Wednesday, November 27, 2013

Day 12 of P. venusta trial 5

This larval run is on track when compared to larval trial 3 (Our best P. venusta run to date). Temps are running about the same and  the larvae are close in development as well. This run does have less uniformity in development with a few larvae being slightly deeper bodied than the rest. We do have a few of the flame back angel larvae included in this run and that could be what I'm seeing.
We started this run with approximately 30% of the amount of eggs we started trial 3 with and I expected to see less larvae in this run. I am counting close to the same numbers of larvae on the same days post hatch as trial 3 but I am cheating in that I have a third of the bottom a lighter color so that I can see into the water column better. I'll feel more confident in the numbers after their first tank move when I can get an accurate count.
Sorry, no photos or video this time.

Monday, November 18, 2013

Quick update

I've been collecting eggs all week planning on starting a new larval run with a higher stocking density than the last.  There were small spawns all week with lower fertility rates (50% t0 60%). I ended up starting a new run with 284 eggs which isn't much more than the last batch! The spawn is again from the P. venusta and there are also 20 eggs from the flame back angels that were donated as part of the Fabio project. The flame back male has been involved in pre spawning behavior for a while and the female was somewhat interested. This last week the female has been initiating the spawns. There have been 50 or so eggs with each spawn and the spawn I used had 20 fertile eggs. I'm sure they will continue to improve their production and we'll have more of their eggs added to the larval runs in the future. Today is day 4 for this new run.

Saturday, November 9, 2013

sad news

Yesterday I could not find the lone surviving larva.
The tank she is in is a 6 gallon (24liter) bare bottom tank with just an airstone. How could I not find the larva in that? I took the air stone out and looked with a flashlight even though the room is brightly lit. I searched around the tank wondering if she could have jumped out! I wondered if my dog had drank out of the tank and lapped her up! I even wondered if someone had broken in and stolen her!! This is crazy, I thought!

Then I noticed the water level was a few mm higher than normal because I had added a little algae to the water I had returned to the tank after siphoning. I wiggled the plastic frame that's around the top edge of the tank and out she came, swimming erratically. She had gotten herself stuck in there. She looked a little weak and tippy as she swam around and I took some video which I had intended to do anyway since I wanted to share where she was at in her development. She has been so tough that I hoped she would pull through. I added Euterpina acutifrons copepods which are easier to catch and hoped for the best.

Here is the video of her swimming soon after being released from "the trap".

Today she was swimming in spirals and I couldn't let her suffer so I euthanized her at 34 days old and 7mm total length (you can't see all of her tail in the photo). I feel that her development had slowed as a result of the bacterial problem and lower temps this last week.

I learned a lot from this batch and in some ways it was my personal best up until the 50 larvae die off. Although it is sad there is value in what I have learned and it will help us to get further on the next run.

I still have the next larval run going which is at day 6 today. We started with a small number of larvae and I'm only seeing two or three larvae each time I work on the tank. They do look good with nice full guts. I will continue on with it and also continue to check for eggs to start a new larval run.

Tuesday, November 5, 2013

day 30 for the lone survivor

Just want to give a quick update that our lone survivor is doing well. She developed her caudal peduncle over the weekend (day27 and 28 of her life). She's hunting and clearing out much more food than I expected. I'm changing water in her tank daily and cleaning her tank every 3 days. She's such a trooper, I just scoop her up in a beaker and set her on the side while I do her house cleaning. I'm still treating her with antibiotics and using wild plankton. Tomorrow I plan to introduce newly hatched Artemia to her menu.

I've collected eggs from the P. venusta brood stock over the last four evenings and only had one spawn with fertile eggs and in that spawn only half the eggs were fertile. I did start our next trial with those eggs. There were 211 fertile eggs (compared to just over a thousand last time) and today is day 2. The protocol for this run will be the same as the last and I will be more vigilant for signs of bacterial problems and nip them in the bud!

Saturday, November 2, 2013

The Lone Survivor

The lone survivor P. vebusta is responding well to antibiotics. Yesterday the larval tank which had a cleaning two days prior had a golden colored bacterial slime on the walls and floor. I've moved our survivor to a new clean tank and am continuing antibiotic treatment. She is being fed wild caught plankton at 1 food item per ml. She looks a little thin to me but is hunting and exploring her environment.

I've chlorinated everything having to do with the larval tank and am ready to start another run when fertile eggs are available. I collected eggs the last two nights and both batches were infertile.

Here is a video taken yesterday at 26 days old.
Sorry for the quality but it's better than nothing! :)