Siamese Fighting Fish

When it comes to mating rituals, humans can sometimes be hampered by a lack of ability in sending out clear signals, or indeed in interpreting them. However, the male Siamese Fighting Fish (Betta splendens) has no such problems, as the female of the species makes it abundantly clear as to whether his advances are welcome or whether she’s simply not in the mood.

Originating from the still and sluggish waters of central Thailand, Bettas have quickly become one of the hobby’s most popular ornamental freshwater fish, due in no small part to their fantastic array of colours and their reputation for spectacular displays of aggressive territorial behaviour. Yet their mating behaviour is equally fascinating.

When it’s time to spawn, the male will construct an impressive and elaborate floating “bubble-nest”, laboriously constructing them one bubble at a time and clustering small bubbles on the surface of the water or under leaves or debris. After this impressive show of responsible parenting, the female will then signal her readiness or otherwise by changing colour. If willing, she will display vertical bars on her body, showing that she's ready to spawn. However, if she displays horizontal bars, then this indicates fear or stress and reproduction probably won’t be on the cards that night…