The Fish Vet's Blog

Check out this video I just uploaded: http://youtu.be/iySbeEP5Ii4

For those of you in the northern hemisphere, the flu season will be arriving or might even be in full swing. To give us some sort of immunity, we ought to get vaccinated….

Can similar principles work in crustaceans? This paper says, “Yes”!

Aquaculture
Volume 337, Number 1 (March 2012)
	Vaccines and crustacean aquaculture—A mechanistic exploration
	Authors:	Andrew F. Rowley, Edward C. Pope
	Author Affiliations:	no affiliations available
	Source:	Aquaculture, Volume 337, Number 1 (March 2012)
	Page Numbers:	1 – 11
	Available Full Text:	Full Text: Subscription Required to view full text Format: PDF Size: Unknown Location: Publisher’s Site Authentication: Publisher’s Site
	Abstract:	One of the dogmas of comparative (evolutionary) immunology for the last few decades has been that all invertebrates lack any form of immunological memory similar to that found in jawed vertebrates. Vaccinating invertebrates, such as shrimp, should therefore be an ineffective management strategy resulting in no more than short-lived, non-specific immune stimulation. Recent studies in crustaceans and insects, however, suggest a form of immune memory in these animals described variously as ‘immune priming’, ‘specific immune priming’ or ‘line specific immune memory’. Workers have injected various arthropod species with inactivated pathogens and then later challenged them with a dose of the same pathogen capable of killing the host, reporting enhanced survival or increased reproductive fecundity compared with animals vaccinated with an unrelated organism. Interestingly, in some studies this enhanced immunity is trans-generational (i.e. passed on to progeny). This brief review focusses on a mechanistic exploration of ‘specific immune priming’ with particular reference to shrimp culture. Humoral antimicrobial factors, such as antimicrobial peptides and lysozyme, do not possess the required specificity to explain this phenomenon. Instead, recent studies have demonstrated elevated phagocytic activity after “vaccination” that does not result from general (non-specific) stimulation in phagocytosis. This enhanced phagocytic activity is likely linked to specific recognition of determinants on the outside of microbes by the haemocytes of these “vaccinated” animals. In some cases, at least, the mechanism for recognising these determinants appears to rely upon an invertebrate homologue of the Down syndrome cellular adhesion molecule (Dscam) and the ability of the Dscamgene to produce variants of this molecule with specific binding capabilities. Pioneering studies have demonstrated that Dscam is intricately involved in phagocytosis in insects and able to produce pathogen-specific splice form variants after immune challenge or infection. This would enable an animal to tailor an immune response specifically to a pathogen. It should be noted, however, that the phenomenon of immune priming is certainly not universal, possibly because of the much lower numbers of different immune receptors that arthropods are able to produce compared with jawed vertebrates. The review concludes that immune priming in invertebrates should be re-evaluated on an animal to animal and pathogen to pathogen basis. It also notes that whilst there is evidence that vaccinating shrimp against viral and bacterial infections shows promise, the practicality of such processes and their benefit to shrimp requires further evaluation.
	Citation:	Andrew F. Rowley, Edward C. Pope . Vaccines and crustacean aquaculture—A mechanistic exploration. Aquaculture, Volume 337, Number 1 (March 2012), pp. 1-11, <http://ejournals.ebsco.com/direct.asp?ArticleID=41B7B051E0ABE319B79C&gt;
	URL:	http://ejournals.ebsco.com/direct.asp?ArticleID=41B7B051E0ABE319B79C

Link to this article shared by

http://www.nytimes.com/2012/11/08/nyregion/hurricane-filled-new-york-aquarium-with-dangerous-substance-water.html?_r=0

Dissolved oxygen and water temperature are the two most important water parameters at this stage.

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Yours sincerely,

Dr Richmond Loh
BSc BVMS MPhil MANZCVS (Aq & Pathol)
The Fish Vet, Perth, Western Australia.
Veterinary Medicine for fish.
http://www.thefishvet.com.au
Ph: +61 (0)421 822 383

This was a newspaper article title and I quite like it. One of my friends thought that it was an article about me….Why? You may ask.

My passion has always been all things fishy, however, my work has not always been solely fish. While working in the beautiful state of Tasmania, the Tasmanian devils were discovered to have been plagued by a devastating disease which we termed “devil facial tumour disease”. I was part of the initial team who investigated the disease and brought it to the attention of the officials. We found no evidence that it was caused by toxins, viruses or a number of other things, but it was a unique disease that was caused by an infectious cancer cell line that would spread from one animal to another by mechanical means. The work on my part at least, involved quite a lot of field work, laboratory work, weekend work, late nights, research and collaborations. I managed to publish a couple of seminal papers on the disease (in Veterinary Pathology) and produce a Masters thesis. For those who’re interested in things beyond fish, you may wish to peruse through my thesis which can be found at this link – http://researchrepository.murdoch.edu.au/id/eprint/162

Free sample pages of "Fish Vetting Essentials" and "Fish Vetting Medicines – Formulary of Fish Treatments" are available for viewing and download on Scribd.

Fish Vetting Essentials

Fish Vetting Medicines – Formulary of Fish Treatments

To purchase a hard copy, go to: http://thefishvet.com.au/shop/shopping.html

There have been quite a few rumours that feed companies have been substituting fish meal with non-fish proteins such as mammal proteins and plant proteins. These on feed analysis might show nothing different in terms of the protein-nitrogen content, however, the finer make up of the different amino acids and fatty acids and others may not be quite in balance with the fish’s requirements. As such, cultured fish may start developing different diseases with their muscle (myopathy), skeleton, etc. So it is very important that you establish a good working relationship with the feed company and make sure that nobody is short changing one another. For if one industry collapses, the other will soon follow. This is what I call product integrity and business integrity.

Aquaculture
Volume 341, Number 5 (March 2012)
	Replacement of fishmeal with poultry by-product meal in the diet of Florida pompano Trachinotus carolinusL.
	Authors:	Waldemar Rossi, D. Allen Davis
	Author Affiliations:	no affiliations available
	Source:	Aquaculture, Volume 341, Number 5 (March 2012)
	Page Numbers:	160 – 166
	Available Full Text:	Full Text: Subscription Required to view full text Format: PDF Size: Unknown Location: Publisher’s Site Authentication: Publisher’s Site
	Abstract:	The development of cost-effective and growth-promoting diets for Florida pompano (Trachinotus carolinusL.) is necessary for a feasible pompano aquaculture industry in the United States. However, research efforts to reduce the utilization of marine ingredients in aquatic feeds are needed to accomplish such a goal. Three independent growth trials were conducted to evaluate the replacement of fishmeal in the diet of Florida pompano. The basal diets were formulated to contain 40% crude protein and 10% lipid using solvent extracted soybean meal and corn gluten as the primary and fixed protein sources. In Trial I (10weeks) the basal diet containing 15% fishmeal (FM15) was modified by the isonitrogenous replacement of fishmeal with poultry by-product meal resulting in diets containing 10% (FM10), 5% (FM5) and 0% (FM0) fishmeal. In Trial II (12weeks), the FM0 diet was supplemented with methionine (M), lysine (L), and taurine (T), serving as the basal diet (MLT) for the evaluation of potential limitations in these amino acids. By deleting individual amino acids, test diets without methionine (LT), lysine (MT) or taurine (ML) supplements were formulated. In Trial III (8weeks), the FM0 diet from Trial I served as the basal diet (0% Tau) for the evaluation of potential limitations in taurine. Fish in replicate tanks (n=3) were fed one of the randomly assigned test diets two times daily. The total replacement of fishmeal in Trial I resulted in depression of fish performance while the performance of fish offered test diets with 5–15% fishmeal did not differ significantly. Reductions in weight gain (from 338.1 to 260.4%), feed efficiency (from 0.53 to 0.40), protein and energy retention (from 19.6 to 12.4% and from 20.4 to14.2%, respectively) were observed in fish fed the FM15 and FM0 diets, respectively (P<0.05). In Trial II, growth performance of pompano did not change (P0.05) by the removal of supplemental methionine, lysine or taurine from the FM0 diet albeit, numerically the removal of taurine produced the smallest fish. In Trial III, the supplementation of taurine to the FM0 diet at 0.75g/100 (0.75% Tau) improved the weight gain (from 587.7 to 773.3%), feed efficiency (from 0.50 to 0.64), and protein retention (from 20.5 to 24.3%) of pompano (P<0.05). Based on these results, we concluded that poultry by-product meal is a good alternative ingredient for fishmeal in the diet of Florida pompano and that this species appears to have a minimum dietary requirement for taurine.
	Citation:	Waldemar Rossi, D. Allen Davis . Replacement of fishmeal with poultry by-product meal in the diet of Florida pompano Trachinotus carolinusL.. Aquaculture, Volume 341, Number 5 (March 2012), pp. 160-166, <http://ejournals.ebsco.com/direct.asp?ArticleID=47918E8E0D99E4C6AE2B&gt;
	URL:	http://ejournals.ebsco.com/direct.asp?ArticleID=47918E8E0D99E4C6AE2B

For those new or struggling with fish microanatomy, this book is a great resource.

Check out the book out using this link shared by Dr Jo Bannister –

Atlas-of-Fish-Histology

For help and advice with wild turtle issues ring:
0424 727 411 or 0424 727 624
www.turtleoblonganetwork.org.au/contact-us.html

Check out the Australian Veterinary Association’s (AVA) website, shared by Dr Jo Bannister:

http://www.ava.com.au/newsarticle/latest-fish-welfare-%E2%80%93-aaws-promotes-humane-despatch

Following the recent post on the potential for saprolegniasis affecting fish after a cold snap (mainly from depressed host immunity), many fish owners turn to malachite green as a potent antifungal cure. This chemical is still widely available in the ornamental fish sector.

But did you know that malachite green has long been banned for use in food fish production because of their carcinogenic potential. Actually, I met a guy who had inadvertently treated his silver perch with this chemical, only to find out some time later that it’s rather toxic and banned for use in food fish. So, he can’t eat his fish and instead, his cultured fish will now become lifelong pets.

This paper describes a different compound (peracetic acid) that may warrant further investigation and it could be something that can be used safely for fish that are destined for human consumption.

Journal of Fish Diseases
Volume 35, Number 7 (July 2012)
	Peracetic acid is effective for controlling fungus on channel catfish eggs
	Authors:	D L Straus 1, T Meinelt 2, B D Farmer 1, A J Mitchell 1
	Author Affiliations:	1: U.S. Department of Agriculture, Agricultural Research Service, Harry K. Dupree – Stuttgart National Aquaculture Research Center, Stuttgart, AR, USA 2: Department of Aquaculture and Ecophysiology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
	Source:	Journal of Fish Diseases, Volume 35, Number 7 (July 2012)
	Page Numbers:	505 – 511
	Available Full Text:	Full Text: Subscription Required to view full text Format: PDF Size: unknown Location: Publisher’s Site Authentication: EBSCOhost EJS
	Abstract:	Peracetic acid (PAA) is a relatively new compound suggested for use to treat pathogens in aquaculture. It is approved for use in Europe, but not in the United States. This study determined the effectiveness of PAA for fungus control on channel catfish, Ictalurus punctatus(Rafinesque), eggs. The study consisted of five PAA concentrations (2.5, 5, 10, 15 and 20 mg L-1) and an untreated control in a flow-through system. A single spawn was used for each replication (N= 4). Eggs were treated twice daily until the embryos developed eyes. When hatching was complete for all viable eggs, fry were counted to determine the percent survival in each treatment. Fungal growth was severe in the untreated controls resulting in 11% survival. Treatments of 2.5, 5 and 10 mg L-1PAA were significantly different from the controls (P <;0.05). The highest percent survival of hatched fry was with 5 mg L-1PAA administered twice daily; the 2.5 mg L-1PAA treatment had slightly less survival, but gives a higher margin of safety in case of treatment error. Very little fungus was present in treatments receiving 2.5 mg L-1PAA or higher, and concentrations of 15 and 20 mg L-1PAA were toxic to the eggs. The mean survivals in the 0, 2.5, 5, 10, 15 and 20 mg L-1PAA treatments were 11%, 60%, 63%, 62%, 32% and 0%, respectively. Therefore, PAA may be a compound that merits further investigations regarding its use in U.S. aquaculture.
	Citation:	D L Straus, T Meinelt, B D Farmer, A J Mitchell . Peracetic acid is effective for controlling fungus on channel catfish eggs. Journal of Fish Diseases, Volume 35, Number 7 (July 2012), pp. 505-511, ;
	URL:	http://ejournals.ebsco.com/direct.asp?ArticleID=44C3AF30379B5B3A5154

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