Now in our 13th year of bringing you beautiful imagery from biomedical science every day

Search the archive of over 4000 images

Endless Eggs

Clues to treating infertility from jellyfish

30 June 2020

Endless Eggs

This brightly-coloured specimen is a male Hydractinia polyp – a tiny sea creature closely related to corals, which lives on dead crab shells. Despite their small size and simple lifestyle, these animals still have some surprising similarities with humans, especially when it comes to sex. Like humans, Hydractinia have specialised sex organs which make either eggs or sperm from precursors known as germ cells. But while we have a fixed number of germ cells that are set aside before we’re born, limiting the number of eggs or sperm that can be made in a lifetime, Hydractinia keep on making new germ cells as long as they like. Understanding more about how these curious organisms organise and control their germ cells could shed light on the formation of reproductive cells in more complex animals, including humans, and help to explain what goes wrong in infertility when germ cells fail to appear at all.

See a beautiful image of a female Hydractinia by the same group here

Written by Kat Arney

Search The Archive

Submit An Image

Follow on Tumblr

Follow on Instagram

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC Laboratory of Medical Sciences until Jul 2023, it is now run independently by a dedicated team of scientists and writers. The website aims to engage everyone, young and old, in the wonders of biology, and its influence on medicine. The ever-growing archive of more than 4000 research images documents over a decade of progress. Explore the collection and see what you discover. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.