SRC & Crabs

Stonefish

Triploid, Humpy & Seaplane Hater....Know Grizzler
I hit the canal today.
Fishing was tough due to the bright sunshine and stiff NE wind. Lots of whitecaps.

I encountered something early in the day before the wind came up.
There were lots of 1/2" or slightly larger dead crabs floating on the surface.
I saw several rather aggressive swirls in the area before the wind came up.

I had one of the crabs in my basket to take a picture of it, but my line must have pull it out of the basket. The crabs were all a pale peach color by the way.

I'm sure searuns feed on crab larva.
Has anyone witness them feeding on small crabs or had a cutt spit up a crab as they were landing it? They looked like a possible food source.
SF
 

Nick Clayton

Well-Known Member
WFF Supporter
Way to brave the elements, Brian. You were a bigger man than I. I woke up, went outside and drank a cup of coffee on the porch. The wind was whipping! I debated headin out for a while, but finally wused out. stayed home, worked on the boat, and tied flies.

Interesting about the crabs. Never seen anything like that down here.
 

Stonefish

Triploid, Humpy & Seaplane Hater....Know Grizzler
Didn't look like sheds to me.
It seems they would be larger then what I was seeing before they molt for the first time, but I'm no crab expert.
SF
 

Scott Salzer

previously micro brew
WFF Supporter
Crabs do molt, are your sure they weren't molting? Big /small, they out grow their hard shells.

MB
 

chrome/22

For him there whould always be the riddle of steel
Crab shells are excellent source of fiber for those SRC looking to bulk up
 
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Stonefish

Triploid, Humpy & Seaplane Hater....Know Grizzler
Scott,
Like I said, I'm no crab expert and I'm aware crabs molt.
Maybe someone with better knowledge of crab life cycles can chime in.
Do 1/2" crabs molt or how large are our local crabs before they molt for the first time?
I've seen lots of molts in the past on beaches, but they were larger crabs.
What I saw today didn't look like molts. I didn't really closely examine the one I threw in my basket. I was to busy trying to keep my hat on and not impaling myself with a clouser due to the wind.
This was the same beach I encounted the marine worm spawn on last year.
SF
 

cabezon

Sculpin Enterprises
WFF Supporter
Hi SF,
Crabs molt very frequently when they are small. In order to grow, they have to molt because they have outgrown their existing exoskeleton. For a brief time after molting, they take on some extra water so that when the exoskeleton hardens, they have some scope for growth. Its kind of like buying clothes that would fit a six-year old for a five-year old; you know that they will be there soon enough. For small crabs, molting probably takes place every few weeks or months.

Adult crabs molt once a year, generally in the spring. Males guard females that are about to molt because it is when the females have molted that they are receptive to males.

Also, live or dead crabs don't float, but the molted shells of crabs that have filled with air at low tide would float. And I believe that we have been having some big spring tides recently.

Steve
 
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Nick Clayton

Well-Known Member
WFF Supporter
Not related, but I watched Ira fillet a flounder last year that was stuffed full of little tiny crabs. We talked of tying a small crab fly and fishing a lightweight rod for flounder.

I know most of what I know about what the fish I fish for eat by having gone thru their stomach contents. Ive never done so with a src so I really wouldn't know....But it sure seems logical that they wouldnt pass up an easy meal. Seems a pretty common trait among saltwater species.... Never pass up a free meal.

I think thats part of why I love fishing the salt around here so much. Screw fish that are picky about what they eat! ;)
 

Stonefish

Triploid, Humpy & Seaplane Hater....Know Grizzler
Thanks to everyone for the info. It is always good to learn something new regarding the canal and sound.
I wasn't aware that crabs that small could molt. Based on their color and size, they looked like they would be an easy food source for searuns.

Don,
Probably should have used the word assume versus sure. Since I've caught cutts and resident coho in the same area and coho eat crab larva, I'd think cutts would as well but don't really know for sure.
SF
 

Jim Ficklin

Genuine Montana Fossil
At first I thought maybe this had something to do with a beach encounter involving risqué sea loins while on an outing for SRC . . .
 

cabezon

Sculpin Enterprises
WFF Supporter
I am sure that trout feed on crabs in their "megalops" stage of life, when thy have yet to develop a shell. And it is likely that they would feed on molted crabs when they are exposed.

http://www.microscopyu.com/staticgallery/smz1500/megalopsofcrab.html
Hi Bob,
All crustaceans have a shell (exoskeleton) throughout their life (albeit soft when molting). The zoea have spines which make them harder for fish predators swallow (mechanical defense); I have watched juvenile rockfish eat a zoea but then have to cough them out because hte spine made the zoea too big a meal.

Individuals in both the zoeal and megalops larval stages form aggregations which appear to be a defense against predators. I have seen similar 2-dimensional aggregations of cryptically-pigmented, newly-settled Cancer magister on sand patches off the west side of San Juan Island.

Megalops and newly-settled juveniles are swallowed whole by fish predators. Digestive enzymes can break down the contents of the crab in the stomach/intestine and the exoskeleton is excreted, largely intact.

Tom Carefoot, retired UBC marine biologist, has developed a very cool web site which summarizes many studies of local marine invertebrates; you can see the section on crab recruitment here: http://www.asnailsodyssey.com/LEARNABOUT/CRAB/crabSett.php.
Steve
 

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