Dark tales around the fire (1): Spiders Lullaby, making the ultimate sacrifice

 Spiders weave the most unimaginable life stories; bizarre stories, yes, but as true as old mother nature is.
 

And yes, some of these stories seem directly drawn from the imagination of a sadistic author because many species of spiders practice what is known as matriphagy that is just a long word with which scientists describe that moms are regularly and obligatorily in their offspring menu.

Honor to a caring mother: Stegodyphus lineatus Image - Stegodyphus lineatus

 Each female spider of the species Stegodyphus lineatus hatches only one brood in her lifetime, and you will understadn why.  

But this story is different, it is a love story. The story starts in the warm and sheltering nest that the spider mum of the species has built for her eggs, in its special corner in her spider web. When the little spiderlings are born, Mom is responsible for drilling the silk that protects the nest to free them and she starts caring for them with real dedication. For two full weeks, mom feeds her dozens of youngs by regurgitating a transparent liquid that the babies drink directly from her mouth, a very nutritive soup that keep them growing strong and healthy. Her dedication is so impressionant that Mom does not eat anything during these two weeks.[1]

Mom Stegodyphus lineatus feeding her young with her special soup, spiderlings lovingly clustered around her mouth. (Arachnid Matriphagy: These Spider Mothers Literally Die for Their Young)

 

It is a love story, as I said. Just the love story that a psychopath would like to write. What mom is giving her little ones are the nutritional reserves she has stored in her body, along with her own dissolved guts.

Preparation for this part of the meal starts early. The mother’s midgut begins to break down while she is still guarding her eggs. And by the time the pale youngsters hatch, liquefied gut - suitable for baby mouthparts - is building up in her abdomen. Along the whole proccess, only ovaries and heart will remain at they were, the rest of Mom body participates in this soup. At the end of these two weeks Mom will regurgitate 41 percent of her body mass to feed her babies.

 An exhausted spider mom ready to be devourated by her spiderlings. Matriphagy is the final act of this love tale: https://www.earthtouchnews.com/wtf/wtf/meet-the-spider-mom-that-makes-a-meal-of-herself/

There is only one thing left to teach the youngsters. And she will give her life for them, she will literally give her life and her body for them. She needs to teach them to kill. She calls them, gently moving the cloth, and when her little golden cannibals, the pride and torment of this sacrificed mother approach to her in all excitment, she slowly throws herself onto them to make them even more nervous. Dozens of small chelicerae pierce the body of Mom, and the final act of this tragedy takes place. Yes, these spiders are in the matriphagy club, but they have taken it a step further. Mom commits suicide for her little ones, she is not the involuntary victim of some form of strange reproduction by which the growing youngster eat her form inside, until finally ripping her body (like some mites and caecilians experience). When the astonished researchers touched the legs of spiders that were beginning to be devoured, they never made the slightest attempt to escape. This is called suicidal maternal care[2][3].

You can watch the video of youngsters festing on mom in this link, if these things are of your taste... (youngsters taste, it is, of course).

However, this is not the only spider species that lives this love-horror story. A closely related species, Stegodyphus dumicola, has an even more dramatic version.

 

Stegodyphus dumicola

 Small cannibals are born in large family groups. They have access not only for mommy maternal care, but for several single aunts who act as devoted adoptive mothers. The story is very similar, in all its details (the porridge of intestines of mom and the aunts, as well as the final act of cannibalism on the body of mom, and on more than one occasion of the aunts).

And the males? In the dumicola the males live very little time, which is one of the reasons why so many females remain without fertilizing, single auts invest their lives in their genetic relatives, their nephews (and nieces, you understand me).  In the lineatus, as far as I know, something similar happens.

So, in the species in which matriphagy occurs, as it is very easy to understand, females have the curious habit of reproducing only once in their lives, and not surviving to be cannibalized alive by their young. It is still effective, if Mom is not going to be there forever and also will not have more offspring, Mom can be the best and cheapest protein dish for her offspring. It is pure logic, psychopathic logic.

Now, as I say, in making sacrifices for their youngster, these spiders go one step further. They offer themselves to their offspring.

Footnotes

[1] What’s for dinner? Mom. | Science News for Students

[2] What’s for dinner? Mom. | Science News for Students

[3] Maternal Investment in a Spider with Suicidal Maternal Care, Stegodyphus lineatus (Araneae, Eresidae)