Clown Loach breeding and export study

[ewurm]

Here's a good article on Clown Loach export, and also a bonus on clown loach patterns. Definitely worth reviewing:

The Trade of Clown Loaches
Clown loaches are harvested from the wild for food and aquarium trade. Approximately 20 million fish are exported annually. Due to their popularity, many small (preferably 2 - 8cm) loaches are captured every year and dispersed world wide. Interestingly, Indonesia has posed a ban on the export of fish larger than 10cm. This policy is hoped to protect breeding adults and make captive breeding by external groups more difficult. Larger specimens are considered to be unsuitable for aquarium life (due to their carnivorous nature and adaptability difficulties) hence large breeding populations are generally left intact. Young fish are only caught during the high water seasons whilst they are abundant and highly concentrated in one area. This makes trapping easier and the economics of such programs are therefore viable during this time. Juvenilles adapt easily to prepared foods and captivity.

Collection procedures differ slightly between Borneo and Sumatra. In Sumatra, clowns are caught by using perforated bamboo poles stuck into the river bank substratum. This allows loaches of a preferred size to enter the cavities of the bamboo poles. The poles are set at a pre-determined distance apart, where they are later collected by boat. The contents are emptied directly into the bottom of the boat that is filled with water. The loaches are then taken back to a holding facility where they are sorted according to size and sold to a wholesaler.

In Borneo, a slightly different collection method is implemented. Bamboo poles are bundled and tied together then sunk with stones. Rope is used to attach the trap to stakes that are driven into the river bed. When the trap is retrieved from the river, any loaches that have taken refuge inside the bamboo configuration are shaken into a collection vessel. This shaking action is more detrimental to the well-being of the loaches than the method adopted in Sumatra.

Most fish caught in Kalimantan are used for food and few numbers are exported for aquarium trade.

Although the clown loach trade has heavily exploited numbers in the wild, relatively large populations still exist. This is mainly due to the efforts of the individual governments to control numbers that are caught and the fickle nature of the market.

Although some fisheries in Thailand have capitalised on the artificial breeding of these fish, generally this practice is not viable at this point in time. Before the pressure is taken off wild populations, huge technical advances in the field of aquaculture must be reached. Hopefully this is in the “not too distant future”. It would be disasterous to lose this fish from the wild. Environmental disasters (natural and human induced) continually threaten the clown loach in the wild. We don’t need fisheries mis-management also contributing to their demise.

Andrea Watts

Credits for this article include:
http://www.loaches.com/index.html
http://rmbr.nus.edu.sg/biodiversitii/bio/a…more.html#clown

Article from:

http://westerncichlids.com.au/clown-loaches/

 

[ewurm]

Article regarding imports:

http://www.skepticalaquarist.com/docs/fishes/loaches.shtml

Pertinent:

Botia macracantha (Clown Loach). "Macracantha" refers to the big spine by the eye, no bigger than you'd expect, though, and perfectly in proportion to this giant among Botias, who slowly reaches 12 inches in a roomy aquarium, and apparently gets to 15 inches in the wild. I've heard several times that males have a longer tail fin with a more pronounced fork, but since they scarcely ever breed in aquaria and take years to reach sexual maturity, only dissection would confirm this. Singapore sources tell one that the Sumatran specimens generally have a silvery sheen over the body; whereas the Kalimantan (Borneo) specimens have a more intense reddish coloration. This could be due to the habitat. The Sumatran specimens inhabit murky water rivers, whereas the Kalimantan ones prefer brown water rivers or even blackwater tributaries. B. macracantha is one of the fishes found in the seasonally flooded Lake Sentarum in the last large vestige of a lowland peat swamp habitat in Borneo. The dissolved tannins and humic acids in black water tend to accentuate their reddish colours, according to a University of Singapore report. I would also think that paler Clown Loaches might be more obvious to predators in the dark waters. And I find Botia colors fade or darken according to their general health and stress level.

Clown Loaches are the easiest Botia to come by. Though they are tentatively being pond-cultured in Thailand, the wild-caught populations from central Sumatra and central and eastern Kalimantan (Borneo) are still cheaper. They are only seasonally available; the price fluctuates severely: sometimes late summer finds the best bargains.

I prefer the brighter red and more golden Borneo Clown Loaches. When I'm looking for a Clown Loach, I select it for strong orange-gold body color and bright red fins, and for deep velvety black banding. I avoid individuals with pinched bellies, for Clown Loaches very often carry Camallanus intestinal nematodes. I also make sure the black bands are in the correct classic configuration, with the front edge of the main body band continuing uninterrupted onto the dorsal fin. Sometimes the genetic information gets scrambled and the pattern suffers. Some people actually look for these misfits; like a six-toed cat, I suppose.

Clown Loaches are the least furtive of Botia. They're day-active and sociable by nature and seem to be more secure in one another's company: sufficient reason to keep them in groups of three or more. Match your community for size, because these Botia maintain a pecking order and the littlest clown may be picked on. Often it's noticed that in a small swarm of Clown Loaches, one or two will grow noticeably faster than the others. This might just be successful competition for food, but the fishes really don't seem that aggressive towards one another. Some fishkeepers think it's a question of growth suppressant hormones diffused into the water, but no scientist has been able to isolate such a hormone. I think it's just a matter of time before the hormone is found.

The National University of Singapore maintained at its website an account of wild Clown Loach collecting that is very illuminating. Juveniles are found in abundance in the large rivers of central Sumatra and central Kalimantan Province during the high water seasons. The adults breed at the beginning of the high water season and locals catch the young soon after. At other times of year, the individuals are too dispersed or too large to be of value to the trade. The size range preferred by aquarists being three to eight centimeters, smaller fishes are held in grow-out pools, where growth is more rapid than anything we ever see in aquaria. Some exporters also keep excess stock to sell later at higher prices when the fish is not in plentiful supply. Size is important in the export aquarium trade. According to the University of Singapore, larger specimens (adults can attain sizes up to 40 centimeters, equivalent to 15 3/4 inches) tend to be more carnivorous and do not fit in well in community tanks. Most individuals are caught at two to four centimeters size as they come downstream from their breeding grounds upriver. About 20 million B. macracantha are exported from Indonesia through Singapore yearly, but the fishes caught are all juveniles, and breeding populations are left intact. So it looks as though the practice is sustainable. The breeding grounds are not yet precisely known. Indonesia has imposed a ban on the export of specimens larger than 10 cm in length to protect breeding adults, but also quite consciously to impede captive breeding programs.

The collecting techniques are interesting. In Sumatra, local collectors catch Botia macracantha in bamboo poles stuck every meter or so into the river bank. The poles have previously been drilled just below the nodes of the bamboo to provide holes adjusted to the size of the fishes that are to be attracted. At regular intervals during the peak season, the collector will lift out each pole in turn and empty the resident fishes into containers or dump them directly into water filling the boat's bottom. Later, the catch will be sorted and transferred into holding tanks, before sale to a middleman. In Kalimantan, in a variation of the technique, a bundle of trimmed and split bamboo poles are tied together, secured to the riverbank and sunk with stones. Fish take refuge in and among the bamboo poles. The collector lifts up the whole bundle and shakes out the refugees into a container. This technique is somewhat more stressful to the fish. In the more inaccessible central Kalimantan, the exploitation of B. macracantha is not as intense and the locals catch adults for food.file:///C:/SA2/index_files/

Captive artificial breeding of Botia macracantha is possible and has been accomplished in Thailand; however, it is still not cost effective, as the wild-caught stock is still much cheaper. The species has some unusual breeding characteristics. Captive breeding technology might be developed to be commercially viable, in order to take pressure off wild stocks. The University encourages the trade to have "foresight to counter the inevitable extirpation of wild stocks." ("Inevitable" suggests an unpromising official fatalism, doesn't it?) If the technology has not been developed in advance, the University warns, then the whole species may face extermination due to unscrupulous fishing methods, and, more worrying, habitat destruction.

I condensed this material from the website of the National University of Singapore, which formerly carried an article "Freshwater Fishes of Southeast Asia: potential for the aquarium fish trade and conservation issues." The original has been deleted from the N.U.S. site:http://www.science.nus.edu.sg/~webdbs/biodiversitii/bio/aquarium_more.html#clown along with the other material on fish farming.

There is a brief article on B. macracantha in Aquarium Frontiers, species index, at: http://www.animalnetwork.com/fish/profiles/profileview.asp?RecordNo=226

Audra Calvin's detailed introduction to making Clown loaches comfortable in the aquarium is at www.fishprofiles.com.

The spawning of mature B. macracantha is briefly described in the entry at AquaWorld.
It does take quite a while for Clown Loaches to reach sexual maturity. The spawning loaches of a British fishkeeper were eighteen years old!

I'll research the links offered for further information.

 

[ewurm]

This is new information for me, I hadn't heard before the actual species of internal parasites common in clown loaches described.

"Camallanus intestinal nematodes"

 

[ewurm]

Excellent article on loach exportation as well as surprising information on juvenile growth:

Clown loach (Botia macracanthus)
photo: Clown loach, Botia macracanthus

The clown loach, Botia macracanthus. Small specimens are important for the aquarium trade whilst large ones are sometimes sold for food. This is one of the most popular fishes in the trade

and is a clear Category I species. Juveniles are found in abundance in the large rivers of central Sumatra, west Kalimantan and central Kalimantan during the high water seasons. The adults breed at the beginning of the high water season and locals catch the young soon after. This is the only time in the year when the fish is caught. At other times, the individuals are too dispersed, scattered or large to be of value to the trade. The size range preferred by aquarists is three to eight centimetres. Larger specimens tend to be more carnivorous and do not fit in well in community tanks. Adults can attain sizes up to 40 centimetres long. The most commonly marketable size range is from two to four centimetres in length, with the optimum at around two cm. This is because it is at this size when most individuals are caught as they come downstream from their breeding grounds upriver. At this size, they are also easier to maintain in captivity and is easily fed with available fish feed.

The current trade in this species is estimated to be about 20 million pieces exported annually. According to a major dealer in Sumatra, handling up to one million pieces annually is common. It is important to note here that while the minimum breeding size of this fish is about 20-30 cm, the trade is only interested in much smaller individuals. As such, the fishes caught are basically juveniles, and breeding populations are left intact. This is possible also due to the current method for catching these fish (see later) which pre-select for the sizes to be caught. The breeding grounds are not yet known and even if discovered, it is unlikely that there will be any fisheries directed here as the individuals would be too large anyway. In any case, Indonesia has imposed a ban on the export of specimens larger than 10 cm in length. This ban, not only protects breeding adults, but also makes the captive breeding of this species by external agencies more difficult. Some dealers now culture clown loaches. 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. Juveniles exhibit incredible growth rates. A doubling in size is discernible in a week, if sufficient food, adequate aeration and filtration are provided. Some exporters also keep excess stock to grow out and sell later at higher prices when the fish is not in stock and prices are high.

Collection of Botia macracanthus is slightly different in Borneo and Sumatra. In Sumatra, Botia macracanthus are caught by using perforated bamboo poles stuck into the river bank substratum. The perforations are situated just below the nodes of the bamboo pole, and the size of the perforations will determine the occupant size. To obtain fish of a certain size range, the correct perforation size is made. This will catch fishes up to that size. The collector sticks these poles at regular intervals of about one metre apart in the river substratum. During the peak season, the collector will collect at regular intervals by lifting the whole pole out and pouring out the contents into containers or directly onto the boat's bottom, which is filled with water. Later, the catch will be sorted and transferred into holding tanks, before selling to a middle man. In Borneo, a variation of the abovementioned technique is used. A bundle of trimmed and split bamboo poles of a pre-selected diameter are tied together and sunk with stones. The bundle is attached with a rope that is tied onto stakes driven into the river substratum or onto overhanging bankside tree branches. Fish will take refuge in and amongst the bamboo poles. The collector lifts up the whole bundle and shake out the refugees into a container. This technique used is somewhat more stressful to the fish, as they are shaken out. The technique used in Sumatra only requires pouring out the contents, and thus less harm inflicted on the fish.

The clown loach has been heavily exploited in Sumatra and west Kalimantan for over 20 years now, but can still be found in good numbers in the wild. The reasons, as mentioned earlier is due mainly to the nature of the fisheries and the market, and to a lesser extent on government guidelines which controls its trade.

In Central Kalimantan, the exploitation of B. macracanthus is not as heavy and the locals catch adults for food (pers. comm., D. Siebert, BMNH). Specimens from Sumatra can be discerned from the Kalimantan specimens by the fish exporters. The overall colour is subtly different between the populations. The Sumatran specimens generally have a silvery sheen over the body; whereas the Kalimantan specimens have a more intense reddish colouration. This could however due to the habitat. The Sumatran specimens inhabits murky water rivers, whereas the Kalimantan ones prefer brown water rivers or even black water tributaries. The dissolved tannins and humic acids in black water tend to accentuate their reddish colours.

Captive artificial breeding of Botia macracanthus is possible and has been accomplished by the Thais. However, it is still not cost effective to captive breed them, with the wild caught stock being much cheaper. The species has some unusual breeding characteristics and it is not one of the easiest fish to breed in any case. The technology must be developed to be commercially viable, in order to take pressure off wild stocks. The trade must have enough foresight to counter the inevitable extirpation of wild stocks. If the technology has not been developed in advance, then the whole species may face extermination due to unscrupulous fishing methods, and more worrying, habitat destruction.

http://www.science.nus.edu.sg/~webdbs/biodiversitii/bio/aquarium_more.html#clown

 

[JD_MAN]

Good work wurm! It's too late to start reading this all now, but I will be back to check this out.

Thanks.

 

[jcardona1]

can this be made into a sticky? really good info here.

and people eat clown loaches?!?!?! why???

 

[ewurm]

Good work wurm! It's too late to start reading this all now, but I will be back to check this out.

Thanks.

A lot of good articles. It was well worth my morning. Haven't heard back from any of the distributors.

 

[Lupin]

This is new information for me, I hadn't heard before the actual species of internal parasites common in clown loaches described.

"Camallanus intestinal nematodes"

Camallanus is just one of the most challenging nematodes to get rid of. Only levamisole hydrochloride and flubendazole can completely eradicate these. They get their red coloration due to the blood they suck from the fish and can be spotted immediately as red threads hanging in the fish's anus.

and people eat clown loaches?!?!?! why???

Adult clowns are bulk. They are eaten locally in Indonesia. Actually a lot of loaches are eaten around Asia.

 

[ewurm]

Camallanus is just one of the most challenging nematodes to get rid of. Only levamisole hydrochloride and flubendazole can completely eradicate these. They get their red coloration due to the blood they suck from the fish and can be spotted immediately as red threads hanging in the fish's anus.


Adult clowns are bulk. They are eaten locally in Indonesia. Actually a lot of loaches are eaten around Asia.

I think I may have one with these persistent parasites. Praziquantel just isn't doing it.

 

[its_an_obsession]

so when my lfs is advertising a breeding pair of clown loaches... they are full of ****?