What is that!! A R2R guide to common new tank hitchhikers.

ros3to

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Has anyone come across this one? Any help is greatly appreciated.
 

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Matt Carden

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This is moving on the glass not water coumn.
About a quarter inch total length.
20230909_175407.jpg
 

Matt Carden

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Found this beast a couple days ago. Kinda scared me.
 

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aqua.reefer

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One of the greatest things about starting a reef tank is getting your live rock in and admiring all the diversity within it. The rock comes to life different creatures. This is a guide that I, along with a very well known critter identifier @KJ , have put together for the new reefer on what these hitchhikers are and whether they're a keeper or to pull them out.

Bristleworm -
Eurythoe.jpg

Very common good hitchhiker. The jury is out on whether they're beneficial or not. Most consider them a vital part of your clean up crew. The hide within your live rock, coming out to pick up scraps of food and other detritus. Their numbers can become overwhelming based off how much food is available in the tank. If you overfeed, and they have access to an abundance of food, their numbers will increase dramatically. Be careful not to touch as the bristles on the sides of their bodies can be very irritating and cause an allergic reaction in some.


Fireworm -
bearded-fireworm_9813.jpg

Bad hitchhiker. Similar to the bristle worm, however if stung by the bristles on this little guy, its 10 times worse. DO NOT TOUCH UNDER ANY CIRCUMSTANCES! If found it is best to remove with a trap.

Pineapple Sponges -
DSC04626_Sponge_Pineapple-vi.jpg

Very common good hitchhiker. These little guys are a type of sponge. They are most commonly found in overflows and in high flow areas of the sump. However, they can sometimes bee seen in shaded areas of your rockwork.

Asterina Starfish -
7MNZ66-2-20160704-124010.jpg

Another common neutral hitchhiker. Jury is out on these guys as to good or bad. Some people love them, some hate them. They've been rumored to munch on coralline algae. They are also known to multiply very rapidly. Manual removal when seen is best to control their numbers.


Aiptasia -
Aiptasia.jpg

Bad hitchhiker. This is a type of anemone that multiplies very quickly, and stings and kills anything that gets near it. Depended on how many you have, they're best removed by manually scraping them off the rock, and then using epoxy/superglue/kalk paste over where they were to prevent them coming back. A few predators that you can get for them include the peppermint shrimp, berghia nudibranch, and with a large enough tank, copperband butterflyfish.

Majano -
majano7.jpg

Bad Hitchhiker. This is another pest anemone that multiplies quickly and stings anything near it. Best removed by manual scraping off and super glue/epoxy/kalk past over its spot. Peppermint shrimp will reportedly consume them as well.

Vermedit Snail -
vermetid_hop.jpg

Very common neutral hitchhiker. They are generally harmless, but can multiply quickly based off nutrients in the tank, and can irritate corals. Manual removal or starving them out by putting a dab of superglue on the end of the tube is best to keep their numbers in check, as well as nutrient control.

Spirorbid Worm -
serpuliabigger.jpg

Very common neutral hitchhiker. These guys are most commonly found in overflows, and high flow areas of your sump. Can multiply very quickly and have been rumored to disrupt equipment such as pumps. Nutrient control keeps their numbers in check.

Ball Anemone -
aquarium-frogmanx82.jpg

Common neutral hitchhiker. They are found in shaded areas of live rock, and tend to not bother anything and numbers are kept in check with nutrient control. Are removed by the same means as the aiptasia and majano.

Stomatella Snail -
Stomatella-Varia.jpg

Very good hitchhiker. These guys are a great clean up crew member. They can be very elusive and most commonly found after lights out and are very fast moving. They feed off different algae in the tank.


Copepod/Isopod/Amphipod -
copepod2.jpg

upload_2018-8-22_22-7-8.jpeg

pods1.jpg

Very good hitchhikers. Often referred to as simply "pods" These little guys live within your rock work and make great food for your fish and corals. They can be the primary diet of certain mandarins.

Spaghetti Worm -
screen-shot-2013-11-10-at-3-07-02-pm.png

Good hitchhiker. Commonly found in the sand bed or live rock. They extend out multiple tentacles to catch floating detritus. Good member of your clean up crew.

Hydroids -
hydroids-3-reefs.jpg
upload_2018-8-22_22-19-56.jpeg

Bad hitchhikers. Good news is that they don't tend to live very long and die off on their own as the tank progresses.


Digitate Hydroids
images (1).jpeg

Bad hitchiker- irritates nearby corals


Sponges -
yellow_sponge_macro_0.jpg

Good hitchhiker. Very common filter feeders. Found in shaded areas of live rock

Serpent And Brittle Starfish -
6512_ef69320d-dce0-40e9-a6dd-4c0e5429f208.jpeg

1568__25907.1335122583.jpg

Good hitchhikers. Are most commonly found by the arms extending out from cracks and holes in rock work. Feed off leftover food and detritus in the tank.

Bobbit Worm -
BobbitWormBluePlanet.jpg.653x0_q80_crop-smart.jpg

Very bad hitchhiker. These guys can grow to be very large and can kill fish. Most common means of removal is to remove the entire rock where the worm is housed. Be careful of the pincer teeth at the head of the worm.

Tunicate -
11240123%20Phallusia%20julinea%20-%20Tunicate.jpg

Good hitchhiker. Harmless filter feeder. At first glance looks like a sponge, except it pulses as it takes in and expels water, and reacts to touching it.

Limpet -
limpet-reefs.jpg

Good hitchhiker. Consumes algae. Don't seem to bother anything.

Fleshy Limpet
unnamed.jpg

Neutral hitchiker. Algae grazer, but have been rumored to bother corals.

20210612_205739.jpg

Slipper Limpet - Neutral hitchiker. Commonly attached to other snail shells. Don't cause any harm to the Snail or other tank inhabitants


Elephant Slug
images.jpeg

Good hitchhiker. Algae grazer.

Chiton -
Chiton_04.jpg

Good hitchhiker. Consumes algae. Does not appear to bother anything.

Peanut Worm -

sipunculid.jpg

Good hitchhiker. Lives in live rock and feeds off of extra food and detritus.

Gorilla Crab -
gorilla-crab-reefs.jpg

Bad hitchhiker. Can be found in live rock cracks, caves and holes. They are predatory and will hunt your shrimp and inverts. They can also grow rather large.

Benthic Ctenophores -
1593790297030.png

Been seeing this one pop up more and more lately, so I figured why not add them to the list.
They are a neutral hitchhiker. They mainly filter feed on zooplankton and small particulates in the water. Most commonly referred to as comb jellys.

Red Planaria Flatworm -
1597699202269.png

Bad Hitchiker. While they don't consume any coral, they can grow in numbers to the point where they smother coral. Caution should be taken as when these die off they release toxins that can wipe out a tank quickly.

Ghost Flatworm -
1597699262549.png

Neutral hitchiker. Doesn't harm anything. But does consume pods

Acoel Flatworm -
1597699436831.png

Neutral Hitchiker. Doesn't harm anything, however can grow greatly in numbers quickly

Polyclad Flatworm -
1597699507858.png

Bad Hitchhiker. Predatory towards clams and coral depended on subspecies.

Pumpkin Flatworm (Waminoa Sp)
1597699709551.png

Bad Hitchiker. Predatory. Can smother and kill LPS corals.

Acropora Eating Flatworm -
1597699791719.png

Bad Hitchiker. See name


I did not cover Nudibranch or snails in this thread as there are far too many variations to cover. If you have an unknown, please create a thread or post it in this thread and we'll try our best to ID it for you. If you have any additions to the list please PM me and I'll review it and add to the list.
Any idea what these guys are?
 

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Matt Carden

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I found a crab a few weeks ago now another. Good or bad? I had a new frag plug dissappear could they be the culprit? 20231014_173319.jpg 20231014_173335.jpg
Yes that's a *%&$ ton of bubble algae.
 

paragrouper

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I found a crab a few weeks ago now another. Good or bad? I had a new frag plug dissappear could they be the culprit? 20231014_173319.jpg 20231014_173335.jpg
Yes that's a *%&$ ton of bubble algae.
I believe it to be the red cousin of the Emerald Crab—although your photos are a tad blurry to my tired old eyes.
I’ve attached a photo of one below for reference. The good news: they eat algae. My emeralds do a fair job of keeping bubble algae in check in my tank.

IMG_0823.jpeg
 

Reefkeepers Archive

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Vermedit Snail -
vermetid_hop.jpg

Very common neutral hitchhiker. They are generally harmless, but can multiply quickly based off nutrients in the tank, and can irritate corals. Manual removal or starving them out by putting a dab of superglue on the end of the tube is best to keep their numbers in check
Neutral? Really?


Anyway you should also add sea spiders, extremely Bad hitchhiker that eats soft corals and in my case LPS
20231217_014159.jpg

Been finding these guys eating my leptastrea, platygyras, galaxea and favities. Think after a 3 month battle I've gotten all of them



And what about gall crabs?
 
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Reefkeepers Archive

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One of the greatest things about starting a reef tank is getting your live rock in and admiring all the diversity within it. The rock comes to life different creatures. This is a guide that I, along with a very well known critter identifier @KJ , have put together for the new reefer on what these hitchhikers are and whether they're a keeper or to pull them out.

Bristleworm -
Eurythoe.jpg

Very common good hitchhiker. The jury is out on whether they're beneficial or not. Most consider them a vital part of your clean up crew. The hide within your live rock, coming out to pick up scraps of food and other detritus. Their numbers can become overwhelming based off how much food is available in the tank. If you overfeed, and they have access to an abundance of food, their numbers will increase dramatically. Be careful not to touch as the bristles on the sides of their bodies can be very irritating and cause an allergic reaction in some.


Fireworm -
bearded-fireworm_9813.jpg

Bad hitchhiker. Similar to the bristle worm, however if stung by the bristles on this little guy, its 10 times worse. DO NOT TOUCH UNDER ANY CIRCUMSTANCES! If found it is best to remove with a trap.

Pineapple Sponges -
DSC04626_Sponge_Pineapple-vi.jpg

Very common good hitchhiker. These little guys are a type of sponge. They are most commonly found in overflows and in high flow areas of the sump. However, they can sometimes bee seen in shaded areas of your rockwork.

Asterina Starfish -
7MNZ66-2-20160704-124010.jpg

Another common neutral hitchhiker. Jury is out on these guys as to good or bad. Some people love them, some hate them. They've been rumored to munch on coralline algae. They are also known to multiply very rapidly. Manual removal when seen is best to control their numbers.


Aiptasia -
Aiptasia.jpg

Bad hitchhiker. This is a type of anemone that multiplies very quickly, and stings and kills anything that gets near it. Depended on how many you have, they're best removed by manually scraping them off the rock, and then using epoxy/superglue/kalk paste over where they were to prevent them coming back. A few predators that you can get for them include the peppermint shrimp, berghia nudibranch, and with a large enough tank, copperband butterflyfish.

Majano -
majano7.jpg

Bad Hitchhiker. This is another pest anemone that multiplies quickly and stings anything near it. Best removed by manual scraping off and super glue/epoxy/kalk past over its spot. Peppermint shrimp will reportedly consume them as well.

Vermedit Snail -
vermetid_hop.jpg

Very common neutral hitchhiker. They are generally harmless, but can multiply quickly based off nutrients in the tank, and can irritate corals. Manual removal or starving them out by putting a dab of superglue on the end of the tube is best to keep their numbers in check, as well as nutrient control.

Spirorbid Worm -
serpuliabigger.jpg

Very common neutral hitchhiker. These guys are most commonly found in overflows, and high flow areas of your sump. Can multiply very quickly and have been rumored to disrupt equipment such as pumps. Nutrient control keeps their numbers in check.

Ball Anemone -
aquarium-frogmanx82.jpg

Common neutral hitchhiker. They are found in shaded areas of live rock, and tend to not bother anything and numbers are kept in check with nutrient control. Are removed by the same means as the aiptasia and majano.

Stomatella Snail -
Stomatella-Varia.jpg

Very good hitchhiker. These guys are a great clean up crew member. They can be very elusive and most commonly found after lights out and are very fast moving. They feed off different algae in the tank.


Copepod/Isopod/Amphipod -
copepod2.jpg

upload_2018-8-22_22-7-8.jpeg

pods1.jpg

Very good hitchhikers. Often referred to as simply "pods" These little guys live within your rock work and make great food for your fish and corals. They can be the primary diet of certain mandarins.

Spaghetti Worm -
screen-shot-2013-11-10-at-3-07-02-pm.png

Good hitchhiker. Commonly found in the sand bed or live rock. They extend out multiple tentacles to catch floating detritus. Good member of your clean up crew.

Hydroids -
hydroids-3-reefs.jpg
upload_2018-8-22_22-19-56.jpeg

Bad hitchhikers. Good news is that they don't tend to live very long and die off on their own as the tank progresses.


Digitate Hydroids
images (1).jpeg

Bad hitchiker- irritates nearby corals


Sponges -
yellow_sponge_macro_0.jpg

Good hitchhiker. Very common filter feeders. Found in shaded areas of live rock

Serpent And Brittle Starfish -
6512_ef69320d-dce0-40e9-a6dd-4c0e5429f208.jpeg

1568__25907.1335122583.jpg

Good hitchhikers. Are most commonly found by the arms extending out from cracks and holes in rock work. Feed off leftover food and detritus in the tank.

Bobbit Worm -
BobbitWormBluePlanet.jpg.653x0_q80_crop-smart.jpg

Very bad hitchhiker. These guys can grow to be very large and can kill fish. Most common means of removal is to remove the entire rock where the worm is housed. Be careful of the pincer teeth at the head of the worm.

Tunicate -
11240123%20Phallusia%20julinea%20-%20Tunicate.jpg

Good hitchhiker. Harmless filter feeder. At first glance looks like a sponge, except it pulses as it takes in and expels water, and reacts to touching it.

Limpet -
limpet-reefs.jpg

Good hitchhiker. Consumes algae. Don't seem to bother anything.

Fleshy Limpet
unnamed.jpg

Neutral hitchiker. Algae grazer, but have been rumored to bother corals.

20210612_205739.jpg

Slipper Limpet - Neutral hitchiker. Commonly attached to other snail shells. Don't cause any harm to the Snail or other tank inhabitants


Elephant Slug
images.jpeg

Good hitchhiker. Algae grazer.

Chiton -
Chiton_04.jpg

Good hitchhiker. Consumes algae. Does not appear to bother anything.

Peanut Worm -
sipunculid.jpg

Good hitchhiker. Lives in live rock and feeds off of extra food and detritus.

Gorilla Crab -
gorilla-crab-reefs.jpg

Bad hitchhiker. Can be found in live rock cracks, caves and holes. They are predatory and will hunt your shrimp and inverts. They can also grow rather large.

Benthic Ctenophores -
1593790297030.png

Been seeing this one pop up more and more lately, so I figured why not add them to the list.
They are a neutral hitchhiker. They mainly filter feed on zooplankton and small particulates in the water. Most commonly referred to as comb jellys.

Red Planaria Flatworm -
1597699202269.png

Bad Hitchiker. While they don't consume any coral, they can grow in numbers to the point where they smother coral. Caution should be taken as when these die off they release toxins that can wipe out a tank quickly.

Ghost Flatworm -
1597699262549.png

Neutral hitchiker. Doesn't harm anything. But does consume pods

Acoel Flatworm -
1597699436831.png

Neutral Hitchiker. Doesn't harm anything, however can grow greatly in numbers quickly

Polyclad Flatworm -
1597699507858.png

Bad Hitchhiker. Predatory towards clams and coral depended on subspecies.

Pumpkin Flatworm (Waminoa Sp)
1597699709551.png

Bad Hitchiker. Predatory. Can smother and kill LPS corals.

Acropora Eating Flatworm -
1597699791719.png

Bad Hitchiker. See name


I did not cover Nudibranch or snails in this thread as there are far to many variations to cover. If you have an unknown, please create a thread or post it in this thread and we'll try our best to ID it for you. If you have any additions to the list please PM me and I'll review it and add to the list.
Digitate hydroids are neutral IMO, Have some small ones growing on the tissue of my pectinia (cant really remove them, were there since i brought it) haven't been irritating it and it's still showing full PE
 

cbfrommo95

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Ok, so I got Zoa frag today. Dipped it, and within 5 seconds these appeared? What are they?
 

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Crabs McJones

Crabs McJones

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Look like parts of brittle stars
 

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