Month: February 2013

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Yours sincerely,

Dr Richmond Loh 
BSc, BVMS, MPhil (Vet Path), MANZCVS (Aquatics), MANZCVS (Pathobiology), DipPM.
Veterinarian | Adjunct Senior Lecturer Murdoch University | WAVMA President-Elect |
Secretary Aquatic Animal Health Chapter – Australian and New Zealand College of Veterinary Scientists (ANZCVS)
The Fish Vet, Perth, Western Australia, AUSTRALIA. 

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Follow me on: Facebook “Fin Page” – YouTube  – Blog – Linkedin – Twitter
 
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Yours sincerely,

Dr Richmond Loh 
BSc, BVMS, MPhil (Vet Path), MANZCVS (Aquatics), MANZCVS (Pathobiology), DipPM.
Veterinarian | Adjunct Senior Lecturer Murdoch University | WAVMA President-Elect |
Secretary Aquatic Animal Health Chapter – Australian and New Zealand College of Veterinary Scientists (ANZCVS)
The Fish Vet, Perth, Western Australia, AUSTRALIA. 

This article suggests it is too, with increased disease resistance being one of the benefits.

Read more here:
http://aquatichealth.net/node/70061

Lately, there has been a recent increase in popularity in nano fish keeping. Critters like the cherry shrimp are growing in popularity In Australia, there are reports of people smuggling in these critters in as they’re not legal imports and some enthusiasts have even been so bold as to advertise them for sale on fish forums and the like. Although I don’t condone such activities, perhaps those that are already in Australia and provided that they are disease-free (the biggest concern for importing crustacea is the White Spot Syndrome virus), can be kept in Australia for breeding and populating the hobby.

This research paper describes the breeding behaviour and reproduction of a freshwater prawn and the observations made by the authors might be useful in breeding crustacea like the cherry shrimp. I’m keen on the idea of small scale aquaculture and intend to get more expertise in this area when I travel to Hawaii and Florida in the middle of this year.

Aquaculture Research
Volume 44, Number 3 (February 2013)
On the breeding behaviour and reproduction of the freshwater prawn, Macrobrachium rosenbergii(de Man 1879) (Decapoda-Crustacea) under laboratory conditions

Authors: Madlen M Habashy
Author Affiliations:
no affiliations available
Source: Aquaculture Research, Volume 44, Number 3 (February 2013)
Page Numbers: 395 – 403
Available Full Text:
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Format: PDF
Size: unknown
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Authentication: EBSCOhost EJS

Abstract: The giant freshwater prawn, Macrobrachium rosenbergiiis one of the most common decapod species, and now getting more attention from the aquaculturists world wide due to its high market demand. It is commercially important because of its size as well as its eating flesh qualities. The breeding behaviour, reproduction and hatching of this species were observed for about 8 months during 2009. Juveniles (0.55 ± 0.177 g total weight and 2.7 ± 0.12 cm, total length) were reared in rounded fibre glass tanks (1.3 m, diameter). Pre-mating moult occurs in prawns once the ovaries ripen in their carapace cavity so as to transform the prawn into berried stage. Recorded incubation period ranged from 18 to 24 days. The number of eggs ranged from 2050 to 150 500 and the fecundity ranged from 435.2 to 3849.1 eggs. Number of hatched larvae ranged from 1825 to 123 410 larvae for females of 4.71 to 39.1 g respectively. The number of eggs carried by female prawn was directly proportional to its body weight (no. of eggs = 3441.3 wt. of female – 32 292, r2= 0.819). (fecundity = 82.066 wt. of female – 235.04, r2= 0.7779; fecundity = 317.86 length of female – 2651, r2= 0.833). Hatching rate ranged from 65% to 91%, and there was a correlation between number of hatched larvae and size of female parent (no. of larvae = 10 369 length of female – 102 965, r2= 0.8159; no. of larvae = 2792.9 wt. of female – 26 268, r2= 0.829). This study can greatly help in the management strategies of prawn hatcheries and improve its hatching technology.
Citation: Madlen M Habashy . On the breeding behaviour and reproduction of the freshwater prawn, Macrobrachium rosenbergii(de Man 1879) (Decapoda-Crustacea) under laboratory conditions. Aquaculture Research, Volume 44, Number 3 (February 2013), pp. 395-403,
URL: http://ejournals.ebsco.com/direct.asp?ArticleID=4FCD8DA3D687DDB1CD5A

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Yours sincerely,

Dr Richmond Loh
BSc, BVMS, MPhil (Vet Path), MANZCVS (Aquatics), MANZCVS (Pathobiology), DipPM.
Veterinarian | Adjunct Senior Lecturer Murdoch University | WAVMA President-Elect |
Secretary Aquatic Animal Health Chapter – Australian and New Zealand College of Veterinary Scientists (ANZCVS)
The Fish Vet, Perth, Western Australia, AUSTRALIA.
Mobile Veterinary Medical & Diagnostic Services for fish and other aquatic creatures.
http://www.thefishvet.com.au
Ph: +61 (0)421 822 383

In Vietnam, small scale fish farmers are finding it more profitable to make their own fish diets rather than rely on feed manufacturers. This is also a good idea from the farmer’s point of view because you cannot always rely on the feed manufacturer to make the food to your specifications. Already, there have been reports of manufacturers substituting fish proteins for cheaper proteins and the health of the farmed fishes suffer as a result. Apparently, feed mills change things all the time. The reasons may be that specific ingredients may be too expensive or unavailable, they may then substitute it with another, or reduce the inclusion rate.

One farmer, and likely several others, had experienced the effects of alleged feed substitution by a feed manufacturer such as muscle disease, poor immunity and more. This farmer had a great idea on how they could avoid this issue. They bypassed the local feed supplier and import their feed from overseas. The reason behind this is that the Australian Quarantine Inspection Service (AQIS) is very strict and one of the import requirements is that the ingredients must be reflected on the label and there must not be any changes. There was a lot of paper work to get through, but they’re now reaping the rewards from this ingenious idea.

It troubles me that feed manufacturers could do such things, thinking they can get away with it. Aquaculture in most of Australia tends to be a small industry and they tend to be lower on the priority list as clients. But this feed substitution also occurs in other animal feeds like poultry. Such malpractices will jeopardise the aquaculture industry and eventually, it would impact on the feed manufacturer in a trickle down effect. So, one way of avoiding the loss of control over what you’re feeding your farmed fish is to make your own fish food. This is the experience of the Vietnamese farmers as explained in the research paper below.

Aquaculture Research
Volume 44, Number 3 (February 2013)
Evaluation of potential feed sources, and technical and economic considerations of small-scale commercial striped catfish (Pangasius hypothalamus) pond farming systems in the Mekong Delta of Vietnam

Authors: Chau T Da, Le T Hung, Håkan Berg, Jan E Lindberg, Torbjörn Lundh
Author Affiliations:
no affiliations available
Source: Aquaculture Research, Volume 44, Number 3 (February 2013)
Page Numbers: 427 – 438
Available Full Text:
Full Text: Subscription Required to view full text
Format: PDF
Size: unknown
Location: Publisher’s Site
Authentication: EBSCOhost EJS

Abstract: A technical and socio-economic survey was conducted in Dong Thap, Can Tho and An Giang, provinces of Vietnam in 2009. The results showed that most of the small scale farmers of striped catfish (Pangasius hypothalamus) carry out fish pond culture, developed and operated by self-learned experience and from neighbours knowledge. The mean pond depth varied from 3.5 to 4.0 m, ranging from 2 to 6 m. Most of the fish farms have extremely high stocking density, with an average of about 40 fish m-2, in some cases up to 70 fish per m2. The average yields and net income of small-scales pond farming is about 21–27 kg per m2crop-1and US$ 0.184–0.329 kg-1crop-1respectively. These figures are not significantly different compared with large-scale pond farming. About 75%, 86% and 80% of fish farmers in Dong Thap, Can Tho and An Giang province, respectively, received positive net returns. Farm-made feed is still playing an important role because of higher net profit compared with commercial pellet feeds. Rice bran and trash fish are the main feed ingredients for farm-made feed formulations. Striped catfish farmers are now actively searching for locally produced plant protein sources as alternatives to marine trash fish or fish meal.
Citation: Chau T Da, Le T Hung, Håkan Berg, Jan E Lindberg, Torbjörn Lundh . Evaluation of potential feed sources, and technical and economic considerations of small-scale commercial striped catfish (Pangasius hypothalamus) pond farming systems in the Mekong Delta of Vietnam. Aquaculture Research, Volume 44, Number 3 (February 2013), pp. 427-438,
URL: http://ejournals.ebsco.com/direct.asp?ArticleID=4C58B37C12DF2D660F6B
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Yours sincerely,

Dr Richmond Loh
BSc, BVMS, MPhil (Vet Path), MANZCVS (Aquatics), MANZCVS (Pathobiology), DipPM.
Veterinarian | Adjunct Senior Lecturer Murdoch University | WAVMA President-Elect |
Secretary Aquatic Animal Health Chapter – Australian and New Zealand College of Veterinary Scientists (ANZCVS)
The Fish Vet, Perth, Western Australia, AUSTRALIA.
Mobile Veterinary Medical & Diagnostic Services for fish and other aquatic creatures.
http://www.thefishvet.com.au
Ph: +61 (0)421 822 383

Check out the latest pictures Dr Loh’s uploaded to The Fish Vet’s Facebook Page album.

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From: Dr Brian Palmeiro

Dearest Fish Friends,

Are you interested in board certification in fish medicine?

Fish medicine continues to advance; the time has come to improve
recognition of this specialty.   The American Association of Fish
Veterinarians is in the process of petitioning the American Board of
Veterinary Practitioners (ABVP) to create board certification in fish
practice.  We need your help.  Part of the process involves providing
the ABVP with more specifics on what fish veterinarians do.  This
information is critical to obtaining ABVP approval and advancing fish
practice.  The survey results will also provide valuable information
to the fish veterinary community as they will allow you to see what
your colleagues are doing in practice.  Please contribute by following
the below link:

https://www.surveymonkey.com/s/D82BKBL

The survey has 40 questions (mostly multiple choice) and should take
less than 15 minutes.

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Brian Palmeiro, VMD, Diplomate ACVD
Lehigh Valley Veterinary Dermatology & Fish Hospital
www.petfishdoctor.com

Richmond’s School of Fish’s motto:

“When you don’t know how, take it ‘a pond’ yourself to learn.”

The following three species of fish look almost identical to the common goldfish:
Carassius auratus (common goldfish)
Carassius langsdorfii
Carassius gibelio (prussian carp)
This is the first paper to use genetic analysis to determine which of these fish occur where and how they spread in Europe.

Aquaculture
Volume 383, Number 1 (March 2013)
Phylogeny and biogeographic history of the cyprinid fish genus Carassius (Teleostei: Cyprinidae) with focus on natural and anthropogenic arrivals in Europe

Authors: Katerina Rylková, Lukáš Kalous, Jörg Bohlen, Dunja K. Lamatsch, Miloslav Petrtýl
Author Affiliations:
no affiliations available
Source: Aquaculture, Volume 383, Number 1 (March 2013)
Page Numbers: 13 – 20
Available Full Text:
Full Text: Subscription Required to view full text
Format: PDF
Size: Unknown
Location: Publisher’s Site
Authentication: Publisher’s Site

Abstract: Freshwater fishes of the genus Carassius, widespread throughout Europe and Asia, are important aquaculture fishes and include the world’s most important pet fish, the goldfish. The high morphologic similarity between the species, however, has up to now prevented reliable conclusions on their taxonomy, biogeography and introduction history. A phylogeny of the fish genus Carassius based on the cytochrome b sequence of 404 specimens collected from aquaculture and open water localities across Eurasia identifies most of the presently recognised species as monophyletic lineages, but also that at least one lineage exists that does not correspond to any described species. Within Europe, feral populations of Carassius auratus occur mainly in the Mediterranean area and Great Britain, while Carassius gibelio is found in most of non-Mediterranean Europe and some localities in Italy. Carassius langsdorfii has very scattered points of occurrence in at least six European countries. C. auratus and C. langsdorfii are not native to Europe. The populations of C. gibelio in eastern Central Europe and parts of Eastern Europe are considered as resulting from a natural postglacial range expansion, while the rest of Europe was colonised due to anthropogenic impact. The presence of diploid (2n=100) as well as triploid (3n=150) specimens in the three most widespread species indicates that ploidy level is not a character to identify the species of Carassius. A remarkably low genetic divergence in C. gibelio can be the result of clone selection in the gynogenetic populations. In general, our data present the first comprehensive overview about the genus Carassius in Europe based on genetic data.
Citation: Katerina Rylková, Lukáš Kalous, Jörg Bohlen, Dunja K. Lamatsch, Miloslav Petrtýl . Phylogeny and biogeographic history of the cyprinid fish genus Carassius(Teleostei: Cyprinidae) with focus on natural and anthropogenic arrivals in Europe. Aquaculture, Volume 383, Number 1 (March 2013), pp. 13-20,
URL: http://ejournals.ebsco.com/direct.asp?ArticleID=4319B7FC5DAFCF1F81DF

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Yours sincerely,

Dr Richmond Loh
BSc, BVMS, MPhil (Vet Path), MANZCVS (Aquatics), MANZCVS (Pathobiology), DipPM.
Veterinarian | Adjunct Senior Lecturer Murdoch University | WAVMA President-Elect |
Secretary Aquatic Animal Health Chapter – Australian and New Zealand College of Veterinary Scientists (ANZCVS)
The Fish Vet, Perth, Western Australia, AUSTRALIA.
Mobile Veterinary Medical & Diagnostic Services for fish and other aquatic creatures.
http://www.thefishvet.com.au
Ph: +61 (0)421 822 383

Read more

http://m.guardian.co.uk/environment/2013/jan/09/overfishing-pacific-bluefin-tuna