What is aquatic adaptation

The systematics of the whales - biology and adaptations to the aquatic way of life

content

1 classification of whales (Cetacea)

2 Adaptations of the whales to the aquatic way of life

3 anatomy of the whales

4 Earning food

5 Diving and Deep Diving

6 sense organs

7 reproduction

8 Literature used:

1 Systematics of the whales (Cetacea)

The systematics of the cetaceans points in the literature[1] significant differences on:

1977, 1984 after RICE:

Classification of the tooth (Odontoceti) and baleen whales (Mysticeti) as independent orders in the animal kingdom.

1976 after GASKIN:

Classification of toothed and baleen whales as subordinates of the order cetaceans (Cetacea).

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The most current classification is based on MILIMKOVITCH et al.; CLIMATE; OIL CLUB 1993:

- The systematisation of whales in toothed and baleen whales, which is commonly carried out, is problematic. All whales have teeth at an early stage in their development. Sperm whales, for example, belong to the toothed whales due to their teeth, cell genetics they can be assigned to the baleen whales (due to the similarity of chromosomes).
- All whales originally come from a group of stock or primeval ungulates (Condylarthra). There is a close relationship with the ungulates (deer, giraffes, horses etc.).
- All whales are of monophyletic ancestry, i.e. they have a common tribe. Furthermore, all whales show similar developments of the brain (e.g. acoustic system, structure of the cerebellum) and have tooth systems in the embryonic or fetal stage.

2 Adaptations of the whales to the aquatic way of life

All aquatic mammals are descended from land mammals, including cetaceans[2].

Advantageous achievements of the whales adopted by the land mammals are:

- Warm bloodedness (makes the whales independent of their ambient temperature, as they can regulate their body temperature themselves). They are therefore found in all the world's oceans.
- Intense metabolism (Whales have increased activity and adaptability).
- Coreless blood cells (allow a multiple connection of oxygen).
- Efficient cycle (is made possible by the separation of the body and pulmonary circulation).
- Placenta formation (enables protected embryonic development in the womb).
- Intensive brood care (pronounced mother-child bond, pronounced social behavior).
- Advanced CNS (big brain).
- Sound-producing vocal organs.
- Well developed sense of hearing (as a basis for echo orientation).

In summary, this means that the Cetacea are far superior to the rest of the aquatic population. This is supported by the following phenomena.

The whales are:

- the fastest and most agile swimmer in the water;
- the most effective food processor;
- the smartest aquatic life at all;
- the water dwellers with the most pronounced social behavior;
- the largest living thingwho ever lived or live on earth (sizes vary from 1m <-> 30m length and 30 kg <-> 150,000 kg body weight; dolphin <-> blue whale).

3 anatomy of the whales

By adapting to life in the water, the whales have some peculiarities with regard to their anatomy[3] on.

- The rear extremities are completely regressed (see bone remnants in the pelvic area)
- The front extremities are transformed into fins (flippers) (for stabilization).
- Propulsion takes place through the tail fin (fluke), which has a horizontal position as an anatomical feature. Accordingly, the whale does not move sideways through the water like the fish do. Rather, the whales generate buoyancy by beating up and down the mighty caudal fin. Physical and technical investigations have shown that a drive at the rear end of the body is absolutely the cheapest. The horizontal position of the fluke is determined by the spine and its mobility. Due to the typical S-shape of the spine, dorso-ventral movements (towards the abdomen and back) are the most effective. The fluke consists of connective tissue and collagen fibers (not bones and / or muscles!).
- The dorsal fin also has a stabilizing function for swimming and is skeleton-free.[4]

[...]



[1] Klima, M .; Oelschläger, H.A .: Phylogeny and Systematics of the Cetacea.
In: Niethammer, J .; Krapp, F .:
Handbook of Mammals of Europe. Volume 6: Marine Mammals / Part 1: Whales and Dolphins-Cetacea.
Aula-Verlag Wiesbaden 1994, pages 32-48.

[2] Klima, M .: Adaptations to the aquatic way of life
In: Niethammer, J .; Krapp, F .:
Handbook of Mammals of Europe. Volume 6: Marine Mammals / Part 1: Whales and Dolphins-Cetacea.
Aula-Verlag Wiesbaden 1994, pages 49-79.

[3] Klima, M .: Adaptations to the aquatic way of life
In: Niethammer, J .; Krapp, F .:
Handbook of Mammals of Europe. Volume 6: Marine Mammals / Part 1: Whales and Dolphins-Cetacea.
Aula-Verlag Wiesbaden 1994, pages 49-79.
The world of whales. The catalog for the Greenpeace exhibition.
An exhibition by Greenpeace Umweltverlag GmbH, Hamburg,
in cooperation with Woite, Bauch & Partner BmbH, Berlin.
Exhibition tour May 1994 to June 1996 in Bonn, Museum König.
The modern animal lexicon in 12 volumes.
Lexicon Institute Bertelsmann [Ed.], Lexikothek Verlag GmbH, Gütersloh 1981 b.

[4] Veterinarians can even determine cardiovascular diseases from the appearance of the killer whale's dorsal fin. This is what happened with the movie favorite "Free Willy", whose dorsal fin hung down on the side of the body, caused by a pool that was too small or a lack of exercise.

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