Harlequin shrimp sex ID?

[colourmop]

i've read many FAQs about harlequin shrimp and how to determind their gender, but none of them have a very clear picture. so if anyone know about harlequin shrimp, could you check for me if the larger one in the picture is a female? note the plate near it's butt have this redish dot on it, while the smaller one dont have it.
p.s. the big 1 being a bully, they use to live together fine :\

[Travis L. Stevens]

I would guess sexing them is similar to lobsters. There are a few distinguishing features on the underside of the male and females, just like crabs. Essentially, the female is usually built to carry more eggs.


Notice the large ventral vent area and the large "flaps" that help carry the eggs.

***DISCLAIMER***: I do NOT actually know how to sex Harlequin Shrimp, but it's an educated guess.

BTW, Nice Hymenocera elegans

[dc]

I can't remember which is which, but I believe one's plates are kind of irredescent, and the other's are solid. Let me see if I can find the info.

[Travis L. Stevens]

Originally posted by dc
I can't remember which is which, but I believe one's plates are kind of irredescent, and the other's are solid. Let me see if I can find the info.

What do you mean by "plates"?

[dc]

http://archive.reefcentral.com/forum...mp#post4236243

Here's the page I was looking for.
http://www.sihawaii.com/sydkraul/harly.html

[dc]

Originally posted by Travis L. Stevens
What do you mean by "plates"?

Same thing colourmop was. You need a closer look, but they may both be females.

[SDguy]

If they are not getting along, they are probably both the same sex.

[Travis L. Stevens]

Interesting. Does that go for both H. elegans and H. picta?

[colourmop]

wwell, they were together when i got them. after 2 days the small one went into a cave and the big 1 took another cave. now they are separate :x

[dc]

I have no idea Travis. I know when I had mine, they seemed to get along for a short time, then the larger one just ripped off the paddle of the smaller one. I had to separate them. They were both females.

[colourmop]

hmm thats bad if i got 2 females, hope they wont fight :x

[spawner]

The big one is a female, the smaller one looks like a smaller female, but could be male. These shrimp pair bond very quickly, if you put a male with a female you will get a pair and the male will never leave the female. The intrapair distance will not be fore than a few inches. Females will fight to the death with each other.

The best way to check the sex is to look at the abdomone (tail) of the shrimp. Females are much wider than the males. Of course if you have a large shrimp and a tiny shrimp you'll have trouble.

If I was purchasing two shrimps (I buy 6 when I get new broodstock) I would only buy larger ones (1.5" or larger) and put them together at the LFS prior to purchase in an empty 20 gallon tank. Watch them over several hours, go eat lunch or dinner. When you come back if the two shrimp in a 20 gallon tank are more than a few inches apart, you don't have a pair, most likely same sexes. If they are glued together, take a net or PVC rod, glass cleaner, put that between the larger and smaller shrimp and move the "female" away from the smaller shrimp. If they smaller shrimp always follows the one your a pushing away you'll get a pair.

Some times two females will find each other when you do this and will be agressive and look like a pair but will really be fighting. I have never seen two females follow each other around when you push the larger one around the tank.

Good luck.

[SDguy]

So I'm resurrecting this thread because I recently lost one shrimp of my pair of H. elegans. I'd like to replace it. I've been reading the info, and several places mention this colored vs. clear "scales" or flaps on the abdomen, for female vs male respectively. My pair were VERY tight, but the flaps on both were colored white/blue. The shapes of the flaps was quite different, but not the color. Furthermore, I have yet to see a picture of these clear flaps anywhere on the net. Why is that?

Here's what I think. This is an example of one sex, I believe male:


Notice the small flaps extending down from the abdomen. They don't overlap or even touch.

My surviving "bulky" shrimp has touching, almost overlapping large flaps, like the one at top in this pic:



Actaully, here's an even better pic of what I'm talkling about:

What do you all think?

[Travis L. Stevens]

SDguy, I agree with you. I believe that the morphology between the male and female's "flaps" are different for the purposes of carrying eggs. Once again, it's just my opinion like the first post I made in this thread.

[SDguy]

I'm talking about the side flaps extending down from the abdomen, not the swimmerettes.

[spawner]

You are correct, with your sexes. The females have wider abdomens for carring eggs. There is also coloration differences between the sexes.

andy

[Travis L. Stevens]

Originally posted by SDguy
I'm talking about the side flaps extending down from the abdomen, not the swimmerettes.

I was implying both the flaps and the swimmerettes, but I was a little unclear. Sorry

[SDguy]

Thought I would add to this thread rather than start a new one. I lost what I believed to be my male harlequin several months ago for unknow reasons. Like he was ready to shed, but never formed a new shell underneath. It was overall a pretty gross situation/death.

Anyways, the female meanwhile has gotten HUGE! Well, the LFS had a tiny pair, and going by those flaps as I mentioned above, I bought what appeared to me to be the male. Well, he found the female, and they are happily (overlapping claws) munching on a CC star togther. So looks like I picked right. Time will tell.