YOUR EVERYDAY FIELD GUIDE

Discover the world on the other side of the glass.

Fishes / Health

How to Tell Betta Fish Gender: Identifying Male vs. Female

Sexing a betta is usually straightforward in a healthy adult, since captive breeding for elaborate finnage and colour has made males and females look considerably more different from each other than t

3 min read

Fishes / Health

Coral Eating Flatworms in Reef Tanks: Spotting and Treating AEFW

Acropora eating flatworms, often shortened to AEFW, are a reef keeper's specific nightmare. Unlike the fish parasites covered elsewhere in this series, AEFW target coral directly, particularly Acropor

2 min read

Fishes / Health

Nitrite Poisoning in Marine Aquarium Fish: A Smaller Risk Than You'd Think

Nitrite poisoning is a genuine concern in freshwater fishkeeping, but marine fish have a real, well-documented biological advantage here that's worth understanding rather than testing for out of habit

2 min read

Fishes / Health

Is My Betta Fish Too Fat?

Bettas carry weight in a very particular way, and the difference between a healthily filled-out fish and a genuinely overweight one is not always obvious at first glance. Getting this right matters, s

3 min read

Fishes / Health

Saprolegnia: The Fungus That Only Attacks Weakness

Saprolegnia is genuinely everywhere, its spores exist in essentially every aquarium and every body of freshwater, floating invisibly until they find something to colonise. In a healthy fish with intac

3 min read

Fishes / Health

Anchor Worms: The Parasite You Actually Can See

Unlike most parasites that trouble aquarium fish, anchor worms are large enough to spot with the naked eye, thin, thread-like protrusions, usually white, green or reddish, hanging from a fish's body.

3 min read