Lysmata amboinensis larva

[Luis A M]

<a href=showthread.php?s=&postid=9282467#post9282467 target=_blank>Originally posted</a> by spawner
Your missing the AI and mine have an AM developed as well on the last stage, so Pp are not quite fully developed; one more stage to go.
So how big is it now?? 1.5-2.0mm??

Andy,great you came to help here!
Yes,I can´t see an AI,and exop.look like they still have to grow.
What is AM?.
So I expect another stage.It is 15mm now and has to grow to 20,so some marking time is expected.
A2 is closely banded and a little shorter than A1.Could colour marks assist in staging?

 

[purplehaze]

<a href=showthread.php?s=&postid=9283137#post9283137 target=_blank>Originally posted</a> by Luis A M
What is AM?

Appendix masculina...

Andy, so the PL 1 has on pp2 AI and AM present...how big is the AM in relation to the endopod?

 

[spawner]

I know crazy, sexually developed during the larval stage. If I remember correctly it had 3 spines and looked fully developed. The speicmen I preserved that was in the last stage is out of the country right now.

 

[purplehaze]

Well, maybe another evolutionary characterisitc we should take in account...remember the lenght of AM of L. wurdemanni and boggessi compaired to our new species one ..think about that for a moment

 

[Luis A M]

<a href=showthread.php?s=&postid=9286919#post9286919 target=_blank>Originally posted</a> by purplehaze
Appendix masculina...

Andy, so the PL 1 has on pp2 AI and AM present...how big is the AM in relation to the endopod?

You guys are going too technical for us non specialists...
PL=post larva or pleopod?
pp=pereiopod or propodeus?How does the AM look?.I thought it appeared in the post larva,in the 1st pleop.and later disappears with the onset of hermaphroditism?.
I have seen chelae (claws) in pp 1 and 2 in the last larval stages of boggessi.

On a more lively note,it is nice to see how this big larva uses the paddles of pp3 and pp4 for feeding.When food is introduced and smell reaches the zoea,it starts fanning quickly with these paddles,creating a water current aimed to the mouth parts.

 

[purplehaze]

<a href=showthread.php?s=&postid=9288863#post9288863 target=_blank>Originally posted</a> by Luis A M
You guys are going too technical for us non specialists...
PL=post larva or pleopod?
pp=pereiopod or propodeus?How does the AM look?.I thought it appeared in the post larva,in the 1st pleop.and later disappears with the onset of hermaphroditism?

PL - post larvae
pp - pleopods

The AM is on pp2, between AI and endopod. It appears in male phase individuals and disappears in females phase individuals.
You should not see the AM on boggessi larvae...it is only present a few molts after settlement.

Nice observation on the paddle function

Give me you email address, Ill send you a pic or drawing of the AM and its location

 

[Luis A M]

Errata

Errata

I had an error in my description of the branches of the pleopods (swimmerttes)
What I called exopods are actually the endopods and my endopods are the real exopods.
So in my last pic,captions should be interchanged.
Thanks to Andy and Helio for informing me about that.
I took the description from Wunsch monography,so I copied his mistake.Hard to believe he could mix up pleopod branches in such an important work.Wunsch was the first to raise L.amboinensis (and L.debelius).

Anyway,my larva reached 95 days today.Looks larger but the pleops don´t show obvious changes.Only that I think I see a bud of AI in the smaller,narrower branch (now the endopod)

Almost breaking my 99 days record...

 

[FuEl]

Re: Errata

Re: Errata

<a href=showthread.php?s=&postid=9320531#post9320531 target=_blank>Originally posted</a> by Luis A M
Anyway,my larva reached 95 days today.Looks larger but the pleops don´t show obvious changes.Only that I think I see a bud of AI in the smaller,narrower branch (now the endopod)

Almost breaking my 99 days record...

Looks like it's going well, maybe time for some shaved shrimp or steroids?

 

[Luis A M]

Re: Re: Errata

Re: Re: Errata

<a href=showthread.php?s=&postid=9321980#post9321980 target=_blank>Originally posted</a> by FuEl
Looks like it's going well, maybe time for some shaved shrimp or steroids?

If I change the protocol and it dies,I wouldn´t know what to blame
"If ain´t broken..."

 

[MimicTang]

try now luis

 

[Luis A M]

100 days!

100 days!

My larva is 100 days old,breaking my survival record!:rollface:
It molted today,and it is larger.A couple of days ago I noticed a very incipient hydroid growth,and moved the zoea right away to a clean tank.
This seems to be the trick,fighting hydroids

 

[purplehaze]

Congrats.... I was wondring how do you get hydroids in your tank... I ve never seen one in my system

 

[Luis A M]

<a href=showthread.php?s=&postid=9361318#post9361318 target=_blank>Originally posted</a> by purplehaze
Congrats.... I was wondring how do you get hydroids in your tank... I ve never seen one in my system

Lucky you! Everybody is pested with them.They sure come in the LR,though there was a myth that they come in bs eggs.
They show an explosive growth where bbs is supplied.

 

[Luis A M]

Well,I checked the pleopods again and they don´t show any change I could notice.Exopods (see previous errata) remain well developed and covered with setae all around.Endopods remain shorter and much narrower,the 1st pair being undeveloped.
But I definitely see the AI in the endops,will post pics later.
So I suspect the zoea is in the last larval stage.But it keeps molting and growing, "marking time".It is about twice as big as peppermint last zoea.

Is this the normal strategy of this species prolonging the larval life to produce a larger post larva?"Giant larvae" are also known for S.hispidus...

Or the larva,which should be now ready to settle,is lacking the famous "settling clues"or some other stressing factor keeps it "bumping"in the last larval stage?.

I am inclined towards the first.Larvae unable to settle should die,not keep growing.

Besides a "masochist game",it is a thriller;you lose just one larva and you lose everything

 

[purplehaze]

<a href=showthread.php?s=&postid=9367961#post9367961 target=_blank>Originally posted</a> by Luis A M
Endopods remain shorter and much narrower,the 1st pair being undeveloped.

What do you mean by 1st pair undeveloped...

Either way, if a settling cue is missing, they will still eat, molt and grow....so the end result will still be big larvae..

Besides, if the pleopods arent completly developed like you mentioned, they arent ready to morph...

 

[Luis A M]

<a href=showthread.php?s=&postid=9371017#post9371017 target=_blank>Originally posted</a> by purplehaze
What do you mean by 1st pair undeveloped...

Either way, if a settling cue is missing, they will still eat, molt and grow....so the end result will still be big larvae..

Besides, if the pleopods aren't completly developed like you mentioned, they arent ready to morph...

I mean the 1st pair of pleopods is less developed than the others,both in L.amboinensis and L.boggessi (see pics in this thread and in http://reefcentral.com/forums/showthread.php?s=&threadid=851511&perpage=25&pagenumber=1
And the endopod of 1st pair is rudimental,poorly developed in the last zoea of both species.

The endops are shorter about 80%,but much narrower,about 30% than the exops.They won´t develop further in the larva.But they show what I believe is an AI (appendix interna).

Andy says that the presence of AI and setae all around define the last larval stage.
And my larva matches Wunsch description of the last zoea of amboinensis,at 120 days.

Therefore,I think my larva is in the last stage but perhaps has to hang around and grow a little more.

Your statement that a larva not finding settling conditions will keep time marking and growing,is seductive albeit not right.A larva that fails to transform will die.There is no shrimp neoteny.You won´t get a peppermint larva the size of the giant larva of amboinensis.

 

[purplehaze]

The 1st pair of pleopods is just like you said..but it wont have an AI nor AM..the coupling hooks will appear on the tip of the endopod.

Well, I am not saying that the larvae will grow forever...but it won´t die either..

 

[Luis A M]

Pleopods of the 100 days old larva.

Pleopods of the 100 days old larva.

This is a close up of the pleops,showing the appendix interna.I had more pics,but my disk capacity was over. I asked for some more space...

 

[Luis A M]

They said no
So we won´t have more pics till I find a place to keep them.

The larva molted again,at 105 days.It seems it is molting every 5 days.

 

[Baalz]

I had a peppermint shrimp hatch get mixed in with a clown hatch once.
Was really cool watching all the different stages of development of these shrimp.