How does the defensive mechanism of Ananteris actually end up killing them?
- bioworld090
- Jul 21, 2022
- 2 min read
Image Source: Wikipedia
Ananteris is a genus of scorpions found in South America, It consists of around 84 species that range from 9mm-42 mm in size.
DEFENCE MECHANISM
Image Source: plosone
The defence mechanism of ananteris scorpion is autotomy or self-amputation. Autotomy is the behaviour of certain animals to discard a part of their body as a defence mechanism. Ananteris scorpions discard their tail when they are caught by the tail. The detached tail moves vigorously after detachment and in some cases reacts to an external stimulus. The time for which the tail moves after detachment ranges from 8.8 seconds to 169.95 seconds.
The metasoma or tail of a scorpion is made up of 5 segments. According to a study, the detachment occurred mostly between the III and IV segments. The detachment between II & III is less likely to happen and the detachment between I & II is rare.
Image Source: plosone
Once the tail is detached, scar tissue formation takes place quickly to prevent the loss of haemolymph(a fluid that runs in the body of invertebrates and is equivalent to blood). Some amount of haemolymph is lost up to five days after the detachment but after five days there is no loss of haemolymph.
Why does the tail detachment occur mostly between the III and IV segments?
The scientists studying the caudal autotomy in Ananteris scorpions observed that additional autotomy occurred in two scorpions some days after the initial autotomy. In both cases, drops of excrement were expelled. This suggests that the detachment between the III and IV segments leaves room for additional autotomy and seems to aid in excretion.
How does caudal autotomy end up killing the Ananteris scorpions?
Image Source: researchgate
Caudal autotomy affects the digestive system and excretory ability of the Ananteris scorpions. The gut of a scorpion extends all the way to its tail and ends on the 5th segment just before the stinger. So, when the scorpion discards its tail, the anus is also lost. Also, the scar tissue formed seals the digestive tract and leaves no possibility for the scorpion to excrete.
As a consequence of losing a part of its tail, the scorpion can neither excrete nor capture big prey. However, it can still live for up to 8 months and reproduce.
REFERENCES:
Comments