Help with gonodactylus chiragra

Moort82 · 05/02/2017, 03:46 PM

Hi, I rescued a chiragra from someone's tank around 5 years ago and its massively grown since then (a good 4" or so now) and shown excellent health. During the day or as the lights go out you can hear it thwacking hell out of its food, rock, den but lately its been quiet. I now notice that both its raptorial appendages have been lost. So I'm trying to work out why and was looking for ideas. Could it have been a bad moult? old age? it still actively feeds (used to offer a mmix of soft and hard foods like mussel/cockle in the shell to keep its armoury strong) and I've just been offering soft foods. I have heard clicking since but i'm surrounded by unwanted hitchhikers so have many pistols also in adjoining tanks.

TIA

Gonodactylus · 05/03/2017, 09:05 AM

When raptorial appendages are damaged, the only way they can be repaired is to remove them and regenerate new ones. To develop functional new ones thats 3 or 4 molts . This process will take 6 - 9 months.

There are several reasons stomatopods lose their raptorial appendages. They can become stuck during a molt, damaged due to excessive use, broken during a miss-hit, the muscles destroyed by a lack of oxygen, temperature extremes or toxic chemicals, etc.

The fact that both were lost suggests the problem was not simply a miss-hit. From what you've said, I think it likely that the animal was trying to modify its cavity by chipping away at it and broke through the cuticle of its raptorial appendages. When this happens, there is a good chance that the rapts will become stuck during the molt or to prevent this, the animal physically tears the appendages off (Stomatopods cannot autotomize appendages.).

Roy

Hadla · 05/03/2017, 09:13 AM

Hope it recovers well! Does yours hide from you or is it comfortable being seen? Lol my female only comes out and rushes around if something's wrong! Glad to know she can live for a few years

Moort82 · 05/04/2017, 05:35 AM

Thank you Dr Roy for the complete explanation. It looks a little odd in profile with the weaponry missing but I think I can see a couple of tiny ones there, so it's possible it may have already moulted once and started the process.

Moort82 · 05/04/2017, 05:40 AM

Quote:

Originally Posted by Hadla

Hope it recovers well! Does yours hide from you or is it comfortable being seen? Lol my female only comes out and rushes around if something's wrong! Glad to know she can live for a few years

Thank you. I wouldn't say it's the most interactive species I've seen but it does come out when my ugly mug is staring right at it. It happily takes food from me and will sit there seeing what I'm doing. It's in a natural light lit tank and is most active when it's dusk.

05/02/2017, 03:46 PM	#1
Moort82 Registered Member Join Date: Sep 2008 Location: Norfolk, England Posts: 1,576	Help with gonodactylus chiragra Hi, I rescued a chiragra from someone's tank around 5 years ago and its massively grown since then (a good 4" or so now) and shown excellent health. During the day or as the lights go out you can hear it thwacking hell out of its food, rock, den but lately its been quiet. I now notice that both its raptorial appendages have been lost. So I'm trying to work out why and was looking for ideas. Could it have been a bad moult? old age? it still actively feeds (used to offer a mmix of soft and hard foods like mussel/cockle in the shell to keep its armoury strong) and I've just been offering soft foods. I have heard clicking since but i'm surrounded by unwanted hitchhikers so have many pistols also in adjoining tanks. TIA

05/03/2017, 09:13 AM	#3
Hadla Mantis Whisperer Join Date: Dec 2014 Location: Sacramento, CA Posts: 574	Hope it recovers well! Does yours hide from you or is it comfortable being seen? Lol my female only comes out and rushes around if something's wrong! Glad to know she can live for a few years __________________ Aquarium count: 7 salt: 2x10g, 29 biocube, 30g, 55g, 75g, 225g, and one fresh 20g planted tank! Puffer, octopus, and mantis shrimp fanatic!

05/03/2017, 09:05 AM	#2
Gonodactylus Premium Member Join Date: Aug 2001 Location: Berkeley, CA, USA Posts: 5,024	When raptorial appendages are damaged, the only way they can be repaired is to remove them and regenerate new ones. To develop functional new ones thats 3 or 4 molts . This process will take 6 - 9 months. There are several reasons stomatopods lose their raptorial appendages. They can become stuck during a molt, damaged due to excessive use, broken during a miss-hit, the muscles destroyed by a lack of oxygen, temperature extremes or toxic chemicals, etc. The fact that both were lost suggests the problem was not simply a miss-hit. From what you've said, I think it likely that the animal was trying to modify its cavity by chipping away at it and broke through the cuticle of its raptorial appendages. When this happens, there is a good chance that the rapts will become stuck during the molt or to prevent this, the animal physically tears the appendages off (Stomatopods cannot autotomize appendages.). Roy

05/04/2017, 05:35 AM	#4
Moort82 Registered Member Join Date: Sep 2008 Location: Norfolk, England Posts: 1,576	Thank you Dr Roy for the complete explanation. It looks a little odd in profile with the weaponry missing but I think I can see a couple of tiny ones there, so it's possible it may have already moulted once and started the process.