Thumped By A Goliath Grouper

[MBH]

I dove a wreck just offshore of Destin, Fl yesterday. This wreck is home to THREE Goliaths. Two of them I'd estimate to be well over 250lbs and the third one is maybe 150ish. They didn't act the least bit agressive or territorial and actually all three seemed to be quite curious of this strange man in black.

Anyway, I had descended a couple of feet into a small hold and as I hovered there watching two of them I saw the other large one out of the corner of my eye. I did a slow and easy half helicopter turn to my left and just as I'd turned about 90 deg. WHUMP! I could actually feel the pressure wave hit my side and chest! I didn't know a Goliath could do that! It's hard to describe the sound, it was like a dull, booming, muffled thump, sound that I could actually feel.

The Grouper and I had a long "stare down" competition after that and I think we both called it a draw.

Anyone ever had this happen to them? How does a Goliath do that and what does it mean? Inquiring minds want to know.
Brent

 

[Hemlon]

It sounds like a territorial behavior.

 

[bvmjethead]

I'm not sure I understand exactly what the Goliath did...

Did he make a sound at you?

Did he actually charge you and run into you?

What made the thump?

 

[MBH]

I'm not sure I understand exactly what the Goliath did...

Did he make a sound at you?

Did he actually charge you and run into you?

What made the thump?

This was a noise that the Grouper made from about 3' away. He never touched.

 

[TwoBitTxn]

Its territorial behavior. It told you that you had invaded its space and you needed to go away.

I don't know how they do it. I have always heard it called booming or thumping.

TwoBit

 

[adurso]

The drumming is a warning, as mentioned it is a territorial thing. Spearfishermen often hear the booming before their catch is snagged.....I cannot remember the mechanism of the drumming off the top of my head

 

[diversteve]

Anyone ever had this happen to them? How does a Goliath do that and what does it mean? Inquiring minds want to know.
Brent

Don't think he was happy to see you...

This fish is solitary by nature, with the adults occupying limited home ranges. It is territorial near areas of refuge such as caves, wrecks, and ledges, displaying an open mouth and quivering body to intruders. Additional warning may be delivered in the form of the goliath grouper's ability to produce a distinctly audible rumbling sound generated by the muscular contraction of the swim bladder.

Florida Museum of Natural History Ichthyology Department: Goliath Grouper

 

[dumpsterDiver]

Anyone who has any experience diving on wrecks in the southern 2/3 of the Florida penninsula has probably felt it many times. It means they are pissed.

 

[CBulla]

If you get thumped, leave. Period. I've got a friend with a nice scar on his leg where he was sucked into the mouth of a big mama jamma who then shook him around like a rag doll for a few minutes before spitting him out sans right fin. Oh yeah, this big ole jewfish...er.. goliath now a days, gave a nice audible boom... boom.... he didn't leave.. boom... ragdoll!

Yeah, its funny now... but then!

 

[Missdirected]

If you get thumped, leave. Period. I've got a friend with a nice scar on his leg where he was sucked into the mouth of a big mama jamma who then shook him around like a rag doll for a few minutes before spitting him out sans right fin. Oh yeah, this big ole jewfish...er.. goliath now a days, gave a nice audible boom... boom.... he didn't leave.. boom... ragdoll!

Yeah, its funny now... but then!

Bulla, I was just going to say the same thing.

If they are "booming" u have upset them and it is time to go! Back down, leave the area, but go away. They can be quite dangerous.