The Stingrays of Hong Kong

I have just added a page about all the different species of ray that are found in Hong Kong. Here is a little preview on just the stingrays. Check out the full list of rays here.

The Stingrays of Hong Kong:

 

Round ribbontail Ray / Black-spotted stingray (Taeniura meyeni)

Round Ribbontail Ray (via WikiCommons)
Round Ribbontail Ray (via WikiCommons)
A bottom-dwelling inhabitant of lagoons, estuaries, and reefs, generally at a depth of 20–60 m (66–197 ft). Reaching 1.8 m (5.9 ft) across. Generally nocturnal, the round ribbontail ray can be solitary or gregarious, and is an active predator of small, benthic molluscs, crustaceans, and bony fishes. Although not aggressive, if provoked the round ribbontail ray will defend itself with its venomous tail spine. In Hong Kong, it is found mainly in the relatively clear southern and eastern waters, but it has also been found in the northern part of Lantau and in brackish water near the Pearl River estuary. It is also one of the species that has been found on Hong Kong’s artificial reefs. Check out Eric Keung’s spooky photo of a this stingray in Hong Kong waters.
Between July 2005 and June 2008 there were two cases of people being stung by stingrays in HK – fortunately with mild outcomes. The sting and its venom can cause bluish or greyish discoloration around the wound, disproportionate pain, muscle cramp, weakness, seizure, hypotension, cardiovascular toxicity, deep wounds and lacerations. In other words, stingrays are dangerous! Just watch from a distance and don’t touch!


Blue-Spotted Stingray (Neotrygon kuhlii)

Blue-Spotted Stingray, Papua New Guinea (via WikiCommons)
Blue-Spotted Stingray, Papua New Guinea (via WikiCommons)
The body is rhomboidal and green with blue spots with a maximum width estimated at 46.5 centimeters (18.3 in). The rays coloration is a warning for the highly poisonous barbs, thus few animals attempt to overpower this ray. In HK, they are more easily seen in summer in the shallow water along the coast, on coral reefs and in mangrove areas. Because of the venomous sting observers should not get too close or try to touch it!


Pale-edged stingray (Dasyatis zugei)

Pale-edged Stingray (via WikiCommons)
Pale-edged Stingray (via WikiCommons)
A bottom-dwelling ray most commonly found over sandy areas shallower than 100 m (330 ft) and in estuaries. It measures up to 29 cm (11 in) across, has a diamond-shaped pectoral fin disc, a long projecting snout, small eyes, and a whip-like tail. It is chocolate-brown above and white below and feeds mainly on small crustaceans and fishes. In HK it is mainly found in the western Pearl River estuary south of Lantau Island.

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How to Treat a Cyaena (Lion’s mane) Jellyfish Sting in HK

Ouch! It’s the time of year when HK waters are visited by jellyfish of the genus Cyaena also known as the lion’s mane. Although I have written a previous post about the lion’s mane, I realised that I gave no advice on treating stings from this jelly. As last weekend both my kids got stung, I have learnt a thing or two from the experience!

This image from About.com closely resembles what a typical Cyaena sting looks like.

Cyaena nozakii (Lion’s mane) at Star Ferry Pier in Central

Obviously much depends on where you get stung and how big an area of sting there is, but here is some basic advice on dealing with the stings:

– urinating on the sting is absolute nonsense (I knew that already). If anything the person urinating is only adding to the problem causing possible secondary infection! Lemon juice is also ineffective.

The widespread but misguided belief that urine will counteract jellyfish stings is perpetuated in this scene from the TV show “Friends” where Monica gets stung and her husband Chandler has to pee on her. Funny but not true.
– vinegar is only effective for some species e.g. the deadly box jelly (Chironex fleckeri). Jellyfish have been around for over 500 million years making different jellyfish groups as genetically different from each other as humans are from squid (appearances are deceiving). What works for one jellyfish type, does not necessarily work for others.

– the best thing to do is to rinse the sting with warm – preferably sterile – saline solution. If that’s not available use warm seawater, just make sure there are no more stinging tentacles in the water your using! Whatever you do, DO NOT RINSE WITH FRESHWATER OR BOTTLED WATER! This could shock the remaining stinging cells causing them to fire more venom and make things worse!

 

Salt water , NOT urine is the best thing to use for a sting.

– if rinsing with salt water is not feasible or ineffective at removing tentacles, use pliers, or even your finger pads (safe) or a credit card to remove the tentacles.

– young are more sensitive to stings and should be taken to a doctor or a hospital A&E department. Don’t take chances.

if the sting is on the face especially mouth, nose or eyes, or if you ingested any stinging tentacles, go to the hospital A&E as soon as possible! This is dangerous: swelling of the sting can cause breathing problems or eye damage. sting on the genitals (male or female) is also serious and needs medical attention. genital sting can cause urinary track blockages from swelling, which is dangerous! So no skinny-dipping or letting kids play naked  in the water – at least from March to September.

Try to avoid getting stung in the first place (duh!). Wear rash vests, wet suits or similar protection…your dermatologist will thank you, because you will be avoiding skin-cancer inducing sun burns. Be safe and have a good summer!