Clown Loach breeding and export study

RD.

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The following was posted earlier on in this discussion, which does tend to support the fact that very small loaches can be collected in the wild.

Often, fishermen are able to trap individuals smaller than two cm. These are cheap and too small to be marketable but if they are grown out, a profit of up to 300% or more can be realised if a juvenile of 1.5 cm is raised to 3 cm.
For the non metric folks, 2cm is approx 3/4".

I also recall reading where some collectors would harvest CL's in flooded areas when they were still in a larvae state, then grow them out for later resale.

While it appears that CL's have definitely been successfully bred & raised in captivity, it has yet to be proven that this practice is viable on a large scale commercial basis. It's one thing to make it happen, it's another to make it a money making venture.

Earlier on some members were questioning as to exactly what hormones were being used to induce spawning in captivity, I had mentioned human chorionic gonadotropin being used in Indonesia on other species, and its relatively low cost, and the following article from just this past year discusses much of this.

http://china.verticalnews.com/articles/7438510.html


Data on Aquatic Research Reported by M. Legendre and Co-Researchers

2012 AUG 28 (VerticalNews) -- By a News Reporter-Staff News Editor at China Business Newsweekly --

Fresh data on Aquatic Research are presented in a new report. According to news originating from Depok, Indonesia, by VerticalNews correspondents, research stated, "The clown loach Chromobotia macracanthus, endemic to Indonesia, is a major species on the international market of ornamental freshwater fish. In order to satisfy an increasing demand with a sustainable alternative to the massive capture of wild juveniles, research has been dedicated to the artificial propagation and domestication of this species."

Our news journalists obtained a quote from the research, "The present study, the first of a series, focused on favourable maintenance conditions for broodfish sexual maturation, criteria for identification of ripe fish, efficiency of hormone-induced breeding treatments, predictability of their latency response, and on the comparison of reproductive performances of fish from populations of Sumatra and Borneo Islands (in total, 112 females of 46 to 404 g body weight). When reared in fully controlled conditions in large water recirculation systems, broodfish originating from Sumatra had reproductive performances similar to or slightly higher than those maturing in the wild (ovulation rate of 93% vs. 82%, relative fecundity of 109 277 vs. 103 550 ova kg(-1) and fertilization rate of 73% vs. 61%, respectively). In the same rearing conditions, captive females from Borneo (n = 22) showed lower ovulation rate (77%), relative fecundity (76 262 ova kg(-1)) and fertilization rate (50%) than those originating from Sumatra (n = 28). By contrast, the mean individual weight of ova (around 0.8 mg) was independent from the origin or maintenance conditions of females. An initial modal follicle diameter >= 1.02 mm generally led to high ovulation success (>80%) after hormonal treatment and is recommended as the main criterion for selecting female broodfish. Two hormonal treatments for inducing oocyte maturation and ovulation (T1: two successive injections of Ovaprim at a 6 h-interval; T2: one injection of human chorionic gonadotropin (hCG)-and one of Ovaprim 24 h later), produced similar results in terms of ovulation rate, quantity and quality of ova collected."

According to the news editors, the researchers concluded: "With both treatments, the latency decreased with increasing water temperature, then increased again at temperatures >28-29 degrees C. To our knowledge,."

For more information on this research see: Biology and culture of the clown loach Chromobotia macracanthus (Cypriniformes, Cobitidae): 1-Hormonal induced breeding, unusual latency response and egg production in two populations from Sumatra and Borneo Islands. Aquatic Living Resources, 2012;25(2):95-108. Aquatic Living Resources can be contacted at: Edp Sciences S A, 17, Ave Du Hoggar, Pa Courtaboeuf, Bp 112, F-91944 Les Ulis Cedex A, France. (EDP Sciences - publications.edpsciences.org/; Aquatic Living Resources - www.alr-journal.org)

The news correspondents report that additional information may be obtained from M. Legendre, Balai Penelitian & Pengembangan Budidaya Ikan Hia, Depok 41152, Indonesia.



While I do not have access to the full papers, there is more info in the following abstracts;




http://journals.cambridge.org/actio...&previous=true&jid=ALR&volumeId=25&issueId=02

Biology and culture of the clown loach Chromobotia macracanthus (Cypriniformes, Cobitidae) : 1- Hormonal induced breeding, unusual latency response and egg production in two populations from Sumatra and Borneo Islands


Abstract

The clown loach Chromobotia macracanthus, endemic to Indonesia, is a major species on the international market of ornamental freshwater fish. In order to satisfy an increasing demand with a sustainable alternative to the massive capture of wild juveniles, research has been dedicated to the artificial propagation and domestication of this species. The present study, the first of a series, focused on favourable maintenance conditions for broodfish sexual maturation, criteria for identification of ripe fish, efficiency of hormone-induced breeding treatments, predictability of their latency response, and on the comparison of reproductive performances of fish from populations of Sumatra and Borneo Islands (in total, 112 females of 46 to 404 g body weight). When reared in fully controlled conditions in large water recirculation systems, broodfish originating from Sumatra had reproductive performances similar to or slightly higher than those maturing in the wild (ovulation rate of 93% vs. 82%, relative fecundity of 109 277 vs. 103 550 ova  kg-1 and fertilization rate of 73% vs. 61%, respectively). In the same rearing conditions, captive females from Borneo (n = 22) showed lower ovulation rate (77%), relative fecundity (76 262 ova kg-1) and fertilization rate (50%) than those originating from Sumatra (n = 28). By contrast, the mean individual weight of ova (around 0.8 mg) was independent from the origin or maintenance conditions of females. An initial modal follicle diameter ≥1.02 mm generally led to high ovulation success (>80%) after hormonal treatment and is recommended as the main criterion for selecting female broodfish. Two hormonal treatments for inducing oocyte maturation and ovulation (T1: two successive injections of Ovaprim at a 6 h-interval; T2: one injection of human chorionic gonadotropin (hCG)- and one of Ovaprim 24 h later), produced similar results in terms of ovulation rate, quantity and quality of ova collected. With both treatments, the latency decreased with increasing water temperature, then increased again at temperatures >28–29 °C. To our knowledge, such U-shaped relationship between the latency response and temperature has never been documented in teleost fishes.

(Received January 10 2012)
(Accepted April 23 2012)
(Online publication June 25 2012)



http://journals.cambridge.org/actio...&previous=true&jid=ALR&volumeId=25&issueId=02

Biology and culture of the clown loach Chromobotia macracanthus (Cypriniformes, Cobitidae) : 2- Importance of water movement and temperature during egg incubation


Abstract

In comparison to older life stages, the embryonic stages of fishes generally have narrow tolerance ranges for environmental conditions, as regards water quality, temperature and mechanical shocks. The knowledge of these factors is indispensable to appraise the threats brought about by climate or anthropogenic changes upon their resilience, and to define adequate ways of incubating their eggs for an efficient propagation of the species under controlled conditions. Clown loach eggs have a narrow thermal tolerance range in comparison to other tropical and temperate fishes. Hatching occurs at 22–30 °C, and non-deformed larvae can only be obtained at 23.8–30.2 °C. Furthermore, the thermal tolerance of any particular progeny was found dependent on the maintenance temperature of the female parent, thereby making the actual tolerance no broader than 4.5 °C. The (log-log) relationship between the duration of the incubation period and temperature was characterized by a shallow slope, which is more typical of coldwater fishes, as is a narrow thermal tolerance range. On the other hand, clown loach hatched more rapidly (20 h at 26 °C) than predicted by existing models on the basis of water temperature and egg diameter, a feature that is shared by other warmwater fishes producing eggs that undergo a strong swelling process (about three times the ova diameter in clown loach). Clown loach embryos are strongly sensitive to mechanical shocks, but their development is not viable either in protracted steady state conditions, in absence of water movement, as they develop various deformities (e.g. pericardial oedema). This is thought to originate from a hypoxic microenvironment around the embryo, as a consequence of an oxygen gradient developing inside and outside the egg, since the boundary diffusion layer is not refreshed by water movement. This issue is worsened by strong egg swelling and incubation at warm temperature.

(Received January 10 2012)
(Accepted April 23 2012)
(Online publication June 25 2012)


http://journals.cambridge.org/actio...&previous=true&jid=ALR&volumeId=25&issueId=02

Biology and culture of the clown loach Chromobotia macracanthus (Cypriniformes, Cobitidae) : 3- Ontogeny, ecological and aquacultural implications


Abstract

Hatchlings of clown loach (3.8 mm in total length, TL) are pelagic. When reared at 26&#8722;28 °C, they become benthic 3 days after hatching (dah), when their swim bladder is inflated. The fin development sequence (pectorals < caudal < dorsal = anal < pelvic) is typical of the clade Ostariophysi. All fins and finrays are fully elongated at 20 mm TL, but the finfold persists until 25 &#8722; 26 mm TL (start of juvenile stage). Melanophores appear at 3 dah, they form a 5-bar pattern at 5 dah, then two bars (III and V) vanish progressively, producing at 26 mm TL the 3-bar pattern that is typical of adults. Throughout the ontogeny, the pigment pattern exhibits a structural regularity (bars spaced at regular intervals), which is interpreted in a functional perspective by reference to the maintaining of crypsis and signalling throughout. Exogenous feeding commences at 4 dah (5.5 mm TL). Food intake (FI) increases rapidly, from 6% wet body mass (WM) at 5.5 mm TL to >20% WM in fish > 7 mm TL. Gut evacuation rate (Rg) increases with increasing meal size and fish size, as a result of gut coiling (from 8 to 15 mm TL), and is highest at 11 mm TL (about 10% WM h-1 in fish feeding maximally). The allometric increase of FI and Rg during the early larval stages is accompanied by increasing capacities for growth, so early sizes differences amplify rapidly during the ontogeny. Nevertheless, growth remains slow (mean of 0.4 mm TL day-1 from 4 to 29 dah; 0.9 mm TL day-1 for top growers). By contrast, unfed fish display long resistance to starvation (until 14&#8722;15 dah). The combination of slow growth and long resistance to starvation is discussed in respect to the reproductive phenology of the species, as the capacity of making metabolic economies prevails over fast growth for seasonal strategists spawning mainly at the start of the rainy season.

(Received February 1 2012)
(Accepted May 14 2012)
(Online publication July 06 2012)




http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8641889

Biology and culture of the clown loach Chromobotia macracanthus (Cypriniformes, Cobitidae) : 4- Thermal biology of embryos and larvae


Abstract

The knowledge of how fish survive and grow at different temperatures, and how these traits vary between life stages, is essential to evaluate the effects of climate change on wild fish and implement effective strategies in aquaculture. These issues are addressed in this study through a series of experiments that evaluate the effect of temperature (23&#8211;34 °C) on the embryos and larvae of clown loach, Chromobotia macracanthus. This species is endemic to the rivers of Sumatra and Borneo, highly praised on the ornamental fish market, and has been reproduced in captivity recently. No embryo survived a 24-h exposure to 34 °C until the age of 3 days after hatching (dah); mortality was high at 32 °C at 2 and 3 dah, whereas it was low and similar from 1 to 4 dah at 23&#8211;29 °C (<10%). Yolk absorption was proportional to water temperature (Q10°C of 1.69 in the 23&#8211;32 °C range), but fish reared at cold temperatures were larger than others at the start of exogenous feeding (5.7 vs. 5.5 mm TL, at 23 and 32 °C, respectively). The survival of larvae fed Artemia nauplii ad libitum was high at 23&#8211;32 °C (80&#8211;100%), but almost null at 34 °C. Growth models at different temperatures were produced from weekly measurements in two experiments, and tested by comparing their predictions with the results of a third experiment. Throughout the larval stage, the optimal temperature for growth (T°opt) was close to 29 °C, and departures from T°opt resulted in substantial growth penalties (&#8211;30% SGR for &#8211;5.1 °C and + 3.1 °C). High survival, fast growth (0.7 mm day-1) and limited size dispersal at T°opt are encouraging perspectives for the aquaculture of clown loach. From an ecological perspective, the species has an atypical thermal biology, as it is less thermophilic than other tropical fishes, but more stenothermal than temperate fishes exhibiting similar values of T°opt , both traits being of particular concern in the context of global warming.

(Received February 1 2012)
(Accepted May 14 2012)
(Online publication July 06 2012)
 
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RD.

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........ and from the 3rd abstract it's interesting to note that there is no mention of an unusual or higher rate of oddball markings in the offspring of these loaches, vs their wild counterparts. These researchers don't mention oddball markings at all.


Melanophores appear at 3 dah, they form a 5-bar pattern at 5 dah, then two bars (III and V) vanish progressively, producing at 26 mm TL the 3-bar pattern that is typical of adults. Throughout the ontogeny, the pigment pattern exhibits a structural regularity (bars spaced at regular intervals), which is interpreted in a functional perspective by reference to the maintaining of crypsis and signalling throughout.
 

RD.

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...........as previously stated.

While it appears that CL's have definitely been successfully bred & raised in captivity, it has yet to be proven that this practice is viable on a large scale commercial basis. It's one thing to make it happen, it's another to make it a money making venture.




There was never any doubt that clown loaches have been bred in Indonesia, and Florida, and in the EU using hormones.

But, it does not appear that they are being bred in mass quantity, as in to supply the ornamental fish trade. If you have some kind of evidence to support that by all means post it. Thanks for posting those pics.
 

RD.

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george - do you have any idea how many clown loaches are exported out of Indonesia in a single season?

The only semi-official report that I have found (which was also mentioned early on in this discussion) was at the time -20 million. I'm guessing that number has greatly increased since it was first published over a decade ago. When one considers that smaller loaches the size of the ones shown in the previous photos wholesale in Indonesia for maybe 50 cents US, that is NOT a lot of money, bra, nor is it near enough CL's to come even remotely close to filling the needs of importers & fish traders world-wide.

What you don't see in those photos is how each individual female CL has to be handled one at a time through the entire hormone induction process. It's a very timely very costly way of producing fish, fish that for the most part sell very cheapely in Indonesia. This is also why Indonesia continues to ban the export of any clown loach over 15cm (6"), as the larger sized loaches are the prime breeding stock in the wild. http://www.practicalfishkeeping.co.uk/content.php?sid=4047

I have been in contact with a number of exporters over the past several years, including those who live in Indonesia, Singapore, etc and who trade in live fish, including clown loaches, and those people working on the ground in Kalimantan, and Sumatra, are collecting/buying/selling wild loaches, not ones raised in kitchen colanders. :)



If you or anyone else can offer up a wholesale list, or some kind of actual proof that clown loaches are being bred in mass on a commercial basis, and exported to North America, I'm certainly interested.
 

David R

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Seeing those pics and reading that actually makes me sad, how many of the millions of clowns sold world-wide each year make it into a 6'+ tank and grow to 6-8-10"+ .......
 

RD.

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Very true, unfortunately in Kalimantan the environmental impact from gold mining, oil palm plantations, and logging (which apparently runs rampant even within national parks & protected forests) will most likely place some species of fish in jeopardy before they have even been discovered.

Which is precisely why I am all for leaving CL's that are in the wild, in the wild, and would be more than happy for someone to prove me wrong. I am all for the commercial breeding of captive clown loaches.
 

David R

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The odds of cls reaching adulthood in nature is not so good neither .
Good point, but there is a big difference (in my mind, at least) between nature taking its course and animals suffering and dying while in captive care.

The big problem with clowns IME is that they don't physically "outgrow" a tank like say a silver arowana would in getting to 2'+ even in a tiny tank, therefore end up being kept in tanks that are too small (and with inadequate flow) despite appearing to have plenty of room. I was a bit sceptical of the effects of stunting and just how much space they really need, but have now seen the effects of clowns being kept/raised in smaller tanks first hand. I sold a group of 6 ~4" clowns to a friend when I shut down my 150g tank and left home back in '02, he kept them in his 75g tank for years and none of them got much over 6", eventually one by one they slipped away and the last one died ~12 months ago. Around ten years may seem like a good life for a pet fish, but we all know clowns can live for much longer, and get to a much larger size.



Anyway, enough of the sidetrack, at least the 'technology' to induce captive breeding exists before their natural environment is destroyed, even if it isn't commercially viable yet. Part of me would love to be able to buy some massive wild-caught clowns, but the other half agrees with RD that they're better left in their native rivers...
 
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