Stegodyphus lineatus
The act of reproduction, regarding the female, leads to an increase of digestive enzymes. This allows her to eat more prey and to stock more nutrients. The digestive enzymes then start to digest the inside of the organism itself, except for the heart, guts, and mostly the ovaries. Once the offspring are born, and until the mother dies, the mother regurgitates for two weeks the fluids stocked inside as highly nutritive food for the progeny. Ninety-five per cent of the mother's mass is digested by the offspring. They will grow to three times their original size between their birth and dispersion. During the period when female spiders are caring for their hatched offspring, the mothers do not eat, and their offspring only eat the food that the mother regurgitates along with the mother's body at the end of this time.
Parasitic nutrition
Endoparasites have various anatomical and biochemical adaptations, typically at the host-parasite interface, to maximise nutrient acquisition. One such adaptation is the tegument, a metabolically active external cover that plays an important role in nutrient extraction from the host. The parasite tegument is permeable to various organic solutes and has transporters for the facilitated or active uptake of nutrients. Various studies have attempted to characterise these transporters in a number of parasites e.g. the amino acid transporter molecules in protozoa. Cestodes do not have a gut so the tegument is therefore critical for nutrient uptake. In cestodes the tegument is highly efficient with spine-like microtriches, similar to microvilli, to increase the surface area available for nutrient acquisition. In many parasites the tegument structure has folds or microvilli to maximise the surface area available for diffusion and uptake of nutrients. The tegument also commonly has additional organelles and features with important functions in metabolism including the glycocalyx. The glycocalyx is a carbohydrate-rich layer that enhances nutrient absorption and secretes enzymes to aid primary digestion.