Lysmata amboinensis larva

[Luis A M]

Seven little indians still holding on.Seems like they were less delicate in these last stages,provided they are kept clean and hydroid free!
Checked them again and they are three Z13 and four Z12.Staging is not easy,as the pleopods show marked individual differences.Again,the antenna helps as a more reliable and constant character;in Z12 it reaches about half the length of the branches of A1,the antennula.In Z13 it is longer,just a little shorter than A1.
Following Ricardo´s table,up in this thread,there are just four stages showing pleopods.So I must expect only one more stage.
The Z12 show about 10 setae (hairs) in the exopods and 2 in the endopod,except for that in the 1st pair which remains bare.One showed 4 apical setae in the exop.and two spines in the rostrum.The others show 3-4 spines.
Z13 have 4-5 spines,15-25 setae in the exop.and 5 in the endop.

[Luis A M]

Additional pics of pleopods of the 13th zoea.Usually both branches,exopods and endopods overlap in the side view.But in these snapshots I could capture them spreaded.Pleopods are now motile.Larger branch is the exopod,smaller the endopod.

[ahancey]

Your pictures are really amazing.

[Luis A M]

Thanks! Not very fancy but useful.See that you can count the setae in the last one.Try to do that "on live"with a kicking larva!

[Luis A M]

70 days,about half larval time.All seven are OK and getting big.
Four Z13,Three Z12.
Uropods have about 70 setae.Telson is 1/2 of uropods,ending in a convex point with ten spines.

[Luis A M]

This is the 14th zoea at 76 days.Pleopods are functional and covered by setae all around,about 40 setae in the exop.The endop.now has an AI.
Again in this pic,the two branches can be seen.The smaller is the endop.and the little spur in it´s left border,the AI.



This is the last larval stage,so this species has 14 zoeal stages.In any other species,the larva should be ready to settle at this point.
But L.amboinensis is now only in the middle of it´s larval life,and about half the size it must reach before settling.

I lost one of the larvae, but accidentally.It got trapped in the tank´s pipework.So six remain.

[melev]

I thought AI stood for artificial intelligence.

Congrats on what you've accomplished. So what can you do with this data? Can you speed up the process of getting them to the settling stage sooner?

[GreshamH]

Speed up the life cycle how Marc?

[melev]

Hi Gresham! It isn't so much speeding up a life cycle as what I'm just beginning to understand about getting the shrimp to settle more quickly. I've been recently talking with a couple of people (Brian at ProjectDIBS and one LFS owner that is propagating corals and has worked with peppermints) and it seems that if you can speed up the settling, you have a better success rate.

I really don't know enough to have a real conversation about this. All I know is what I've read and that is really bits and pieces. I need to go through this thread again to understand all the lingo Luis uses to get better educated.

Btw, are you going to go to MACNA again? I'll look for you.

["Umm, fish?"]

The idea is to reduce the number of "marking time" molts. Sometimes the larvae will molt because they have to molt, but they won't have gotten what they needed (nutritionally? environmentally?) to move to the next developmental stage with this molt, so they are stuck at the developmental stage they were in previously. If you can keep them on track to change developmental stages with each molt, the time to settlement will be reduced.

[Luis A M]

Originally posted by melev
I thought AI stood for artificial intelligence.

lol,it is also artificial insemination.

Congrats on what you've accomplished. So what can you do with this data? Can you speed up the process of getting them to the settling stage sooner?

Well,I´m not sure if speeding the settlement of amboinensis would be advantageous at all,assuming it could be done
The natural history of this shrimp seems to be to remain long time as a larva,grow to be giant larvae and then settle into a big,commercial size shrimplets.
And it seems these giant larvae are not more delicate or difficult to raise than small shrimps,so having them settle before or after is about the same.

[Luis A M]

Originally posted by melev
I need to go through this thread again to understand all the lingo Luis uses to get better educated.

Just go past the post larva pic and you will see the Appendix Interna and it´s function,and some terms being explained.

[melev]

Oh. As I stated before, I don't know nearly enough to be of any help at all.

[Luis A M]

Originally posted by "Umm, fish?"
The idea is to reduce the number of "marking time" molts. Sometimes the larvae will molt because they have to molt, but they won't have gotten what they needed (nutritionally? environmentally?) to move to the next developmental stage with this molt, so they are stuck at the developmental stage they were in previously. If you can keep them on track to change developmental stages with each molt, the time to settlement will be reduced.

Well put,Andy! A healthy larva changes stages at each molt.
A sick,or weak larva molts keeping the previous stage,it "marks time"(they can´t avoid molting).It´s like students having to repeat a course after failing a test.
But what happens with amboinensis larvae from 70 to 140 days?
Besides growing,do they have morphological changes or not?
In the first case,we´d have lots of further "mini"or "sub"stages(but stages after all).In the second we´d have technically "marking time".But not the "bad"marking time explained before but physiological,"normal"marking time.
Fascinating subject for biologists,but of little practical value for hobbyists;after Z14,larvae will grow until they become 1 inch monsters at 140 days and then settle.
With six larvae instead of one,normal settling time will be better determined.

[ABlundell]

Awesome! What are you feeding them at this point?
Adam

[Luis A M]

Originally posted by ABlundell
Awesome! What are you feeding them at this point?
Adam

Same food since day one:Otohime B1 and bbs.

[GreshamH]

crushed up B1, or whole?

[Luis A M]

Whole,otherwise I´d used "A"
Unlike fish larvae, shrimp zoea can grab large pieces of food and chew it into little pieces.
They are also taking algae pieces came with the water flow.Dunno how nutritious,but they love it!

[Luis A M]

80 days.Two Z14,18mm long,pereiopod 5 measures 25mm.
AI seems more developed.
And four Z13.

[Elmo18]

Go Luis!!! Amazing stuff, to say the least.

Best,
Ilham

[Luis A M]

Thanks,Ilham!
MODS-I need to delete a couple of posts,wrote to the administrator without response.

[Luis A M]

Originally posted by Luis A M
MODS-I need to delete a couple of posts,wrote to the administrator without response.

Whatever
Anyway,the six larvae are 90 days and are still two Z14 and four Z13.Marking time,obviously,yet still growing.Large Z14 are now reaching 20mm.

[Luis A M]

100 days
Lost another one probably because of system malfunction.
All five are Z14 now,though one is larger and seemingly more developed than the rest.

[melev]

Are you saying you need more space in your gallery to post a few more pictures? Send a PM to DgenR8 and see if Larry can help you with that.

[Luis A M]

That was long ago...I did send PMs asking for more space,without success...I now have an acct in Photobucket.com.Thanks anyway
If you have better access to the new mods of this forum,I also requested in vain to edit my thread of some duplicated post.