Swell Shark — Ain’t so Swell

 Order Carcharhiniformes — Cat Sharks—Family Scyliorhinidae

A swell shark from the Cayucos Pier

Species: Cephaloscyllium ventriosum (Garman, 1880); from the Greek words cephalo  (with a head) and scyllium  (like a dog or monster) and the Latin ventr  (referring to the belly).

Alternate Names: Catshark, puffer shark and balloon shark. Called tiburón inflado, pejegato globo or gato hinchado in Mexico.

Identification: Swell sharks have a broad flat head with a rounded snout, and sharp, pointed little teeth. Their first dorsal is back of the middle of body and directly above pelvic fins; second dorsal above anal fin. Their skin is rough and appears flabby while coloring is yellowish-brown to creamy, with black or brownish spots and saddles; sometimes with white spots. When caught, the swell shark may inflate its belly with air or water until its circumference nearly triples in size. However, young swell sharks are not able to duplicate this neat little trick. So see, sometimes it pays to be an adult.

Size: To a little over three feet in length.

Range:  Acapulco, Mexico and the Gulf of California to Monterey Bay; most common in southern California.

Habitat:  Usually found near kelp beds or rocky areas that contain some kelp; likes to spend the daytime hours holed up in crevices or caves. A nocturnal feeder, they emerge at night to search for food—mainly small fish. But they seem a little lazy. Although sometimes they suck other fish into their mouth (as would a normal feeding fish), some reportedly simply open their mouths and wait for the smaller fish to swim in. It’s called yawning and perhaps explains why swell sharks have less than an athletic looking body (afterall, how much energy can be expanded in yawning for your food?). The next question becomes how often do you think bait is going to swim into their mouths, especially dead bait? Perhaps this is one reason that they are not more commonly caught.

Piers: Rarely a common species although good numbers are reported from the Avila Pier, Port San Luis Pier, and the Cayucos Pier. Best Bets: Ocean Beach Pier, Green Pleasure Pier (Avalon), Hermosa Beach Pier, Santa Monica Pier, Goleta Pier, Gaviota Pier, Avila Pier, Port San Luis Pier and Cayucos Pier.

Shoreline: Occasionally taken by central California anglers fishing near kelp.

Boats: Rarely taken by boaters although kayakers who can fish fairly shallow waters and kelp beds catch a few.

Bait and Tackle: Most swell sharks that are caught from piers are around two feet in length, so medium tackle with a size 2 to 2/0 hook should work fine. Small fish, crabs, and shrimp, seem to be the best bait.

Food Value: It is reported that eating a swell shark is not so swell! The flesh is slightly toxic and causes stomach cramps and nausea as well as acting as a cheap aperient (result: diarrhea) and emetic (result: vomiting). Unless you’re really into the masochistic routine I would avoid puffer stew. Nevertheless, I can see all those sadistic little eyes lighting up. Wouldn’t it be cute to give Henry some puffer steaks for his dinner? Let’s see how long it is before he heads to the head. Dompfa Bro and a swell shark from Goleta Pier

Of course there’s always the story that’s told in the fascinating book Cod, by Mark Kurlansky. He mentions the unusual methods used by a people (Icelanders) seemingly on the verge of starvation: “They ate what the island produced, which was mainly every conceivable part of a cod-fish and a lamb. They roasted cod skin and kept cod bones until they had decomposed enough to be soft and edible. They also ate roasted sheeps’ heads, particularly praising the eyeballs. Another specialty was hákarl, the flesh of a huge Greenland shark, hunted for the commercial value of its liver oil. The flesh, which contains cyanic acid, a lethal poison, was rendered edible by leaving it buried in the groud until it rotted.” Apparently æstur hákarl (Icelandic for fermented shark) with its ammonia-rich smell and taste is still enjoyed by some of the locals.

Leaving aside this strange diet, and the question of how they discovered these enriching techniques, it makes you kind of wonder if a swell shark could be made edible by burying it in the ground for a few weeks. Anyone want to give rotted swell shark a try? Perhaps the “Iron Chefs” could do a show using æstur hákarl as the featured ingredient?

Swell sharks — Goleta Pier

Comments: An unpleasant and mistaken belief in some areas, especially the central coast, is that returning a swell shark to the ocean after capture ruins the fishing. It’s a rather stupid idea, and wrong, yet you’ll often find misshapen dying or dead swell sharks littering the piers. Since you don’t want to eat swellies (see above), and since they DO NOT hurt the fishing, please return them to the water.  Of course that may not be as easy as it sounds! A puffed up shark returned to the water may simply float away to be attacked by… whatever. Best is to net them and bring them to the top of the pier as quickly as possible. Then, as carefully as possible (since they do have sharp teeth), remove the hook. Try to then keep their mouth shut while returning them to the net and lowering them back down to the water. If successful, they will have gulped as little air as possible and still be able to swim away.

Dead, discarded young swell sharks at the Avila Pier—what a waste!

The issue of burping a swell shark became an interesting thread on the Pier Fishing In California Message Board.

Date: June 28, 2005
To: PFIC Message Board
From: pierhead
Subject: How do you ‘burp’ a swell shark …

Yesterday at Gaviota I observed a young man walking off the pier with a swell shark that he had just caught. I asked if he was going to keep it as they are not fit for food. He replied that he was going to release it closer to the shore. I reminded him that it was important to get it back in the water before it filled with air. Next thing I know he had dropped it in a trash can. I retrieved it but by then it had doubled in size. Remembering that EddieE had successfully burped them I thought I could do the same … no such luck … they have teeth and no way was I going to put my hand in there like Eddie did. I tried massaging it like burping a baby but that didn’t work either. Finally I held it over the rail by the tail and it expelled quite a lot of air … just as I dropped it (no net around) it gulped more air and swelled up again. As it floated away on its back I tried to enlist some nearby boaters to assist but by then it was too close to the breakers for them to approach.
I’m frustrated … any suggestions?

Posted by scooterfish

Maybe… I know someone had mentioned something about “pliers down the throat,” which sounded a bit primitive, but maybe the right tool, such as a smooth-ended tube (turkey baster without the bulb maybe?) would work…
ps- never even seen a swell shark in person, so this is purely conjecture…

Posted by eelmaster

Turkey Baster sound feasible. Squeeze the bulb first then insert and release the bulb? Worth a shot. Either that or Rolaids.
Monte, Support the UPSAC

Posted by pierhead

Here is what you are facing… tried to insert a small pole handle but the shark clamped down on it like a pit bull on steroids! Unless the mouth were propped open somehow it would cut through the turkey baster in no time at all. Don’t tell me we are going to have to construct some sort of dental tool just to start the procedure … there has got to be a better way. I considered the procedure used to deflate air bladders on rockfish … but I don’t think we are dealing with an air bladder here. Guess I’ll just have to do some research on swell shark anatomy.
Pierhead, Proud Supporter of UPSAC

Posted by malibooger

Several layperson’s-level websites describe the swell shark as sucking water or air into its stomach- since it can suck up water as well it seems the upper GI is probably where it is going. I haven’t hit the stores here yet, but when I used to hang out at the kitchen supply store on south Willamette St. in Eugene, OR, they had a selection of stainless-steel turkey basters. I always thought they were overkill until now- maybe you could find one of those. The websites mentioned above (just Google ‘swell shark’ and look for sites ending in .edu) say that the sharks will deflate themselves when they no longer feel threatened.
The real question is, what kind of a**hole tosses a live fish in a trash can?

Posted by pierhead

What kind of person would toss a… live fish in a trashcan? Me. When I was just starting to fish 50+ years ago it was common to leave your catch on the deck all day so passerby’s could oogle, gawk and offer congratulations. All sharks were immediately dispatched by multiple stabbings… the more the macho … sure to draw a crowd interested in your proficiency with a knife and fearlessness in combat with a “killer” shark. In my 30′s I returned from a day’s fishing off the barge at Redondo with a huge gunnysack of mackerel … which had rotted by the time I got home … they ended up in the garbage can as well. It wasn’t until after I first logged onto to this board (1997) that I started practicing consistent catch and release. And the truth is, there is still a bit of that attitude in all of us … thankfully through exposure here most of us have evolved to CPR (Catch, Photo, Release). Better to display your catch on PFIC than on the deck. After the advent of digital photography with it’s instant (and repeatable previews) the practice of CPR took off. Next to a net I think a camera is our most important accessory. I saw a young man catch his first fish this past weekend and he started to cry when his father insisted he put it back. I explained to him he gets more credit for releasing fish he isn’t going to eat than keeping them and offered to take his picture and email it. Seemed to satisfy him.

Posted by Salty Nick

Mouth-to-mouth resuscitation? Are they able to deflate themselves on their own, or is it necessary to “pop” them somehow? (I know nothing about them, being too far north to catch any). Salty.

Posted by pierhead

My experience is that they expel any water when you bring them up but if you handle them roughly on deck they will start gulping air. I’m thinking that inducing a ‘tonic state’ by putting it on its back might cause it to relax enough to burp … If it is put back swollen they flop over on their backs and can’t right themselves … and I don’t believe they can breathe either and so end up dead.

Posted by Seabass_Seeker

I’ve heard of them being burped, but as to the process I have no clue. Whenever we caught one at Goleta we just put it in the net full of air and let it swim away. Figured if the shark had a defense mechanism, which allows it to engulf air/water, it should have a natural way to expel the stuff.

Posted by cayucosjack

They will eventually expel the air. It’s just a matter of time but the problem comes on an incoming tide or big swells that push it onto the beach before it can deflate. The more you touch them and handle them the more they puff. The last 2 that I burped I used my boga grip. Just stick it down the throat a little and push the air out. You don’t have to get it all out. If the skin is somewhat lose they usually can swim away fine after a few moments. Sometimes all sorts of other stuff comes out especially if they had puffed up with water during the fight. Smaller ones I’ve been able to burp by pinching their throats a little so it stays open and pushing. Sounds cruel (especially pliers) but those little guys are tough and I’m sure they’d gladly deal with a sore throat over a beaching any day. I’ve caught about a dozen in the last few trips at Cayucos and haven’t had to burp one yet. It’s all about keeping stress levels low in the fish during the fight, landing and release. And I’ve officially debunked the theory that they release a toxin in the water that scares away other fish (I’ve been told this many times by old timers that try to make me throw my catch away or “at least release it way down there away from our poles”). There has been lots of other action each trip so there…

Posted by pierhead

Ahhh … that explains his trashing the fish…just before he dumped it he stopped to show it to several guys. Later those same guys told me swell sharks poisoned the water to keep other fish away. I bet they convinced him not to put it back. BTW … several articles I read this morning said the skin and flesh is toxic and can result in severe gastric distress if eaten. Perhaps that’s where the myth comes from.

Posted by kaveman

I catch at least one almost every trip to Goleta, I’ve tried massaging which sometimes works (one even burped out a smelt when I was massaging them). When that doesn’t I try something down the throat but sometimes they just wont burp, poor little fellas, hope this thread leads to a good consistent way to get rid of the air before they are released

Posted by gsxr750

Hold it up to your shoulder, with it’s head by your neck, and pat it on the back… oh, wait, that’s a baby… sorry

Posted by pierhead

Right … and babies don’t have teeth!

Posted by pierhead

Throw him over your shoulder. Pat on back… wipe off blood from neck. Continuing patting. Wipe off more blood. Hold compress tightly to neck to stop bleeding. Call paramedics.


Date: November 4, 2007

To: PFIC Message Board
From: yakattack

Subject: Goleta

Me and my son hit Goleta Friday night, about 7:30 to midnight…   About 10:45 the college kids nailed a swell shark and thought it was a leopard; once it was identified it went back in (he wanted a leopard shark skin, something about class credit). From 11 to 11:15 another 5 swellies came over the rail (I got one too) but that was the extent of the shark action, and the crab trap yielded larger spiders but still nothing of real interest.  Saturday night, I showed up about 7pm, sans six year old and crab trap. The spanish mack were running heavy so I filled up a bucket with them, waiting for the other guys to start getting clicker runs before I switched over to shark fishing. Unfortunately, very little happened in the shark arena, with three more swellies coming over the rail… At about 10pm one of the gang brought a 4-foot soupfin to the surface but it was farmed while they were trying to gaff it. The company was good both nights, the bait was happenin’ but the shark were elsewhere.
Question: Rumor has it that the swellies are poisonous, also that once released, when they expel the air/water they use to blow up, they regurgitate a semipoisonous (definately noxious) mass of stuff which drives other fish away. I really would like clarification on the second point as sop on the pier right now is to kill the sharks, leaving them on the pier to die so they won’t affect the night’s fishing and I’d like to avoid this if possible, education is the key. When someone is feeling spry enough, we’ll walk the shark to the shallow water for release but that doesn’t happen very often.

Posted by Ken Jones

Release them gently back into the sea. They are not in any way noxious to the water and do not drive other fish away. It is true though that if you eat them the flesh will cause stomach cramps and nausea—to you. Unfortunately the belief you mention is an urban legend that refuses to die

Posted by yakattack

Thanks Ken, I had a feeling it might be something like that… I will endeavor to kill the myth re: the swellies and get them released back into the water when caught. I’m much more comfortable with that for lots of reasons, including the smell!


Date: February 28, 2009
To: Ken Jones
From: fishboy
Subject: Swell Sharks

Just saw your revised swell shark article. You mentioned that small swell sharks are not able to puff up like the adults. Was just wondering where you found this bit of information. My understanding from those working at the miniature UCSB aquarium/touch-tank is that even with newly hatched swell sharks under a foot long, gulping air is a problem. While I am not sure if they are able to gulp in enough air to create a distended stomach like the adults, it is something they try to avoid, and if one of the small swell sharks does gulp air, they need to burp it. Which leads me to another interesting thing that you may consider adding to your article. They prevent these small swell sharks from gulping air by holding their mouth closed when they are out of water. Because swell sharks are actually gulping air/water, holding their mouth shut prevents them from doing this. I have been using this technique fairly successfully with the swell sharks we catch off of Goleta Pier as well. After we pull a swell shark to the surface, we try to keep it in the water until we can get our crab net ready. As soon as we net the shark and pull it out of the water, we pull it up as fast as we can and grab the mouth and hold it shut. This gives us all the time we need to untangle the lines from the net and remove the shark. Then allow the mouth to open for only as long as we need to remove the hook, and then again lower it as fast as we can in the net to get it back under water. Before learning this trick, we had numerous incidents where released swell sharks had gulped so much air that they were unable to submerge themselves and were left floating belly up, but since learning this technique almost 100% of the swell sharks we release have been able to swim down to the bottom. Roy

Hi Roy,

In Probably More Than You Want To Know About The Fishes Of The Pacific Coast, Milton Love says “Curiously, small swell sharks, which you would think would benefit from the ability, don’t seem to be able to puff up.” That’s my source on the info but I find your note of great interest.

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