FAQs on Freshwater Pests
Related Articles: FW Velvet, Freshwater Fish Diseases, Freshwater Diseases, FW Disease Troubleshooting, Ich/White Spot Disease, Choose Your
Weapon: Freshwater Fish Disease Treatment Options
by Neale Monks, Formalin/Formaldehyde,
Related FAQs: FW
Fish Parasitic Disease 1, Ich/White
Spot Disease, Worm Diseases,
Cichlid Disease, African Cichlid Disease, Aquarium
Maintenance, FW Infectious
Cichlid Disease 1, Cichlid
Disease, Betta Disease
Hydra control 5/3/16
Hello! Thanks for taking the time to answer my question. I read your FAQs about
freshwater hydra - I saw that 3 spot gouramis will eat hydra.
Will the smaller Sparkling gouramis (Trichopsis pumila) eat them as well?
<I do think so>
The hydras are in my 2-1/2 gallon tank, probably came in on some new plants. No
way a big gourami would go in there! Looked like some Bettas will also eat
hydra. I'm getting a pair of those soon so if they will eat the hydra they can
go in the little tank. If all else fails I'll try Fenbendazole,
<I'd use Fluke Tabs...>
but I'd rather try a non-chemical approach first.
Thanks for your help!
<Welcome. Bob Fenner>
FW parasite ID 8/18/13
I wondered if you could help with identifying the attached...
I found 8 of them on the bottom of my quarantine tank after treating a
sick platy with an anti-parasite medication (liquid Praziquantel 'Prazi
Pro') . As far as I know they came from inside the poor fish.
<Mmm; appear to be chitinous in this pic... external, or gill cavity
(which is also ext.)...>>
The heads are dark and visible to the naked eye. About 0.3mm across. The
bodies had largely disintegrated before I got them but looked to have been
maybe a cm or so long and worm-like...
<Hmmm; please do send along an image of a whole specimen if you can>
without the dark cuticle (?) visible on the head part. I did see some other
structures - a node with fine hooks or hairs (bursa? couldn't tell which
part it had been attached to) and the structure coming from the inside of
the head shown on the doc. file.
Hunting around on the web the closest I can find is some kind of hookworm
... what do you think? The teeth and claw structures are really distinctive
but I couldn't find a picture of anything quite like these anywhere...
I'd like to know what they are and whether my main tank is likely to be
swarming with eggs and larvae just waiting to latch onto one of my other
fish and whether there is any point in re-treating my sick fish with the
Prazi Pro - she is still very sick-looking and not eating. (It is 7 days
since I first quarantined and treated her)
<If they are worms, the Prazi has likely eliminated them; if crustaceans;
you'll need to treat w/ another compound. See WWM re such for freshwater
Any help/info would be appreciated!
<The head, mouth parts, are reminiscent of Ergasilus, some other copepods...
perhaps... Bob Fenner>
Re: unknown parasite, FW...
Thanks for the quick response! Had a look at Ergasilus spp on the web -
but nowhere seems to mention they have 'teeth' - which are very
distinctive in the species I have and I think would be commented upon
I have make the attached composite photos of the 2 specimens I have of
bodies ('body 2' has two versions - a light and dark)... I am afraid
both specimens are in pretty bad shape but I had another good look under
the microscope and can't see any obvious structures like legs or chitin
plates etc... so don't know if these help much! I am also not sure if
they are complete or the tail end has broken off - looks broken to me so
there could be missing parts.
<... no apparent legs? Quite common in internal parasites; and of course
worms lack them... But do have eyes; and these too tend to be absent, or
greatly reduced... These appear to be segmented... and still
Did you actually see them being evacuated from the fish's vent?
Am leaning toward (guessing) aquatic insect larvae...
non-parasitic; though can be piscivorous... Do put the string
"freshwater aquatic insect larvae" in your search tool and take a long
look/see at images... do any of these bear close resemblance to what you
Sorry about the quality - I am just holding my camera and taking shots
down the microscope tube.
<Good work; better than I could do. BobF>
|Re: unknown parasite
Oh - that's an idea! I'll send the photos to a friend who is an aquatic
invertebrate person... though I have to say I still think they must be
parasitic. I scooped the sick fish out of the aquarium in a small container
to transfer her to the quarantine tank and I think I would have
noticed if these guys were with her. But maybe not! Perhaps there is
something else completely different wrong with the fish...
<... do look at the system this fish was hauled from... At the surface
Re: unknown parasite
I agree - the mouthparts do look like those of an insect....
Any suggestions as what to do with my sick fish? Any other treatment (if it
's not an internal parasite) you can suggest?
<As you were first directed.>
Symptoms are - very thin, lethargic, not eating or if eats - spits food out,
has been like this for at least last 2 weeks (was away on vacation before so
not sure how she was...), other fish in original tank all fat and bright,
can't see anything obvious on her externally....
Re: unknown parasite
FYI Identified the mystery 'parasite'
It's a midge larva!
Not a parasite at all but residue from feeding bloodworms... must have
been in the water the fish was transferred in (from the main tank) or
from her gut and pooped out once in the quarantine tank...
<Ah yes; as I had guessed>
Back to the drawing board for my diagnosis!
<No worries; not harmful. Bob Fenner>
FW small worms... ID, contr.,
posted... 2/21/08 Hello crew, Thanks for all your help
in the past, and hopefully now you guys can steer me in the right
direction...my 55 gallon freshwater cichlid tank is full of worms...
everywhere. they are about 0.5-1.0 cm long and about 1/3 the thickness
of dental floss... just wiggling and swimming around... they are not
bothering the fish or attached to them in any way, but they are quite
visible as my tank water is very clean (or so I thought). I've
already changed my tank water three times and they are still there..
and I haven't added any new fish or items to the tank,,, what are
these worms, are they dangerous to my fish, and how do I get rid of
them.. Thanks, J.P. <Mmm, please read here:
http://wetwebmedia.com/FWSubWebIndex/fwwormidf.htm and the linked files
above. Bob Fenner>
|Freshwater Aiptasia? Almost As
Bad.... Hydra! - 04/29/2006 Hi Crew, <Hi,
Monte!> I have a question, Is there such a thing as Fresh Water
Aiptasia? <No, but I know EXACTLY where this is going.> I
have what appears to be several small Aiptasia on my plants and
tank walls. The main single body is green and it has about four to
five tentacles on top. They are to small right now for a good
picture but as soon as I can get one I will forward one to you.
<No need, I can tell you precisely what they are from your
description. If I'm wrong on this, I'll buy you
a drink (but you'll have to come to Santa Cruz to cash in on
it!). They're Hydra.> Also I have some very small
flea looking bugs down around the gravel, there white, oval and
very fast, they don't seem to be hurting anything just
wondering what they might be and if I should try to eradicate them.
<Not sure on these, perhaps Daphnia or
Moina.... there are VERY many small invertebrates that
fit this description. They're probably completely
harmless.> Here are the tank inhabitance: 75gal planted tank
These are the only survivors of many fish, (Too many, Too fast, Too
quick). <You've learned your lesson, I trust?> Two silver
hatchets Two Otos <When/if the Hydra "take over", the
Otos may suffer "stings" from them.> Plants: Duckweed
Java Fearn Dwarf Sagittaria Anubias Barteri Vallisneria Spiralis
Cryptocoryne Wendtii, Red I'm working on getting it ready for
four to five Discus and a school of about 30 Cardinal tetras.
It's been running for about three months now and I've been
back and forth with algae blooms. <To be expected with new-ish
tanks.> I believe I have that under control as of now, but it
will be a few more months before I purchase the Discus and
Cardinals as I'm waiting on two large pieces of Malaysian drift
wood. <Sounds nice.> Any help would be much appreciated.
<I, personally, would eliminate the Hydra for a few
reasons. For one, you can't share plants with folks
who don't want Hydra. For two, those Otos may suffer
for 'em. For three, the discus may have trouble with
their young getting damaged or killed by Hydra, should they choose
to reproduce. Please take a look here to find my
experience with eradicating Hydra with Fenbendazole:
(incidentally, I'm "vintage_fish" in the forum.)>
Keep up the great work. <Thanks, mate!> <Wishing you