Yep its a golden loach, used to have one of those. complete nightmare.
At 1 or 2inchs they're not a problem though, but...
I shall tell you my story(silently remembers painful memorys).
I had only been keeping fish for about 10months back then and i admit i was very lucky- despite my lack of knolege i never had any problems apart from a few accidents(landlord getting drunk and dumping a full box of algae tablets into tank for one) and one minor case of fungus.
I started getting a bit of algae in the 2ft tank i had back then so i went down to my lfs and asked if there were any good small comminity fish that ate algae.
The lady who used to own the place back then pointed to a golden loach in a tank that was happily sucking its way across the glass and told me it was a good community fish and didn't exceed 3inchs and was a good algae eater(totall rubbish of course but i had faith in my lfs back then). It was 1inch long.
Ah...Its so sute i thought. So i popped it in my tank(15gal) at the time and it started eating the algae. At first it took no interest in the other fish which were a mix of platys, guppys and mollys at the time but then it started to grow.
It grew over an inch a month and at 4inchs long i woke up one morning to find half a platy.
Next morning, a molly. And a guppy after that. They were horribly eaten up.
The loach on the other hand went around with buisness as usual sucking away at the glass.
The fish deaths continued and at fish death no. 5 i decided to watch the tank at night after the lights had been turned off. To my horror it was chasing everything around in sight and trying to attack and eat them alive. it wasn't like any agression i've ever seen in a fish before- it was just chasing and chasing and chasing....
I went to my lfs and told the woman there what had happened and she told me that they could get a little terotorial but it wasn't anything to worry about, i told her that i thought it was killing my fish but instead she said it was because they had internal bacteria so i ended up going out of the shop with some med.
Loach continued to kill; i tried returning it back to the shop but they wouldn't accept it as well as other lfs's(no wonder though).
In the end they ended up selling the shop a month later after i had lost 7fish.
I ended up buying a 10gal for it because that was all i could afford at the time but 2months later the loach ended up dying in a long powercut anyway.
Moral of the story; golden loachs are not community fish at all.
I didn't hate it for killing so many of my fish cos it was only doing what it would have naturally done in those situations, but i think lfs's should certainly cut down on the amount of these fish they sell and similar loachs as so many of them end up in community tanks.
)
...so should i get rid of this sucker or what 
will this be the exception of a peacfull fish in such a mix 
If anything I reckon the Rds willl eat him aventually...who knows this could be a perfect relationship and combination for aggressive suckers vrs Cichlids. 
