Greenbanded Goby (Elacatinus multifasciatus, Gobidion etc..) Breeding Log

[mwp]

Some more maintenance notes. This evening I've simply thrown away 2 gallons of the culture water, plus took out an additional 3 gallons which were seived for their rotifers. So the tank was brought down to just under 5 gallons of water again. 10 basters of phytoplankton went in (all types) and I'm currently doing a slow trickle of freshly mixed water into the tank.

I checked the salinity of the larval tank and found it to be a bit high, around 1.025, so the new water going in is 1.020.

The 3 gallons worth of rotifers I'm going to leave for selcon enrichment overnight...we'll see what they look like come morning. It sounds like I have as long as another week before I need to start thinking about hatching brine for these little buggers.

Matt

 

[Luis A M]

<a href=showthread.php?s=&postid=7875868#post7875868 target=_blank>Originally posted</a> by mwp
Yup, right you are. The mix is probably 1/4 Nannochloropsis. Now, here's the interesting thing...all the goby articles online point to using T-Iso exclusively in the tank...wierd in my opinion (however, they do also suggest selco / selcon enrichment, but they don't really state HOW since, if following the directions explicitly, you're only supposed to add rotifers at the beginning!)

Glad to hear all the cultures are going well Kathy! SS doing well?

Matt

I asked Todd about that.They used only T-ISO because they didn´t have the lab space and time to culture more than one species.

 

[mwp]

HRM! Well I'm sure the selcon enrichment more than made up for any lackings of T-Iso..thanks for the info Luis!

Some last minute notes before I hit the hay; there are still 20-30 GBG larvae in there, possibly more but they're so darn hard to count. It's been a LONG time since I've seen a baby guppy, but in some respects some of the larvae already look that size...maybe I need to get the BBS going early

Another note on the larvae, they are still very heavily positively phototrophic...moving the flashlight around the tank, with all the lights off, in seconds there'd be at least 10 larvae running to the spot, and 20 or so would be there in probably less than a minute.

I obviously don't have much experience enriching rotifers, but the ammount I collected earlier this evening (around 11:00 maybe?) had already cleared out all 10 drops of Selcon, so I added another 10 drops. I guess they'll either be super enriched come morning...or dead...we'll see!

Matt

 

[mwp]

So it's morning and I think the Rotifers have had their fill of Selcon...many were clumped together; 10 drops is probably a bit much for them. I strained them, got most of the clumps out, and fed them into the tank, along with 10 basters of mixed phytoplankton. We'll see how things are going this evening...I'm expecting a hatch of their younger siblings in the next hour or two

Matt

 

[mwp]

So much for the hatch...it happened sometime between 1:00 AM and 9:00 AM this morning because there hasn't been a hatch yet, and a quick peak into the cave revealed that all the eggs are gone. GRRRRRRRRR!

Matt

 

[mwp]

As per last night's comments, I'm going to skip the microscope shots on the larvae for tonight (and maybe a few more days). 4 more basters of the "mandarin mix" of phyto (T-Iso and Tetraselmis) were added to the tank around 9:30 PM...the rotifer population is doing a really good job of clearing the water QUICKLY now. I may do another water change this evening, but this time the purpose is expressly to dilute the rotifers.

FWIW,

Matt

 

[mwp]

This morning it looks like I've had substantial losses...maybe only 10 larvae left? I'll check again later in the day when they're more concentrated. I added in 8 basters of the phyto-mix, and took out about 20 basters as I was literally to the top of the rim, about to flood if I didn't remove some water. The larvae that remain look healthy and have definitely grown a lot since hatching.

FWIW,

Matt

 

[mwp]

Well, just another update...I kep the larvae up late tonight. 8 basters of phyto did squat earlier today, so I went back up to 10 just now...it's strange but as the water clears up, the larvae tend to congregate more on the immediate surface of the water. Adding in some phyto brings them down a bit and seems to get them feeding better. Maybe not strange if you consider one of the main theories of greenwater techniques and why they work.

Anyway, it's still quite hard to count the larvae...you think you found them all then there's a whole 2nd congregation you've missed off in the corner, but then that first group has scattered, or some are facing straight at you and easily get overlooked in the rotifer blizzard. I'm going to guess there are still 20-25 larvae...they've grown substantially now and I'm REALLY looking forward to "metamorphisis" in another 40-50 days.

Another note, looking at the remaining larvae they are now definitely showing some signs of feeding and "being fat". I think on the next batch I'll need to add in the L-Strain rotifers and copepods sooner in the process...those larvae that looked like they were starving (see prior microscope shots) suggest to me that they perhaps indeed were, looking for a food source larger than the SS-Strain. Just a thought...can't really think of anything else at this point.

I think if I can sell everything I raise at a roughly full retail price, it would possibly generate enough of a convincing monentary argument to justify that 2nd 10 gallon larval tank for the top of the wrought iron stand Looking at these guys I now have the "over the hump" feeling...I got through the rough early days, now I just have to not screw anything up (I'm somewhat dreading the brine shrimp switch..it's been a long time since I had to hatch and harvest nauplii, let alone try to enrich them!). Here's to hoping I can get them onto something prepared rather quickly (Cyclopeze?)

BTW, another nest was laid sometime today.

Surprisingly optimistic for a change...

Matt

 

[Kathy55g]

Hi Matt,
If you use just hatched brine shrimp it is best not to try to enrich them. They don't eat until at least a day after they hatch. For me with decapsulated eggs, it takes 24 hours to hatch at basement temperatures.

Cheers,
K

 

[mwp]

Sounds like a plan Kathy. I was thinking of giving Dan's (Seahorsesource) decapsulated brine a shot...I freakin' hate the eggshells and had really poor results when I tried to decapsulate my own a few months back.

Another update on the GBG husbandry - the algae I added in this morning was cleared out within an hour or two! OK, there are DEFINITELY too many rotifers in there. 5 gallons (50%) of the water was removed, and FWIW it SMELLS...not badly, but there's definitely an odor. I'm adding in 2 gallons of freshly mixed water via a slow siphon, with about another 4 basters of the 'mandarin mix' (T-Iso and Tetraselmis).

The larvae are still overall lookin' good! I might actually be able to get some neat shots with the REGULAR camera if I'm patient!\

Matt

 

[mwp]

3:30 PM - the water is clear AGAIN! 10 more basters of phytoplankton were added, a full mix.

Matt

 

[Kathy55g]

Got a rotifer sieve? If I were you, I would reduce that rotifer population right away. Scented water could mean a rotifer crash, and if that happens, the gobies crash too.

(Siphon half of the water thru the sieve into a bucket, and then add the filtered water back. Repeat as necessary.)

You do not need more than 15 rots per ml in the goby tank. Now that you have a microscope, the counting is easy.

As always, the best of luck to you!
K

 

[mwp]

I'd say we're definitely around 20 rotifers per/ML. Kathy, yes the seive is a partial solution to keeping rotifer populations in check, but basically I'm using the rotifers from the larval tank that come out and feeding them to other tanks and getting rid of the water...it's keeping me on top of water changes/dilutions more than I probably would be otherwise.


I just tried a count on the larvae...got to 14 but darnit they are HARD to see when the main light is on...much easier to count when the flashlight is going 'cause they reflect light and rotifers don't, at least not to the same extent.

The water is AGAIN pretty much cleared out. I added another gallon of water I mixed up last night. I added 6 basters of mixed phyto from the fridge...I've gone through almost 3 gallons of phyto since harvesting just a few days ago! It's getting darn tough to keep the water even slightly tinged.

We're at 11.5 days now if my math is accurate!

Matt

 

[mwp]

Well at 9:30 AM I added in another 1 1/4 gallons of clean (new) saltwater and the last of the phytoplankton, mostly T-Iso and Tetraselmis, that I had harvested just a few days ago! Things look OK, not much else to say other than we're past the 12 day mark now!

Matt

 

[mwp]

I was out of phyto this evening so I set to harvesting Tetraselmis and T-Iso that was probably ready enough. 10 basters of the 50/50 mix went into the larval tank, where we still have plenty of GBG larvae to have fun with (we're past 12.5 days now...time to start considering setting up the brine shrimp hatchers!). We had a mandarin spawn this evening, and rather than just dump it I dumped it IN with the GBG larvae...at least the mandarins will have a fighting chance vs. 0 chance!

That's the news from the front!

Matt

 

[aomont]

At which day you added L rotifers Matt ?
Anderson.

 

[mwp]

I was looking through all the notes and can't believe it, but I think I forgot to add a note about ADDING the L-Strain. I made mention of it aon 8-7-06, so I maybe it was either 8-8 or 8-9, 7 or 8 days of age?

This morning I've added the last of the phyto I harvested yesterday, 7 basters of the T-Iso/Tetraselmis mix. It's amazing how 2 liters of phytoplankton can just get consumed in 12 hours

Matt

 

[mwp]

Here's the quick update...those baby GBGs are still hard to find and count and I'd say over the last 2-3 days they are congregating more loosely. 10 basters of newly harvested phyto, all 4 types in equal portions, were added to the "crystal clear" water at 11:15 PM this evening.

Matt

 

[mwp]

So I'm pretty confident in saying we're down to the last 8-10 larvae on the GBG's, and it's 13.5 days. I pulled one out to give him a look; it seems some of these larvae are getting their mouths stuck open (or something is seriously wrong with the water and they're "gasping"). Anyway, I pulled out one of the larger larvae, put him under the microscope, shot for 2 minutes and by the end of it he was already dying...added him back into the tank and his little body just sank to the bottom.

So this little guy gave up his life so we could see how the group is developing. It's a big change, and I think the pictures justify the loss to get a lot of information on the larval development. Perhaps on future batches I'll "fill in the blanks" as I can. I think I'll wait until at least 20 days before I shoot again.

Here ya go!

Matt

 

[mwp]

I followed up the photographs with a water test...pH 8.2, Ammonia 0.5 ppm, Nitrite 0 ppm, Nitrate 0 ppm. I have my ideas where the ammonia could have come from...basically ANYWHERE, but I'm thinking maybe the phytoplankton (if it wasn't sufficiently mature for harvest)?

The larvae that are alive aren't showing any outwards signs of distress, but as a prophalatic I added in 10 drops of PRIME to bind up that ammonia...just to be safe until I can start another round of water removal and slow refilling. I'd really like to not lose anymore larvae from this batch, but I'd be OK with starting over. Granted, if I get lucky I'll have some Apogon leptacanthus larvae to throw in there as well as the next hatch.

FWIW,

Matt