Ecological and morphological features of Amyloodinium ocellatum occurrences in cultivated gilthead seabream Sparus aurata L.; A case study
Aquaculture, Volume 310, Issues 3–4, 9 January 2011, Pages 289-297
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5. ConclusionsOur results indicate that infestations of […] the gill parasite A. ocellatum can be avoided if a defined pattern of water quality is kept within production ponds with a defined fish stocking level. This pattern of water quality can be achieved by water renewal with night tides, which should be carried out by considering the dissolved oxygen values in production ponds.
- Velvet can be avoided.
- It is not inevitable.
- Even in a scenario where it’s commonplace.
- Stocking levels matter.
- Water quality (not our definition*) matters.
This is something I (and others) have been stating for years — mostly against stiff opposition in social media forums. (Folks who generally see infections as inevitable and chemical treatments as mandatory….which they are if you don’t know or heed this info.)
Finally (c. 2011) in print in a journal. Interestingly, they cite Brown from 1934 on some of this, so the info isn’t new.
To me, their definition of water quality is more or less synonymous with what we in our aquariums get from having mature, functional live rock in a reef tank. (Even more-so if the tank also has healthy, non-distressed fish as well.)
Importantly the authors’ definition has more to do with what’s living in the water than specific chemical or nutrient parameters that we tend to focus on. (Although those things matter too, they are a coincidence.)
This goes hand-in-hand with the info in these articles:
- Hyperparasitism of trichodinid ciliates on monogenean gill flukes of two marine fish
Unstable environments are a cause of pathogenic activity — especially where outbreaks are most intense and most virulent.
- The Nature and Consequences of Indirect Effects in Ecological Communities
More variety of life brings more stability. Less variety brings less stability. Less stability (as stated above) always means more pest organisms that are more virulent than they would otherwise be. My comments in this post are particular to pest dinoflagellate “algae” outbreaks (not parasitic dino’s), but the article applies widely to nature….read the whole article.
- Fish invading dinoflagellates: a synopsis of existing and newly proposed genera.
General info on velvet.
- Personal immunity versus social immunity
How immunity can work outside the body and even be transmitted.