A love bite from my parasite husband: my week as a Krøyer’s deep-sea anglerfish

Monday

Surface dwellers don’t really appreciate light, having far too much of it. When you live more than a mile beneath the surface of the sea, you see things very differently. This is the aphotic zone where less than 1% of the sun’s light penetrates. Down here every glimmer is a miracle. It’s also my little secret.

Tuesday

Very few creatures can live in the depths. Surface dwellers would consider it lonely. Not us. Darkness and solitude are the breath of life to us. Nothing grows here, of course – for that you need much more light. So it all begins with tiny items of living and dying matter drifting downwards: what the sky lets fall in the way of food.

Wednesday

I don’t scavenge for such derisory items myself. Being female, I’m getting on for 3ft long, and drifting morsels won’t keep me alive. I must feed on the eaters of those morsels – but how do I find them in the 3D vastness at the bottom of the world?

Thursday

I don’t. They find me. It happened today, if you can call it a day. That single stalk suspended over my excellently fearsome mouth is equipped with a band of shimmering bacteria, and they shine out like a good deed in a naughty world. You’d have to check it out, wouldn’t you? Check it out he did, and that was dinner. Or maybe breakfast. ’Tis all one.

Friday

If it’s so hard to find prey down here, you’d assume that it’s impossible to find a partner to assist in the essential task of making more anglerfish. Not so. If you admire my fine body, you might notice that I’m carrying a passenger or two. You might even shudder and feel sorry for me. But you’d be wasting your sympathy. That’s no parasite. That’s my husband.

Saturday

The males of our kind are tiny. Say 5in long. Minnows. But they have superb sensory organs – and what they sense is me. Me being really rather gorgeous. This male became aware of me at a quite colossal distance and made his way through the murk as if his life depended on it – because it did. He located me and bit into me: a love bite that saved his life. He then released an enzyme that digested the skin of my body and the skin of his own mouth, and so he fused on to me. Now he gets all his nutrients from my circulatory system – and when it’s time for me to lay eggs, he’ll perform his only other worthwhile trick and fertilise them. Those of us who live in the depths – we certainly know how to live.

*As told to Simon Barnes

Lifespan About 25 years

Eating habits Seeker of the light

Hobbies Shining in the darkness

Sexual preferences Small is beautiful

Photograph by Zoological Museum University of Hamburg