The Fish Vet's Blog

Fisheries Minister Norman Moore has welcomed negotiations between the State’s peak commercial fishing body and resources company Chevron Australia, to set up a mechanism for compensating commercial fishers potentially affected by the new Wheatstone Project.

For details, please follow the link below to see the media release issued by Minister Moore this morning:

http://www.mediastatements.wa.gov.au/Lists/Statements/DispForm.aspx?ID=151238&Source=http%3A%2F%2Fwww%2Emediastatements%2Ewa%2Egov%2Eau%2FPages%2Fdefault%2Easpx

Check out what’s down the scope this time as Dr Richmond Loh, The Fish Vet, coaches a couple of students from Murdoch University on what to look out for and any interesting bits that go with the diagnosis.

http://youtu.be/WaqBXU1Ct2A

Dr Loh offers diagnostic pathology testing of aquatic animals (including histology, cytology, haematology and bacteriology) to fish farmers and for pet owners the like.

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Free webinar on all you wanted to know about fish welfare can be found on my latest youtube video.
Just follow this link:

See link for the full article:

http://aquatichealth.net/node/62537

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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

Aquaculture International: Journal of the European Aquaculture Society
Volume 20, Number 5 (October 2012)
	Factors affecting fish yield and profit in fish pen culture in flooded ricefields
	Authors:	Nam Cao Quoc 1, Nico Vromant 2, Duong Le Thanh 1, Frans Ollevier 3
	Author Affiliations:	1: Mekong Delta Development Research Institute, Can Tho University, Can Tho city, Vietnam 2: Vlaamse Vereniging voor Ontwikkelingssamenwerking en Technische Bijstand, Paramaribo, Suriname 3: Laboratory of Aquatic Ecology and Evolutionary Biology, Faculty of Science, Leuven, KU, Belgium
	Source:	Aquaculture International: Journal of the European Aquaculture Society, Volume 20, Number 5 (October 2012)
	Page Numbers:	827 – 845
	Available Full Text:	Full Text: Subscription Required to view full text Format: PDF Size: unknown Location: Publisher’s Site Authentication: EBSCOhost EJS
	Abstract:	Abstract In recent years, a rotational system consisting of two rice crops followed by a fish pen culture during the monsoon flood period was adopted in parts of the flood-prone region of the Mekong Delta. In this paper, we use the survey data from 51 fish pen farmers at Co Do and Vinh Thanh district, Can Tho City, to investigate the factors affecting fish yield and profit in such fish pen culture system. The net yield of all stocked fish varies from 377 to 3,782 kg/ha/crop while the return above variable costs varies from -5.3 to 9.8 million VND/ha/crop. Low fish price at harvest and the difficulty to sell below market sized fish at a period of oversupply are the main problems for fish pen culture. Fish net yield significantly increases with stocking density and is linked with specific polycultures. Common carp and bighead carp perform best in fish pen culture, both in production and profit considerations. Harvest body mass of common carp is mainly limited by increasing common carp stocking density. Therefore, a stocking density of common carp of about 6,000 fish/ha is recommended to obtain the optimum combination of reasonable body masses, and a good price, as well as a high return above fingerling costs.
	Citation:	Nam Cao Quoc, Nico Vromant, Duong Le Thanh, Frans Ollevier . Factors affecting fish yield and profit in fish pen culture in flooded ricefields. Aquaculture International: Journal of the European Aquaculture Society, Volume 20, Number 5 (October 2012), pp. 827-845, <http://ejournals.ebsco.com/direct.asp?ArticleID=443AB7B63ED5FB6A814A&gt;
	URL:	http://ejournals.ebsco.com/direct.asp?ArticleID=443AB7B63ED5FB6A814A

 
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I watched this show today and one of the scientists said she discovered the secret to anti-ageing when studying Tetrahymena (this, in the fish world, we know as a parasite of fishes). These protozoa are capable of continually dividing/multiplying without limit because they are able to repair and maintain the length of their telomeres (at the ends of their DNA) with telomerase.

Studies have shown that lobsters also have strong telomerase activity, and so, they never age at a cellular level. Theoretically then, they can live for eternity!

In humans, decreasing stress levels can help with extending the telomere length.

Maybe Tetrahymena and lobsters are just cool and calm critters.

Did you know you can make artificial seawater so you can conveniently keep a tropical seawater tank to house your own set of Nemo’s?

Check out a very simple video I’ve uploaded to my YouTube channel –

Looks like genetic selection is the way to forge ahead as a way to avoid the costly freshwater baths and production losses (reduced appetite, poor feed conversion, poor growth rates, mortalities, etc.). Good one!

Aquaculture
Volume 365, Number 18 (October 2012)
	Genetic variation in parasite resistance of Atlantic salmon to amoebic gill disease over multiple infections
	Authors:	Peter D. Kube, Richard S. Taylor, Nicholas G. Elliott
	Author Affiliations:	no affiliations available
	Source:	Aquaculture, Volume 365, Number 18 (October 2012)
	Page Numbers:	165 – 172
	Available Full Text:	Full Text: Subscription Required to view full text Format: PDF Size: Unknown Location: Publisher’s Site Authentication: Publisher’s Site
	Abstract:	Genetic selection is being developed as a management tool for the control of amoebic gill disease (AGD) in Atlantic salmon. AGD is caused by an external gill parasite and is an animal health issue that results in significant economic loss to the Tasmanian salmon industry. This paper presents genetic parameters for AGD resistance, describes patterns of genetic variation over multiple infection cycles, and discusses the development of a selective breeding program to exploit this variation.
	Citation:	Peter D. Kube, Richard S. Taylor, Nicholas G. Elliott . Genetic variation in parasite resistance of Atlantic salmon to amoebic gill disease over multiple infections. Aquaculture, Volume 365, Number 18 (October 2012), pp. 165-172, <http://ejournals.ebsco.com/direct.asp?ArticleID=400DB0C52F19EFF6B346&gt;
	URL:	http://ejournals.ebsco.com/direct.asp?ArticleID=400DB0C52F19EFF6B346

 
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“Whilst it was thought that the presence of a larger fish would suppress aggression in smaller conspecifics this did not occur. In fact aggression was significantly (P =0.036) higher when large trout were present during the first 4 weeks. No significant differences were found between other welfare indicators, self-feeder utilization or production parameters.”

From this interesting article below.

Aquaculture Research
Volume 43, Number 11 (October 2012)
	Can the presence of a large conspecific improve the production and welfare of groups of smaller self-feeder competent rainbow trout?
	Authors:	Matthew J. Flood, Chris Noble, Rem Kagaya, Mitsuo Tabata
	Author Affiliations:	no affiliations available
	Source:	Aquaculture Research, Volume 43, Number 11 (October 2012)
	Page Numbers:	1620 – 1627
	Available Full Text:	Full Text: Subscription Required to view full text Format: PDF Size: unknown Location: Publisher’s Site Authentication: EBSCOhost EJS
	Abstract:	This study examined the production and welfare effects of including a large self-feeder competent rainbow trout, Oncorhynchus mykiss(Walbaum) (~665 g) in groups of smaller self-feeder competent conspecifics (~234 g). Costs and benefits were examined for both welfare (aggression, fin damage, condition and mortality) and production (self-feeder utilization and growth). The 8-week experiment used six groups of small trout; three treatment groups containing a large trout and three control groups. After 4 weeks the large fish were removed from treatment groups and added to control groups, thus reversing the treatments. Whilst it was thought that the presence of a larger fish would suppress aggression in smaller conspecifics this did not occur. In fact aggression was significantly (P =0.036) higher when large trout were present during the first 4 weeks. No significant differences were found between other welfare indicators, self-feeder utilization or production parameters. From a production and welfare perspective these results suggest that with the exception of initially increasing aggression larger fish do not represent a significant benefit or risk to smaller conspecifics being cultured in self-feeder equipped tanks, when all fish are self-feeder competent.
	Citation:	Matthew J. Flood, Chris Noble, Rem Kagaya, Mitsuo Tabata . Can the presence of a large conspecific improve the production and welfare of groups of smaller self-feeder competent rainbow trout?. Aquaculture Research, Volume 43, Number 11 (October 2012), pp. 1620-1627, <http://ejournals.ebsco.com/direct.asp?ArticleID=4EF1BFEAD3C61114F025&gt;
	URL:	http://ejournals.ebsco.com/direct.asp?ArticleID=4EF1BFEAD3C61114F025

 
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