Trophal taxis

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Trophallaxis (seldom also written trophalaxis ) is the zoological name for the transfer of liquid food from the mouth or anus of one animal to another. It is developed in social insects and many brood-caring vertebrates .

Social insects

Four female workers of the species Polyrhachis dives at the trophallaxis

In the case of social insects such as ants, members of a colony store food in their crop for exchange with other colony members and larvae. This creates a kind of “common stomach” (also social stomach ) of the people.

In the case of honey bees , returning foragers pass on the nectar or honeydew stored in their stomachs for transport from trunk to trunk to other, mostly younger bees or drones in the hive . They use part of it to raise the brood, for their own nutrition and, if there are surpluses, also for processing into honey stocks .

The honeybees' stomach is also called the “honey bladder” because the body's own enzymes , the invertases , already convert part of the conversion of nectar into honey .

The animals keep only a small part of the food to themselves. After opening a valve, the so-called proventriculus, this is pumped into the midgut. In bees , wasps and ants , the two-part proventriculus including the stomach mouth (Valvula cardiaca) is equipped with a sphincter that regulates the flow of food to the midgut. In the ants , the proventriculus is very complex and characteristic of subfamilies.

Myrmecophiles

Some ant guests ( myrmecophiles ) such as blue caterpillars (Lycaenidae) and some parasites of the ants such as larvae of hover flies (Syrphidae) are also fed trophallactically by the host ants .

Brood-caring vertebrates

Trophallaxis occurs during brood care in some vertebrates such as birds (e.g. storks , corvids , penguins ) and mammals (especially predators such as dogs ). The trophallaxis is pronounced in the emperor penguin , for example , whose brood food consists of a milky secretion from the stomach of the fathers after hatching, later of predigested fish from the mothers, then again from the fathers. The entire trophallaxis phase of the emperor penguin lasts from mid-July to January.

Web links

Individual evidence

  1. ↑ Adria C. leboef: Trophallaxis . In: Current Biology . tape 27 , no. 24 , 2017, p. R1299 – R1300 (English).
  2. ^ P. Korda: Epimeletic (care-giving) vomiting in dogs: a study of the determinating factors. ( Memento from June 10, 2015 in the Internet Archive ; PDF; 4.4 MB) In: Acta Neurobiol Exp (Wars) . 34, No. 2, 1974, pp. 277-300.