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C. sp. 1 was initially imported as Misgurnus anguillicaudatus © Thomas Frank

Thomas Frank introduces three recent additions to the aquarium hobby…

For loach-lovers 2008 was certainly not the worst year. It started in the middle of the year, when small loaches arrived in Aachen under the name Misgurnus anguillicaudatus but which could easily be identified as members of the genus Cobitis.

They came from the Dutch ornamental fish wholesaler Ruinemans and I was unable to establish the precise identity and origin of the fish so designated them Cobitis sp. 1.

Only later I stumbled upon the website http://blog.xuite.net/snakejoan/snake/28724172 where some undefined Taiwanese Cobitis are depicted which appeared very similar to mine. From Matt Ford I received an additional pointer that some loaches very similar to mine are included in Chen and Chang (2005), this time with the name Cobitis cf. sinensis.

The origin of these loaches should thus almost certainly be Taiwan and this was confirmed in Spring 2009 when Aqua-Global of Seefeld imported some specimens originating from Taiwan under the name Cobitis sinensis.

Some of these animals arrived to the company Schwabenaquaristik in Aulendorf, who thankfully granted my request for a photograph of them very quickly. These loaches also seemed identical to mine, so I assumed that the fish from all of these different sources were the same species.

The males have a rounded lamina circularis (as far as I can tell) and the typical extended second pectoral spine, and the sexes in cobitids can typically be told apart in this pretty clear and simple way. It is a rather small loach with the largest female around 8 centimeters and the biggest male not much more than 6 centimetres in total length.

C. sp. 2 has been traded as Cobitis chinensis in the past © Thomas Frank

The fish have already bred in my aquarium and I will provide details about this in a later report.

At the end of the year the ornamental fish wholesaler Mimbon Aquarium in Cologne joined the ‘loach spotlight’ in which two Cobitis species were imported for the retail sector at the same time (one of them in smaller numbers as bycatch).

This time China was clearly stated as the origin from the time of import and later Hans-Georg Evers (2009) specified them to be collected in Guangdong Province.

The animals were traded as ‘chinensis’ but unfortunately this name has never officially been used within the genus Cobitis, not even as a synonym, and they may even represent an undescribed species (here they are referred to as Cobitis sp. 2).

The fish have an unusual colour pattern which differs quite clearly from other Cobitis spp., so different in fact that at first I thought it may eventually prove not to be a member of Cobitis and perhaps be assigned to the genus Iksookimia.

The pattern of spots arranged along the sides of the body is highly variable and ranges from almost symmetrical rectangles to narrow, vertical stripes or ‘drops’.

Female of C. sp. 3 © Thomas Frank

Here too the males have a rounded lamina circularis and due to the size of the fish it is easy to see that the second pectoral-fin ray is extended and bent slightly upwards.

I was not pleased with the sex ratio of my new loaches, though, because among the group of 18 animals I could see only 2 males and, accordingly, 16 females.

I was able to add two more males to my already more-than-sufficiently large group from Aqua-Tropica in Cologne, and I also took the last remaining females from there.

The most striking character about these fish was their size which was quite impressive for a loach. At time of purchase all of them measured at least 10 centimetres with the largest thirteen centimetres TL. The height of the body is around 15 millimetres. After around 2½ years of maintenance I could no longer detect any growth.

A second species from Mimbon (Cobitis sp. 3) was as already mentioned imported as byctach alongside the ‘chinensis’ fish. They are considerably less deep in the body than the ‘chinensis’ but have a similar length and a typical pattern of spots on the flanks.

In comparison with other Cobitis species the dorsal-fin is placed quite far back on the body, though not to the extent as seen in weather (Misgurnus) or kuhlii (Pangio) loaches. I originally managed to pick up just three of these ‘cobitid bycatch’, all females, but on my aforementioned visit to Aqua-Tropica I was fortunate to find a male and additional female.

Male of C. sp. 3 © Thomas Frank

I have not yet been able to observe a lamina circularis in the male, but at present I am unable to say whether it really doesn’t exist or I am yet to discover it.

The maintenance of these loaches is unproblematic and care only needs to be taken when keeping them alongside other fishes. Cobitids tend to eat slowly and the two large examples presented here are no exception, so any tankmates must be chosen with this in mind.

Moreover, one must not give a lot of thought if wishing to keep these fish in an aquarium. A heater is not always required although higher temperatures are tolerated well.

Two practical examples: I maintained a group of the fish first-exported as ‘C. chinensis’ for two years in a cement tub in temperatures of around 15 °C on average. The temperature only rose above 20 °C on some warm days, and the fish spent winter in the basement at around 5 °C. The other group lives in an aquarium at room temperature.

With prolonged summer heat the aquarium temperature may rise to approximately 30 °C but I there were no losses in either group and all now live together in an aquarium.

A soft, sandy substrate, within which the fish will bury themselves at times, plus several flat stones arranged to form hiding places and some submerged roots complete the set-up. Even plants are not damaged or uprooted by the fish as they forage.

C. sp. 1 is probably collected in Taiwan © Thomas Frank

That said, I tend to keep nothing except cryptocorynes in my loach tanks since with larger stem plants there could be problems, especially in combination with larger and stronger cobitids.

Regarding food the only consideration is that it must sink to the bottom with live black mosquito larvae ideal for cobitids, although they also accept frozen varieties with enthusiasm.

White mosquito larvae are less useful for these fish since they live more in open water plus the defrosted remains tend to float on the surface. Both live and frozen bloodworm or Tubifex are very suitable foods, though.

I feed only live Tubifex because some of them bury into the sand and serve as a more constant source of food for the loaches. Often the loaches are still feeding on the Tubifex the following day, some of which have become deeply buried in the sand, so the fish must perform a ‘headstand’ to find them!

Sinking dried tablets and granules designed for benthic fishes and of a suitable size for their mouths are also happily taken by my Cobitis.

All in all these are easy loaches to keep but as with many other loach genera they do not have a large fan-base.

Literature

Evers, H.-G. (2009): Schmerlen aus China. Amazonas, 5 (3): 72-73

Chang, I.-S. & Chen, Y.-C. (2005): A Photographic Guide to the Inland-Water Fishes of Taiwan: Volume 1: Cypriniformes 254-259

NB: this is a translation of the article “Drei neue Steinbeißer der Gattung Cobitis” which was originally published in the BSSW-Report 3/12.

The books contain beautiful underwater photography © Rune Evjeberg

For fans of Mexican fishes, especially livebearers, the two books written and self-published by the ‘Freshwater Biotopes’ team of Rune Evjeberg and Kai Qvist are essential reading.

Book 1 is extensive and covers numerous habitats in the states of Coahuila, San Luis Potosi, Hidalgo, Michoacán, Quinatana Roo and Campeche, whereas Book 2 is concerned with the highly diverse Yucatan Peninsula.

Focussing not only on the fishes inhabiting the biotopes each locality-specific section also includes information regarding water chemistry, flora, insects, reptiles, mammals and birds to be found at the various localities.

Production quality is high with lavish colour photography throughout, including some memorable underwater images, and overall these books represent an irresistible insight into some of the most beautiful freshwater habitats in the world.

Mexico is a haven for livebearers such as Poecilia latipunctata © Rune Evjeberg

A total of 163 endemic freshwater fish species are known from Mexico and some of them are highly-endangered. In order to assist around 20 % of the cover price of each book is donated to the Fish Ark Project based at the Aqualab, Universidad Michoacána, Morelia.

The Aqualab maintains a number of species in danger of extinction or which are already extinct in the wild, including goodeids and other livebearers, so by buying these books you’re also supporting a worthy cause!

Not only that, SF readers can get a 10% discount by ordering the books from www.freshwater-biotopes.org and entering the discount code ‘SF10‘.

The offer is only valid for a limited period and the first book is now back in stock after the first print run sold out (and at a lower price than before too) so we advise getting in there quickly to avoid missing out this time!

Adult male; red operculum morph (?) © Tino Strauss

Scientists from the University of Alberta, Canada, have ascertained that the pH of water influences both sex ratio and male phenotype in the kribensis, Pelvicahromis pulcher. Continue reading »

Myriophyllum aquaticum, better known as Parrot’s feather, will no longer be legally available in the UK from April 2014. © André Karwath

The sale of five invasive, non-native aquatic plant species is to be banned in the UK in order to protect wildlife and save money, the government has announced. Continue reading »

Many aquarium fishes are maintained under conditions they would never experience in nature. © Elke Weiand

Rüdiger Rautenberg with an alternative look at aquarium heating and how following the ‘rules’ may be costing you money… Continue reading »

© Back to the Roots

This new aquarium is to be marketed as a ‘closed-loop ecosystem’ that cleans itself while also facilitating the growth of fresh produce including beans, basil, thyme, baby greens, oregano, mint, parsley, and spinach. Continue reading »

Rüdiger Rautenberg on a cheap filtration method deserving of greater exposure…

A planted aquarium set up with a Hamburger Matten Filter. © Rüdiger Rautenberg

The HMF (Hamburger Matten Filter) is apparently not all that well known outside mainland Europe, or so I’ve been told. I cannot speak for the whole of Europe but in Germany it is certainly a widespread and well-loved method of filtering fish tanks and is favored especially by breeders and hobbyists who maintain a larger number of tanks in a dedicated fish room. Continue reading »

What are the basic ways of heating an aquarium?

© Viktor Lantos

Along with filtration, heating is among the most important considerations for fishkeepers. The majority of freshwater species that we keep in our aquaria are found geographically in the area between the Tropic of Cancer and the Tropic of Capricorn (23° north and south of the equator respectively), hence the term ‘the tropics’ and therefore ‘tropical fish’.

Ambient temperatures in the tropics rarely fall much below 68°F/20°C, at least for any sustained length of time. Additionally temperatures in the tropics have little seasonal variation.

Even in a modern, centrally heated home, temperatures regularly fall below this minimum level in many countries, meaning that to keep successfully any tropical fish species a heater is required.

What do fish prefer?

When considering heating requirements, it is important to think about the fish you intend to keep. If your intention is a general community tank with a variety of fish, then the required temperature will always be a compromise that suits all the different species you plan on having in your tank.

In general, the majority of commonly available community species will be perfectly happy in a tank where the temperature is somewhere between 70 – 82°F/21 – 28°C.

If you intend to keep a particular species or group of fish then it is good practice to aim for a temperature as close as possible to that which the species would live in naturally.

For example, some species do best at temperatures in excess of 30°C/86°F while others prefer cooler temperatures of 20°C/68°F or less but all are traded as suitable for the ‘tropical’ aquarium.

It is advisable to research the requirements of individual fish when planning your overall setup. Many species will tolerate temperatures outside their natural range, but the aim should always be to replicate the conditions they would experience in the wild as it is only then that they will thrive.

Equipment

A vital complement to a heater is a proper thermometer but avoid the ‘stick-on-the-glass’ type since these are easily influenced by ambient temperature. Simple, submersible, glass aquarium thermometer are cheap to buy, accurate and sufficient for the needs of most fishkeepers.

In terms of heating equipment there are a number of options available, and we’ll consider each in turn.

Heater/Thermostat
The combined heater/thermostat is the near universal piece of equipment that most aquarists use to heat their aquaria. The heaterstat, as it is commonly known, is an automatic device that measures the temperature of the aquarium and turns the heater on and off, as required, until the desired temperature is achieved.

Most heaterstats come with a dial that can be used to select the desired temperature. Heaterstats are available in numerous sizes and wattages and are therefore suitable for the majority of standard sized aquaria. The wattage of the heater should be equivalent to or slightly more than the aquarium volume in litres.

With larger tanks, it is good practice to use two or more heaters as this facilitates a more even heat distribution and also provides a back up should one heater fail. This could also be considered for smaller tanks, for example you may wish to consider having two 150w heaters in your 48″ tank.

This also reduces the risk of your fish being killed if a heater sticks in the “on” position, as it would take longer for the tank to reach life-threatening temperature levels.

When using a heaterstat for the first time (or if you are using a unit that has been out of the water for some time) it’s a good idea to check how accurate the temperature scale is and to test i that it’s working properly.

Fill a (preferably plastic) bucket and install the heater using the suction cups to attach it. Select a temperature value around the middle of the range covered (77°F/25 degrees °C, for example) and leave the unit for a few hours before checking the temperature with a thermometer.

Heaterstats normally have a minimum water-level marked on them, and the unit may crack or fail completely if exposed below this recommendation. Some models now come with an automatic cut-off system but this should not be replied upon as a failsafe.

When doing any kind of maintenance that involves removing the heater or dropping the water below the recemmended minimum level always unplug the unit and leave it to cool for 30 minutes.

For very small aquaria there are also mini-units in the 7.5-25 watts range. Most of these do not feature an adjustable thermostat but are fixed at 77°F/25 degrees °C, and build quality, particularly the internal thermostats, can be somewhat unreliable.

Inline Heater/Stat

A relatively recent development in heating technology has been the in-line heaterstat. This device functions in much the same way as described above but the main difference is that the unit sits outside the tank.

This heater can only be used where you have an external filter as it is designed in such a way that the output from your filter is directed through the in-line heater and back into the tank. The inline heaterstat is a sealed unit with a connector for the water input hose at one end and a connector at the other end to attach a hose to direct the water back to the aquarium.

This type of heater, although more expensive than a standard heaterstat, is an excellent idea if you have large fish such as cichlids and catfish that may attack or otherwise damage any internal equipment.

Thermofilter

Thermofilters are similar to inline heaters in that they remove the actual heating unit from inside the aquarium. As the name suggests, thermofilters combine the heater and the filter into one piece of equipment – in this case, an external filter.

Eheim are the main manufacturers of this type of heater/filter, although some other companies are starting to follow suit. In this arrangement, the heating element is built into the filter and water is heated as it passes through the device.

There is a separate temperature probe which is placed into the tank and connected to the heater via a wire. Temperature can be adjusted via a control panel. As with inline filters, thermofilters are a good way of removing as much equipment as possible from the tank.

The disadvantage of thermofilters is that they cost considerably more than purchasing a heater and a filter separately. Additionally, if you are running a marine tank, you must ensure you purchase a model that is compatible with saltwater.

Space Heating

The final option we will consider is space heating. This solution is only suitable for the fishkeeper with several tanks in a single room or shed and is unlikely to prove cost effective unless there are at least a dozen tanks present, depending on the space.

Rather than heat each tank individually, space heating involves heating the whole area. This can be achieved in a number of ways but the best way to heat the room is by using a thermostatically controlled electric heater such as an oil-filled radiator or an electric fan heater.

This can potentially be a very expensive way of heating your tanks, so it is imperative that the room in which they are situated is very well insulated. Materials such as Kingspan, industrial grade polystyrene, cavity boards and Airtech insulation are all good options.

Consideration should also be given to covering any windows in the room or shed, although double glazing will help mitigate this. The disadvantage of space heating is that all tanks are maintained at the same temperature. One way round this is to heat the room to the minimum temperature required and then place a heaterstat in any tanks requiring a higher temperature.

What should I do if my heater fails?

In many cases there is no need for immediate panic. A tank in the average modern home will lose heat very slowly and many fish species can handle a gradual drop in temperature without problems (in some it may even trigger spawning!).

If you do keep sensitive or heat-loving species it can be a good idea to have a spare heater in stock just in case, however. If a power outage lasts longer than a few hours it’s a good idea to wrap the tank in insulating material; plastic bubble wrap or even blankets work well.

Any other tips?

Heaterstats can be unsightly devices that can spoil the visual effect of a carefully aquascapes aquarium. If unprepared to buy a more expensive inline device you can camouflage your unit by planting around it or placing some wood or other décor in front of it.

Ensure that there is sufficient water movement around the unit, and if planting closely or stocking fishes that like to hide it’s important to install a heater guard to prevent them being burned.

Many thanks to Jeroen Wijnands for comments and additions and Steven Gielis for suggestions.

Although we didn’t say much about it at the time, this new version of the SF website was launched to more-or-less coincide with our fifth birthday. Over that not-inconsiderable period the majority of our efforts have been aimed at improving our species database to include information, and indeed species, that don’t tend to be covered in depth elsewhere on the web.

While we think we’ve done a decent job so far, particularly in terms of fishes from Asian waters, there’s something we feel is missing. Continue reading »