#colouration

This colour map is not set in stone, so feel free to experiment!

Hi! Great question! Bowhead whales indeed wear some beautiful "bead strings" on their chins. They are true markings, and each dot indicates the location of a chin hair! In some whales you'll see that nearer the tip of the chin, the dots become tiny and plentiful, indicating a hairy muzzle. See for example this whale captured by Todd Mintz:

There is a lot of individual variation though. Some whales have few, very large dots, while others have more, smaller ones. The white chin patch itself can also be very big, other times it is very small (like the whale on the left, photo by Kate Stafford), or entirely washed out gray, making the dots stand out less (like the whale on the right, photo by WWF).

Interestingly it seems the "coding" for the hair spots is always present, as they are even a slightly darker shade than their base greyish black colour. See? You can see the "chin" dots run almost up to this Bowhead's cheeks! (Photo also by Todd Mintz or another Arctic Kingdoms photographer).

And while the dots always follow hairs, the bottom of the white chin marking can have all sorts of funky shapes. It can fade out normally, have quite a jagged edge, or a spotted one, like this whale! (photo courtesy of NMFS)

The #4 #Insect I've seen - The #rose #chafer #beetle (Cetonia aurata). One of the most #brilliant, #beautiful #insects you can see in the #UK. #InsectWeek #InsectWeek22 #Entomology #Nature #Wildlife #Britain #coleoptera

Surely one of the most stunning insect species we have in the UK – the rose chafer beetle (Cetonia aurata) (Credit: Me) I was initially going to write a list of top five most striking UK insects but alas when I actually put grey matter to the task I realised the list would be mostly, if not exclusively, beetles. Beetles, the order coleoptera, are a huge group. Of all the species described in…

Spots and Stripes

Although they're almost identical in most respects, it’s easy to ‘spot’ the difference between these two species of Danio minnows. The top one, Danio quagga (named after the quagga, an extinct species of zebra) has a striped pattern of pigment cells in its skin, while the other – Danio kyathit, named after the Burmese word for ‘leopard’ – has spots. Both species are closely related to zebrafish (Danio rerio), which are often used in biomedical research as a model for more complex organisms. In fact, just a single genetic change can switch zebrafish from stripy to spotty. However, researchers studying how these patterns form during development have discovered that the genes responsible for creating spots and stripes in D. quagga and D. kyathit are more complicated than those in their zebrafish relatives, providing new insights into the underlying processes at work that control colouration, whether in fish or other animals.

Written by Kat Arney

Image from work by Braedan M. McCluskey and colleagues

Department of Biology, University of Virginia, Charlottesville, VA, USA

Image originally published with a Creative Commons Attribution 4.0 International (CC BY 4.0)

Published in PLOS Genetics, April 2021