SUBJECT MATTERS OF EXPERIMENTS AND OBSERVATIONS OF WATER ANIMALS IN SCHOOL AQUARIUM VII (REARING OF WATER SPIDER)
Abstract
The diving bell spider or water spider (Argyroneta aquatica) is the only species of spider known to live almost entirely under water. When out of the water, the spider ranges in colour from mid to dark brown, although the hairs on the abdomen give it a dark grey, velvet-like appearance.
Under the water, Argyroneta aquatica displays a silvery appearance due to the presence of the air bubble surrounding its abdomen. Ordinarily, A. aquatica is found in oligotrophic/dystrophic bog ponds, marshes and swamps, resurgences, small lakes and slow-moving streams.
Argyroneta aquatica is a carnivorous animal with a diet differing upon location but typically including water fleas, aquatic isopods such as Asellus aquaticus, insect larvae, fairy shrimp and even other water spiders. Water spiders need water plants as anchors for their "bubble nests" (diving bells) as well as an attachment site after diving down in the water.
The tendency of males (to 18.7 mm) to be larger than females (to 13.1 mm) in this species is an anomaly amongst most spiders. Males tend to be more active then females and actively hunt their prey.
In contrast, females spend most of the time inside the air-bell and catch prey that strays too close to the bell. Following copulation, the female produces a dense white egg sac holding 50-100 eggs, which completely fills the upper half of the nest..
Offspring leave their mother's nest between two and four weeks after hatching to build their own nests. Small aquarium with stagnant water with rich vegetation reaching to the surface is sufficient for breeding.
Small live food is suitable for feeding. Some suggestions for observations and experiments in school aquaria are presented in this contribution.