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#1
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Lysmata amboinensis larva
Lysmata amboinensis is one of the most difficult ornamental shrimp to raise,only second to Stenopus hispidus IME.Main problem in both cases is the very long duration of the larval phase,Larvae(also called zoea) die before attaining last stage when they would settle.
This is a newly hatched larva,zoea1.Eyes are sessile,tail fin is a single piece and it has one pair of walking legs and two pairs of swimming legs.
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Luis A M |
#2
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I was able to get them to 23 days consitenty but couldn't pass that point. This was back when BRList was alive and MMoe was active there, I was thrilled and honerd to get personal e-mail from him saying there was something about that 23 day mark...
I know others have done far better but I gave up, too many concussions from beating my head against the wall. Besides, 20 day old lysmata larvae make great baby seahorse food
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These are my rotifers. Without my rotifers I am nothing. Without me my rotifers are nothing. |
#3
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I don't think L. ambionensis and L. wurdemanii belong in the same genus. The larvae are similar at Z-1 but start to look way different pretty quickly. L. wurdemanii are a piece of cake to raise but ambionensis are frustrating. Those ridiculously long chelipeds are a nuisance and are always getting fouled or caught on something. And who can concentrate for that long? I once got an individual through by accident. I thought they had all died out but never drained or cleaned the tank. Six months later, the tank was needed for something else and there was a little cleaner shrimp in there. Maybe that's the key - give every larvae about 50 gallons of space.
-steve hopkins |
#4
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Hi Luis, hope you don't mind me jumping onto your post. Just thought a clearer picture of zoea I larvae would be of interest to other viewers. My larvae was curled up though, different from your stretched out photo.
I have not heard anything about the 23 day mark so far. Maybe deaths during that time occur due to overcrowding? I have a batch of L. amboinensis larvae now around 55 days, all with very visible pleopods already. I raised about 36 of them in 3 liters for the first 3-4 weeks, after which I halved their stocking density. So far out of the 36 only 2 died. One was crushed by the airstone when I put it down while the other died of natural causes. It was a different experience when I was rearing them in high densities in fish tanks. By 55 days you would be lucky if you even had 50% survival. L. amboinensis and L. wurdemanni are from the same genus as far as I know of. At least that is what many publications say. Different species will develop differently and will have different number of larval stages. The long appendages don't appear to break when they first appear. Only starting when they get longer and longer, usually beyond 30 days. I suspect this breakage occurs during moulting. I have seen a larvae in the midst of moulting once and apparently the moult comes of the 5th periopod last. The moult could have been the stress factor for the frequent loss of the 5th periopods. I doubt the water volume is the key. Most probably it has to do with water current somehow. I had many large ones in an upwelling system that all failed to settle, although they grew much much faster compared to larvae in tanks. Some larvae (about 5 or so) from the same batch were taken from the upwelling before the die-offs occured and placed in a small glass aquarium (probably only 6 liters at max). A simple airstone was set on low output. Viola the first larvae settled at 150 days. The rest died though, the person who was in charge of caring for them during the vacation overfed the tank.
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Bred blood, skunk, peppermint and camel shrimps, sugar gliders, leopard geckos, Phelsuma standingi, Goniurosaurus hainanensis. |
#5
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They are absolutely in the same genus. The larvae are nearly identical, longer larval duration is only reflection of our inability to rear them properly.
My publication on the taxonomic status of peppermint shrimps will be out in July. I’ll have a write up for an aquarium mag come out after it is printed in the peer reviewed journals. But trust me, the cleaner shrimps are more closely related to Lysmata wurdemanni than some of the other peppermint shrimps. I guess it would be helpful if I also wrote up something on the larval development of the groups as well. andy
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Andy "If we knew what it was we were doing, it would not be called research, would it?" Albert Einstein |
#6
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Great Andy, looking forward to that publication! Really curious on how many species of peppermint shrimps actually exist.
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Bred blood, skunk, peppermint and camel shrimps, sugar gliders, leopard geckos, Phelsuma standingi, Goniurosaurus hainanensis. |
#7
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Quote:
But larval shrimp feed well and grow,and then,a % begin to die after every molt.But some few seem to keep growing and your hopes rise again.But no,they die again and then it is only one and this one keeps running and every morning you rush to check it,with your heart bouncing until you find it. Pathetic thing a grown up human so concerned about the fate of a bug about the size of a mosquito,somebody said. And one day,you find it dead.Game over. Last time I had one surviving 99 days. Yeah,I remember you at the old BR Several nice people there Martin,Julian Sprung,Bruce Carlson,Joyce Wilkerson.And our friend Joe L.!
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Luis A M |
#8
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Quote:
While all these shrimps belong to the same genus:Lysmata,I agree with you that there are two well defined natural groups within the genus;the "cleaners"(L.ambinensis and kin -L.debelius and kin)and the "peppermints"(all the others) While some peppers sometimes clean,"cleaners"are obligate specialists and depend of the success of their "cleaning stations"They wag their conspicuous white antennae which are the trade mark of their job,shared by unrelated forms like Stenopus hispidus. Peppers have a (relatively)short larval life and are easier to raise,perhaps because of that.Larvae show a distinct coloration and show large paddles only in the last pair of legs (pp5). Cleaners have long to very long larval phase and are hard to raise.They show three pairs of paddles (pp3,pp4 and pp5),the future walking legs of the adult. I will soon start another thread showing the larval development of one of the peppers,so this can be seen.
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Luis A M |
#9
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BTW,I forgot to give the size of the larva,it is 2.8 mm. Your pic is so clear that even the endopod of mp2 can be seen at the left side. This reminds me that I´m talking about "walking legs"and "swimming legs"as I think this is easy to understand for everybody.This is not technical,however and might be objected by some specialists.So a short glossary and explanation could help because the development of the larval appendix is somewhat complex. "Real"legs are called pereiopods (pp) Maxillipedia (mp)are appendix used for feeding in the adult,the third pair (mp3)are those white "legs"cleaners use to remove fish parasites. Pleopods (pl)are the swimmerettes. In the larva,each of this appendix(except pp5) are split in two branches,called exopodites (my "swimming legs") and endopodites (my "walking legs") . A new born larva,(zoea1)has no pp yet,and swims with the mp2 and mp3. As it develops, real legs,pp will show,one at a time and lastly the pleopods.When these are fully developed the last zoeal stage is reached and the larva is ready to settle. So the "swimming legs"are the exop. of:mp2,mp3,pp1,pp2,pp3 and pp4. And the "walking legs"are the endop. of mp3,pp1,pp2,pp3,pp4 and pp5. That was my best effort to make it simple,which it is not!
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Luis A M |
#10
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Goodness.. even I am confused.
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Bred blood, skunk, peppermint and camel shrimps, sugar gliders, leopard geckos, Phelsuma standingi, Goniurosaurus hainanensis. |
#11
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Luis and Andy,
I realize that they are in the same genus, but the differences in ontogeny makes me wonder whether they should be. For other shrimp genera which are commonly cultured (e.g. Penaeus, Litopenaeus, Palaemonetes, Macrobrachium) you are hard pressed to find vague differences in larval morphology and development among numerous species within a genus. Since larval development is such a primal characteristic, and since members of a genus are supposed to have common ancestors, it just does not make sense that wurdemanii and ambionensis would both be Lysmata. Has anyone ever done any DNA work on these species? -steve hopkins Oh, and I fixed the PM thing, Luis. |
#12
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Quote:
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Bred blood, skunk, peppermint and camel shrimps, sugar gliders, leopard geckos, Phelsuma standingi, Goniurosaurus hainanensis. |
#13
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I have the genetic data tree for most of the genus, and it perfecly confirms the morphology and larval development information. I am still working up the morhpology of the two groups of Lysmata; before we can draw any conclusions we hvae to get a better handle on the taxonomy of the genus, its a complete disaster. andy
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Andy "If we knew what it was we were doing, it would not be called research, would it?" Albert Einstein |
#14
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What part of the larval legs boring speech you did not understand?(don´t say all of it!) Few,but very few people had L.amboinensis settling. Anyway,this is Z2,four days old.Size is 3.27 mm. Stalked eyes:
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Luis A M |
#15
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Hi Luis, never remembered my Z2 larvae being so colorful. What are you feeding the little guys?
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Bred blood, skunk, peppermint and camel shrimps, sugar gliders, leopard geckos, Phelsuma standingi, Goniurosaurus hainanensis. |
#16
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Zoea 3
This is Z3,at 7dah and 3.5mm long. Tail fin is now made of five pieces;central telson,fish tail shaped,two endop.clear and tiny and two large exop.with red marks. Now there are two pairs of colored walking legs (mp3 and pp1) and three pairs of swimming legs (mp2,mp3 and pp1).
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Luis A M |
#17
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Zoea 4
This is Z4,at 12 dah and 4mm. The typical pp5 of Lysmata larvae show at this stage.They are very long legs which make a curve and point forward.The end is expanded and colored like paddles.They can be seen at the front of the larva,like two red spears. Then come the antennula,(A1),which now are forked.They will be the first two pairs of antennae of the adult. After them,two pairs of colored walking legs (mp3 and pp1) and three pairs of clear swimming legs (mp2,mp3 and pp1)can be seen. At the rear end,endopods can be seen between the colored exopod and telson.This last is still fish tail shaped.
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Luis A M |
#18
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Zoea 5
This is zoea 5,at 14dah and 4.2mm. pp2 have shown,so now there are four pairs of walking legs (mp3,pp1,pp2 and pp5).And four pairs of swimming legs (mp2,mp3,pp1 and pp2) A1 branches are 1/3 of total length. And telson is now squarish,same legth as endopods.
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Luis A M |
#19
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Zoea 6
This is Z6,at 18 dah and 4.4mm. pp3 show at this stage.Now there are five pairs of walking legs:mp3,pp1,pp2,pp3 and pp5.And five pairs of swimming legs:mp2,mp3,pp1,pp2 and pp3. Telson is slightly ovoid and shorter than uropods. Branches of A1 are about half total length.
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Luis A M |
#20
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Ya know Luis, I know there's been a lot of speculation on the settlement of L. amboinensis. What's your take? Do you have any info on what's WORKED for people vs. what hasn't?
The other reason I posted (besides to say awesome thread as usual) is that I was reading through the "Hermit Crab" issue of Coral and caught something with regards to the settlement of larval hermits - they're more apt to settle if adults are around. Could it be possible that the presence of an adult L. amboinensis might help que the settlement of these guys? Definitely can't keep it in the tank WITH the larvae, but perhaps putting an adult in a net breeder or other similar form of isoliation that would keep the adult (and perhaps some settlement-triggering chemicals) in the tank but out of the larvae's way? Just thinking... MP |
#21
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Hmm, I tried that but it did'nt work for me. About half of their water came from the adult's tank everyday after water change. Did'nt help in settlement. My take is that it's more of a diet thing. We're feeding them the wrong stuff.
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Bred blood, skunk, peppermint and camel shrimps, sugar gliders, leopard geckos, Phelsuma standingi, Goniurosaurus hainanensis. |
#22
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FuEL, I was thinking that it *could* be chemical, but perhaps the stimuli is a Visual Cue? Thus why it might be worth trying to keep an adult IN the tank, in sight, but perhaps not able to attack the larvae (thus a breeder net or perhaps a glass box with mesh bottom). Just a thought. Granted, it's been done before (or so peopel are claiming) - I wish folks were more up front with their info but I definitely understand the proprietary nature.
MP |
#23
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With Lysmata I think we do not have a settlement issue but a survival issue.If some day I have a lot of last stage zoea that fail to settle,then I will think I face a settlement problem.Until then,my chore is keeping as many alive and reaching as advanced stages as possible.
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Luis A M |
#24
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Zoea 7
This is zoea 7,at 24 dah. Six walking legs:mp3,pp1,pp2,pp3,pp4 and pp5. And six swimming legs:mp2,mp3,pp1,pp2,pp3 and pp4. Now the larva has it´s full set of legs.
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Luis A M |
#25
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Zoea 7
This is zoea 7,at 24 dah. Six walking legs:mp3,pp1,pp2,pp3,pp4 and pp5. And six swimming legs:mp2,mp3,pp1,pp2,pp3 and pp4. Now the larva has it´s full set of legs.
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Luis A M |
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