Sea Snake Sightings or Worm Eels?

February 29, 2016 | Posted in: Bony fishes

Wendy White, the Coordinator for the Normanville Natural Resource Centre, recently sent the following email enquiry to David Muirhead regarding a suspected sea snake sighting (try saying that last bit quickly): –

“Hi David, a local resident came into the centre today asking about a ‘snake’ that she found on the beach at Normanville South. She found it being washed up, it was about 30 cm long and a bit thicker than her finger with a yellow head and a pale whitish/pinkish body. She said she picked it up and put it back in the water where it swam off with its head out of the water. She is not sure if it is a snake, but said it looked like one. Any ideas?

Wendy White, Coordinator, Normanville Natural Resource Centre”

David replied as follows: –

“A tricky one, Wendy…

I’m aware you’ve had 15mm (+/-) rain at Normanville in last few days . . . . so there’s some chance it’s a true land snake such as a juvenile red-bellied black that got washed into the sea, and as they are good swimmers in context of terrestrial Aussie snakes perhaps it preferred staying in shallows till (with tidal help??) it chanced upon a safer beach/dunes/ideally estuarine exit point with less predation risk as it desperately tries to find cover after slithering up an open white sandy beach.

More likely, I think, . . . . that it was a distressed/weakened short-headed worm-eel which is a true marine eel, common, but not often seen by fishers though also known to them as knot-tying eel (does itself into real knots if caught on hook at night) but if it was this critter the head out of water pose would be from ailment, not a normal behaviour.

Finally, we do occasionally see vagrant tropical true sea snakes in SA and I can’t exclude those, especially with global warming!”

I told David that I wasn’t even aware that we occasionally see vagrant tropical true sea snakes in SA. His reply was, “I’ve not seen any but I’ve read of this occurring more than once over time, and my initial scepticism was, if I recall correctly, refuted by at least one expert’s comments quoted in media, agreeing it was factual, with at least one case backed up by a herpetologist’s specimen ID, not just via witness reports. But I’ve not googled it ,ever!”

According to Wikipedia, “The long-finned worm eel or short-headed worm eel, Scolecenchelys breviceps, is a snake eel of the genus Scolecenchelys, found in southern Australia between Rottnest Island and Tasmania, and around New Zealand, to depths of about 50 m, on sandy or muddy bottoms. Its length is between 40 and 60 cm.”

It goes on to say, “The Long-finned worm eel is a Maori traditional delicacy, and is skinned and dried mainly outdoors for a period not exceeding longer than 3 months. The eel is not dangerous to humans, but can pack a fight in the sense of it feeling threatened, where it will nip the person or other mammal as a sense of protection. These eels are also very difficult to handle by hand and can be without water for up to 6 or more hours. The Long-finned worm eel is nocturnal, venturing out at night to hunt for invertebrates.”

As reported in an article published in our November 2012 newsletter (No.397) titled “Sea Snakes in SA?”, Tim Brown had sent us an email enquiry following a strange sighting at Glenelg: –

“Subject: Eel or Snake?

G’day, I dived the Glenelg Tyre Reef this morning (22 September 2012) and was extremely

surprised to come across what looked very much like a snake on the bottom (at about

18m). It was poking around into rock crevices like I’ve seen banded sea snakes do in the

tropics.

After I swam over it, it had a go at my leg. That took me by surprise, I can tell you!

Maybe 70cm long,

Olive green with a thin yellow stripe the length of its back,

No observable fin along its body (i.e. like an eel),

No flattened-looking tail like an eel,

Tail tapered just like a snake with no fin,

Skin like an eel, unless scales were very fine but I don’t think so,

Eyes and head more like a fish than snake,

Wide mouth like a bottom-dwelling fish.

I have searched the Net and found nothing like it – certainly, nothing like it in SA.

I’ve seen a lot of moray eels and they are characterized by long low fins that end in a flat

(i.e. broad fin) tail.

They also tend to have noses. This one had nothing like this.

Can you offer any thoughts on what this creature might be?

Cheers, Tim, Adelaide University Scuba Club”

One of our replies to Tim was as follows: –

“Hi Tim, a sea snake would have obvious scales. An eel probably wouldn’t.

According to http://www.avru.org/general/general_seasnake.html , “some species (of sea

snake) are also found in the southern waters off Victoria, Tasmania and South Australia.”

And “Sea snakes are readily identified by their flattened tails and valvular nostrils. They are,

of course, excellent swimmers and divers, feeding on fish and eels.

“They shed their skins much more frequently than land snakes, as often as every two

weeks.

“The young are born alive at sea, except for those of the banded sea krait (Laticauda

colubrina), which comes ashore to lay its eggs.

“All sea snakes are venomous.”

I’m not aware of the occurrence of sea snakes here myself, but then I’ve never seen a turtle

or grey nurse shark here either.

I would have thought of an eel perhaps, except for the leg biting bit.

You should read the details at http://www.strikehook.com/forum/5-generalfishing/

3253-sea-snakes  which compares worm eels with sea snakes.

According to http://www.environment.gov.au/biodiversity/abrs/publications/fauna-ofaustralia/

pubs/volume2a/36-fauna-2a-squamata-hydrophiidae.pdf , “Hydrophiid sea

snakes have been recorded also from the colder waters of the southern oceans: from

northern Tasmania, Victoria and South Australia (Cogger 1975). These latter records are

presumed to be of individuals caught up in the strong summer Eastern Australian Current

which sweeps down the eastern coast from the warm waters of the Great Barrier Reef.

These individuals are unable to return to their feeding and breeding grounds, and

ultimately find themselves in waters which are lethally cold.”

Cheers, Steve Reynolds”

Another reply from one of our members was as follows: –

“Dear Tim et al, I think the most likely ID is Shorthead Worm Eel Scolecenchelys breviceps

(said to reach 60cm but your estimate @ 70cm could be correct, little is known of our eels),

and your excellent description of your eel-like critter is enough for me to put my money on

this ID as ‘almost a certainty’.

The only other two possibilities that I can offer (greatly helped by knowing this was quite a

big and aggro eel) are: Southern Conger (Conger verreauxi), and Serpent Eel (Ophisurus

serpens).

I’ve only ever seen one or two southern congers (and none for at least a decade now, even

perhaps 2+decades ago), and only two (both much smaller than yours so mine were true

juveniles, neither being more than about 20cm max., and probably more like 10-15cm)

shorthead worm eels.

I’ve never seen a serpent eel (as far as I know!) and having just read that they reach 2.5m,

not sure I want to!! (N.B: The SA state spearfishing record for southern conger was one that

was at least 2m long speared inside one of those caves at Second Valley-just south of the

isthmus, i.e. under mainland cliff-in about 1960, so they can be big . . . too, but seem to me

to be a declining species here, purely anecdotally, and possibly even ‘in peril’).

Despite my high confidence level with regard to yours being a shorthead worm eel,

obviously I can’t be certain, and do you have an UW camera?!

P.S. There’s a rather poor image of a baby shorthead worm eel (with just the ‘head and

shoulders’ poking out of sand) on MLSSA’s PI site, taken by me at night in a small sandy bottomed

pool in a large flat intertidal rocky reef platform somewhere between Streaky Bay

and Elliston. I’ve never taken any pics of the very few southern congers I saw . . .!!

P.P.S.: all the above mainly forage by night but I’ll bet all 3 spp. do it occasionally by day

also, just much less often.

Regards, David Muirhead”

David’s image (1298) was listed as Muraenichthys breviceps. According to FishBase, that name is a synonym of Scolecenchelys breviceps (so our records are being changed to show Scolecenchelys breviceps),

Here is David’s image of a Shorthead Worm Eel, Scolecenchelys breviceps: –

Worm eel2

Shorthead Worm Eel, Scolecenchelys breviceps

(Taken by David Muirhead – at night in a small sandy bottomed pool in a large

flat intertidal rocky reef platform somewhere between Streaky Bay and Elliston)

Tim’s response to our replies was as follows: –

“Thank you so much for your timely and very helpful responses.

The creature I saw wasn’t sufficiently ‘eel-like’ to be a Southern Shortfin Eel or a Southern

Conger. The head wasn’t sufficiently long and sharp for it to be a Serpent Eel.

Like David M, I shall be putting my money on it being a Shorthead Worm Eel; although, it

was a much darker green than I’ve seen in pictures and I could see no fin along its back.

The yellow stripe was quite distinctive.

Cheers, Tim”

Tim also sent the following reply: –

“G’day Steve, Current ID assessment is Shorthead Worm Eel. Thanks to you and the others

from MLSSA who responded in such a timely and helpful manner.

Cheers, Tim”

Our February 2013 newsletter (No.398) included a follow up article titled “More on “Sea Snakes in SA”. It explained that the very same month that our November 2012 newsletter discussed the suggestion of sea snake sightings in South Australia, there was an Advertiser report about a sea snake capture at Brighton jetty in SA.

“Deadly sea snake caught off Brighton Jetty in Adelaide’s south

A snake fished from the water at Brighton Jetty last night was probably a Yellow-bellied sea snake – a specimen 10 times more venomous than a King Brown, an expert says.

The snake was caught by Panorama man Bob Ridge, who had been fishing for whiting, about 9.15pm, drawing a crowd of onlookers.

Mr Ridge, 61, said the snake appeared to be “more than a metre long” and was the last thing he expected to land after feeling a niggle on his line.

`I’ve been fishing all my life and I never even knew they were in our waters, let alone caught one before.”

Australian Venom Research Unit director Dr Ken Winkel said he thought the sea snake caught by Mr Ridge was probably a Yellow-bellied sea snake.

“Yellow-bellied sea snakes are not very common but they do occur in SA and Victorian waters,” Dr Winkel said.

The sea snakes were very distinct in the colouration and had a paddle-shaped tail.

He said it would be very unusual for a tropical sea snake to be found here.

Yellow –bellies were mainly found off-shore and rarely sighted close to shore or caught from jetties, he said.

Dr Winkel said it was very rare to be bitten by a Yellow-bellied sea snake but its bite was lethal.

“The (venom) is more toxic than a King Brown snake.

“Along with other sea snakes it has a ten-fold higher toxicity than the King Brown.”

“It probably happens once in a blue moon being probably one of the most uncommon snake bites in Australia.”

While it was very uncommon for Yellow-bellied sea snakes to cause trouble, there was a risk of getting poisoned, he said.

“Sea snake venom contains toxins that affect the nerves,” Dr Winkel said.

“If not treated it can progress to causing weakness in breathing muscles, which can kill you.”

Mr Ridge said he kept a safe distance, holding his fishing rod over the side of the jetty,  cutting the line to let the snake go free.”

(Source: http://www.adelaidenow.com.au/news/south-australia/deadly-sea-snake-caught-off-brighton-jetty-in-adelaides-south/story-e6frea83-1226516760978)

I asked David Muirhead to discuss the matter with The Advertiser. Following some phone calls to the ‘Tiser, he resorted to drafting the following letter to the editor of the newspaper: –

“Dear Editor,

May I comment briefly on sea snakes in SA waters?

I’m sure Dr Winkel is right in stating true sea snakes occasionally enter SA waters.

But the creature hooked off Brighton Jetty by Bob Ridge at night will certainly have been one of our several larger eel species, not a reptile.

Our eels (e.g. the shortheaded worm eel) can look remarkably similar to sea snakes, are common night bottom feeders in SA’s inshore waters, and unlike sea snakes have mouths large enough to take a hook.

However, I write this mainly to remind all fishers of a seemingly obvious but very important ’take-home message’: Bob’s discretion in cutting the eel free was the only sensible response where there is even slight uncertainty re the correct identification of any and all possibly dangerous hooked critters.

The eels to which I refer can still give a nasty bite, and for several species there exist reliable records of aggressive behaviour towards recreational SCUBA divers who inadvertently disturb them.

Because we know so little about our local marine life(except the tiny percentage of species targeted by commercial and recreational fishers alike) the incidence of similarly risky ‘dodgy hook-ups’ faced by fishers in SA is actually surprisingly high, in my largely anecdotal experience over 5 decades in this my home state.

Yours Sincerely, David Muirhead”

Many comments were added to the web page at

http://www.adelaidenow.com.au/news/south-australia/deadly-sea-snake-caught-off-brighton-jetty-in-adelaides-south/story-e6frea83-1226516760978, including this one (from Tim Brown?): – “I was diving the Glenelg tyre reef a couple of months ago and something green and very, very snake-like had a go at me. After much research and consultation of experts, the confident consensus was that it was a Shortheaded Worm Eel (green, not much eel-like fin, round like a snake, but a largish mouth). The rather blurry picture accompanying the article is consistent with this type of eel.”

I added my own comments about witnessing a fisherman catching a Shortheaded Worm Eel at the Screwpile Jetty on Granite Island at Victor Harbor years ago.  I also added as many of David Muirhead’s comments as I could from his letter to the editor at The Advertiser. (A restriction on the number of words that could be used meant that I had to leave large sections of his comments out.)

I first wrote about short-headed worm eels in our February 1983 newsletter (No.69). I had been diving at the Screwpile Jetty at Granite Island, Victor Harbor in November 1982 when I came across one. It was over 400mm long. I had difficulty netting it for my aquarium. It always managed to slip away with a little help from the silty sea bed which was easily stirred up. A fisherman on the jetty ended up catching the eel on his hook and line. It had taken his squid bait and swallowed the hook. The eel tied itself up in a tight knot around the line. The fisherman wanted me to help him to take it off of the hook which was protruding through the side of the eel’s mouth. We very carefully untangled the eel and reluctantly cut the eye of the hook off. The eel swallowed the hook before we could pull it through the side of its mouth. I took the eel home to see if it would survive in my aquarium after swallowing the hook. I hardly ever saw it in the aquarium though. I even went nine weeks without seeing it at all, so I thought that it had died. One night I saw the eel swimming about at the front of the aquarium glass (whilst the aquarium light was off). I deduced that the eel was a nocturnal feeder and that it would only come out from under the rocks when the house was in total darkness.

I wrote at the time that according to “The Marine and Freshwater Fishes of South Australia”, short-headed worm eels grow to a length of 560mm and are quite common in South Australia. They are frequently mistaken for sea snakes (which I stated dis not occur in SA waters, only in tropical waters).

I later found out that the eel was burying itself in the gravel bottom in the aquarium. It would only come out during darkness at first but, after some 11 weeks or more, it would come out whenever there was some food placed in the aquarium. It survived for almost one year and grew an extra 5omm, reaching about 460mm in length. We grew quite fond of the eel and we were upset to find it dead on our lounge room floor one day. It had apparently managed to jump out of the aquarium through a gap in the cover glass whilst we had a protein skimmer operating.

Back then, I referred to short-headed worm eels as having the scientific name of Muraenichthys breviceps. This has now changed to Scolecenchelys breviceps.

Steve Reynolds is the current President of MLSSA and is a long-standing member of the Society. Steve is a keen diver, underwater explorer, photographer and is chief author of the Society's extensive back catalogue of newsletters and journals.

1 Comment

  1. Steve Reynolds
    March 13, 2016

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    According to the web page found at http://www.themercury.com.au/lifestyle/warmer-waters-makes-tassie-a-hotspot-for-new-fishy-friends/news-story/b8e42dbad2c1231e273782e6f75eeac5 , two venomous yellow-bellied sea snakes have been discovered on the east coast of Tasmania, having made a marathon swim from their usual range in tropical northern waters.

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