Fishing spiders, members of the Dolomedes genus, are large, semi-aquatic arachnids often found near freshwater environments. They are known for their ability to walk on water, a skill aided by specialized leg hairs that repel water. Their appearance typically includes brownish-grey bodies with black and light brown markings, with some species displaying striped legs or distinct abdominal patterns. These spiders inhabit water bodies like lakes, ponds, streams, and marshes, where they find both prey and shelter.
Average Lifespan of Fishing Spiders
Fishing spiders generally exhibit a relatively long lifespan for arachnids, living about 2 to 3 years in natural settings. This duration is notably longer than many common spider species, which often live for only one year. While lifespans vary by species, some like the dark fishing spider (Dolomedes tenebrosus) can live for 1 to 2 years. This extended period allows for multiple reproductive cycles.
Life Stages and Their Duration
The life cycle of a fishing spider begins with the egg stage, protected within a silken egg sac. The female carries this sac, often in her jaws, until the eggs hatch. Before hatching, she constructs a nursery web, typically in vegetation, to house and protect the emerging spiderlings.
Once hatched, spiderlings remain within this nursery web, undergoing their first molt before dispersing to live independently. As they grow, juvenile fishing spiders progress through multiple developmental stages, known as instars, shedding their exoskeletons during molts to accommodate their increasing size. The number of juvenile molts can vary between species, ranging from 9 to 15 stages. After several molts, they reach maturity, with males sometimes maturing earlier than females.
Factors Influencing Lifespan
Several environmental and biological factors influence a fishing spider’s lifespan. Food availability, such as aquatic insects, minnows, tadpoles, or small fish, directly impacts their growth and survival. Fishing spiders are ambush predators that rely on sensing water surface vibrations to locate prey; a consistent food supply is important for their development.
Environmental conditions, including temperature and suitable habitat, also play a part. Cold periods can lead to hibernation, particularly for juveniles, which can extend their development time. Habitat quality, such as access to clean water bodies and vegetation for shelter and nursery webs, is important for overall health.
Predators like birds, larger spiders, wasps, and small mammals can shorten a fishing spider’s life. The reproductive process can also impact longevity, as female fishing spiders sometimes engage in sexual cannibalism, consuming the male after mating.