Sun Loach (Yasuhikotakia (previously Botia) eos)

Does anyone remember who Eos was? It is the creature from Ancient Greek mythology, the “pinkish finger” goddess of dawn, sister of Selene and Helios, mother of Winds (Boreash, Zephyr and Euros) and Stars; by Romans called Aurora. Her name was given, supposedly not accidentally, to the medium sized botia originating from the fresh waters of South-East Asia and belonging to the Modesta complex. At first glimpse Yasuhikotakia (Botia) Eos externally does not differ much from other members of the group such as Silver, Speckletail or Modesta loaches. But if you see her fins you will immediately understand the origin of her scientific name J. In English speaking countries this botia is usually referred to as Sun loach. It is a great pity, however, that despite the fact that this species was first described more than thirty years ago by Japanese ichtyologist Yasuhiko Taki („Botia eos, a New Spiny Loach from Thailand and Laos, with Notes on Some Related Forms In Asia”, Japanese Journal of Ichthyology, Vol.19, No.2, Sept.20, 1972), it falls rather rarely to the aquarias of loachaholics from around the world. There are many myths and legends orbiting around this beautiful fish with respect to her territorial behaviour and extreme aggression. I will try to describe my personal encounters with the members of this species and address issues concerning their compatibility with community tanks.

My first and, for quite a long time, single specimen, was found rather by chance, mixed with a couple of silver loaches (Yasuhikotakia lecontei), similarly to few other rare botia species I was lucky to collect over the years of my devotion to the hobby. Four years ago (January 2000), on one frosty winter day, in local pet shop, my attention, while monitoring new arrivals (a few weeks earlier in the same locality I bought my Mun River Speckletail loaches under the label of silver loaches), was attracted by unusual situation seen in one of the display tanks. One of the supposed-to-be silver loaches had overtaken the central part of the tank and the reaming four fish were scattered throughout tank’s corners. Such behaviour was somehow against my, then yet not too extensive, knowledge about silver loaches, so I started to observe patiently this mysterious and a bit quarrelsome specimen. Unfortunately, as it happens with fish freshly introduced to the shop tanks, hardly furnitured with suitable shelters or even plants, served only to maintain fish live at minimum expense until first buyer will merge over horizon, it was pretty hard to determine undoubtedly identity of this little “browler”. There was already no signs of characteristic, for juvenile Sun loaches, blackish, narrow, vertically oriented stripes on fish flanks (seen also in case of juvenile specimens of other closely related botia species) and what could then be stated for sure was the conclusion that it certainly was not Silver loach. In this case intuition have played decisive role in collecting .new, fascinating taily diamond.

New fish has landed in the tank already populated by a number of various loaches coming partially from Malay Peninsula (Silver and Speckletail loaches) and partially from Indian waters (Queen, Striata and Rostrata) plus a small group of barbs (Puntius nigrofasciatus) occupying central and upper part of the tank. The beginning wasn’t too optimistic, the hot dispute with, then dominant in the tank, one of the Speckletail loaches (Yasuhikotakia caudipunctata), about the place, in centrally located in the tank cockonut shell, accompanied by notorious pushovers had begun. The latter fish, despite bigger size had finally to give up the battlefield (though after solid resistance) to the new inhabitant. The remaining members of tank community seemed to act as statists only. A new order has been set and no other consequtive conflicts have later on been observed. Possibly it was due to the moderate temperaments of tank community members, possibly due to the sufficient number of various shelters and hideouts for the home seeking fish. There are known, however, descriptions of extremely aggressive behaviour of Sun loaches that, quite frequently, to despair of their owners, had resulted in moving browling fish to separate tanks. My goddess appeared to be much more tolerant with respect to other tank sharing community members.

Yasuhikotakia eos, in nature met in large river basins of the South_East Asia (Mekong, Menam Chao Phya), exhibits noticeable differences in body coloration within the species. Some of the specimens have uniform dark-brownish, mixed to some extent with black, pigmentation. On the other hand darks spots and blotches are seen as a result of mechanical wounds, acquired for instance during fish fights, so, possibly, such a dark coloration, may result from fish stress or excitement and thus, being not necessarily a regular character for this species. Adult, relaxed specimens have pectoral, pelvic and anal fins beautifully painted with reddish color with black distal margins. Central part of caudal fin has also specific, a bit dusky, reddish pigmentation, while its outer regions yellowish-brownish background covered with subtle dark brown-to-black dust. Members of this species can easily be recognized by very characteristic, relativelyôbroad dorsal fin containing 10-11 branched rays. Base of caudal fin is marked with large blackish vertical band/blotch. A subtle white distal margin is visible at the verge of the dorsal fin. There is also one special sign seen on fish body, for unknown reasons frequently forgotten in morphological descriptions, which, at least in my personal opinion, may be useful at the stage of fish id, i.e., small blackish dot placed just above the lateral line in close proximity to the end of operculum (it was one of the very first differences noticed by me between members of this species and Silver loach (Yasuhikotakia lecontei)). Adult specimens of Sun loach attain total length of approximately 10cm (4 inches), so it means they are rather medium sized loaches. The “lack in length” is certainly compensated by higher than average temperament (J).

Sun loach is considered by many aquarists (if not by majority) as one of the most bad-tempered and aggressive members of Botinae subfamily. I do not want to deny the objectivity of dramatic descriptions of these fish activity in home tanks, because I also was, personally, shown the results of one-night activity of two young Sun loaches placed in relatively large (370l) display tank in LPS on their much massive and bigger tank-mates (Clown loaches).The owner couldn’t resist such a situation and quickly sold out troublesome inhabitants. In the meantime a group of nine new Sun loaches from the same shipment had landed in socially stable tank with a variety of loaches (Botia dario, striata, rostrata, histrionica, almorhae, Yasuhikotakia lecontei, Syncrossus hymenophysa and Chromobotia macracanthus) and a decent shoal of different in size barbs. They quickly adapted without any serious conflicts to possibly a bit over-populated 240l tank community. Later on, relatively large specimen of tiger loach (Syncrossus beauforti) was added. Once upon a time, sharing personal experience and impressions concerning loach keeping (species compatibility) question, I raised a thesis that final success is largely dependent on fish psychological security, whatever it should mean. The main point in argumentation was, in contrary to wide spreading opinions, that this so called psychological security is not a simple function of tank volume or bottom area. Of course, it shouldn’t be read quite literally, because amount of water and, especially, surface area of the bottom, has to be correlated with size of our loaches. They, being natural born territorial creatures, tend to behave like soldiers on a guard, being always ready to prepare action (unfortunately not always defensive L) on a more or less real enemy, spotted in the line of sight. The practical solution of this painful for loach enthusiasts problem is surprisingly easy and obvious - it is necessary to model adequately the architecture of the bottom of a tank in the manner enabling potential victim, in case of increased other loach aggression, quick disappearance from the line of sight of attacker. To this aim I use cockonut shell pieces and bamboo pipes, and so far, having kept at once (of course in a couple of tanks) almost three hundred loaches, I haven’t had any serious compatibility problems, having, to the contrary, many optimistic conclusions resulting from mixing specimens that come from widely acclaimed aggressive-to-be species J.I have also followers who successfully maintain community tanks with Sun loaches. Yasuhikotakia eos, beautiful and relatively seldom met in the trade member of the Modesta complex does certainly deserve decent and objective goddess related description. A lot of harm and injustice to this species can make gossips having very little in common with reality, quite frequently resulting simply from the lack of knowledge and human ignorance as well as long time preserved incorrect mental templates and logical shortcuts.