A Closer Look at Goldfish Ick – Part 1 (The Life Cycle)
Ick (also known as ich) is short for ichthyophthiriasis and is caused by a parasite called Ichthyophthirius multifiliis. This organism is a protozoan, which is a general term for single-celled animals. Although it is only made up of a single cell, it has many features that make it extremely good at what is does. In fact, ick is so successful it has become the most common disease of captive goldfish, and is responsible for more goldfish deaths than any other disease.
Trophozoite
This is the phase of the ick life cycle when the parasite is living in the skin of the goldfish. It is a spherical shape with a cup shaped mouth at one end. The mouth contains very fine hair-like structures called cilia, that beat rhythmically and continuously inwards. These cilia scrape tissue from the body of the goldfish and pass it into the mouth.
Goldfish produce a natural reaction to the trophozoite – they surround it with a hard casing that forms a cyst. It is these cysts that are the most noticeable symptom of ick – the appearance of being sprinkled with salt.
Depending on the temperature of the water, the trophozoite grows to between 0.1mm and 1mm wide, and after about a week it falls off the goldfish. It swims in downward spirals to the bottom of the aquarium, or sticks to a plant or ornament.
Tomont
Once the released trophozoite has settled, it absorbs its own mouth and secretes a gel around itself, becoming known as a tomont (or trophont). It then starts to replicate inside the gel casing. The cells produced by the first few divisions form an internal wall on the gel casing, but the rest of them develop into parasites.
The number of cells produced in the tomont can reach 1000, and will usually be at least 600. This phase of the ick life cycle will be complete in anything between 8 hours and several weeks, depending on water temperature.
When complete, the tomont bursts and releases the individual cells called theronts. These look for goldfish to burrow into.
Theront
Theronts (also known as tomites) are microscopically small and oval in shape. They are good swimmers and move about the aquarium until they find a goldfish to latch on to and burrow into.
They swim with cilia and are thought to burrow into goldfish skin using these cilia, and possibly a combination of mechanical and chemical attacks on the integrity of the goldfish skin using a pointed structure and a capsule of chemicals found at the front of the parasite. It is after they burrow into the skin that they grow their mouths.
Theronts can survive for a maximum of 4 days without finding a goldfish to feed on, and in most cases they will die after 2 days.
How long does it all take?
It all depends on water temperature. The warmer the water, the quicker the ick life cycle is complete. At a temperature of about 20 Celsius (70 Fahrenheit) the cycle would take up to 4 weeks. Raising the water temperature to 26 Celsius (80 Fahrenheit) would see the process complete in about a week.
As the optimum water temperature for goldfish is at the lower end of the scale, the ick life cycle will take much longer in a goldfish aquarium or pond.
Tags: ich, ichthyophthiriasis, Ichthyophthirius multifiliis, ick
September 15th, 2008 at 9:51 pm
We set up r 1st tank, a 10 gal freshwater tank to raise Oranda Gold Fish. We bought 1 Red Cap Oranda, a Calico Oranda, a telescopic gold fish (not an oranda) and a Black Moor aslo not an Oranda. 3 days after we got the Black Moor he died. Petco replaced him and now we have a badk case of Ick that has all of our fich sick and lathargic. We are very concerned and believe that the Ick was introduced to the tank by the Black Moor. As a result, we have decided not to bey any more fish from Petco because the problems did not start intil we bracht the Moor home from there.
October 9th, 2008 at 9:59 pm
not sure what’s wrong with my gold fish really worried he got frayed tail and is just laying at bottom of tank and has no appitite have also noticed some tiny black/brown dots any ideas of treatment would be much appricated thanks xx
October 10th, 2008 at 9:49 pm
Cassie, check out the articles about tail and fin rot, and black spot disease. If you think that’s what is wrong then follow the advice there. You should also think about getting a vet to look at your goldfish if you don’t reckon you can deal with it.
Good luck. I hope he gets better soon.
January 22nd, 2009 at 4:10 pm
i had a gold fish tat the ick ate its tail and spread throgh out its body and i didnt eavan know what it was eather and it died and the ick killed half of my fish too
January 29th, 2009 at 10:08 pm
I just happened across this sight, and I have a question about my goldfish. I have three common goldfish ranging from about 6 inches to about 8 inches (give or take, just estimating size.) I cleaned my fishtank out, boiling litereally everything before putting it back together (I had a snail breakout). The next day, the middle sized goldfish started getting lighter. about 3 or 4 days later it was completely white, and Im afraid I might have hurt it or something. Its not acting any different, and it still eats and everything. Im hoping its nothing but Im really worried, because I have had these fish 2 years, going onto 3 and I have never seen this before. Any body know what it is or if its normal?
March 21st, 2009 at 12:03 pm
i got 2 goldfish & a sucky fish 4 my birthday (march 4th). I noticed my fish had got little white spots on them and they seemed unwel. my mum got some goldfish disease safe to treat them but both of my goldfish have died and the sucky fish has now got white spots on it’s underside. i have 2 living plants in my tank & a coral rock. how should i prepare my tank for new fish as i dont wan’t any new fish i get to die.
March 24th, 2009 at 11:47 am
Hi, i had my goldfish for few months. One of them (Pepek) is just resting down on the leafs of plants, doesn’t want to eat more than 2 flakes and his tail is hanging down too. He’s breathing and swimming about from time to time so I ended up putting him in to separate fish bowl as other goldfish is picking on him and poking him. Now he is just laying down at the bottom of the the bowl, still breathing and saw him swimming a bit too. But it looks like he’s feeling worse… Shall I try soaked mashed peas? I have looked at all the illnesses but he doesn’t match them. Please can you help???
March 24th, 2009 at 11:56 am
Hello Very Confused, I have heard that fish left in a dark can get very light.
May 23rd, 2009 at 6:01 pm
Hello. I have a small pleco, small ryukin goldfish, and small black moor in a 10 gal.
The water is cloudy but I bought some AccuClear and it’s clearing up. About a week ago, my fish got ich (but the black moor didn’t seem to have gotten it) and I stopped treatment yesterday because the symptoms disappeared about 3 days ago (using Rid Ich)
Now, the black moor has a white cloudiness over his bubbly eyes and some whiteness on his tail and fins (especially on the edges)…now the edges are starting to fray and I think the ryukin is getting the same thing (her fins are fraying)
What is this and how do I treat it? Can this be ich again?
June 3rd, 2009 at 4:42 pm
I bought 2 caloco orandas about three weeks ago, both of them seemed perfectly healthy and after about a week – week and a half they died. They had this fuzzy white stuff all over them and i am pretty sure it was ick. After they died I cleaned out my tank and washed everything thing with warm water and refilled my tank and used some water conditoner to help neutralize the water. I am just wondering if there is anything else i can do to prvent the ick from comming back and killing any future fish i might get?
June 8th, 2009 at 10:28 am
windgirl: you made a big mistake: you dont want to take a fish away from counter-fish. I know they were picking and poking him, but, that, over time, will stop. I have a comet, a large doldfish, a small calico comet, a medium black moore, and a green algae eater in a three gallion tank and they are doing fine. Also, I got a large black moore in a one gallion tank and he has ich. the only treatment i use and will use is called wardley ich-away. old school and the best. also, all fish species have a albino. i hope this helps anyone whom had a question. for ich, i fully recommend wardley ich-away. i trust it. i have kept fish all my life.
June 9th, 2009 at 4:48 am
Hi,
I have a common goldfish only an inch or maybe even smaller, i only got her the other day at petco. Today i noticed she had three white spots that looked very much like these discriptions. One on her tail (it fell off about an hour ago) one on her dorsil fin and one on one of her flippers. Shes not lathargic but shes had a very stressful week because i had to return the tank twice to buy a new one, so shes been in a few large vases i got out of a box in the garage. I’ve added the fish medicine called MELAFIX and im wondering if that will do any good? on the directions it says I’m supposed to change it after three days, but that doesn’t sound like it’ll help alot. What am i supposed to do? what can i do? and will this always be there or will it eventually go away?
June 27th, 2009 at 5:53 am
The way I treat ich on my goldfishes may not be conventional but it works. I quarantine new or infected goldfish in a 1 gallon bowl (because it’s a smaller environment to control, easier to do frequent water changes and only a temporary set-up. When they are better, I put them back in my 55gallon tank).
I use a drop of “Had-A-Snail” for every water change. I change the water in the morning, and at night for 7 days. The parasites fall off within 12-24 hours. I heard of this from a guy who owned a fish store and so glad I tried it. It also works with Flukes! Hope this helps.
August 2nd, 2009 at 4:36 am
I’m concerned of my Blackmoore named Black Jack. I’ve had him for about a month and a half, I also have another Ryukin with him. But, I have just recently discovered 2 little white spots by his mouth, could this be Ick? If it is Ick i’ve allready purchased some Ick cure, but should i quarenitine the fish with Ick to treat him, because I have a carbon activated filter along with beneficial bacteria, or should i just unplug the filter and treat the entire aquariam?
September 12th, 2009 at 8:40 pm
I have four goldfish in a twenty gallon tank!! I have had the tank set up for nine months now.. I have had three goldfish before this four that died back in January from ick.. I treated the water, and it was fine.. I am seeing the systems again. Cloudy water, bubbles, one of my fish is rubbing or just laying on the rocks rapidly breathing, and I noticed his fin looks ragged a bit.. Could this be ick again? I am treating it with these Lifequard tablets.. My other three fish are swimming and doing fine.. If it is ick why is the water cloudy? Is it safe for baking soda to go ito the tank to bring the bubbles down and the PH level back? Lost in thought here!! Hope you can give me some answers!! Yes, I did have two snails die recently after having them for two to three months, I also put in a new plant and changed a percantage of the water.. I need some advice of why this is reoccuring in the tank??
September 12th, 2009 at 9:19 pm
More from above.. Can fish really go to a vet? Should I take my sick fish to the vet, if he does not improve? Seeking advice..
September 22nd, 2009 at 2:10 am
Hi Susan,
I’m not sure about where you live but the vets around where I live do not treat fish. They don’t know about how to take care of goldfish or fish and how to treat them. They are basically just for dogs and cats.
From what I read above it sounds like poor water quality is causing your ich to re-occur. If the water is cloudy there is a problem. I bet you your ammonia is off the scale. You should test your water right away and do an immediate partial water change. Sounds to me like there is a breakdown in your nitrogen cycle.
I am 100% positive that water quality is causing your ich problem.
October 14th, 2009 at 5:49 pm
My black moor is just laying at the bottom of the tank. I tried to feed him and he won’t go after the food. Today I have just noticed his eyes are a tad cloudy. He rarely swims but when he does, he is very unbalanced. I have even caught him swimming upside down a few times. He isn’t growing any tumors or fugus anywhere. help?
November 16th, 2009 at 8:45 am
I have 2 gold fish about 2 years old one has a film growing over its eyes I think it is haveing difficulty seeing the other keeps facing up as though it standing on its tail.
Can you let me know what is wrong with them as I would not keep them if they are stressed in any way.
Thank you
November 18th, 2009 at 6:54 pm
Can humans or other pets like dogs get the parasite that causes ich from the tank water?
January 7th, 2010 at 1:14 am
Hi! i have a Q. I bought a calico goldfish yesterday and it had the following colors: Black, orange, & white. Then today, i noticed the black spots are ALL gone! I have 6 fish: Calico, Chase (dalmation molly), Cheeto (unknowed species but small and orange NOT goldfish) Aqua (a female guppie) and my other one Apple (a regular goldfish) live with Callie my calico goldfish. Whats wrong with her?!
January 7th, 2010 at 1:15 am
its a 10 gallon tank.
January 24th, 2010 at 2:15 pm
i have a question i just bought a oranda goldfish yesterday and my fish isnt swimming he just lays there all day unless i touch him he starts swimmimg and then he tucks in his fins and sinks back down.. do u think he is in shock ?
(i have a 10 gallon tank with litlle guppies in it)