Fishing spiders, also known as Dolomedes spiders, are not considered to be poisonous in the same way some venomous spiders are. The terms “poisonous” and “venomous” have distinct meanings in biology:
- Venomous: An organism is venomous if it produces and delivers a toxic substance actively, typically through a bite or sting. Venom is a specialized secretion that is injected into the prey or predator, usually to immobilize or kill.
- Poisonous: An organism is poisonous if it is harmful when touched or consumed. Poison is usually a passive defense mechanism, and the harmful substance is often present in the skin or tissues.
Most spiders are venomous, and fishing spiders fall into this category. However, their venom is not dangerous to humans. Fishing spiders use their venom to immobilize their prey, which primarily consists of insects and other small aquatic creatures. They do not pose a threat to humans unless a person is allergic to spider bites or experiences an unusual reaction.
Fishing spiders are widespread across North America, with numerous species found in different habitats such as ponds, streams, and marshes. Some well-known species in this region include Dolomedes tenebrosus and Dolomedes scriptus. Fishing spiders are also present in Europe, with species like Dolomedes fimbriatus found in various water bodies. The largest number of species are found in Asia, with particularly high species diversity in South-east Asia, from China and Japan to New Guinea. The second largest number of species occur in tropical Africa. South America has only four species.
Fishing spiders are well-adapted to their aquatic environment. They are capable of walking on water, which aids them in hunting for prey. For fishermen or anyone spending time in areas where fishing spiders are present, it’s advisable to exercise caution and avoid unnecessarily provoking or handling these spiders. While their venom may not be harmful to humans, bites can still cause mild irritation or allergic reactions in some individuals. As with any spider or insect encounter, it’s best to observe from a safe distance and let them go about their natural behaviors.
In summary, fishing spiders are not poisonous to humans, and their venom is primarily used for hunting prey rather than defense against larger animals. If bitten, the effects are generally mild and localized, resembling reactions to other spider bites, such as redness and swelling. However, individual reactions can vary, so it’s always a good idea to seek medical attention