shrimp larval video

[FuEl]

http://www.youtube.com/watch?v=sUNl4Gr6Nso

Lysmata vittata larvae from Clownfish75, currently just above 30 days old.

Stenopus cyanoscelis larvae, at 86 days as of today.

 

[FuEl]

L. amboinensis larvae at 70 days feasting. Look the same size as it was at 30 days old. Zzzz

http://www.youtube.com/watch?v=3_lli-rg_1M

 

[Luis A M]

Very nice!
The three pairs of paddles,pp3,pp4 and pp5 can be seen clearly.
The flagellums of A1 are long and the larva is colorful.
Can you see the pleopds,or the flagellum of A2?Is the telson much shorter than the uropods and pointed?.
It looks pretty advanced,Z8,Z9 or more....
Good luck,keep posted!

 

[FuEl]

Hi Luis, apparently the pleopods are already very visible around days 50+. As for the telson, I will check up on it..but that is the case for the S. cyanoscelis larvae. It still has a lot of growing to do, somehow it looks the same size as it was around days 50+.

I found this intriguing trend with L. amboinensis larvae. Somehow it's always the largest and fastest growing ones which die. The slower growing ones tend to have a better chance of settling. And for the breaking of the periopods, seems to be more related to larval tangling. Yesterday I had to use my conical containers for my experiment so I put all the larvae into a rectangular tank. 2 wooden airstones placed in there and the current was similar to what I originally used. The larvae seem to congregate at both opposite ends of the tank near the airstones. Next day I came in and so many periopods were on the tank floor. Should have put them in anything but a rectangular tank.

 

[Luis A M]

Pleops are sometimes folded against the body and hard to see.
Yet I can see two long white tipped filaments pointing ventrally in your video,could they be A2 flagellum?.
The only constant I find is that mortality always occurs at molt time.

 

[FuEl]

Yes Luis, those do appear to be A2 flagellum. I never really take note of their development after their pleopods appear. So not really sure what stage are they at now. By the way Luis, has anyone done a field measurement of late-stage L. amboinensis larvae as far as you know?

 

[Luis A M]

<a href=showthread.php?s=&postid=7485509#post7485509 target=_blank>Originally posted</a> by FuEl
By the way Luis, has anyone done a field measurement of late-stage L. amboinensis larvae as far as you know?

Not that I know,perhaps Andy?
They grow to more than 20mm in captivity,you expect something different in the field?

 

[FuEl]

Yea hope Andy could chip in on this. Calado has talked about inappropriate larval rearing conditions leading to giant sized caridean larvae and subsequently larger post larvae. So if there has been no field measurements done for L. amboinensis, there is a possibility that lab cultured larvae are "giants" and not normal sized. I've got some pretty interesting results feeding both microalgae and artemia compared to artemia alone. Apparently the larvae develop faster but they end up being smaller. Interesting huh.

 

[FuEl]

Hi Luis, I have checked on the amboinensis larvae today. Their telson is indeed pointed and shorter compared to the uropods. Does this mean anything?

 

[Luis A M]

<a href=showthread.php?s=&postid=7489975#post7489975 target=_blank>Originally posted</a> by FuEl
Hi Luis, I have checked on the amboinensis larvae today. Their telson is indeed pointed and shorter compared to the uropods. Does this mean anything?

Yes,the telson gets more pointed and comparatively shorter as development progresses and is about half the length of uropods by day 40.
It seems that giant larvae occur in both slow and difficult species,L.amboinensis and Stenopus hispidus.
I see you put larvae of both genera together.Have you noticed if Lysmata prey on Stenopus?.

 

[FuEl]

Hi there Luis, I put both Lysmata and Stenopus larvae together only for easy video documentation of them as I'm using a digital camera with limited memory space.

My personal observations on Lysmata larvae are that they are not really that cannibalistic if you do not starve them. If abundant food is present like Artemia they don't exhibit much signs of cannibalism at all. The periopods break off mainly from handling and larval tangling. For L. amboinensis larvae, they are not very strong hunters. Large larvae beyond 1cm don't seem to be good at catching adult Artemia, unless they are weak ones that are injured or about to die. I suppose they are more opportunistic feeders as compared to predatory feeders.

For Stenopus larvae they are very cannibalistic. The only way to solve this is to feed large prey items that are dead. I have good luck feeding them 2 week old frozen Lysmata larvae. They seem to have a hard time catching the live ones. Once you stop this they start eating one another again. You can reduce this by tuning the aeration to the max, but this seems to cause dented and eventually broken tails in larvae, which is another major reason why larvae die.

 

[Luis A M]

Hi Junkai,I never saw a Lysmata larva prey on other Lysmata larva,unless it was previously dead.But I see that when I put Lysmata and Stenopus larvae together,these last dissapear,so I wondered if it was predation.Funny that you found the opposite,that Stenopus might prey on Lysmata!.

 

[FuEl]

Hi Luis, I suspect my Stenopus larvae preyed on live Lysmata larvae as well. The L. vittata larvae started with 5. I placed them with 5 other Stenopus larvae. The vittata were even larger than the Stenopus. The day before, 1 vittata went missing, no body whatsoever. I thought I must have had blur eyes and dumped one without remembering. I distinctly remembered putting 4 vittata larvae back with the Stenopus larvae. Today I checked on them again and only 3 vittata larvae were left, with no signs of the other one, not even a dead body. I decided to take out the Stenopus. If I'm still left with 3 vittata larvae tomorrow I think that should be enough proof that the 2 which went missing were being eaten by the Stenopus.