Q: If seaweed had breasts, what would they wear?
A: Algae-bra.
Month: February 2013
Response of a freshwater air-breathing fish to salinity changes – indicators of stress.
Though not an animal welfare type paper, this research details what parameters are used to quantitatively identify stress in the fish.
In cases of stress, the following parameters would be depressed and they include liver and muscle glycogen, ascorbic acid levels in organs, acetylcholine esterase (AchE) and metabolic enzymes (e.g. alkaline phosphatase (ALP) and adenosine triphosphosphtase (ATPase) activities in liver and muscle tissues).
| Aquaculture International: Journal of the European Aquaculture Society | |||||||||||||||||
| Volume 21, Number 1 (February 2013) | |||||||||||||||||
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Response of a freshwater air-breathing fish, Clarias batrachusto salinity stress: an experimental case for their farming in brackishwater areas in Andaman, India | ||||||||||||||||
| Authors: | Kamal Sarma 1, K. Prabakaran 1, P. Krishnan 1, G. Grinson 1, A. Anand Kumar 1 | ||||||||||||||||
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| Source: | Aquaculture International: Journal of the European Aquaculture Society, Volume 21, Number 1 (February 2013) | ||||||||||||||||
| Page Numbers: | 183 – 196 | ||||||||||||||||
| Available Full Text: |
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| Abstract: | The study was conducted to assess the effects of salinity on growth and biochemical composition of freshwater catfish, Clarias batrachus. A static nonrenewable acute toxicity bioassay test was conducted and LC50of salinity for 96-h exposure to the fingerling (14.5 cm) was 12.52 ‰. Based on these results, two sublethal salinity levels, viz. 4 and 8 ‰ were selected to study the long-term effects of salinity on C. batrachusfor a period of 90 days. From the study, it was found that growth and survival rate were less in saline water (4 and 8 ‰). Maximum growth and survival were recorded in freshwater (0 ‰ salinity) and subsequently at 4 and 8 ‰. To assess the biochemical alteration, few important biomarkers were estimated. At the end of 90 days rearing period, glucose level in the brain and blood of C. batrachuswas found to decrease with salinity. The level of liver and muscle glycogen in the fish reared at 4 ‰ was lower than that of control. Ascorbic acid in all organs under study was found to decrease with increasing salinity, which was attributed to stress mitigation effect of vitamin C. Acetylcholine esterase (AchE) activity recorded a gradual decrease with increasing salinity. Metabolic enzymes, alkaline phosphatase (ALP) activity and adenosine triphosphosphtase (ATPase) activity also reduced both in liver and muscle tissues with increasing salinity. From the present investigation, it can be concluded that exposure to higher salinity significantly (P< 0.01) affects the growth and physiological response of Clarias batrachus.The study was conducted to assess the effects of salinity on growth and biochemical composition of freshwater catfish, Clarias batrachus. A static nonrenewable acute toxicity bioassay test was conducted and LC50of salinity for 96-h exposure to the fingerling (14.5 cm) was 12.52 ‰. Based on these results, two sublethal salinity levels, viz. 4 and 8 ‰ were selected to study the long-term effects of salinity on C. batrachusfor a period of 90 days. From the study, it was found that growth and survival rate were less in saline water (4 and 8 ‰). Maximum growth and survival were recorded in freshwater (0 ‰ salinity) and subsequently at 4 and 8 ‰. To assess the biochemical alteration, few important biomarkers were estimated. At the end of 90 days rearing period, glucose level in the brain and blood of C. batrachuswas found to decrease with salinity. The level of liver and muscle glycogen in the fish reared at 4 ‰ was lower than that of control. Ascorbic acid in all organs under study was found to decrease with increasing salinity, which was attributed to stress mitigation effect of vitamin C. Acetylcholine esterase (AchE) activity recorded a gradual decrease with increasing salinity. Metabolic enzymes, alkaline phosphatase (ALP) activity and adenosine triphosphosphtase (ATPase) activity also reduced both in liver and muscle tissues with increasing salinity. From the present investigation, it can be concluded that exposure to higher salinity significantly (P< 0.01) affects the growth and physiological response of Clarias batrachus. | ||||||||||||||||
| Citation: | Kamal Sarma, K. Prabakaran, P. Krishnan, G. Grinson, A. Anand Kumar . Response of a freshwater air-breathing fish, Clarias batrachusto salinity stress: an experimental case for their farming in brackishwater areas in Andaman, India. Aquaculture International: Journal of the European Aquaculture Society, Volume 21, Number 1 (February 2013), pp. 183-196, <http://ejournals.ebsco.com/direct.asp?ArticleID=459A98EB734F97A3C403> | ||||||||||||||||
| URL: | http://ejournals.ebsco.com/direct.asp?ArticleID=459A98EB734F97A3C403 | ||||||||||||||||
Solution for kamikaze tuna.
Tank wall collision is one of the major causes of mortality during the early-stage rearing of Pacific bluefin tuna. This paper details changing the water flow rate as a preventive measure.
I wonder if an air-bag would work… But seriously, have a ring of air around the tank sides.
| Aquaculture International: Journal of the European Aquaculture Society | |||||||||||||||||
| Volume 21, Number 1 (February 2013) | |||||||||||||||||
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Critical swimming speed and maximum sustainable swimming speed of juvenile Pacific bluefin tuna, Thunnus orientalis | ||||||||||||||||
| Authors: | F. S. Sabate 1, Y. Nakagawa 1, T. Nasu 1, W. Sakamoto 1, S. Miyashita 1 | ||||||||||||||||
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| Source: | Aquaculture International: Journal of the European Aquaculture Society, Volume 21, Number 1 (February 2013) | ||||||||||||||||
| Page Numbers: | 177 – 181 | ||||||||||||||||
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| Abstract: | Tank wall collision is one of the major causes of mortality during the early-stage rearing of Pacific bluefin tuna, Thunnus orientalis(PBT). Therefore, to design a rearing environment that meets the needs of juvenile PBT, it is important to gather information about their swimming capabilities. We conducted experiments to examine the relative critical swimming speed (RCSS) and maximum sustainable swimming speed (MSSS) of early-stage PBT. The fish were kept in 3-tonne tanks and fed on artificial pellets every 2 h from dusk to dawn. We conducted two sets of experiments to measure swimming speed; the fish were introduced one at a time into a water funnel, and the water current velocity was gradually increased over time to estimate RCSS, or the water current was kept at a constant velocity to estimate MSSS. We measured the RCSS of 72 PBT juveniles (24–29 days after hatching (DAH); standard length (SL), 15.0 ± 2.3 mm) and the MSSS of 32 PBT juveniles (28–37 DAH; SL, 20.0 ± 5.1 mm) in the laboratory. The RCSS ranged from 4.7 to 20.3 SL/s (average, 12.4 ± 3.3 SL/s), and the MSSS was estimated to be approximately 4 SL/s. We speculate that introducing a water current in the rearing tank of no more than 4 SL/s could positively affect the survival of juvenile PBT.Tank wall collision is one of the major causes of mortality during the early-stage rearing of Pacific bluefin tuna, Thunnus orientalis(PBT). Therefore, to design a rearing environment that meets the needs of juvenile PBT, it is important to gather information about their swimming capabilities. We conducted experiments to examine the relative critical swimming speed (RCSS) and maximum sustainable swimming speed (MSSS) of early-stage PBT. The fish were kept in 3-tonne tanks and fed on artificial pellets every 2 h from dusk to dawn. We conducted two sets of experiments to measure swimming speed; the fish were introduced one at a time into a water funnel, and the water current velocity was gradually increased over time to estimate RCSS, or the water current was kept at a constant velocity to estimate MSSS. We measured the RCSS of 72 PBT juveniles (24–29 days after hatching (DAH); standard length (SL), 15.0 ± 2.3 mm) and the MSSS of 32 PBT juveniles (28–37 DAH; SL, 20.0 ± 5.1 mm) in the laboratory. The RCSS ranged from 4.7 to 20.3 SL/s (average, 12.4 ± 3.3 SL/s), and the MSSS was estimated to be approximately 4 SL/s. We speculate that introducing a water current in the rearing tank of no more than 4 SL/s could positively affect the survival of juvenile PBT. | ||||||||||||||||
| Citation: | F. S. Sabate, Y. Nakagawa, T. Nasu, W. Sakamoto, S. Miyashita . Critical swimming speed and maximum sustainable swimming speed of juvenile Pacific bluefin tuna, Thunnus orientalis. Aquaculture International: Journal of the European Aquaculture Society, Volume 21, Number 1 (February 2013), pp. 177-181, <http://ejournals.ebsco.com/direct.asp?ArticleID=45D686120F3F3CD3180A> | ||||||||||||||||
| URL: | http://ejournals.ebsco.com/direct.asp?ArticleID=45D686120F3F3CD3180A | ||||||||||||||||
Where can you get advanced fish vet training?
It’s not been an easy road to acquire specialised knowledge, skills and training as described by a colleague, even in the US. So, they have compiled a list of training providers and their courses on their blog.
Check it out here:
http://avsnca.com/aquatic-veterinary-medicine-resources/comment-page-1/
There will also be a couple of courses being run in Australia this year; in July (https://thefishvet.com/2013/01/11/2013-frdc-australasian-scientific-conference-on-aquatic-animal-health/)
and another in August (https://thefishvet.com/2012/12/28/the-24th-international-conference-of-the-world-association-for-the-advancement-of-veterinary-parasitology-will-be-in-perth-australia/).
Also, join WAVMA to network with other fish vets.