Every photo used here is licensed (CC BY / CC BY-SA / CC0 or public domain). Click i to expand source and licence. Use this to confirm identification — don't rely on memory alone.
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Quick ID Matrix
Match the organism to the first-aid rule: box jelly → vinegar ≥30 s; bluebottle/Physalia → hot water ~45 °C (~20 min); elapid → pressure-immobilisation; viper → immobilise at heart level; unknown mushroom with delayed onset (>5 h) → go to hospital ASAP.
“"Hapalochlaena maculosa black background.jpg"” by Julian Finn — CC BY 4.0 · Wikimedia Commons
License: CC BY 4.0. The venom is in the salivary gland and is delivered by a bite. There is no antivenom — respiratory support is the treatment.
Sea & ShoreBlue-ringed octopus (Hapalochlaena maculosa)Hazard: tetrodotoxin — paralysis and respiratory failure. Do: do not touch; call 1669 immediately; be ready to help with rescue breathing. Don't: handle it because it looks small and harmless.
“"Chironex-indrasaksajiae.jpg"” by Marshal cmd — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Follow posted warnings and DMCR advisories before entering the water. Vinegar is the first step for Chironex stings — not for bluebottles.
Sea & ShoreBox jellyfish (Chironex / Carukia-type)Hazard: cardiorespiratory collapse in severe envenomation. Do: vinegar 4–6% ≥30 s; remove tentacles with tweezers. Don't: fresh water, urine, alcohol, rub.
“"Common lion fish Pterois volitans.jpg"” by Michael Gäbler — CC BY 3.0 · Wikimedia Commons
License: CC BY 3.0. Invasive in the Andaman Sea. Venom is delivered by spine, not by a bite.
Sea & ShoreLionfish (Pterois volitans)Hazard: venomous spines. Do: hot water immersion, clean the wound, remove spines you can see. Don't: touch the spines with bare hands.
“"Live Physalia utriculus showing zooids and fishing tentacles.jpg"” by Jessicager93 — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. First-aid differs from box jelly — hot water ~45 °C for ~20 min, no vinegar.
Sea & ShoreBluebottle / Portuguese man o' war (Physalia spp.)Hazard: neurotoxic sting, intense pain, nausea. Do: hot water ~45 °C for ~20 min; remove tentacles. Don't: vinegar — it is not indicated for Physalia.
License: CC0. Never eat a pufferfish. There is no safe preparation method and no home antidote.
Sea & ShoreGreen spotted puffer (Tetraodon nigroviridis)Hazard: tetrodotoxin in the skin and organs. Do: do not eat or handle it raw. Don't: prepare, cook or eat any pufferfish — cooking does not reliably destroy the toxin.
“"Serpiente marina de hocico ancho (Laticauda colubrina), Anilao, Filipinas, 2023-08-23, DD 04.jpg"” by Diego Delso — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Sea snakes are not aggressive — they bite when grabbed or netted. Most of them cannot harm a swimmer.
Sea & ShoreBanded sea krait (Laticauda colubrina)Hazard: neurotoxic venom, but bites are rare and usually follow handling. Do: never touch; if bitten, wash and seek medical care. Don't: handle or corner a sea snake.
“"Blue Spotted Ribbontail Ray, Pulau Perhentian, Malaysia (4011471612).jpg"” by yeowatzup — CC BY 2.0 · Wikimedia Commons
License: CC BY 2.0. Bury in hot water for 30–90 minutes to neutralise the venom. Tetanus cover is also worth checking with your clinician.
Sea & ShoreBlue-spotted ribbontail ray (Taeniura lymma)Hazard: barbed tail spine — a deep puncture wound. Do: rinse, remove the spine, use hot water, seek care. Don't: stand on or provoke rays; do not dig for spines with bare hands.
“"Stonefish (Synanceia verrucosa) (6083207466).jpg"” by Bernard DUPONT from FRANCE — CC BY-SA 2.0 · Wikimedia Commons
License: CC BY-SA 2.0. The most venomous fish in shallow tropical water. It is nearly invisible when camouflaged — shuffle in murky shallows.
Sea & ShoreStonefish (Synanceia verrucosa)Hazard: venomous dorsal spines — excruciating pain and swelling. Do: immerse the wound in hot water, remove visible spines, seek care for systemic signs. Don't: walk barefoot on reef; do not cut or suck the wound.
“"Erizo diadema (Diadema setosum), parque nacional Ras Muhammad, Egipto, 2022-03-27, DD 143.jpg"” by Diego Delso — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Spines carry no venom, but they can carry bacteria and fragments that need medical removal.
Sea & ShoreLong-spined sea urchin (Diadema setosum)Hazard: long hollow spines — very painful, and fragments can break off in the wound. Do: soak in hot water, have spines removed, seek care if the wound is deep. Don't: step barefoot on reef flats.
“"Scolopendra subspinipes.jpg"” by Matt Reinbold — CC BY 2.0 · Wikimedia Commons
License: CC BY 2.0. Active at night in damp ground cover. Check boots, sandals and folded clothing before putting them on.
UndergrowthGiant centipede (Scolopendra subspinipes)Hazard: venomous forcipules — intense pain, swelling, and rarely tissue damage. Do: wash, use a cold compress, seek care if the tissue darkens or symptoms spread. Don't: handle it.
“"Naja-kaouthia-8956.jpg"” by LCPL RYAN T. LEDOUX, USMC — Public domain · Wikimedia Commons
License: Public domain. A spitting cobra species is also present in Thailand. Do not try to identify the species in the field — treat any elapid bite as an emergency.
UndergrowthMonocled cobra (Naja kaouthia)Hazard: elapid neurotoxin — descending paralysis. Do: stay calm and still, pressure-immobilise, get to hospital fast. Don't: run, panic, or try to catch it.
“"Sitting Asian elephant (Elephas maximus) bathing in Tad Lo river, Laos.jpg"” by Basile Morin — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Elephants move through the hills behind Phuket and cross roads at night. If one approaches, give it space and get behind solid cover.
UndergrowthAsian elephant (Elephas maximus)Hazard: trampling and goring, especially with calves. Do: give a very wide berth, back away slowly, never get between a cow and a calf. Don't: feed, touch, or block its path.
“"Ophiophagus-hannah-king cobra-kaeng-krachan-national-park.jpg"” by Rushenb — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Prefers forest edges and water courses in the hills behind Phuket. It avoids people unless cornered or defending eggs.
UndergrowthKing cobra (Ophiophagus hannah)Hazard: large quantity of neurotoxin in a bite. Do: retreat slowly, always leave it an escape route, call fire or wildlife services. Don't: approach, provoke or corner it.
“"Bungarus candidus, Blue krait - Cha-Am District (27480193626).jpg"” by Rushen — CC BY-SA 2.0 · Wikimedia Commons
License: CC BY-SA 2.0. A night-active, land-snake species often found near villages and in rubber and fruit plantations. Bites are frequently reported on the lower limbs at night.
UndergrowthMalayan krait (Bungarus candidus)Hazard: potent neurotoxin, and bites may be painless. Do: pressure-immobilise immediately, get to hospital fast. Don't: wait for symptoms; don't cut or suck the bite.
“"Tiger leech (Haemadipsa picta).jpg"” by Charles J. Sharp — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Attaches to ankles in wet forest. It is a nuisance rather than a danger, but the bite is a good entry point for infection.
UndergrowthTiger leech (Haemadipsa picta)Hazard: blood loss, wound infection, bites in wet jungle. Do: remove it, clean the bite, apply antiseptic, cover. Don't: tear it off if it is attached deeply — let it detach or use salt or heat.
“"Nycticebus coucang, Sunda slow loris - Kaeng Krachan National Park (25704660113).jpg"” by Rushen — CC BY-SA 2.0 · Wikimedia Commons
License: CC BY-SA 2.0. Protected under Thai and international law. Slow loris from the pet trade are a common illegal-trafficking target, and the animals are usually in poor condition.
UndergrowthSunda slow loris (Nycticebus coucang)Hazard: venomous bite from a gland in the elbow. Do: do not touch. Don't: capture, handle, or photograph it for money — it is illegal and the bite is venomous.
“"Macaca fascicularis Ao Nang 5.jpg"” by kallerna — CC BY-SA 3.0 · Wikimedia Commons
License: CC BY-SA 3.0. PEP is time-critical. A wound washed and assessed within hours is a very different situation from one assessed days later.
UndergrowthLong-tailed macaque (Macaca fascicularis)Hazard: bites and scratches — rabies and herpes B virus. Do: wash with soap and water for 15 minutes, cover the wound, get PEP assessment the same day. Don't: feed, threaten, or take food away.
“"Macaque Monkeys from Monkey Hill, Phuket, Thailand (45007232455).jpg"” by Mike's Birds from Riverside, CA, US — CC BY-SA 2.0 · Wikimedia Commons
License: CC BY-SA 2.0. A well-known viewpoint and a well-known risk point. Almost every macaque bite in Phuket traces back to a person who was carrying food.
UndergrowthMacaques at Monkey Hill, Phuket (habitat)Watch for: habituated troops that take food and bags. Do: keep food and bags closed, never carry food visibly. Don't: feed monkeys — it is illegal, it is how bites start, and it is what makes them dangerous.
“"Calloselasma rhodostoma, Malayan pit viper - Kaeng Krachan District, Phetchaburi (33670021633).jpg"” by Rushen — CC BY-SA 2.0 · Wikimedia Commons
License: CC BY-SA 2.0. The most common antivenom-treated snakebite in Thailand. Bites are often on the lower limbs, from stepping on a camouflaged snake.
UndergrowthMalayan pit viper (Calloselasma rhodostoma)Hazard: haemotoxic venom — swelling, coagulopathy, shock. Do: keep still, immobilise the limb at heart level, remove rings and watches, get to hospital for antivenom. Don't: cut, suck, tourniquet or apply ice.
“"Asian forest scorpion (Heterometrus spinifer), Entomica 2.jpg"” by Fungus Guy — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Large but not unusually venomous. The pain can be severe and last for hours; a cold compress helps more than people expect.
UndergrowthAsian forest scorpion (Heterometrus spinifer)Hazard: painful sting, rarely life-threatening. Do: wash, use a cold compress, seek care for severe pain or systemic signs. Don't: handle it.
“"Abrus precatorius seeds.jpg"” by Steve Hurst @ USDA-NRCS PLANTS Database — Public domain · Wikimedia Commons
License: Public domain. A common decorative bead plant in the tropics. The seeds are used in rosaries and jewellery — keep them away from small children.
Green & PoisonRosary pea (Abrus precatorius)Hazard: abrin — a chewed seed can be fatal. Do: never eat, keep away from children. Don't: chew the red-and-black seeds; whole seeds are far less dangerous than chewed ones.
“"Amanita phalloides 2011 G1.jpg"” by George Chernilevsky — Public domain · Wikimedia Commons
License: Public domain. Delayed symptoms are what make this deadly. People feel fine, then deteriorate overnight. Go to hospital on suspicion, not on symptoms.
Green & PoisonDeath cap (Amanita phalloides)Hazard: delayed hepatotoxicity, often 6–24 h and sometimes beyond 48 h. Do: go to hospital immediately, call 1367 / 1422, keep a sample, never wait for symptoms. Don't: rely on folk tests; don't cook it.
“"Cerbera odollam 07637.JPG"” by Vengolis — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Also called the sea mango. The toxin is a cardiac glycoside; there is no specific antidote and treatment is supportive.
Green & PoisonSuicide tree (Cerbera odollam)Hazard: cardiotoxic seeds — a single chewed seed can be fatal. Do: keep away from children, never eat the fruit. Don't: chew or handle the seeds.
“"Dieffenbachia seguine kz08.jpg"” by Krzysztof Ziarnek, Kenraiz — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. A common indoor and garden plant in Thailand. Swelling can compromise the airway — treat mouth irritation seriously.
Green & PoisonDumb cane (Dieffenbachia seguine)Hazard: insoluble calcium oxalate raphides — intense mouth and throat irritation, possible swelling. Do: rinse the mouth, seek care if breathing or swallowing is affected. Don't: let children chew the leaves.
“"Aedes aegypti CDC-Gathany.jpg"” by James Gathany — Public domain · Wikimedia Commons
License: Public domain. Public domain image from the CDC. Aedes aegypti bites during the day, unlike the malaria mosquito — morning and dusk are the risk window.
Islands & BodyYellow fever mosquito (Aedes aegypti)Hazard: dengue, chikungunya and Zika. Do: use repellent, cover up at dawn and dusk, clear standing water. Don't: take aspirin or ibuprofen if you have a fever until dengue is ruled out.
License: CC0. A reef signal rather than a personal hazard. It is included because the same heat stress drives the jellyfish and coral disease cycles documented in the Deep Dives.
Islands & BodyBleached coral (Porites lobata) (habitat)Watch for: bleaching is a sign of heat stress on the reef, and stressed reefs recover slowly. Do: treat it as an environmental warning, not a swimming rule. Don't: assume a bleached reef is safe to stand on.
“"Coral Reef in the Andaman Sea, Thailand.jpg"” by Nata Mostova — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Coral habitat is where most of the Phuket marine hazards live. Identification matters more than distance here.
Islands & BodyAndaman Sea coral reef (habitat)Watch for: stonefish, lionfish, urchins, strong currents and sudden drop-offs. Do: wear reef-safe footwear, keep to calm days, and never stand on coral. Don't: swim alone in a current.
“"Phuket, Thailand: Warning flag at Mai Khao Beach"” by CEphoto, Uwe Aranas — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. Systems vary slightly between beaches, so read the sign rather than the colour alone. Flags are the last word on a given morning.
Islands & BodyBeach warning flags, Mai Khao Beach (protocol)Do: obey the flag posted on the day. Red = do not enter. Yellow = caution. Purple = marine pests such as jellyfish. Don't: swim when red or purple is posted, whatever the water looks like.
“"Aerial Panorama of Naiharn Bay in Phuket - Thailand"” by Masksaver — CC BY-SA 4.0 · Wikimedia Commons
License: CC BY-SA 4.0. The south-west monsoon pushes a rip out past the headland. Lifeguards patrol in season — ask them where the channel is that day.
Islands & BodyNai Harn Bay, Phuket (habitat)Watch for: rip channels, boat traffic and a drop-off at the bay mouth. Do: swim at the guarded area, check the flags, go in with company. Don't: swim alone or during heavy rain.
“"Hyperbaric Chamber Used For Experimental Diving.jpg"” by Tim Sheerman-Chase — CC BY 4.0 · Wikimedia Commons
License: CC BY 4.0. Reference image only — not a photograph of a Phuket facility. This is a reference image of a hyperbaric chamber, not a photograph of a Phuket facility. Check current contact details before you need them.
ReferenceHyperbaric chamber (reference)Do: ask early for the nearest recompression facility. Phuket: Bangkok Hospital Phuket and SSS Hyperbaric Services Thailand. Don't: delay a diver with decompression symptoms while you look for a facility.
Sources & Notes
All images are from Wikimedia Commons with the license shown. Custom illustrations (box jelly/flags/first-aid matrix) are used where noted. This atlas is for identification/harm-reduction only — not a field key for foraging.
Disclaimer: This page is for practical harm-reduction and education only. It is not medical advice. Ossuary Atelier is not medical staff. Follow local authorities, lifeguards, and medical professionals.
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