Mediterranean Social Spider

• It practises matriphagy: the mother liquefies her own internal organs to feed the young by mouth and, when there is nothing left, the young devour her alive.
• Its close relatives are fully social spiders that live in colonies of hundreds of individuals with shared webs, and this species represents an intermediate step towards that group life.
• The female prepares the retreat and never hunts again after the eggs hatch: all her energy goes to the young.
• It practises matriphagy: two weeks after the young hatch, they kill and completely devour their mother, leaving only the empty exoskeleton.
• It is neither an accident nor an oversight. The mother makes no attempt to escape, and her tissues begin to break down even before the eggs hatch: she digests herself so that her young can consume her.
• Before that she feeds them by regurgitating fluid, because on leaving the cocoon they are entirely helpless and would die without her.
• She lays a single clutch in her whole life, which explains such extreme maternal investment.
• It is the only European species in its genus, and it is subsocial: there is prolonged maternal care but no permanent colonies.
• It adjusts web size to its nutritional state: well-fed spiders build webs 20 to 30% smaller so as to expose themselves less.

Skeleton type

Invertebrate - chitin exoskeleton (arachnid)

Habitat and environment

Dry scrub and thorny shrubs of the Mediterranean and the Middle East

Litter / clutch size

A single clutch in the female's whole lifetime

Sources consulted: Salomon et al. (2015), Journal of Arachnology · Kullmann (años setenta) · Ward y Lubin (1993)