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FAQs about Sea Star Reproduction
Related Articles: Sea Stars, Brittle Stars,
Asterina Stars,
An Introduction to the
Echinoderms: The Sea Stars, Sea Urchins, Sea Cucumbers and
More... By James W. Fatherree, M.Sc.
Related FAQs: CC Star Reproduction,
Linckia Reproduction,
Sandsifting Star Reproduction, &
Sea Stars, Sea Stars 2, Sea
Stars 3, Sea Stars 4, Sea
Stars 5, Brittle Stars, Seastar
ID 1, Seastar
Selection, Seastar Compatibility, Seastar
Systems, Seastar Behavior,
Seastar Feeding, Seastar
Reproduction, Seastar Disease, Asterina Stars,
Chocolate Chip Stars, Crown of
Thorns Stars,
Fromia Stars,
Linckia Stars,
Linckia Stars 2, Sand-Sifting Stars,
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Sea Star Regeneration? – 03/10/08
Hello,
<Hi Ross.>
Back in September, Marco responded to a question I had about my cold,
salt water tank. Since I'm not sure who will be responding, I'll give a
quick overview before my question.
<You got me again. I remember your case.>
I have a 100 gal., cold (68°F) salt water tank. It currently only has
invertebrates from the New England area (Boston, to be more specific). I
was having trouble with my Nitrates and have since been adding sand to
create a DSB.
<In your pictures it does not look very deep, but I may be wrong. How
deep is it?>
My Nitrate problem is still there, but it fluctuates...
<How high and how are the fluctuations? Do you still use bioballs? Do
you use absorbing resins? How much water do you change regularly?>
but that is not the reason for my question today...or perhaps
contributes to it. (Nitrites and Ammonia are 0ppm)
Recently, one of my larger sea stars (I believe it is an Asterias
forbesi) started acting strangely. The central disk looked like it
became soft.
<That’s bad. Sorry to hear.>
Then one day there was an arm on the ground. A few days later, the
central disk was completely gone
<An important information.>
and 4 arms were left. I've attached two pictures of one of the arms. In
one, the arm is crawling away. In the other, it is on it's side and you
can see the tube feet. Now my questions: 1. If this is some form of
asexual reproduction, I can't say it was very successful.
<No, not if the central disk dissolved. For asexual reproduction the
arms keep a part of he central disk. In addition, they rather form two
halves, not five.>
Even though the arms survived for a day or two, they ultimately were
preyed upon by my hermit crabs and sea urchins. I had to remove them
from the tank. 2. Even if the arms had survived, how could they?
<They can’t without a part of the central disk, which will form new
organs pretty fast and in part prior to the division.>
When the arm is regenerating, how does it eat, get oxygen...even move
(there is no madreporite to bring water into the water vascular system).
<Exactly the reason why a part of the central disk has to be attached
for successful regeneration. If not, it’s up to osmosis, maybe diffusion
and using what is left as good as possible. With the nervous system
acting independently the arms of your stars survived a few days,
amazingly more than mine would if separated.>
Everything I've read just says "sea stars have amazing powers of
regeneration"
<Only under good environmental conditions and with proper nutrition. In
aquaria many don’t survive very long.>
but don't explain how they survive during
this period...or even how long it takes.
<A new disk and tiny arms form pretty fast, within a few weeks. The part
of the central disk connected to the arm will do the supply with a
little madreporite (and other organs) that divided itself. It can take a
few years (!) until the sea star has long arms again.>
3. If the fragmentation wasn't for reproductive purposes, what do you
think it was?
<Many possibilities, temperature too high for too long, insufficient
water quality, wrong nutrition are options, you may know what is most
likely… by the way did you measure nitrates prior to its death or
afterwards. Such a dead sea star can significantly contribute to the
organic load.>
I was really bummed that one of the arms didn't survive because I
thought it would be cool to document the regeneration process. Any
thoughts on what happened to my poor sea star would be appreciated.
Thanks. –Ross
<I hope this helps. Also have a look at
http://www.wetwebmedia.com/starreprofaqs.htm and
http://www.wetwebmedia.com/stardisfaqs.htm and the further FAQs on
disease (see how many people loose their Seastars?). Cheers, Marco.>
Re: Sea Star Regeneration?
Nitrates; positive feedback 03/12/08 4/7/08
Hi Marco,
<Hello Ross.>
I wanted to give you an update on my tank. So far, good news
<Nice to hear.>
(better knock on some wood, I guess). I don't know if you recall, but I
inherited the tank from some students, I didn't set it up myself. After your
last email, I did a close examination of everything. It turns out the air pump
to the protein skimmer was very weak. I replaced it with a much stronger pump
and the efficiency of my protein skimmer has improved dramatically.
<Very good.>
I removed some bio balls and got a Nitratelock resin bag.
<I’m not a fan of the latter, but certainly an efficient short term solution.>
The tank has never been cleaner. The nitrates were 160+ but this morning they
were 20ppm.
<That’s much better.>
I did lose another small sea star close after one of my others broke itself
apart, but I have a large one left who seems healthy. Part of my urgency in
lowering the nitrates etc. was that I knew a student was going to be getting a
cuttlefish for a research project and the tank needed to be healthy. We've had
him (her?)
<Males often become aggressive towards their reflection in a mirror, but that's
not 100% reliable at all.>
now for almost two weeks and things seem great. (again, knock on some of that
wood). Thanks so much for your help and suggestions. –Ross
<Thank you very much for the feedback. It’s very good to know what happens after
the emails. Good luck with your cuttlefish. Marco.> |
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Mating Starfish? 3/10/07
Hi,
<Brian>
I have two sand-sifting starfish in my tank. They are almost always on
top of each other (see attached photo).
<I see>
I can't find anything on the site about this? Are they mating?
<Likely so, at least trying, yes>
Both seem to be fine. They've been in the tank for about a month, and
whenever they aren't joined up, which is rare (at least during the day
when I can observe them), they move
about fine. Any ideas what they're up to?
Thanks,
Brian
<Mmm... perhaps a trip to a large/college library that has a life
science, organismal biology arm (e.g. Zoology)... for a helping hand at
searching the literature (reference librarian)... re Archaster
reproduction... I do think this species is a "typical" Asteroid (not a
brooder, but a broadcaster) of fertilized eggs... pelagic larval
stages... much that you can't provide in a captive setting as a mixed
hobbyist aquarium... Do take a read here:
http://www.wetwebmedia.com/starreprofaqs.htm
Bob Fenner> |
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Starfish Reproduced? Not this time - 08/15/06
Hey guys,
Quick question for you. I have two green Bahama starfish in my 90gal
tank. Tonight, it looked like one of the starfish everted its stomach,
but after about 10 minutes, I looked back and it left a whole section of
what I thought was its stomach on the glass and it moved on. The 'gunk'
was sticking to the glass with some tube feet, so I thought it may have
eaten one of my sandsifting starfish and it disagreed with him, but upon
closer examination, the 'gunk' started to unravel and move about. I'm
guessing it just reproduced, but right now it looks like a cucumber. I'm
attaching pictures, so if you could confirm what I'm seeing, I'd
appreciate it. Hope the pics are not too large.
First pic is the starfish.
Second pic is what it 'released'
<Does appear to be an actual sea cucumber... might have been ingested...
and egested (for sure!)... not palatable. Thanks for sending this
account, pix along. Bob Fenner> |
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Re: Starfish Reproduced? - 08/15/06
Bob,
Thank you for the quick reply. I do have one concern though. I did not
have any sea cucumbers in my tank to start with. I avoided purchasing
them for the potential of poisoning a tank upon stress/death.
<Likely a "recruit"... most likely came in as part of live rock...
perhaps live sand, or other hard substrate with other livestock>
I'll keep researching I guess. It has very similar skin to the green
Bahama starfish with greenish color and small spikes on the body. I
don't have enough knowledge about reproduction,
<Can be found in textbooks, the Net... looks to me to be a Holothuroid
though...>
so I can't say that is what happened though. If you'd like me to send
you occasional updates, let me know.
<Thank you, please do. Bob Fenner> |
"Baby Starfish" 7/12/06
Hello WWM Crew, I am a Marine Hobbyist. I have a 75 gallon reef tank.
Learning things all the time. Loving it. Tried to search the web on this new
issue, but can't find my answer. Did find you, and I'm hoping you have the
answer. I'll only mention in this e-mail what I think is relevant to keep this
short
for you. I have a relatively big (hopefully fully grown) gray (with stripes)
serpent starfish, and also an orange starfish (don't know the species off
hand--slow moving, smaller).
Anyway, this evening I saw a tiny baby starfish in the tank. It moved fast like
the serpent. Looked like somebody had tried to take a bite out of a couple
legs. It didn't have any color though--just white. I was trying to figure out
how the starfish reproduce. Everything I found on reproduction talked about
splitting, which didn't happen here. Is it possible my single starfish laid eggs
and fertilized itself? They don't cross breed, right? And are they "born" white
and color up as they age? And while I'm writing.
<No mystery here! The tiny brittle stars are a separate species and were
probably introduced with live rock or corals. They often reproduce prolifically
in reef tanks. The reproduce by splitting and by direct development (brooding)
of young. The are a joyful and beneficial addition!>
I lost my very large (7 or 8 inches) Mr. Goby. And then I lost my cleaner
shrimp. My daughter thinks the serpent star ate them. Although the coral banded
shrimp may have taken the latter. Do you think that is possible that the serpent
star ate my fishes?
<It is possible, but not likely. Generally, smooth armed (serpent) starfish are
considered safe while spiky armed (brittle) starfish, especially the green ones
are considered at least risky to small fish and inverts.>
I have not been feeding him frozen fish because I was afraid of how much bigger
he could get, but maybe I should feed him frozen to keep him from eating
everything else. What do you think about that? Thanks in advance for your
wisdom. Vickie
<As these animals get larger, it gets harder for them to get enough
food. Feeding it small bits of food will not only help prevent it from
resorting to predation, but will more simply save it from starving. If it
eventually outgrows your system, you can either trade it or use it as an excuse
to get a bigger tank! Best Regards, AdamC.>
Starfish Regeneration (5/9/05)
Hello Bob.
<Steve Allen covering Echinoderms tonight.>
I know that starfish are great at regeneration and can become whole animals from being cut apart but I never thought I would watch one split itself in half! These are the starfish that came with the live rock and I have no idea what kind they are.
<Are we talking about the tiny ones that never get bigger than a penny? These are genus Asterina. They often have an unusual number of limbs or irregular limb length. The often reproduce by fission.>
I thought it was dead until I saw the two parts move away from each other.
No, flying will probably never get better for me as a work related accident, shortly after high school, did some damage to my back, neck and knee.
<Sorry to hear. As one who flies 12,000 miles per month, I'm sure flying is even more uncomfortable with the lingering effects of injury.>
Now that we are getting to know how to use the camera we will take some pictures of the tank. I should have some good stuff over the weekend.
<Cool. Do consider joining our chat forum and posting them there for all to enjoy.>
I hope you have a great weekend.
<I don't know about Bob, but I sure did--I got to be home.>
Sexual Dimorphism of Chocolate Chip Stars (11/17/04)
Difference in male and female chocolate chip sea stars.
<I am not aware of any visible external differences between the two. Steve
Allen.>
Archaster Babies?....Or Asterina? (11/1/04)
Believe it or not, MORE Archaster craziness! Anthony, you are a patient man
for answering all my questions. Bless you indeed! :) <I will pass this on. Steve
Allen responding since Anthony is out.> To add to the insanity, one of the
Archaster's had BABIES. I've got a few, literally, the size of an eraser head. I
tried to take a picture, but it was incredibly difficult as it was far back in
the tank, glass distortion, very small, etc. So everything around it looks HUGE.
Here's the pic:
http://65.124.75.190/babystarfish.jpg
I'm not really sure how many I have as only two were visible, now only one.
Hopefully some of these guys will survive and won't suffer from predators so I
can pass them on. :) <Looked at the picture. Sorry to rain on the parade, but I
doubt that this is a baby Archaster. Looks more like an Asterina to me. These
common hitchhiker mini stars seldom exceed 1 cm in diameter. Look at some pix on
our site and elsewhere to compare and be more certain.>
Starfish Asexual reproduction
My sand sifting starfish recently looked like it was in a molting stage. Its
legs were deteriorating off and she was still alive so I was giving her a chance
to prove herself worthy of staying in my tank. Guess what, she disappeared and
now I have over 50 baby starfish in my tank. <Are you sure its the same kind of
starfish? Often there are little tiny star that appear in fish tanks that can
become nuisances.> I’ve never had a daddy in the tank. And I’ve had this
starfish for about 6 months. Do you know what the reproduction cycle is as to
maybe she was pregnant when we received her or did she a-sexually repro in my
tank. <Sounds like asexual if they are indeed from her. A picture of some of the
babies would help.>
My 55 gallon tank won’t support this many stars, so if any one wants to make a
purchase, just contact me. <Sorry we can't help you with the selling part but
I'm sure if you want to post them on some of the multiple web sites you'll have
much success>
A Star Is Born...Well- Several Stars!
Hi,
<Hi there! Scott F. here today!>
My name is Nanci and I have 2 sand sifting star fish which have
successfully reproduced. I saw the first babies about 1 1/2 weeks ago.
<Very cool!>
I have no idea how many are in the tank, due to the fact they are so small (1/8”
– ¼” in diameter) and are the same color as the sand. They seem to be at various
stages of growth. Some are still oval in shape while others have already
started growing their arms. Does this indicate they have reproduced more than
once or just different growth rates?
<Hard to say. Probably different growth rates in different individuals...>
The “parents” are about 4”-5” in diameter. What is the time
line for growth?
<Growth rates vary by species, but I imagine that you'd be looking at several
months at the least.>
Do I need to add anything to my tank to help these little ones survive? Should
I move them to another tank, and if so, at
what stage?
<I'd leave everything as is- and I'd let them remain in the same tank>
My 55 gallon tank is pretty self sufficient at this time,
it’s only been running for about 9 months. I have 1 Kauderni Cardinalfish, 1
White-Tailed Damsel, 1 Orange-Spotted Watchman goby, 1 Kole Tang, 1 Ocellaris
Clown, 1 Fridmani Pseudochromis, 1 Blue Damsel, 1 Condylactis anemone (nuisance,
but cool), Finger Leather, Button Polyps, Xenias, Yellow Polyps, Green Polyps,
hermit crabs, Turbo snails, Bumblebee Snails and 1 Blood Red Fire Shrimp. Will
any of these harm the babies? Will the babies harm any of these?
<Depending upon the species that you have, there will probably be little danger
to the corals. If the adults are leaving 'em alone- chances are that the babies
will, too!>
The babies do climb the live rock, unlike the parents. Any and all advice would
be helpful. I haven’t been able to find any info on the net. Thanks a lot and
have a great night!
Nanci
<Nancy- if we could get a good picture, we could make a reasonable attempt at an
ID, and give you some more definitive answers. Best of luck with your little
stars! Regards, Scott F>
Mating Stars? (7/28/04)
Hi there: <Hi. Steve Allen here.>
I took this picture a few min.s ago (photo attached), these two have
been this way for about two days now. Just wondering if they are indeed
mating, and if there are any precautions we need to take to keep the
little ones safe. <Could be, but hard to be certain. Echinoderms spawn
into the water. No copulation involved. If they do reproduce, there is
nothing you can do in a reef tank setting to protect the eggs or baby
starfish. It is almost impossible for them to survive and grow to
adulthood in there. Too many other things available to eat them. That's
why they produce millions eggs in the wild--only a few survive. In the
confines of a tank, they are even less likely to survive.> We have
shrimp, crabs, snails, a yellow tang, two clown fish and a fish that
looks like Dory from Finding Nemo. <Paracanthurus hepatus> It’s my
husband’s tank, so I don’t know all the fishes proper names :-)
Thanks for any help or tips you might have and feel free to use the
picture if you’d like. <Nice picture. Hard to say what they're really
doing. As far as actually breeding starfish, you might want to do some
searching on the internet for info if anyone is doing this
successfully.> Thanks, Lecia Zinna |
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Starfish Couple? (3/17/04)
Bob, <Steve Allen tonight>
I have a pair of sand sifting starfish that I purchased from the
same tank. After I first introduced them to my tank they did a great job sifting
around. Now they have found each other and the one just lays on top of the other
and they don't seem to do much but lay in one spot all day. They are both still
alive. Are they breeding? <Hard to say. Starfish are known to be rather still
at times. You could always separate them & see how they react. If your water
is good, there is food available, and they don't show any signs of decay,
they're probably fine. Thanks, Rob <Hope this helps.>
Attack of the Star People!
>Hey everybody!
>>Hey you!
>Hope your holiday was fun. I have a question about my starfish,
he is gray with burgundy spots and blue tips at the end of his arms.
>>Sounds purty.
>It seems that someone bit off one of his arms and the arm is on the live
rock.
>>Mm.. kinda like that one old movie with Michael Caine, "The
Hand", yeah? (The one where he's driving with his hand hanging
out the window and a truck comes along too close and kinda.. whacks it off? I
was pretty little when I saw it..)
>My question is, have you ever seen an arm survive on its own?
>>Only in the movies.. Oh wait! You mean a starfish arm, doncha? Yeah,
sure have. Needs to have just a bit of the central disk and yeah,
it'll regenerate. Pretty strong weirdness vibe thing going on there.
>It appears to be getting longer and not changing colors as if it were dead!
>>Oh yeah, you've got a star-ltergeist.
>I've left it there to see what would happen.
>>Watch out if it starts throwing things and moving furniture. You
may need an exorcist.
>I really thought that someone would come along and eat it, but it seems to
be growing. Any clues what's going on?
>>Yeah, funky nature in action!
>Weird science!
>>Big time.
>Thanks, Valerie
>>Welcome, Marina
Urgent!!! Starfish Spawning
To Bob Fenner, and other great WWM team,
Just few hours ago, I bought two Protoreastor nodosus to my aquarium (my
aquarium is so small, only 60 x 30 x 36) and surprised when I see the
transport bag fulfilled with milky solution with two big stars in it. So, I
just thought it's only former water quality, but I remembered the former was
as normal as yours. So, I move the stars to my aquarium, and I noticed one
of them having a typical body secretion between arm's joint. It seems to be
a sperm batch, and now it clouds my aquarium. He was still emits the
unpleasant concoction to the water, and I only hopes the filter can
eliminates every sperm cell. And other starfishes like my four Archasters,
two Fromias, and six Sabellastartid worms are unknown in condition. But,
three of the four Archasters looked very nervous and stressed when the new
"housemates" come. Very unusual, they climbs the aquarium wall and
moving
with a fast coordinated motion. And their skin was exuding slime, a clue for
invertebrate's stressed condition. Did the aquarium should to be cleaned or
it will cleaned itself?
Did the sperm will poisoned and toxified other
inhabitants? Did they will eat other starfishes too? And how to stop this?
Thank you very much, Anargha.
<I would keep a close eye on your water quality (testing for nitrogenous
wastes at least daily for a while). If the other livestock appear to be
stressed, I would initiate a considerable water change (25%) and have more
pre-made water on hand for further changes. No way I know to "stop
it"... conditions are likely "so good" in your system that
spawnings are induced. Bob Fenner>
- What Are They Doing? -
hey gurus-
<Hello to you, JasonC here...>
i have 2 sand sifting stars. one has been draped on top of the other for about
24 hrs. now. the one on the bottom has moved around the tank, so i know he's not
dead. is this a mating ritual or what? thanks Justin
<Perhaps, but hard to say for certain. Cheers, J -- >
Re: question on starfish
Hello again i read up on breeding starfish and wondered if my sand sifting
star splits or lays eggs?
<Can actually do both. Split asexually and produce either eggs or sperm>
i have one that loves my tank thanks JM. Also could you direct me two the
decorator crab facts on your page I've typed it in google and nothing has came
up? thanks again JM
<Sure. Please see here: http://www.wetwebmedia.com/marine/inverts/arthropoda/crabs/swcrabs.htm
and the Related FAQs (linked in blue at top). Bob Fenner>
Starfish breeding
Hey Bob:
I have been wanting to breed starfish. I was able to do this once before with a red
Fromias but due to a lack of proper maintenance (lazy me) had a nitrate blow up and lost them all saved everything else though.
I know you do not recommend blue Linckias but how about the purple Linckias?
<Gorgeous creatures... Tamaria stria... just look something like the genus
Linckia... can be quite hardy in fully established reef systems of size>
Or should I just go back to the cheaper Fromias? I would like to raise the starfish that would be more popular but also way more hardier.
<Go with the Fromias>
Needs to be soft coral safe, I do so like my xenias and leathers.
And would you recommend foods?
<Hmm, yes... a little joke here. Tablets likely... as are easy, nutritious, sink...>
Also do not much care for the brittle and serpent stars.
<Not appropriate technology in many cases, settings>
And what about the crabs? Should they all come out? I have 1 sally lightfoot, several left handed hermits, and a unidentified
stowaway (kinda looks like a shamefaced, I'll send pics once it is caught).
Please advice and once again thanks for all the help.
<Would keep eye on any, all crabs...>
If not for your advice I would have already scratched this hobby and went back to the old tinker-toys and play-dough.
<Ahh, glad to have helped... and glad you're "still with us". Bob Fenner>
Kevin Johnson
Sand Sifting Star
Wow, you're quite a versatile person. When I first started keeping a shark I
contacted you, and thank you for your response. It so happens that I have a couple of sand sifting stars, Archaster typicus in my tank right now, and
they seem to be doing what pseudocopulating starfish do when you have a male and a female (who knew??!!). Anyway, according to what I've read so far,
she's going to dump about 2 million eggs into my 125 gallon aquarium, and he'll successfully fertilize, I don't six of them. Anyway, I have pretty
good circulation and filtration on the tank, including UV filtration. I am also, apparently, host to some bristle worms (remind me to get a trap). I
have a medium sized cat shark, and three four very brave and smart damsels, a very large cowry, some turbo snails and about 4 blue legged small hermit
crabs. So, am I going to have baby starfish in two months?
<Not likely... Seastars reproduce asexually in captivity at times... and there are brooding types that produce young in aquariums, but the sexual type... requires long enough planktonic stages, feeding... that the filtration, other life in a contained space take all out>
Should I break out the cigars? Or, am I just going to have to cut down on the brine shrimp
for a while because the damsels will eat them all??
There is literally zero information on the Internet about breeding starfish in captivity. Can it happen? If so, what can I do to improve success? If I
have 2 million of them at $11 a piece I could retire. I now know more about Archaster typicus than I ever wanted to know, including the placement of all
its major organs. I know what the larvae looks like in all of its stages, but am I the first to see the miracle of life happen in my home aquarium? Is
my tank that dirty? :-) Thanks, Ted Coombs
<These are great aquarium animals... but all wild-collected. Take a read through the "bibliography/further reading" areas (on the bottom) of the "marine invertebrate" sections of the site: www.WetWebMedia.com for ideas on where you might look for more information. Bob
Fenner>
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