Great raft spider (Dolomedes plantarius)
Invertebrates · Difficulty: Expert
Key facts and care guidance for Great raft spider (Dolomedes plantarius) (origin: Europe; very rare, on undisturbed nutrient-poor lake shores and bogs). Adult size around females up to ~22–25 mm, males ~13 mm (somewhat stockier than D. fimbriatus). Life expectancy approx. 2–3 years. The values below are carefully researched guidance.
Short answers
Great raft spider: How big does the enclosure need to be?
An aqua-terrarium or paludarium ~40×30×40 cm with a large water surface and dense bank and water plants.
Great raft spider: What temperature does it need?
Daytime 18–24 °C, at night 12–18 °C.
Great raft spider: Does it need UVB lighting?
UVB: UVB not essential; a clear day/night rhythm.
Great raft spider: How long do they live?
Life expectancy: approx. 2–3 years.
Great raft spider: Is it suitable for beginners?
No – better suited to experienced keepers (difficulty: Expert).
Climate
- Daytime temperature
- 18–24 °C
- Night temperature
- 12–18 °C
- Basking spot
- —
- Humidity
- 80–95 % (bank/wetland biotope with open water)
- UVB
- UVB not essential; a clear day/night rhythm
Enclosure
- Minimum size
- an aqua-terrarium or paludarium ~40×30×40 cm with a large water surface and dense bank and water plants
- Substrate
- A bank zone plus open water, dense planting
Feeding
- Food
- Insects, small aquatic animals (tadpoles, small fish); a surface hunter
- Feeding interval
- 1–2×/week
Key facts
- Adult size
- females up to ~22–25 mm, males ~13 mm (somewhat stockier than D. fimbriatus)
- Life expectancy
- approx. 2–3 years
- Origin
- Europe; very rare, on undisturbed nutrient-poor lake shores and bogs
- Protection status
- Endangered on the German Red List, IUCN "Vulnerable"; specially and strictly protected in Germany → wild collection is prohibited, and keeping it is practically only possible with an exemption
- Brumation
- Yes – a cool overwintering (about 2–8 °C) following the annual cycle
- Cohabitation
- Keep them singly – solitary and cannibalistic. The reason is not fighting but feeding: these animals take anything that fits in the mouth, and a second animal in the enclosure counts.
Notes
One of the rarest spiders in central Europe; strictly protected under conservation law – taking or keeping it without a permit is unlawful. Otherwise care as for D. fimbriatus (semi-aquatic).
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Related species
- Raft spider (Dolomedes fimbriatus) – Expert
- Woodlouse spider (Dysdera crocata) – Intermediate
- Huntsman spider (Heteropoda venatoria) – Beginner
- Brown recluse spider (Loxosceles reclusa) – Expert
- David Bowie huntsman spider (Heteropoda davidbowie) – Intermediate
- Tube-web spider (Segestria florentina) – Intermediate
- Segmented spider (Liphistius sp.) – Expert
- Domestic house spider (Tegenaria domestica) – Beginner
What you need to start
To keep Great raft spider (Dolomedes plantarius) you typically need: a suitable enclosure (an aqua-terrarium or paludarium ~40×30×40 cm with a large water surface and dense bank and water plants), substrate (A bank zone plus open water, dense planting), a heat source with a thermostat, UVB lighting, thermometer and hygrometer, a water dish and hides. You will find equipment in the Reptoria marketplace.
The complete, interactive care database is in the Reptoria app.
Last updated: 9 October 2026 · Editor: Reptoria editorial team · Sources include: https://de.wikipedia.org/wiki/Gerandete_Wasserspinne, https://en.wikipedia.org/wiki/Dolomedes_plantarius
All values are non-binding guidance and do not replace expert advice. Research thoroughly from several sources before acquiring and keeping an animal, and observe the applicable law (species and animal protection in particular).