The Fish Vet's Blog

Question from a colleague:

My response:

I believe you are correct. With most fish, gender manipulation may be possible only when very young.

Q: Where do fish go to get ideas?

A: A think tank.

I came across this website and their report recently and thought some of the arguments are interesting.

This report details the welfare of fish in commercial fishing. According to the report 970 – 2,740 billion individual fish are caught each year compared to the farmed 3 billion mammals and 57 billion birds reported by the Food and Agriculture Organisation of the UN in 2008.

Considerable suffering is caused to wild-caught fish during capture, landing and subsequent processing. Fish are likely to experience fear, pain and distress as they are, for example:

• • pursued to exhaustion by nets
• • crushed under the weight of other fish in trawl nets
• • raised from deep water and suffer decompression effects e.g. burst swim bladders
• • snared in gill nets
• • confined in constricted seine nets
• • spiked with hooks (gaffed) to bring them aboard
• • caught on hooks, often for hours or days
• • thrown live to tuna as bait
• • impaled live on hooks as bait

Available to be downloaded from http://fishcount.org.uk

Check out some of the great stuff that is available to the public.

Download the latest AVN that has become available by clicking on this link.

There’s this story I heard and that I’d like to share with you.

There once was an Emperor in China who wanted the best medical care he could get. So, he sent off his servants to scour the land for the best doctor they could find. His servants came across this village where there was a doctor renowned for being able to cure anyone and everyone. They were elated to find such a man and went to meet him. They discussed the reason for their meeting this doctor and the doctor said, “I’m only an OK doctor and I always try to do my best. You should really travel across those mountains to meet a different doctor who is even better than I.”

To this, the Emperor’s servants asked, “But you’re able to cure all illnesses. Why is this other doctor better than you?”

To which the doctor replied, “It is true that I cure patients with illnesses and they get better after seeing me. The reason why this other doctor is better, is because the patients he treats never get sick!”

Why am I sharing this story with you, you might ask.

With the water temperatures increasing and your pond fish coming out of their winter condition, this is the high risk period for fish to get sick. You’ve read about herbs and foods being good for your immune system such as green tea, garlic, cinnamon, etc. Earlier this year, I worked with the compounding pharmacy to create an immunostimulant feed additive called “immunoBOOSTER” which can be used as preventive medicine. Check out the information at this link – see link.

Some of you may be considering and planning artificial spawning of your koi, rather than leaving them to their own devices. There are many things that can help you increase your success/fertility rate (link to previous post) such as feeding them up,  using hormonal induction methods (link to previous post), hand stripping (link to previous post), milt extenders (link to previous post) and others. This paper details efforts made by some scientists to increase the longevity of toad sperm and I wonder if the findings are transferable to fish.

Aquaculture
Volume 399, Number 2 (June 2013)
	Effects of aeration and antibiotics on short-term storage of Fowler’s toad (Bufo fowleri) sperm
	Authors:	Jennifer M. Germano, Lucía Arregui, Andy J. Kouba
	Author Affiliations:	no affiliations available
	Source:	Aquaculture, Volume 399, Number 2 (June 2013)
	Page Numbers:	20 – 24
	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 importance of developing assisted reproductive technologies (ART) for captive assurance colonies of threatened amphibians is increasing as ex situmanagement of amphibians has been challenged with low reproductive outputs for some species. One hurdle to developing ART in amphibians is the short-term storage of gametes for in vitrofertilization. This study tested the application of two common aquaculture techniques, aeration or the addition of antibacterial solutions, to spermic urine to determine if this would improve the longevity and quality of non-invasively collected sperm samples using hormone therapy. Spermic urine samples were collected non-invasively from Fowler’s toads (Bufo fowleri) and either left alone, aerated for 30min a day, or treated with penicillin–streptomycin. All samples were kept refrigerated at 4°C. Sperm motility declined within each treatment group over time (P<0.01); however, aerated samples retained significantly greater motility (70%) during the first 24h after collection than samples in both the control (57%) and antibacterial group (51%). The addition of penicillin–streptomycin solution to spermic urine had a negative effect on viability; with significantly fewer sperm still alive 2–4days post collection (P=0.032). Sperm viability was highly correlated with motility on all days and with forward progression 1–4days post collection (P=0.002). Our results show that aerating amphibian spermic urine samples may provide a simple and low-cost method to improve sperm storage that could be used for in vitrofertilization and ex situmanagement of threatened amphibians. Antibiotics appeared to have a negative effect on sperm viability, suggesting that further research on bacterial contamination and antibiotic doses is necessary.
	Citation:	Jennifer M. Germano, Lucía Arregui, Andy J. Kouba . Effects of aeration and antibiotics on short-term storage of Fowler’s toad (Bufo fowleri) sperm. Aquaculture, Volume 399, Number 2 (June 2013), pp. 20-24, <http://ejournals.ebsco.com/direct.asp?ArticleID=44A386C579E93ABB4F5D&gt;
	URL:	http://ejournals.ebsco.com/direct.asp?ArticleID=44A386C579E93ABB4F5D

Thumbs up for this!

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Yours sincerely,

Dr Richmond Loh
DipProjMgt, BSc, BVMS, MPhil (Pathology) Murdoch, MANZCVS (Aquatics& Pathobiology).
The Fish Vet, Perth, Western Australia.
Veterinary Medicine for fish.
W: http://www.thefishvet.com.au
E: thefishvet
P: +61 (0)421 822 383

Oh the ‘Hu-manatee’!

Recently, I was asked whether there is a need in Australia to have the FASTest KOI HV ( KOI HERPESVIRUS RAPID TEST ).

My response:

KHV is currently exotic to Australia but there are 2 potential ways it’ll inevitably establish in Australia.

1. The Australian Animal Health Laboratories (AAHL in Geelong) is studying the virus for use as a biocontrol of carp.
2. Enthusiasts illegally importing fish.

There is no need for it now, but in the future, it’ll be useful to have.

Additionally, because KHV is an OIE listed disease and Notifiable in Australia, a positive result (regardless of whether it is a true positive or a false positive) there would be potential significant political and economic implications. Thus, I suspect that the first definitive diagnosis needs to be conducted by the government laboratories at least, if not, by the AAHL.

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—
Yours sincerely,

Dr Richmond Loh

KH stands for carbonate hardness and it’s a measure of the buffering capacity of your water against fluctuations in pH which could be stressful for fish. A KH of 3-4 degrees (or 50-70mg/L) is recommended as a minimum. A lower value means you need to add buffers.