Home | About Us | Contact Us


Koi Forum - Koi-Bito Magazine straight from Japan
Page 1 of 2 12 LastLast
Results 1 to 10 of 13

Thread: Holes in dorsal fin

  1. #1
    Sansai weesec01's Avatar
    Join Date
    Mar 2007
    Posts
    153

    Holes in dorsal fin

    Hi,

    Today, I notice my Kojaku's dorsal fin has many tiny holes. Is that due to parasites or what others possibility? My water parameter is within the range at all time, PH 7.2 - 7.4, ammonia 0, Nitrate 0, & Nitrite 0, I always have 10% water change weekly. All others koi do not have these problem. Any feedback? Thanks in advance.
    Attached Thumbnails Attached Thumbnails Holes in dorsal fin-fin-holes.jpg  

  2. #2
    Fry
    Join Date
    Sep 2008
    Location
    Westbury, Wiltshire, UK.
    Posts
    3
    Hi, i have a 21year old Kohaku with numerous holes in its dorsal fin, i was of the opinion that they got there due to a bout of new pond syndrome (Poor water conditions and baterial problems) when i transfered it too my new pond some 5 years ago. the fish was never sick and the holes are slowly growing out as time goes on. Of the three 21year olds that were transfered this was the only one to produce these holes.

  3. #3
    Daihonmei MikeM's Avatar
    Join Date
    Dec 2003
    Location
    Orlando, Florida
    Posts
    11,128
    I have seen perfectly spaced holes in the dorsal like the fish posted... on koi that developed them as they grew large with absolutely fine water conditions at all times. It seems to be a genetic trait to which some koi are prone. These holes have stable edges and no fraying whatsoever. This is completely different from holes created by a bacterial infection, which will have frayed edges caused by the rotting tissue being attacked by the microbes. A hole created by bacterial action may heal after the infection is eliminated, depending on circumstances. The regularly spaced dorsal holes do not close up. They are rather interesting, I think. I cannot imagine an evolutionary purpose served, but not everything has a purpose.

  4. #4
    Oyagoi kntry's Avatar
    Join Date
    Oct 2004
    Location
    Louisiana - KHA
    Posts
    2,459
    It's interesting that every hole is on a bone and not between bones.

  5. #5
    Sansai
    Join Date
    Dec 2003
    Location
    Malaysia
    Posts
    175
    Quote Originally Posted by weesec01 View Post
    Hi,

    Today, I notice my Kojaku's dorsal fin has many tiny holes. Is that due to parasites or what others possibility?
    Dont know what causes them but if you want to close them up, just use a sharp blade and slice thru the hole. The split will heal in no time.

  6. #6
    Daihonmei
    Join Date
    Sep 2006
    Posts
    7,642
    Bacterial erosion ( bacteria uses the fish as substrate) at the points of thinning mucous coating. It is the same for nose and head as well as the 'mechanical parts' on fins- especially dorsal fins. JR

  7. #7
    Jumbo
    Join Date
    Dec 2003
    Location
    Ojiya, Niigata, Japan
    Posts
    875
    Interesting, I've seen it many times, including here in Japan, also on an All Japan Grand Champion, and never been able to obtain any kind of reasoning beyond a shrug of shoulders.

  8. #8
    Jumbo l113892's Avatar
    Join Date
    Jan 2004
    Location
    louisville, ky usa
    Posts
    660
    It is common to see on large fish if you look closely.

  9. #9
    Sansai weesec01's Avatar
    Join Date
    Mar 2007
    Posts
    153
    Quote Originally Posted by hwong View Post
    Dont know what causes them but if you want to close them up, just use a sharp blade and slice thru the hole. The split will heal in no time.
    Thanks hwong, Very interesting! I will try this method to heal the holes.

    Can anyone advise me how much anesthetic should I use? This is my 1st time putting it in practise.

    Bacterial erosion ( bacteria uses the fish as substrate) at the points of thinning mucous coating. It is the same for nose and head as well as the 'mechanical parts' on fins- especially dorsal fins. JR

    Hi JR, if there are bacteria erosion, why isn't it rotting? The holes look like so perfectly punches.

  10. #10
    Daihonmei
    Join Date
    Sep 2006
    Posts
    7,642
    It's not caused by flexibacter clan so you don't see any virulent infection.

    This is part of that thing I mentioned many times about realities of closed systems and erosion of koi gills and skin.
    In another thread we talked about the many 'environmental' diseases of all captive pet fish ( pond fish, tropical fish, marine fish). The group of symptoms is often blamed on water quality ( nitrate) or diet or some missing ingredient from the wild setting . In koi we zero in on mud and rooting behavior as lacking in a closed koi pond. In marine tanks they zero in on nitrates and lack of wild food like live coral and in freshwater tropicals that zero in on nitrate, lighting and lack of whole live food.
    What ever they true causes one thing is clear- life in captivity can produce long life spans but the fish often look much older than they really are. I have mentioned the concept of premature aging in koi as a natural result of 'wearing' water chemistry, crowding, nagging ambient ammonia, lack of live food and hard water.

    In any pond there is a natural bacteria count. The fish's body is covered with a normal fauna bacteria and the mucous coat traps and removes the bacteria regularly so that the count remains stable. This is not disease causing. But if the mucous coat is thin or the cells that produce it are exhausted, a certain amount of erosion is expected. you will notice a pitting on the koi's head around sensory organs. This colored skin often goes white ( scarred) in older fish. It is normal aging in pond fish living in a closed system. JR

Page 1 of 2 12 LastLast

Similar Threads

  1. Holes in dorsal
    By Appliance Guy in forum Main Forum
    Replies: 14
    Last Post: 05-19-, 12:16 PM
  2. My Tancho's broken its dorsal fin spine
    By kaysee in forum Main Forum
    Replies: 8
    Last Post: 12-11-2010, 10:15 AM
  3. Split dorsal fin
    By l113892 in forum Main Forum
    Replies: 5
    Last Post: 06-07-2010, 09:16 AM
  4. Split dorsal fin
    By Flounder in forum Main Forum
    Replies: 3
    Last Post: 06-22-2009, 04:41 PM
  5. Dorsal fin injury...can this heal??
    By Brutuscz in forum Main Forum
    Replies: 2
    Last Post: 07-06-2008, 07:47 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Articles - Sitemap - FAQs and Rules

KB Footer Graphic
Straight from Japan... For the serious hobbyist!
All content and images copyright of: Koi-bito.com