Peacock Mating

[Gonodactylus]

I've been looking at how size effects mating success in stomatopods. These photos are instructive. Both matings involve the same 12 cm male who is sexually mature, but does not yet show all of his secondary sexual traits. (Uropod spines are not polarized.) In the first image he is mating with a 9 cm female. She is just becoming sexually mature, but has not yet developed ovaries or cement glands. She had never encountered a male. As soon as the male seized and mounted her and started courtship scratching, she settled down, exhibited some courtship and eventually mated. The second image shows sperm cords in both of her gonopores indicating that the copulation was successful.

The third image shows a very large 16 cm female mating with the same male. She showed no aggression and mated seconds after the male grasped her.

In most gonodactylids that I have studied, mating success depends to at least some extent on the male and female being size matched. This seems to be less the case in O. scyllarus.

Roy

 

[Islandoftiki]

Wow, so size really does matter.

Absolutely stunning photos and a particularly fascinating subject matter. Thank you for this amazing look into the more sensual side of stomatopods. They aren't just hammers and spears. They are so much more than that.

 

[Gundo5000]

Great photos, thanks for sharing I love Mantis shrimp photography!

 

[faariwasi]

"Shortcuts don't exist here, rush it, and there will be a shortcut to problems"

 

[Calappidae]

"Shortcuts don't exist here, rush it, and there will be a shortcut to problems"

???

 

[rishu_pepper]

Dr. Caldwell, a couple nights ago, my wife and I came home and saw our O. Scyllarus holding some pink jelly food. We were initially puzzled but soon realized it was an egg sack after Googling up some images. What a surprise! She ended up eating a bit of it and the damsels finished the bits she left behind.

I assume that's a normal behaviour (and not due to stress or anything unhealthy) for a O. Scyllarus? We've had her for two months now, regular feeding live clams, frozen shrimp, etc.

 

[Fartin'Gary]

They can carry sperm with them between molts so sometime before you got her she was frisky.

 

[Gonodactylus]

It is more likely that the eggs were unfertilized. Sperm are not carried through the molt. Generally, O. scyllarus females brood fertilized eggs, but eat unfertilized egg masses.

Roy

 

[rishu_pepper]

It is more likely that the eggs were unfertilized. Sperm are not carried through the molt. Generally, O. scyllarus females brood fertilized eggs, but eat unfertilized egg masses.

Roy

Good to know, Doc.

Will this egg business happen again?

 

[rishu_pepper]

Paging the doctor: My peacock has not been doing well since the egg sack episode. Last night I was doing a water change and she still hits the vacuum as usual, but for the last few hours she hasn't moved at her home at all. The wife even tried to move the LR near her and there was no response. Her antennae and eyes are barely showing any movement. She wouldn't eat either.

Water params are in check.

Should I fear the worst? Or is this something "normal" after the egg thing?

 

[rishu_pepper]

Short update: she's doing fine, back to normal behaviour. We've re-constructed her home which greatly reduced light inside (at the cost of our viewing pleasure), and she seems to be pretty happy.

Ammonia is still between 0.25 - 0.50 due to a spike probably caused by her eggs decomposing. Seachem prime has been dosed and tank mates have been doing fine. Hopefully the ammonia will get rid of itself soon.

 

[Fredericks]

Any updates on her?

 

[rishu_pepper]

Yeah she's doing fine and dandy. From now on we're gonna keep it on LED strip light only, so basically the tank (especially her burrow) is only lighted when we want to see her. The fish in there don't seem to mind. The corals are done for but she's more important.