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

[vetteguy53081]

Rodi, in basement but the right side of tank has a window about 12 feet away, north facing window so not much light coming in at all parameters all looking good with nitrite/nitrate at 0
Salinity is little high and working on bringing it down slowly, would like it to be 33 instead of the 34 it's at now

Iys not the sun but the UV that will penetrate shades-blinds-curtains. Likely your algae issue. Blocks the side facing window with construction paper from Walmart and you will see a high reduction

 

[Crabs McJones]

Wondering if anyone, I'm sure someone will lol, be able to ID these guys going in overflow, thank in advance

Pineapple Sponges

 

[hid1203]

Hey guys such a convenient article this!
As of a few weeks I’ve been seeing a lot more little snails in my tank. I’m not to worried tbh because they don’t seem te doe any harm. I must say the population is growing pretty fast. They tend to o LY come out after lights off but if I try I can find them during the day as well. I set up a new nano tank and thought I’d pick some out of my main tank and add them in the nano as the beginning of a CUC. Just wanted to be sure if these are in fact some of the “good” hitchhikers and aren’t an actual disaster waiting to happen.

 

[Sherrie]

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.


Digitate Hydroids

Bad hitchiker- irritates nearby corals


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.

Fleshy Limpet

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

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


Elephant Slug

Good hitchhiker. Algae grazer.

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.

Amazing number of tank hitchhikers. Thanks for your wisdom!

 

[Sherrie]

I would not consider Spirorbid worms to be good - they can bloom out of control and clog up pumps

Thanks for your reply on my issue with dots on my glass. The dots don’t seem to move. Looks like it might be the worms

 

[QuickrdenU]

Chiton? Nudibrach of some sort? Amphipod? All good?
Thanks in advance. I’m learning

 

[Cthulukelele]

Chiton? Nudibrach of some sort? Amphipod? All good?
Thanks in advance. I’m learning

Yeah I'd agree with chiton. Second looks like flatworm of some variety. Third yea is an amphipod

 

[Soren]

Chiton? Nudibrach of some sort? Amphipod? All good?
Thanks in advance. I’m learning

1st does look like a chiton.
2nd looks like a nudibranch from the Elysia genus. I've seen pictures similar before, but I forget specific ID.
3rd definitely looks like a Gammarid amphipod to me.

 

[OneMerissa]

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.


Digitate Hydroids

Bad hitchiker- irritates nearby corals


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.

Fleshy Limpet

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

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


Elephant Slug

Good hitchhiker. Algae grazer.

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.

 

[Crabs McJones]

Looks like a type of tunicate

 

[Float]

Hello to all reef tank fans!

I want to ask for help in case of these guys on the aquarium glass:



They are 2 mm long, some of them green some of them brown and they all have forked tails.

Some recommendations will be accepted with gratitude!

Thank you in advance!

Best regards,

Float

 

[Crabs McJones]

Hello to all reef tank fans!

I want to ask for help in case of these guys on the aquarium glass:



They are 2 mm long, some of them green some of them brown and they all have forked tails.

Some recommendations will be accepted with gratitude!

Thank you in advance!

Best regards,

Float

Acoel flatworms

 

[Float]

Homelander,

Ok, we will try to get more information about fight against them.

Thank you a lot.

Best regards,

Float

 

[DD Corals]

I have Digitate Hydroids in my substrate and somewhat on the aquascape. Is there any way I can get rid of these? They are starting to really get out of hand, and my substrate is a crushed shell, so I'm guessing I should just replace the crushed shell with a sand substrate. Since most of them live in the crushed shell substrate. (also got red planaria, but the numbers have become a manageable population)

 

[kjkszpj9]

Ive read that fish, hermit crabs and shrimp eat digitate hydroids eventually but its not guranteed at all but they disappear on their own i think

 

[kjkszpj9]

Hey guys such a convenient article this!
As of a few weeks I’ve been seeing a lot more little snails in my tank. I’m not to worried tbh because they don’t seem te doe any harm. I must say the population is growing pretty fast. They tend to o LY come out after lights off but if I try I can find them during the day as well. I set up a new nano tank and thought I’d pick some out of my main tank and add them in the nano as the beginning of a CUC. Just wanted to be sure if these are in fact some of the “good” hitchhikers and aren’t an actual disaster waiting to happen.

Looks like collonista snail. Harmless CUC that dont geg large at all. I have 2 of them in my 13.5g

 

[OldRed1]

I have Digitate Hydroids in my substrate and somewhat on the aquascape. Is there any way I can get rid of these? They are starting to really get out of hand, and my substrate is a crushed shell, so I'm guessing I should just replace the crushed shell with a sand substrate. Since most of them live in the crushed shell substrate. (also got red planaria, but the numbers have become a manageable population)

My tank also has an abundance of these! None of my fish or hermits seem interested in eating them. When I think to, I’ll pluck out the pebbles that the hydroids are attached to. Once they dry out, I’ll throw the pebbles back in to the tank. It’s an uphill battle tho…

 

[lubeck]

Don’t have a good pic but saw this guy on the glass today. Its body is somewhat feathery. It’s the size of a small amphipod

 

[vetteguy53081]

Don’t have a good pic but saw this guy on the glass today. Its body is somewhat feathery. It’s the size of a small amphipod

Looks like a monti eating nudibranch and one you want to get rid of

 

[lubeck]

Looks like a monti eating nudibranch and one you want to get rid of

If I haven't added anything to the tank for over 5 months Is that possible?