Dear Mr. Pro
I have a reef aquarium that contains ich. I maintain an apparently healthy population of fish. The ich I speak of is an occasional outbreak on the Regal Tang. I am trying to pin down the quarantine philosopy that you support. Do you believe in treating all and any potential carriers of Cryptocaryon prior to installation in the display? Or, do you only support the theory of treating animals with visible signs during the quarantine process? If you support only treating only livestock with visible signs, whats your take on the following study of Cryptocaryon infection levels in wild populations. It is apparent from this study that parasitic infections are much higher than previously thought as evidenced by some authors who write on the subject. Low level infestation on apparently healthy livestock from the wild were only detectable through biopsy. Not suitable for the hobbyist and not helpful to the fish hee, hee.... these numbers are as high as 79% on some species. I am aware of the myth that "ich is always present" is not absolutely true, but according to this study, damn near! Visible inspection is not effective for fish that control infestations to a manageable level. So with that in mind, should the hobbyist treat all potential hosts with the treatment of choice? Copper? I realize that wild hosts dealing with the disease in the wild should exibit visible signs due to the transport stress etc. However, I have watched new arrivals at a rather large LFS I frequent lose all visible signs of Ich when acclimated into pristine water, food and reef conditions. If you don't support treating any and all new acquisitions with a cure of choice, how would you contrast that position with the following study? Thanks
Z
DAO 25:159-167(1996) - AbstractInfections of Cryptocaryon irritans on wild fish from southeast Queensland, Australia
Diggles BK, Lester RJG
Wild-caught marine fish from 3 sites in SE Queensland, Australia, were examined over a period of up to 13 mo for infections of the parasitic ciliate Cryptocaryon irritans. Infections of C. irritans were found to be common on the fish sampled. Out of a total of 358 fish (14 species), 239 (66.7%) from 13 species were found to be infected. At Site 1 at the mouth of an estuary, the prevalence of C. irritans infections was 79% and the mean intensity was 12.9 parasites fish-1. At Site 2, a coastal bar area, the prevalence of infection dropped to 66% and a mean intensity of 5.0 parasites fish-1, whilst at Site 3 on the Great Barrier Reef, prevalence was lowest at 51% with a mean intensity of 2.3 parasites fish-1. The study concentrated on 2 sparid fishes, Acanthopagrus australis from Sites 1 and 2 and Gymnocranius audleyi from Site 3. The prevalence of infections on A. australis from Site 1 (n = 101) was 100% with a mean intensity of 14.6 parasites fish-1, whilst at Site 2 (n = 74) the prevalence was 88% at a mean intensity of 5.2 parasites fish-1. There was no apparent seasonality in prevalence or intensity of infections at Sites 1 and 2 despite water temperatures ranging between 15 and 27*C. At Site 3, the prevalence of infections of G. audleyi (n = 39) was 38% with a mean intensity of 1.9 parasites fish-1. The diameter of the tomonts collected from A. australis from Sites 1 and 2 varied inversely with water temperature, and was not related to host size. Our results show that infections of C. irritans are common on wild fish, not rare as previously thought. This may be partially due to the increased sensitivity of our tomont collection technique. Our data suggest that C. irritans may exhibit a degree of host specificity in the wild, and also that its natural distribution can be extended into estuaries and seasonally into warm temperate waters. Your thoughts?
Z
I have a reef aquarium that contains ich. I maintain an apparently healthy population of fish. The ich I speak of is an occasional outbreak on the Regal Tang. I am trying to pin down the quarantine philosopy that you support. Do you believe in treating all and any potential carriers of Cryptocaryon prior to installation in the display? Or, do you only support the theory of treating animals with visible signs during the quarantine process? If you support only treating only livestock with visible signs, whats your take on the following study of Cryptocaryon infection levels in wild populations. It is apparent from this study that parasitic infections are much higher than previously thought as evidenced by some authors who write on the subject. Low level infestation on apparently healthy livestock from the wild were only detectable through biopsy. Not suitable for the hobbyist and not helpful to the fish hee, hee.... these numbers are as high as 79% on some species. I am aware of the myth that "ich is always present" is not absolutely true, but according to this study, damn near! Visible inspection is not effective for fish that control infestations to a manageable level. So with that in mind, should the hobbyist treat all potential hosts with the treatment of choice? Copper? I realize that wild hosts dealing with the disease in the wild should exibit visible signs due to the transport stress etc. However, I have watched new arrivals at a rather large LFS I frequent lose all visible signs of Ich when acclimated into pristine water, food and reef conditions. If you don't support treating any and all new acquisitions with a cure of choice, how would you contrast that position with the following study? Thanks
Z
DAO 25:159-167(1996) - AbstractInfections of Cryptocaryon irritans on wild fish from southeast Queensland, Australia
Diggles BK, Lester RJG
Wild-caught marine fish from 3 sites in SE Queensland, Australia, were examined over a period of up to 13 mo for infections of the parasitic ciliate Cryptocaryon irritans. Infections of C. irritans were found to be common on the fish sampled. Out of a total of 358 fish (14 species), 239 (66.7%) from 13 species were found to be infected. At Site 1 at the mouth of an estuary, the prevalence of C. irritans infections was 79% and the mean intensity was 12.9 parasites fish-1. At Site 2, a coastal bar area, the prevalence of infection dropped to 66% and a mean intensity of 5.0 parasites fish-1, whilst at Site 3 on the Great Barrier Reef, prevalence was lowest at 51% with a mean intensity of 2.3 parasites fish-1. The study concentrated on 2 sparid fishes, Acanthopagrus australis from Sites 1 and 2 and Gymnocranius audleyi from Site 3. The prevalence of infections on A. australis from Site 1 (n = 101) was 100% with a mean intensity of 14.6 parasites fish-1, whilst at Site 2 (n = 74) the prevalence was 88% at a mean intensity of 5.2 parasites fish-1. There was no apparent seasonality in prevalence or intensity of infections at Sites 1 and 2 despite water temperatures ranging between 15 and 27*C. At Site 3, the prevalence of infections of G. audleyi (n = 39) was 38% with a mean intensity of 1.9 parasites fish-1. The diameter of the tomonts collected from A. australis from Sites 1 and 2 varied inversely with water temperature, and was not related to host size. Our results show that infections of C. irritans are common on wild fish, not rare as previously thought. This may be partially due to the increased sensitivity of our tomont collection technique. Our data suggest that C. irritans may exhibit a degree of host specificity in the wild, and also that its natural distribution can be extended into estuaries and seasonally into warm temperate waters. Your thoughts?
Z
