Skunk loach...

[Brinn2397]

I hope I picked the right thread for this, anyways... I have one skunk loach and he is SO aggressive, I was thinking about giving him away but that doesn’t sit right with me. I’m wondering if I can put 4 of them in a 20 gallon tank, if not, can I keep 3 with them being satisfied with the size of the school?

 

[Byron]

This is naturally quite an aggressive loach. They not only can tear into each other, they can readily tear into other fish depending upon the individual fish's temperament. And this can be affected by the number and the tank size.

Loaches are social fish, but with this species it is a little bit different. Yasuhikotakia morleti is a feisty loach that should be kept in a small group to spread aggression. Not advisable to mix with Botia species loaches, but other semi-aggressive loaches such as Syncrossus species are possible. Upper tankmates must be robust, hardy and active, such as medium barbs, larger rasbora and danios. Sometimes specimens will turn particularly aggressive to other fish.

Attaining four inches (10 cm) one alone would manage in a 20g but not four--any group needs a 4-foot (120 cm) tank. And there should be more in the group to spread out the aggression.

In other words, there is no guarantee but three or four is the worst of the options so you might want to re-home these fish.

[Edited to correct data, see post #4 for more detail.]

 

[Brinn2397]

So will he be happy all alone?

 

[Byron]

So will he be happy all alone?

No, definitely not, and I am grateful you asked because my previous answer was misleading so allow me to correct something. I had copied a paragraph from a profile I wrote on this species a few years ago and it needs revision clearly. To save time, the following is from Seriously Fish:

Yasuhikotakia spp. are gregarious, form complex social hierarchies and should be maintained in groups of at least 5 or 6 specimens, preferably 10 or more. [edit: this requires the 4-foot/120 cm length tank]

When kept singly they can become withdrawn or excessively aggressive towards similarly-shaped fishes, and if only a pair or trio are purchased the dominant individual can stress the other(s) to the extent that they stop feeding.

That said they seemingly require regular contact with conspecifics, a fact exemplified by a number of behavioural rituals which have been recorded consistently in aquaria:

Some behavioural routines exhibited by Yasuhikotakia spp. have been recorded often enough that they’ve been assigned non-scientific terms for ease of reference.

For example during dominance battles (these occur most frequently when the fish have been introduced to a new tank, or new individuals added to an existing group) the protagonists normally lose much of their body patterning and colouration, a phenomenon that’s come to be known as ‘greying out’. Such displays will sometimes also happen within an established group as individuals seek to improve social ranking but are usually nothing to worry about.

Interestingly some observations suggest that the character of the highest-ranked, or alpha, fish appears to affect that of the whole group though it must be said that scientific studies of botiid loach behaviour are virtually non-existent. It certainly seems that they display a degree of ‘personality’ with some specimens being naturally bolder or more aggressive than others, for example. The alpha is normally the largest specimen within the group and often female.

‘Shadowing’ is an interesting behaviour in which younger individuals swim flank-to-flank with older, mimicking their every movement. Some keepers report that more than one smaller fish may shadow a larger simultaneously, with even three or four on each side! The reason for it is unknown; it may relate to a group staying in touch with one another when rivers swell during times of flooding, perhaps reducing drag by swimming ‘in formation’ or having some other communicative function. It’s been observed in aquaria with both high and low water flow and seems to be habitual to the extent whereby some individuals will shadow other fishes if no conspecifics are present.

Sound also appears to be an important factor in communication since these loaches are able to produce audible clicking sounds, these increasing in volume when the fish are excited. The behavioural aspects of this phenomenon remain largely unstudied but the sounds are thought to be produced by grinding of the pharyngeal (throat) teeth or subocular spines.

A further curiosity is the so-called ‘loachy dance’ which involves an entire group swimming in a constant, restless fashion around the sides of the tank, usually utilising the full length and height. The reasons for this are unknown and reports as to when it occurs vary but the most common triggers appear to be the addition of food, fresh water or new conspecifics, and it can last anything from a few minutes to a day or more.

[edit: Some of the fore-going behaviours are present in many other species of botiid loaches.]

 

[Brinn2397]

What do you think of keeping 7 skunk loaches with some cichlids in a 55 gallon tank? Or should I go with 10 loaches alone in a 55 gallon?

 

[Byron]

What do you think of keeping 7 skunk loaches with some cichlids in a 55 gallon tank? Or should I go with 10 loaches alone in a 55 gallon?

I would go with more of the loaches, but I would also find some upper level fish. Ten loaches in a 55g will be rather sparse. Cichlids are probably not a good option though; first, most tend to be lower-level fish, close to the substrate, right in the loach's space, and second, this leaves the upper half of the tank empty. Some of the barbs would be good options. The Black Ruby Barb comes to mind; this is a nice fish. Danios perhaps, there are several species aside from the very common Zebra.

There is always the possibility that one of the loaches might become a nuisance to upper fish, but with a group of ten this is less likely and the offender could be removed if it became serious. Floating plants as always will help al of this.

 

[Brinn2397]

I would go with more of the loaches, but I would also find some upper level fish. Ten loaches in a 55g will be rather sparse. Cichlids are probably not a good option though; first, most tend to be lower-level fish, close to the substrate, right in the loach's space, and second, this leaves the upper half of the tank empty. Some of the barbs would be good options. The Black Ruby Barb comes to mind; this is a nice fish. Danios perhaps, there are several species aside from the very common Zebra.

There is always the possibility that one of the loaches might become a nuisance to upper fish, but with a group of ten this is less likely and the offender could be removed if it became serious. Floating plants as always will help al of this.

Thank you so much for your help!