size of females

[rcleary35]

When I crab, I never keep any females.  A couple of years ago somebody working at a marina I goto told me that it is ok to keep females that are over 6.5 inches because by the time they get to that size they are too old to produce eggs.  Is there any truth to this?

[Mr. Breeze]

The size of a mature female, or sook has absolutely nothing to do with age.  Just as some people the same age are taller than others, some crabs are bigger than others.  There is a wealth of info on this site, just scroll down to the bottom of this or any page and click on the small blue crab symbol in the center of the bottom border.

Here are a couple of links about mating and spawning.
http://www.bluecrab.info/mating.html

http://www.bluecrab.info/spawning.html

Studies done by Duke University for the North Carolina Sea Grant Program have shown that some mature females will hold sperm and set up to eight sponges during the season that they spawn.  The same studies show that the larger females, while producing more eggs per sponge set, do so less often than the smaller females.  Given the many enviromental requirements necessary for a successful recruitment of juvenile crabs to the population, it would be beneficial to have sooks set more sponges thru out the season, thereby increasing the chances of a successful recruitment, than to have an animal set one or two sponges, thereby limiting the chances for good spawning.

So.........If you feel you must harvest females, take the larger ones and let the smaller ones swim to have lots of babies.  But evey time you put a sook in a basket, think that you are preventing millions of eggs from being released 

PS  I have the links to those Duke studies, should anyone want to see them, but they are somewhere on this computer and I'm too lazy to look for them.  If you want to see them, I'll try to find them tonight.















































 

[jack1747]

"PS  I have the links to those Duke studies, should anyone want to see them, but they are somewhere on this computer and I'm too lazy to look for them.  If you want to see them, I'll try to find them tonight."

I would like to have the links.  Not sure that I have read the ones you are refering to.. Thanks, Jack


PS:COMB has also documented 8 spawns.... 

[rcleary35]

still not getting a size or time frame when females will not produce eggs.  I don't want to take them, but if there is a size that is safe I'd like to know.  I've thrown back females that were almost 7 inches long, and want to know if it is ok to keep them.  thanks

[Mr. Breeze]

The problem here is that females incur what is called a terminal molt.  This is the last molt that the female crab will experience.  The terminal molt occurs at the age of maturity.  This is the molt where mating takes place, as the female's apron changes from 'V' shaped to a shape similar to the capital dome.   After this molt, the female will no longer devote any energy to growth, instead focusing on propagating the species.  so......Whatever size she is after that molt is the size she will remain until her death.   SIZE HAS NOTHING TO DO WITH WHETHER SHE IS DONE SETTING SPONGES.

[jefftoleft]

The problem here is that females incur what is called a terminal molt.  This is the last molt that the female crab will experience.  The terminal molt occurs at the age of maturity.  This is the molt where mating takes place, as the female's apron changes from 'V' shaped to a shape similar to the capital dome.   After this molt, the female will no longer devote any energy to growth, instead focusing on propagating the species.  so......Whatever size she is after that molt is the size she will remain until her death.   SIZE HAS NOTHING TO DO WITH WHETHER SHE IS DONE SETTING SPONGES.

So you should throw all females back as there is no way to tell if they are done spawning or not.

[Mr. Breeze]

So you should throw all females back as there is no way to tell if they are done spawning or not.

Well,  If they're black, heavy, dirty, and maybe have barnacles growing on the shell, it's probably a safe bet that she's spawned out.  Other than that, you are correct