Practical Fishkeeping -julkaisun February 2026 -irtonumeron sisällysluettelo

ALTHOUGH THE EVER-GROWING presence of online retailers has granted the fishkeeping community with access to countless species in recent times, I’m still very much a sucker for wandering into the store and looking the shopkeeper in the eye as my life savings go on to fund yet another aquatic endeavour. There’s just a simple joy that arises from perusing the aisles and banks of tanks, seeing what’s new and what inspiration might be sparked. However, there’s also something very important that happens when you come face-to-face with potential new livestock. With a keen eye, a little time spent staring, and – at some point in your hobby – sufficient knowledge and experience, you can gauge exactly what is both right and wrong with the fish in front of you. This…

IN THE AUGUST ‘25 edition of PFK, I discussed at length one of my favourite oddball fish: the urchin clingfish, scientifically known as Diademichthys lineatus. In said article, I mentioned that although an urchin clingfish doesn’t technically require the presence of a sea urchin to survive, it’s certainly more fun to keep it with its natural host. That’s all well and done, but I never actually told you how to keep a sea urchin alive in your home aquarium, nor which of the many species available you should consider buying. Today, allow me to correct the lack of information in my previous article. All hail the humble sea urchin! What even is a sea urchin? A valid question. We all know they’re both round and pointy, but where do sea…

Going with the flow The oceans are constantly moving, and water flow is actually even more critical to corals than light. Many corals in the deep oceans survive without any light, gaining all their nutrition from capturing zooplankton, but no coral in the ocean can survive without water movement. The flow of water provides corals with food and washes away their waste. Water flow in the oceans is strong and chaotic and corals have adapted to that way of life whereby they can be blown one way for a few seconds, then the complete opposite way after that. Tides, storms, swells, eddies and currents all play their part on coral reefs and they are essential to their survival, carrying eggs and sperm to far-off places where new polyps will settle…

ONE OF THE most mesmerising spectacles in the animal kingdom, is a group of fish swimming in unison. Almost as though they are a single entity, these synchronised fluid formations appear like choreographed dance routines, with their shimmering scales reflecting in the sunlight like sequined gowns. This behaviour, known as shoaling, is a complex and fascinating aspect of fish biology, and forms the basis to the survival and success of many fish species. From the protection it offers in terms of sheer numbers, to the benefits to foraging efficiency, shoaling behaviour has evolved thanks to the range of benefits that enhance their chances of survival to maturity. While we can easily see the evidence of shoaling behaviour in modern fishes in documentaries and aquariums, there’s compelling evidence that it was…

WAY BACK WHEN I first started keeping fish I was instantly drawn to, what were at the time, the genus Corydoras. Their cute demeanour and the constant shuffling over the substrate had me captivated in fish shops. My first ever tank, therefore, featured a small group with limited success – the base of the tank was covered in pea gravel and the panda corydoras (Hoplisoma panda) unsurprisingly didn’t enjoy the life on this abrasive substrate. I soon learnt my lesson, and when I upgraded to a larger tank, with a soft silica sand substrate, I returned to keep these small catfish. This time opting for a mix of orange (Osteogaster venezuelanus) and masked corys (Hoplisoma metae). There were two species that I always admired from afar. They were, and still…

I HAVE BEEN frequently asked about my photography secrets and how I’m able to take such good fishy shots, even of small species. Well – here they are. I hope my tips below will help you to improve both your photography skills and the quality of your pictures. The basics One of the biggest problems budding aquarium photographers face is light, more precisely the lack of it. As photography literally means ‘drawing with light’ not having enough of this resource could cause some trouble when trying to take pictures of your aquatic creatures. You might say “Hang on, I can clearly see my fishes, why does my camera have issues with it?” The truth is that the human eyes can compensate for low light levels and deliver a clear picture…

Many species of fish are well-suited to shoaling behaviour in the aquarium, and the best choice will depend on the specific tank conditions, and the other type of fish that you wish to incorporate with them. Although you may think some of the species I have suggested are just for beginners, think again, they can provide a great insight into this complex behaviour. FACTFILE RUMMYNOSE TETRA Scientific name: Petitella bleheri. Size: Up to 4cm (1.6”). Origin: Occurs in both the Negro and Meta river basins across Brazil and Colombia. Habitat: Found in blackwater areas with a soft substrate littered with fallen leaves and twigs. Tank size: 80x30x30cm (31x12x12”). Water requirements: Soft and acidic water with a pH below 7 and hardness below 15°H. Temperature: 22-27°C (72-81°F). Temperament: Peaceful and gregarious, they…