Marine Spiders? ID?

Aquarius_Bella · 09/28/2009, 09:19 PM

Hello,
help!
I noticed a number of small spiders living in the live rock, closer to the zoo colonies. just found one in the sump and took it out. here is a description:
*round body is about 1/16 of an inch in diameter.
*6 legs, dark red/burgundy striped (horizontally to the length of the leg);
*3 of the legs are longer and darker,
*other 3 are smaller and lighter in colour.
* legs look like they have tiny hairs running along both sides if looking at the spider from the top.
* total diameter of this spider is no more than a quarter, but i have observed much longer legs sticking out of zoo colonies in the tank.

What are they? Any advice, suggestions?

thx. bella

Fretfreak13 · 09/28/2009, 09:27 PM

Try to pluck out as many as you can and flush them! I think they're zoo eating spiders. If you notice your zoos looking irratated and chomped on, they're your culprits.

Elysia · 09/28/2009, 09:30 PM

There are sea spiders, but IIRC they are usually white and they are predators. If you hadn't mentioned a spider in the title, I would have thought you were describing mini brittle stars.

Crustman · 09/28/2009, 09:32 PM

They are called pycnogonids or sea spiders. They are not true spiders. They can eat coral polyps and are specialist feeders. I have also heard of them eating bryozoans and other sessile inverts.

ChrisKirkland · 09/28/2009, 09:33 PM

Did you happen to take a pic of the one you pulled out of the sump?

Crustman · 09/28/2009, 09:38 PM

Good link http://www.marinespecies.org/pycnobase/

Aquarius_Bella · 09/28/2009, 09:43 PM

at first i thought they were stars too, except for the 6 legs ... sounds like i need to get the zoos onto the surgical table and use tweezers

I tried to pluck them by hand but they just hide into the rock. One of the Zoo colonies is loving the conditions and does not seem to be irritated or chomped on. The second, tri-colored colony, has been taken over by larger sized, lighter colored polyps. zoos do not seem to be chomped.

any remedy/medicine?

Aquarius_Bella · 09/28/2009, 09:45 PM

I did take a picture, just haven't had a chance to post yet... will try to get it posted tomorrow

greenbean36191 · 09/29/2009, 06:31 AM

Other than the title of this thread and the fact that you found them around zoanthids, nothing of this description makes me think these are pycnogonids. Sea spiders don't have round bodies. Their bodies are so thin that their organs are actually in their legs. They also usually have more than 6 legs of roughly equal length. Sometimes They will have 2 longer legs. They also don't usually have hairy legs or fancy coloration.

A round body with 6 striped, hairy legs sounds to me like a miniature brittle star. They're harmless.

Aquarius_Bella · 09/29/2009, 07:06 AM

Thanks everyone, for all your replies! Being somewhat new to the hobby, I truly appreciate all the support!
Having done a bit more research and looking into it, I, too, think that they resemble a miniature brittle rather than any of the spider species described in the link Tom provided... btw very helpful link, Tom. Thx.

The only confusion for me was the fact that they have 6 legs and I always thought stars have 5.

here are 2 pics....

http://i707.photobucket.com/albums/w...a/IMG_1989.jpg

greenbean36191 · 09/29/2009, 07:21 AM

Yes, they are miniature brittle stars. While 5-part symmetry is the ancestral condition for echinoderms, many of them have evolved away from that and now have as many as 26-part symmetry. For these particular stars, 6 legs is an adaptation to the way they reproduce, which is primarily through splitting. Brittle stars need at least 3 legs to get around effectively, so if a 5-leg species split, one of the offspring would die. The extra leg on these guys allows them to split and make 2 viable offspring. Yours apparently did that recently, which is why half of the legs are different than the rest- they're newly regenerated. Scientists actually use the number of legs on brittle stars to guess whether new species primarily reproduce sexually or asexually.

jtrasap · 09/29/2009, 07:28 AM

Yes, definitely mini brittle stars.

arredondojason · 09/29/2009, 10:20 AM

bs they eat zoos. do some research look at the link i provided.

EnglishRebel · 09/29/2009, 10:26 AM

Quote:

Originally Posted by jtrasap

Yes, definitely mini brittle stars.

+++ on that. I have a ton in my tank. Funny to watch them as they are in the rock crevices and they wave their legs hoping to catch some food that drifts by.

arredondojason · 09/29/2009, 01:59 PM

here is some info hope it helps.

http://www.melevsreef.com/id/pycnogonid.html

Fretfreak13 · 09/29/2009, 02:25 PM

Those are harmless. =P

arredondojason · 09/29/2009, 03:21 PM

ok mini brittle stars nothing to worry about.

09/28/2009, 09:19 PM	#1
Aquarius_Bella Registered Member Join Date: Feb 2009 Location: Toronto, Canada Posts: 11	Marine Spiders? ID? Hello, help! I noticed a number of small spiders living in the live rock, closer to the zoo colonies. just found one in the sump and took it out. here is a description: round body is about 1/16 of an inch in diameter. 6 legs, dark red/burgundy striped (horizontally to the length of the leg); 3 of the legs are longer and darker, other 3 are smaller and lighter in colour. * legs look like they have tiny hairs running along both sides if looking at the spider from the top. * total diameter of this spider is no more than a quarter, but i have observed much longer legs sticking out of zoo colonies in the tank. What are they? Any advice, suggestions? thx. bella

09/28/2009, 09:32 PM	#4
Crustman Registered Member Join Date: Oct 2008 Location: Mobile, Alabama Posts: 941	They are called pycnogonids or sea spiders. They are not true spiders. They can eat coral polyps and are specialist feeders. I have also heard of them eating bryozoans and other sessile inverts. __________________ Tom Current Tank Info: 65 gallon reef with 8 T-5's, ATI Blue Plus, Blue Special, KZ Fiji Purple, Vertex IN 100, phosphate and carbon reactor Coralife Turbo Sea Pump

09/28/2009, 09:33 PM	#5
ChrisKirkland Reef and Coral Fanatic Join Date: Jul 2008 Location: Lexington, Ky. Posts: 1,739	Did you happen to take a pic of the one you pulled out of the sump? __________________ Chris Kirkland Reef Nerd. Current Tank Info: Getting back into the hobby.

09/28/2009, 09:38 PM	#6
Crustman Registered Member Join Date: Oct 2008 Location: Mobile, Alabama Posts: 941	Good link http://www.marinespecies.org/pycnobase/ __________________ Tom Current Tank Info: 65 gallon reef with 8 T-5's, ATI Blue Plus, Blue Special, KZ Fiji Purple, Vertex IN 100, phosphate and carbon reactor Coralife Turbo Sea Pump

09/29/2009, 06:31 AM	#9
greenbean36191 Premium Member Join Date: Jun 2003 Location: Ft. Lauderdale Posts: 10,598	Other than the title of this thread and the fact that you found them around zoanthids, nothing of this description makes me think these are pycnogonids. Sea spiders don't have round bodies. Their bodies are so thin that their organs are actually in their legs. They also usually have more than 6 legs of roughly equal length. Sometimes They will have 2 longer legs. They also don't usually have hairy legs or fancy coloration. A round body with 6 striped, hairy legs sounds to me like a miniature brittle star. They're harmless. __________________ Some say the sun rises in the East. Some say it rises in the West. The truth must be somewhere in the middle. Current Tank Info: tore them down to move and haven't had the time or money to set them back up

09/28/2009, 09:27 PM	#2
Fretfreak13 I am not a boy! Join Date: Sep 2009 Posts: 1,114	Try to pluck out as many as you can and flush them! I think they're zoo eating spiders. If you notice your zoos looking irratated and chomped on, they're your culprits.

09/28/2009, 09:30 PM	#3
Elysia Registered Member Join Date: Oct 2007 Location: Central PA Posts: 1,718	There are sea spiders, but IIRC they are usually white and they are predators. If you hadn't mentioned a spider in the title, I would have thought you were describing mini brittle stars.

09/28/2009, 09:43 PM	#7
Aquarius_Bella Registered Member Join Date: Feb 2009 Location: Toronto, Canada Posts: 11	at first i thought they were stars too, except for the 6 legs ... sounds like i need to get the zoos onto the surgical table and use tweezers I tried to pluck them by hand but they just hide into the rock. One of the Zoo colonies is loving the conditions and does not seem to be irritated or chomped on. The second, tri-colored colony, has been taken over by larger sized, lighter colored polyps. zoos do not seem to be chomped. any remedy/medicine?

09/28/2009, 09:45 PM	#8
Aquarius_Bella Registered Member Join Date: Feb 2009 Location: Toronto, Canada Posts: 11	I did take a picture, just haven't had a chance to post yet... will try to get it posted tomorrow

09/29/2009, 07:06 AM	#10
Aquarius_Bella Registered Member Join Date: Feb 2009 Location: Toronto, Canada Posts: 11	Thanks everyone, for all your replies! Being somewhat new to the hobby, I truly appreciate all the support! Having done a bit more research and looking into it, I, too, think that they resemble a miniature brittle rather than any of the spider species described in the link Tom provided... btw very helpful link, Tom. Thx. The only confusion for me was the fact that they have 6 legs and I always thought stars have 5. here are 2 pics.... http://i707.photobucket.com/albums/w...a/IMG_1989.jpg Last edited by Aquarius_Bella; 09/29/2009 at 07:12 AM.

09/29/2009, 07:21 AM	#11
greenbean36191 Premium Member Join Date: Jun 2003 Location: Ft. Lauderdale Posts: 10,598	Yes, they are miniature brittle stars. While 5-part symmetry is the ancestral condition for echinoderms, many of them have evolved away from that and now have as many as 26-part symmetry. For these particular stars, 6 legs is an adaptation to the way they reproduce, which is primarily through splitting. Brittle stars need at least 3 legs to get around effectively, so if a 5-leg species split, one of the offspring would die. The extra leg on these guys allows them to split and make 2 viable offspring. Yours apparently did that recently, which is why half of the legs are different than the rest- they're newly regenerated. Scientists actually use the number of legs on brittle stars to guess whether new species primarily reproduce sexually or asexually. __________________ Some say the sun rises in the East. Some say it rises in the West. The truth must be somewhere in the middle. Current Tank Info: tore them down to move and haven't had the time or money to set them back up

09/29/2009, 07:28 AM	#12
jtrasap Elite Member Join Date: Apr 2008 Location: St. Elmo, Illinois Posts: 2,361	Yes, definitely mini brittle stars. __________________ Jason Knowledge is knowing a tomato is a fruit; Wisdom is not putting it in a fruit salad.

09/29/2009, 10:20 AM	#13
arredondojason Registered Member Join Date: Apr 2007 Location: Portland, OR Posts: 988	bs they eat zoos. do some research look at the link i provided.

09/29/2009, 01:59 PM	#15
arredondojason Registered Member Join Date: Apr 2007 Location: Portland, OR Posts: 988	here is some info hope it helps. http://www.melevsreef.com/id/pycnogonid.html

09/29/2009, 02:25 PM	#16
Fretfreak13 I am not a boy! Join Date: Sep 2009 Posts: 1,114	Those are harmless. =P

09/29/2009, 03:21 PM	#17
arredondojason Registered Member Join Date: Apr 2007 Location: Portland, OR Posts: 988	ok mini brittle stars nothing to worry about.