Cyano, Inbreeding, Hybridisation Killing my pep larvae?

Cyano, Inbreeding, Hybridisation Killing my pep larvae?

Postby chris melb » Mon Sep 17, 2007 4:18 am

I have been able to breed peps before and raise them to post larvae, my last six attempts however have failed. I cant seem to get any maybe one or two to make it past first molt.

I use NSW (parent tank water), oxygenate larval tank with air bubbles, temp is 27c, and fed with NHBS.

Things i have tried

* decaped brine
* Sterlizing larval tank - bleach - drain - then a good rinse - dryout.
* fresh NSW instead of parent tank water
* fresh NSW treated with carbon (large amount of carbon was rinsed and placed in a cannister filter with a 200lph pump aimed to treat 10l of water)for 2 days prior to introducing larvae
* fresh NSW with microwave (10mins for 2litres) water and container itself was placed in the mircowave for sterilisation (full 10mins)
* using different broodstock

Arghh what else should i try, any suggestions, i also noticed that my tank which has one broodstock of peps has a bit of cynobacteria, but when using my second broodstock pair which is housed in a separate system has very little cyno at all, all peps died on the same second night.

One thing that i did do recently was place a couple of peps in my mysid tank, which has a litte xenia in it and also cyno, the water in there has not been changed in 3months, fed them the same NHBS and they nearly all survived.

Broodstock are fed, frozen fish, squid, CE etc. Larvae show good strong response to light on night of hatch. Actively eat NHBS, then the night i expect them to molt for the first time, they all lay their on the bottom, occassionally they flick and then fall back down.

Anyone experienced this?

Could the Cyno in the parent tank cause them all to die? if so why did the ones in the mysid tank survive?

My thoughts, the NSW that is collected may still have some toxins in it that my carbon was unable to remove after 2days (for those of you who dont know, dredging has started in the bay in Melbourne AU). Appreciate peoples thoughts, suggestions.

Thanks


Chris
Last edited by chris melb on Tue Oct 09, 2007 8:26 pm, edited 3 times in total.
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia

Postby Amie » Mon Sep 17, 2007 11:59 am

Are you enriching the BBS? I would get rid of the carbon step completely. You should concentrate on the food quality more than their water quality. I bet they would survive longer in their parent water without a water change than in the sterilized water. Also, how strong is the water movement? They shouldn't have to fight against a current.
User avatar
Amie
Moderator
 
Posts: 2029
Joined: Sat May 12, 2007 7:57 pm
Location: US
State/Region: Utah
Country: USA

Postby chris melb » Mon Sep 17, 2007 8:00 pm

HI Amie

thanks for your advice, im curious as to why you suggest not to use carbon.

The NHBS is what i have used in the past with good success, enriching brine IMO is not needed > in order to enrich, brine needs to advance to the second molt stage, and is thus nearly twice fast, early larval shrimp find it difficult to capture.

Im thinking its more a Cyano toxin thing, Kathy L on here has discussed this in the Larviculture forum. One thing im not currently doing is protein skimming in the broodstock tank. Im wondering if this could be the cause. Has anyone else noticed this?

My water flow is the same in previous attempts when i have had great success.
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia

Postby bawater » Tue Sep 18, 2007 12:21 am

Hi Chris,

Why not before the next batch - try skimming the broodstock tank.
This way you can use parent water & eliminated carbon use, or at least lower carbon usage to 1gram per liter.

It could help to narrow down the cause.
bawater
 
Posts: 20
Joined: Wed Apr 11, 2007 3:54 am
Location: Singapore

Postby chris melb » Tue Sep 18, 2007 12:47 am

Yes im off to buy a skimmer tonight, hopefully it helps, will update this thread with my findings. Still interested to know if anyone else has come across this.
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia

Postby KathyL » Tue Sep 18, 2007 7:49 am

Just to clarify, are you using Artificial Salt Water ASW, or water from the bay?
User avatar
KathyL
 
Posts: 3442
Joined: Wed Feb 28, 2007 12:13 am
Location: Missouri, USA

Postby chris melb » Tue Sep 18, 2007 8:02 am

Sorry Kathy my mistake NSW, i never use ASW ill edit my orginal post
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia

Re:

Postby spawner » Thu Sep 20, 2007 6:42 am

To be clear your talking about zoea not juv. shrimp???

chris melb wrote:Sorry Kathy my mistake NSW, i never use ASW ill edit my orginal post
User avatar
spawner
 
Posts: 1610
Joined: Mon Mar 05, 2007 8:28 am

Postby chris melb » Fri Sep 21, 2007 1:53 am

Yes im talking about Zoea maybe ill get one or two that make it to Z2, the night they are due to molt they lie on the bottom (some twitch) of the larval container and are dead by the next morning.
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia

Postby chris melb » Thu Sep 27, 2007 11:35 pm

Ok well i had a batch of peps hatch a couple of days ago, broodstock tank water was skimmed heavily for approx seven days prior to hatch, was a little bit of skimmate in the cup, today i noticed that some about 5-10% made it to Z2, so i guess i could suggest that the skimmer did help, as nothing else was done differently. Cyano is still present in broodstock tank though which could explain why only some made it to Z2. Im might have to eliminate the cyano completely and see what happens or move my shrimp carrying eggs into the larval rearing chamber (with fresh NSW) on the night of release. But so far it looks like Cyano maybe the culprit.
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia

Re:

Postby spawner » Sat Sep 29, 2007 3:05 pm

How old is the broodstock, wild or captive??


chris melb wrote:Ok well i had a batch of peps hatch a couple of days ago, broodstock tank water was skimmed heavily for approx seven days prior to hatch, was a little bit of skimmate in the cup, today i noticed that some about 5-10% made it to Z2, so i guess i could suggest that the skimmer did help, as nothing else was done differently. Cyano is still present in broodstock tank though which could explain why only some made it to Z2. Im might have to eliminate the cyano completely and see what happens or move my shrimp carrying eggs into the larval rearing chamber (with fresh NSW) on the night of release. But so far it looks like Cyano maybe the culprit.
User avatar
spawner
 
Posts: 1610
Joined: Mon Mar 05, 2007 8:28 am

Postby chris melb » Sat Sep 29, 2007 8:12 pm

Hi Andy

Broodstock is approx just over a year old, one was captive bred by me and the other was purchased at a LFS, i believe it too was captive bred. I also believe that my shrimps have all somewhere down the line orginated from the same breeder who breeds them here in AU. Could this be the problem?

Regards

Chris
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia

Postby chris melb » Wed Oct 03, 2007 10:45 pm

I had previosly siphoned all the cyano i could , cleaned the few rocks that were in the tank, replaced 80% of the water, tank was very clean, larvae was due to hatch 2 days from now, kept the lights off for those 2 days, continued to skim.

Larvae hatched, in parent tank, removed and placed in rearing chamber, using the same setup and procedures as before, and most nearly all survived to Z2, whats more half the larvae were placed in a another rearing container, where i added amboneisis larvae from a different tank which had cyano those larvae both pep and ambonesis failed to make it past Z2.
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia

Postby chris melb » Tue Oct 09, 2007 7:33 am

second attempt at the larvae didnt make it past Z2 again :cry: and there was no Cyano, the same procedure as my previous attempt where larvae made it past Z2. Could there be genetic problem, with these i noticed that the ones that did survive past Z2 were from the shrimp i had recently purchased and the larvae in all my previous failed attempts were from my shrimp that i have raised. So folks it may not be the cyano after all so wish i knew what it was. :?:
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia

Re:

Postby FuEl » Tue Oct 09, 2007 10:15 am

chris melb wrote:Broodstock is approx just over a year old, one was captive bred by me and the other was purchased at a LFS, i believe it too was captive bred. I also believe that my shrimps have all somewhere down the line orginated from the same breeder who breeds them here in AU. Could this be the problem?

Regards

Chris


Hi Chris, there might be a slight possibility that they are 2 different species that look similar? Andy will be more familiar on hybridisation issues. I have larvae that don't last past few days as well. Upon closer observation of the broodstock, there were subtle differences in appearance.
I love Artemac!
User avatar
FuEl
 
Posts: 1186
Joined: Sat Mar 03, 2007 11:23 pm
Location: Singapore

Postby chris melb » Tue Oct 09, 2007 8:25 pm

FuEl thats interesting, although originally i had tried with raising young off the two peps i had raised myself from the same batch, i initially thought that inbreeding may have been the cause off die off prior to Z2, so i purchased another pep from a LFS, and paired that up with one of mine that i had raised. And the same result occured, although i noticed that the young released from the one that i purchased survived past Z2. Whilst the one that i had raised released young that did not make it past Z2 (on both occasions broodstock tank was skimmed and cyano not seen to be present. In AU i thought that there was only one speicies of pep Lsmata Vittata (spelling not sure off). Im trying to track down another two peps to try although i have no way off telling if these are inbred, or as you say hybrids, be interested to know more, about this.
User avatar
chris melb
 
Posts: 235
Joined: Fri Mar 23, 2007 1:12 am
Location: Australia


Return to Lysmata - Cleaner & Peppermint Shrimps



Who is online

Users browsing this forum: No registered users and 7 guests

cron