Six-spotted fishing spider

Appearance

This spider can be identified by its large size and distinctive markings. They have eight eyes with good vision and the body is grey to brown. They have a white to a pale cream colored stripe running down each side of the cephalothorax. The abdomen has many light colored spots and also has light colored lines running down the sides of the abdomen. When this species is seen from below, there are six dark spots present on the bottom of the cephalothorax in which the common name is derived.

Like many spiders, this species shows sexual dimorphism. The female is larger than the male. The female is about 60 millimetres long including the legs; her body length is 15–20 mm and the male's body is 9–13 mm long. The juvenile spiders look similar to adults but are smaller and they go through a series of molts within their lifetime to grow and reach adult size.

Distribution

These spiders are native to the Western Hemisphere and can be found throughout the contiguous United States and southern Canada, more common east of the Rocky Mountains and Great Plains. They can also range into Mexico.

Behavior

This species is diurnal which hunts during the day as it waits patiently for hours until depending on whether it is stimulated by prey. They are often seen with their legs sprawled out by the water while they are waiting for prey.

Habitat

They are semi-aquatic and live in wetland habitats such as ponds, lake shores, and they can also inhabit slow-moving streams. They can be found among vegetation, rocks and other structures near the water such as boat docks. They often dive underwater and grab onto a plant when frightened.

Reproduction

Egg production can happen anytime between June to September and sometimes in April but this is not often. Breeding takes place when the male does his courtship ritual. This can be the end of the male's life because cannibalism does occur. After mating, the spherical egg sac is then produced. Before hatching, the female builds a "nursery web" over vegetation and guards it. The egg sac is placed among the leaves to help keep it concealed. After the offspring have hatched, they sit under her protection in the web until they are ready to disperse into the outside world. The offspring leave the web about a week after they hatch.

Food

These spiders eat other invertebrates, tadpoles and occasionally small fish. They hunt by the water’s surface in which they can walk on water and dive under up to 18 cm to capture prey. Their good vision contributes to their success when diving to capture prey. They capture underwater prey as well as prey that fall on the water's surface or travels on water such as water striders.