Fish and decompression.

[DivetheRock]

This is perhaps a strange place to post this thread, but I felt it was somewhat relevant.
A friend of mine was working on a fishing vessel off Greenland last year. He told me that when the fish were brought up in the net, and quite quickly from depths to surface he added, often their innards had come out of their mouths, and their eyes popped out.
My question is, is this a form of decompression? Can fish get decompression?...How much would it cost for a fish to get recompressed in a hyperbaric chamber, and does DAN cover this? I couldn't resist!!!

 

[beautybelow]

It's more like an over expansion...they hold their breath.

 

[DivetheRock]

beautybelow, can you elaborate on "...they hold their breath"? What exactly does this mean? Why do fish hold their breath?
BTW, awesome, and I mean awesome pics you've taken. WOW!

 

[beautybelow]

well, it was actually a joke. thanks

 

[Midnight Star]

It sounds like one or two problems; gas in the intestinal tracts, swim bladder for bouyancy control, and behind the eyes (some diseases and/or parasites could cause this particular incidence), causing an "expansion" injury.

Alot of deep sea species are not only "sensitive" to pressure changes, but also water temperature and salinity.

-----

Mike.

 

[DivetheRock]

Geez...you actually had me there for a minute, beautybelow. I was trying to apply logic, and figure out why fish hold their breath upon ascent. See, overthinking - I was using OW No-Nos to explain fish behaviour (as in never hold your breath when ascending).

 

[DivetheRock]

...gas in the intestinal tracts, swim bladder for bouyancy control, and behind the eyes...

This sounds plausible.

 

[FishDiver]

This is perhaps a strange place to post this thread, but I felt it was somewhat relevant.
A friend of mine was working on a fishing vessel off Greenland last year. He told me that when the fish were brought up in the net, and quite quickly from depths to surface he added, often their innards had come out of their mouths, and their eyes popped out.
QUOTE]

Most fish have a swim bladder, a form of natural BCD. It is a membrane filled with air that the fish can gradually adjust to maintain neutral buoyancy at a range of depths. I don't recall the exact rate of adjustment and it probably varies between species. For freshwater black bass, they require something like 12 hours to make a 10 foot adjustment.

When a deep water species is caught and brought quickly to the surface, the gas in the swim bladder expands much more quickly than the fish can release it. The membranes are very elastic and distend rather than bursting, pushing whatever is in their way through the point of least resistance, often the fish's mouth.

 

[Cheekymonkey]

Yea dude, deep water fish can't all make it up, thats why when we bring up these super deep squid they are super swollen, They have gas in their blood just like us.

 

[Midnight Star]

I've seen deep sea species (on the net), brought up that didn't have those symptoms (like a giant squid that comes up from depth without "blowing itself apart"); being distorted or pop eyed. This leads me to believe they (one's having expansion deformities) are the exceptions, instead of the rule.

-----

Mike.