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

[vetteguy53081]

Got it! Do they also have bristles that irritate? Wondering for my seahorses. Thanks for all your help!

Nope. Much nicer citizens

 

[duke000]

Why do you think they are killing your fish? How many do you have? Tons of people keep pistol shrimp (myself included) without issue.

Because fish were disappearing....but then I solved the mystery when I found a mantis shrimp in the tank

 

[CornishCrustyCorals]

Thank you!!! By the way I got another pic of the worm. It never goes out far (that i can see anyway)

0

 

[carpetlover]

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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

Sponges -

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

Serpent And Brittle Starfish -

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 -

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 -

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 -

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

Chiton -

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

Peanut Worm -

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

Gorilla Crab -

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 -

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 -

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 -

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

Acoel Flatworm -

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

Polyclad Flatworm -

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

Pumpkin Flatworm (Waminoa Sp)

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

Acropora Eating Flatworm -

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.

What is this guy, found him on wet live rock I bought

 

[Crabs McJones]

What is this guy, found him on wet live rock I bought

Looks like an aiptasia

 

[SoCAL_Reefer]

Just moved to new home and had my 18 month old reef tank broken down and reset back up. That being said, the rock structure was completely rearranged and this evening I noticed 2 long flat white tentacle looking objects coming out of one of my rocks and then detached in the current about an hour later. Any clue what this could be? Harmless?

 

[ssunthar]

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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

Sponges -

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

Serpent And Brittle Starfish -

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 -

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 -

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 -

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

Chiton -

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

Peanut Worm -

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

Gorilla Crab -

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 -

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 -

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 -

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

Acoel Flatworm -

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

Polyclad Flatworm -

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

Pumpkin Flatworm (Waminoa Sp)

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

Acropora Eating Flatworm -

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.

 

[ssunthar]

Very useful post... thank you very much for sharing.

 

[lafarrow]

Just found this guy in my sump. About the size of your thumbnail.

 

[Crabs McJones]

Just found this guy in my sump. About the size of your thumbnail.

Aiptasia anemone

 

[lafarrow]

Aiptasia anemone

and that is what i was trying to confirm but sorry to hear.
Thank you sir.

 

[lafarrow]

Can I safely assume this is the larval state of the aptasia then? That is a 2" marine pure cube for scale.

 

[kels64]

Awesome resource! Thank you so much for putting this together and thank you for the great pictures. You’re the best!

 

[GoReefin]

Awesome write up thank you for taking the time to do this it will help many!

 

[olonmv]

Nice thread, very intuitive! I have one..... tiny black dots that came out of Duncan coral mouth, moved about, regrouped and disappeared when I turn flow back on. One more came out with flow on and disappeared into the water column.

 

[smca3]

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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 -

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

Sponges -

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

Serpent And Brittle Starfish -

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 -

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 -

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 -

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

Chiton -

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

Peanut Worm -

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

Gorilla Crab -

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 -

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 -

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 -

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

Acoel Flatworm -

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

Polyclad Flatworm -

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

Pumpkin Flatworm (Waminoa Sp)

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

Acropora Eating Flatworm -

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.

Thank you for sharing this informative post. Much appreciated. We were able to i.d. Some of the items in our tank.
We have had a population explosion in our tank of creatures that look like they could be feather duster worms or atiphasia. Some pics are attached. We would much appreciate any help identifying/advise.
thank you.

 

[Woodyth]

This is the end of my tank? I've survived many issues only to get taken down by a hitchiker. I'd take out the rock, but he's not in one. It's in the sand bed. I'm assuming it's where my little watchman goby disappeared to. Sad.

 

[eleslie3]

Found this snake like wormy thing yesterday after picking up a clove coral from LFS. Thoughts?

 

[sdreef]

Can I safely assume this is the larval state of the aptasia then? That is a 2" marine pure cube for scale.

Looks like it's a medussa or sticky worm. Filter feeder. Related to Sea cucumbers and can grow large. Reef safe except that they can release a toxin if stressed which can injure fish and other inhabitants similar to other cucumbers (not sure how likely this is).

I had one come in as a hitchhiker with some chaeto. In my case, I decided not stick him back in.

 

[sdreef]

I have some new frags under observation and one of them is a well encrusted efflo. I noticed some little v-shaped attena looking things coming out of three of the corallites. At first, I suspected vermetid snails, but I don't think that's what they are. No mucus net and seem a little more barnacle type.

Not sure what they are, and I'm trying to decide whether to excise them or leave them alone. Identification will help me decide the best course of action. I appreciate your help