoms of the Deep Sea (March 13, 2017)
- ↑ Filmed for the first time: Der True-Wal orf.at, March 7, 2017, accessed March 8, 2017.