Yes I have read about yo-yo loaches needing a shoal, but also that they can be aggressive to others of their kind. If I buy two more, they will be about 1” long. It seems like a recipe for bullying when the one I have is so big and he’s also super active. He’s about 3 years old.
No, this is not likely to work. It depends how long you have had the lone loach, and it depends upon the temperament of this fish. And the latter cannot be seen until it occurs, by which I mean the loach is likely under serious stress now but this will not manifest itself until it is too late. And adding two or three or four loaches could trigger a real aggressive dominance that could kill the new loaches.
All loaches are cyprinids, and cyprinids are shoaling fish that must be in a group from very early on...i.e., when you acquire them from a tank of many in the store. Loaches are highly social fish. Early in their placement in a new environment the group will develop their own hierarchy. An alpha fish, usually a female, will control the group and depending upon their individual "personalities" the group will settle in and all will be well. There must be at minimum five, preferably a couple more. This is how the fish lives and it is not going to change just because we want it tom as all this is part of the genetic makeup of the species.
If this is the true "Yo Yo" loach, it is
Botia almorhae. They establish a social structure within the group and there will be some in-fighting though not damaging if the fish are maintained in a group of at least five and there are numerous hiding places in the aquarium--each loach must be able to select its "home" which will be a tunnel or crevice in a chunk of wood (or artificial decor providing the same function). Long-finned upper fish should be avoided to prevent possible fin nipping; suitable upper fish are barbs, rasbora, danios, characins. This species is very active, and as noted needs a spacious aquarium with plenty of hiding spots so it can be kept in a group of at least 5 or 6, otherwise some members may be relentlessly picked on and succumb to stress and injury. A riverine aquascape would be ideal; a substrate of fine smooth gravel or sand with smooth rocks representing boulders, caves made from bogwood or rock, and subdued lighting partially achieved with floating plants.
I mentioned the "probable" species, this is partly because the body markings of the yo yo loaches can vary quite considerably from fish to fish. As the fish matures the pattern fills in to be more reticulated. From time to time a fish may "gray out" as it is commonly called, usually two together and often during "fights" or when feeding; the base colour darkens considerably. Episodes of this interaction between two fish can last for several hours. This is more evidence of the necessity of the group. A lone fish will be highly stressed.
Taxonomic information for those interested:
The exact species name of this fish is still uncertain. Originally it was deemed to be
Botia lohachata, the name assigned by B.L. Chaudhuri in 1912, and it is still widely seen under this name.
Botia is derived from an Asian word for soldier or warrior. In the early 1990's it was suggested that this species epithet was a synonym for
Botia almorhae, the true species, which had been described in 1831 by J.E. Gray. Dr. Maurice Kottelat (2004), an acknowledged authority on this family, assigned the name
B. lohachata as a synonym of
B. almorhae and not a distinct species in his major revision of the genus which he separated into seven genera. More recently, Kottelat (2012) and several other ichthyologists have accepted B. lohachata as a distinct species.
Steven Grant (2007) has proposed that
B. almorhae may in fact consist of five distinct but closely-related species:
Botia almorhae Gray, 1831
Botia birdi Chaudhuri, 1909
Botia lohachata Chaudhuri 1912
Botia sp. "Kosi", possibly a variant of
B. almorhae
Botia sp. "Teesta", possibly a variant of
B. almorhae
The striking similarity in pattern among these fish certainly makes this feasible; the California Academy of Sciences--Ichthyology has accepted the validity of the first three distinct species. The authors of Loaches Online accept
B. almorhae as the species of the subject fish. The occurrence in Pakistan is restricted to the species
B. birdi described by Chaudhuri in 1909.
The subfamily Botiinae within the family Cobitidae is also uncertain; Nalbant (2002, 2004) and Kottelat (2004) raised the subfamily to family status as Botiidae and divided it into two tribes:
Tribe Leptobotiini - includes the genera
Leptobotia, Parabotia, Sinibotia.
Tribe Botiini -
Botia, Chromobotia, Syncrossus, Yasuhikotakia.
Tang et.al. (2005) agreed. Slechtova et. al. (2006) basically agreed but proposed two Subfamilies rather than tribes, and moved one genus:
Subfamily Leptobotiinae -
Leptobotia, Parabotia.
Subfamily Botiinae -
Botia, Chromobotia, Sinibotia, Syncrossus, Yasuhikotakia.
