Trevor! An Australian eel-tailed catfish (Tandanus tandanus), otherwise known as Big Fish! And what a fish! I first met Trevor in early 2019 after returning to Sydney. Trevor had originally come from SuperNick (Nick) and had been around since at least 2017, when he was still just a little fellow. By the time I came along, he was growing into quite the character. Probably one of the friendliest, most curious fish I’ve ever had the pleasure of looking after!

First up, Eel-tailed Catfish Detected! Yes, apparently detecting fish is now a legitimate pastime. Nothing quite like having an aquarium and then having to go looking for its inhabitants. Trevor seemed rather interested in whatever was happening outside the glass too. I’m not entirely sure who was supposed to be studying who here!

Trevor as a youngster, 3 September 2017. This photograph was taken before I met Big Fish!

It’s rather fascinating looking back at these early photographs, knowing just how substantial Trevor would eventually become. Eel-tailed catfish aren’t exactly tiny little aquarium fish once fully grown, and Trevor was certainly heading in that direction! They’re also capable of changing their colouring to better suit their surroundings, which is a pretty neat biological trick. Changes in colour can have several explanations, though, so appearances alone aren’t proof that a fish is stressed.

Another early photograph of Trevor, 21 October 2017. Still a youngster, long before Big Fish became quite so big!

The following day we have Eel-tailed Catfish Hiding. Very exciting stuff! By this point I’m starting to wonder who’s watching who. The fish are probably wondering why this strange being keeps pointing a camera at them. Trevor was generally a curious, friendly fellow, and it was always entertaining watching what he decided to investigate next. There’s something rather endearing about a fish that seems genuinely interested in the world around it.

Aquarium Adventures and Biological Filtration

Trevor was living in an AquaStyle 510 75-litre aquarium, complete with a top-mounted biological filtration system and an increasingly enthusiastic amount of water testing. Ammonia, nitrites and nitrates! Because apparently watching fish wasn’t nerdy enough, we needed to throw some chemistry into the mix too. One of the more fascinating parts was the bacteria colonising the stones in the top filter. An entire little biological community working away to process waste through the nitrogen cycle. Pretty neat stuff!

Unfortunately, bacteria aren’t magic. The aquarium was becoming increasingly difficult to maintain as Trevor grew, and some of the water-testing results were rather alarming. Fish Tank World’s original records show ammonia/ammonium readings marked NH4+ reaching 8 ppm in early September 2019. Not exactly what you want to see when checking the water! Substantial water changes were needed to bring the readings down, and I spent quite a bit of time trying to keep everything as comfortable as possible. Even the most enthusiastic biological filtration system can’t make an aquarium physically larger, unfortunately.

Come the 20th of September and we’ve got three more exciting instalments! First up, Trevor the eel-tailed catfish, up close and personal. Look at that face! Not quite the little fish from the 2017 photographs anymore. Big Fish was certainly living up to the name, and it was becoming obvious that a substantially larger aquarium would eventually be necessary.

Next up, Trevor goes swimming! That’s right, actual footage of a fish swimming around in an aquarium. Groundbreaking material here at McRetro! Although I must admit, I could happily watch Trevor for ages. Such a friendly, curious fellow, and always something interesting to observe. Fishkeeping is rather addictive once you start paying attention to all the little things happening inside an aquarium.

And finally, Trevor resting. We’ve now covered pretty much the entire daily schedule of an eel-tailed catfish. I know, I spoil you all! Between maintaining the filter, monitoring water chemistry and keeping up with the water changes, there was certainly plenty to keep me occupied. It was a fascinating little lesson in aquatic biology, even if the practical limitations of the aquarium were becoming increasingly difficult to ignore.

And finally, on the 24th, Eel-tailed Catfish Cornered! That sounds rather dramatic, doesn’t it? Seven videos in ten days. I don’t think anyone could accuse us of neglecting the eel-tailed catfish coverage!

Trevor really was a wonderful fish to spend time around. Friendly, curious and quite the character. But as interesting as the aquarium biology was, there was one problem that no amount of water testing, filter maintenance or rearranging could solve. Big Fish was getting bigger, and the aquarium wasn’t!

Update: The Big Fish Tank Troubles (2020)

Unfortunately, things became considerably more complicated the following year. By June 2020, Trevor was approximately 25–30 cm long and still living in the Aqua One AR510 75-litre aquarium, measuring just 51 cm across and 34 cm from front to back. That’s a rather substantial fish in a rather small aquarium! I’d been trying to arrange a larger home for some time, including proposals involving a bigger tank and an outdoor pond project, but none of these arrangements had worked out.

The property situation wasn’t helping either. There were restrictions on additional aquariums, and the property owner eventually confirmed that the extra tanks hadn’t been approved. The household disagreements surrounding Trevor were becoming increasingly frustrating, especially when the whole objective was to improve the living conditions of a growing fish. I was willing to contribute a larger 240-litre Juwel aquarium at another location, but after more than 100 days without a satisfactory resolution, that proposal had gone nowhere either.

By 24 June, I was contacting aquarium shops in the hope of finding a suitable permanent home for Trevor. The emails described a male Australian eel-tailed catfish, approximately two to three years old, measuring 25–30 cm and living in water around 23°C. The existing aquarium was already well beyond what I considered appropriate for a fish of that size. Rehoming wasn’t something I particularly wanted to pursue, but finding somewhere with sufficient room seemed far preferable to continuing indefinitely in unsuitable conditions.

Things eventually became heated enough that I contacted the police assistance line regarding Trevor’s welfare and sought advice from the RSPCA. Yes, actual police involvement over a fish! Not exactly where I expected these aquarium adventures to end up. SuperNick (Nick) was normally remarkably tolerant of me, and I suspect this whole situation tested that tolerance rather severely. It certainly wasn’t a pleasant disagreement, and I never wanted things to reach that point.

But what was the alternative? Trevor couldn’t exactly pick up the telephone and explain that the aquarium was becoming too small. Someone had to speak up for Big Fish! I certainly didn’t have all the answers, and there were limitations on what could realistically be done, but simply continuing with the existing arrangements wasn’t a satisfactory long-term solution either.

What Happened to Trevor?

By the end of July 2020, everything had changed. I moved house on 30 July, while SuperNick (Nick) moved into a separate home around the same period. None of the fish came with me, and unfortunately I don’t know what ultimately happened to Trevor or the others. I can only hope they ended up somewhere comfortable, with plenty of room and the care they needed.

Looking back, I suspect I seriously upset SuperNick (Nick) over the whole affair, which is something I never really wanted. But Trevor was a wonderful, friendly fish who deserved better than spending the rest of his life in an aquarium that couldn’t accommodate his growth. I’d only known Big Fish since early 2019, yet it was impossible not to become attached to such a curious little character. I learned quite a bit about aquarium biology along the way, although perhaps the most important lesson was that no amount of maintenance can replace having an appropriately sized home.

I still wish I’d been able to do more.

Wherever you ended up, Trevor, I hope you got your enormous aquarium.

Fish rock!