Backyard Aquaponics
A place to discuss aquaponics

i was of the understanding that marron hold onto their eggs until they hatch. have you been told otherwize by farmers?

No, I think you're right, I meant that the females are clutching very new eggs (or that is what I understood from the conversation) and if they are disturbed it means a lower survival rate for the littlies. In a dual sex pond it is impossible to harvest (by draining or trapping) only the males and leave the females be.

got ya.

did they mention why they felt the females berried so early this year?

i have been told that they can berry up to 3 times a year in some cases. perhaps this year will be one of those years?

the reason i ask is that my original marron (6 of them) all turned out to be males. i went back to the supplier to get a few females and they happed to have 2 berried females. i took them home and by the end of the week most of the eggs were dropped. i did a bit of research as i thought they may lay their eggs. turned out they don't, so looks like they got too stressed. obviously the females are quite sensitive to environmental changes during motherhood.

hopefully the females will adapt to my system and have a chance to berry up again before summer. if not i will constuct an indoor hatchery.

time will tell.

Bio, if the are anything like yabbies, then they'll start breeding with an increase in temp. For yabbies i think its about 24C. The earlier and the longer that the water temp is maintained at or above this, the more tmes they will berry in a season. Dissolved oxygen is very important for the devoping babies, you'll often see a yabbie mum perched with her tail open fanning the eggs

S77 - I was told by "the salesman" that Laserlite 2000 Clear would let the UV through. My only reason for not using it is the huge cost for the area I need to cover (36m2) You've also got to use their fittings.

Jaymie, it blocks 99.9% UV see link. I hate (some) salespeople

http://www.softwoods.com.au/roofing.htm ... YQodq2es7Q

Nice one Steve.

Thanks guys on the laserlite, not worth spending extra for UV shielding as its only for the plants. I'll just get clear plastic, as long as it is nice and strong.

He didn't mention but I suspect it is due to the change in temp over the recent weeks. Sounds silly, but for the first time this morning when I went outside I could smell spring in the air, if you know what I mean. The air was nice and warm despite it being 8AM there was not a drop of dew even on the shaded side of the house.

Lost a marron this morning, one of the smaller males. Found him at the back of the tank on his back, he still had both his claws but all of the legs on one side were ripped off, and there looked to be some damage to his underside and tail.

The tank that the death occurred in is home to one of the largest male marron and as soon as dusk arrives he is out of his hidey hole circling the tank and harassing the other marron. They are all shit scared of him and duck away as quick as they can, I hope they are managing to feed OK... Theres plenty of pvc pipe for them, at least as couple spare per tank. I will watch them again tonight, but if it continues I might end up fixing some wire on the leftmost tank and spread their numbers out a little more across all 4 tanks.

hey simmo have you got different size pipe in your tank to prevent canabilisation? i have just got some blueclaw and am keen to know if that helps
and do your babies get sucked up the sump?

should have read from the start first....

Nah Beeso, you've prolly read the thread now neways but they are all roughly the same size.... around the 150-200g mark.

I just finished rehoming and inspecting them, and I have come to the conclusion that I am an idiot.

I really don't know why I didn't spread them out more besides the fact that the pump was in the leftmost tank and the water level fluctuated so much in that tank. In hindsight (isn't it a wonderful thing) I should have realised that they would have appreciated more floor space to stretch out in rather than not having the water depth fluctuate so much.

I inspected all of the marron in the same tank as "Biffa", who already has one scalp under his belt. NONE of them had any claws left, and one of them had both of his large antennae nipped off as well.

I removed all of the defenseless marron and put them into the leftmost tank with lots of PVC hideouts, 3 Marron in all. I then checked all the other tanks and everything was reasonably good, only 1 other marron was missing a claw, all of others had a pair of guns. I found what seemed to be the largest male marron with a big shiny set of claws and put him into the tank with "Biffa" so it's just the pair of them in there.

I'll check on "Biffa" and "Lucky" tomorrow morning to see if there have been any arguments.

hey simmo,

sorry to hear about your loss.

i was wondering if you have any females in there with the males?

the reason i ask is that i believe the males become very aggressive around females.

perhaps you may need to have seperate tanks for both sexes.

btw did you cook up the dead male or didn't risk it?

Nope, all of the ones I removed to the left tank were males, but I did have two females out of the other ones I picked up today and inspected, so perhaps there is some pheromone or something in the water that he is picking up and making him aggressive. Pure speculation here on my part of course...

About eating him, that was the 1st thing my GF's dad asked . I didn't, cause I didn't think it was a good idea to eat something that is essentially carrion. Am I wrong here?

On my GF's dad, and another topic... He is absolutely mad for crustacea, and regularly dives for Western Rock Lobster off the coast of Perth, mainly around the back of Garden Island. I have been told that WRL is really a crayfish, but for marketing reasons in the US where "Crawfish" is a different, and most would say inferior eating specimen, they have decided to rename them WRL.

your right about the wrl actually being a crayfish. at least thats what us west aussies call them and thats what counts. some people think i'm mad when it comes to my hobbies but when i tell them i'm growing marron theyre all interested. funny how that works.

what stocking rate you looking at per m^2?