November 15, 2018, 10:32:14 AM
 
*
Welcome, Guest. Please login or register.
Did you miss your activation email?
 
 
 
Total time logged in: 0 minutes.
 
   Home   Help Login Register  

     
 

A D V E R T I S E M E N T

Pages: [1]   Go Down
  Print  
Author Topic: Migration of Crabs  (Read 1083 times)
0 Members and 1 Guest are viewing this topic.
POINT TO POINT
Registered User

Offline Offline

Gender: Male
Posts: 4
Location: Baltimore




Ignore
« on: March 19, 2018, 12:10:40 PM »

I crab in the upper bay but always have thought about if the crabs that I am catching in the Northeast, or Bush river have crawled all the way up from the wintering grounds in Virginia or do they go into the harbor or main shipping channels in the deepwater to winter instead of going all the way down to Virginia?
Logged
jack1747
Lifetime Member
Global Moderator
*
Offline Offline

Gender: Male
Posts: 18502
Location: Virginias Eastern Shore - Pocomoke Sound


Crab'n is a way of life....


WWW
« Reply #1 on: March 19, 2018, 04:25:42 PM »

"After the females mate and migrate to spawning areas, they either remain there for the rest of their lives or move only short distances out to sea. In warmer months, males generally stay in low-salinity waters such as creeks, rivers, and upper estuaries. Research on blue crabs in the Chesapeake Bay indicated that females over-wintered at the mouth of the bay and spawned there in spring, whereas the migration of males was non-directional. Crabs bury themselves in mud in winter and emerge when temperatures rise in spring. The maximum age for most blue crabs in the Mid-Atlantic Region is three years; adults thus live an average of less than one year after reaching maturity."

Click on the little crab at the bottom of any page to open up a ton of info.
Logged

"Helping to Moderate the BCA since 2003"
SHELLFISH
Lifetime Member
*
Offline Offline

Gender: Male
Posts: 4730
Location: New Smyrna Beach, FL.


Formerly Bogman102




Ignore
« Reply #2 on: March 22, 2018, 12:49:59 PM »

Good info Jack. I have read several reports about Blue Crabs and learned some things I had never heard before!
1.  After a single mating a female may retain viable sperm for at least a year resulting in up to three separate spawnings.  
2.  The maximum age for a blue Crab is 8 years for a tagged male!
3.  In Florida where there is no or very short hibernation/brumation period and sexual maturity is reached in one year.
4.  The female will mate following her terminal molt; never to molt again.
5.  Evidently there is no predetermined growth in a Blue Crab and they will continue to grow.

I question #4 as I measured a soft female Blue Crab (CT) that was 9.25 inches meaning she was probably approximately 7.5 inches prior to her last molt! CT crabs have a long hibernation period and I do know how this might figure in to this female oddity. Also with question #4 I wonder if males continue to molt throughout their lives?

I have been searching for Blue Crab information from studies done on the species. There have been many short term studies performed but I have yet to find a definitive study that answers many of the questions I have regarding Blue Crab biology.  Very good papers  have been from the College of William & Mary was written by Curtis Newcomb (1945) Biology & Conservation of the Blue Crab, Gandy et al (2011) Review of the Biology and Population Dynamicsof the Blue Crab USFWS, Leffler (1996) Blue Crab Biology of Abundance in Maryland Marine Notes and Mazotti et al (2006) U. of Florida Blue Crab Biology. For such a money making fishery throughout its range I am surprised there are not a plethora of such studies!
« Last Edit: March 22, 2018, 02:48:22 PM by SHELLFISH » Logged

Retired in paradise!
jack1747
Lifetime Member
Global Moderator
*
Offline Offline

Gender: Male
Posts: 18502
Location: Virginias Eastern Shore - Pocomoke Sound


Crab'n is a way of life....


WWW
« Reply #3 on: March 22, 2018, 02:41:36 PM »

#1  When the BCA toured COMB they told us that they had documented "8" spawning from a single mating.
#4  Years ago RD and Joe Crabs documented a "Sook" shedding.   Not long after that I had a Sook that had spent her whole life in a fish tank shed.  She died during the shed due to hanging up.  Here is the pic of her.
Logged

"Helping to Moderate the BCA since 2003"
SHELLFISH
Lifetime Member
*
Offline Offline

Gender: Male
Posts: 4730
Location: New Smyrna Beach, FL.


Formerly Bogman102




Ignore
« Reply #4 on: March 22, 2018, 02:45:41 PM »

Very interesting Jack and thanks for the photo!
Molting is physically demanding and very stressful for a crab resulting in many mortalitys.
In the studies I read they reported this is one of the reasons females move to lower salinity water: for easier molting.
Logged

Retired in paradise!

A D V E R T I S E M E N T

POINT TO POINT
Registered User

Offline Offline

Gender: Male
Posts: 4
Location: Baltimore




Ignore
« Reply #5 on: March 22, 2018, 05:02:03 PM »

I was always told by the biologist, that females do not molt once they become a sook. Thanks for that story.
Logged
Redbone
Registered User

Offline Offline

Gender: Male
Posts: 123
Location: Pasadena




Ignore
« Reply #6 on: March 29, 2018, 10:43:15 AM »

That female wasn't fully mature you can tell by her points and the apron
Logged
Big Liar
Registered User

Offline Offline

Gender: Male
Posts: 666
Location: Cambridge





Ignore
« Reply #7 on: April 02, 2018, 01:47:52 PM »

That female wasn't fully mature you can tell by her points and the apron

Why?   Because she was not making a samwich.   Grin
Logged

Just one of the few bad apples that keeps wizzing in the MSSA's and TF's milk.  Not because I have violations (because I don't'), but because I'm catching the resources that they claim to own and have more rights to.

A D V E R T I S E M E N T


Pages: [1]   Go Up
  Print  
 
Jump to:  

 
 
Home
 
Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Simple Audio Video Embedder


Google visited last this page October 29, 2018, 10:27:52 PM
wordpress