Animal Body Plans and Movement: Symmetry in Action

Brittle stars can use any one of their five arms as a “head”. Photograph by Brocken Inaglory

Animals may be asymmetrical, or have radial, bilateral, or pentaradial symmetry. Each type of organism moves differently, some more efficiently than others, but the locomotion of the brittle star has been a puzzle to zoologists. Now, however, research has uncovered the method behind the movement of this unusual aquatic organism.

Animals in Disguise: An Introduction to Camouflage and Mimicry

This flounder is almost invisible against gravel on the seabed. Photograph by Moondigger.

Escaping predation and finding food are challenges faced by all living creatures. Hiding and hunting are obvious solutions, but many animals – both prey and predator – have evolved a more subtle approach. By disguising themselves as other animals, plants or even inanimate objects, mimics and camouflaged creatures have an evolutionary advantage over their less duplicitous counterparts. Camouflage: Hiding in […]

Endosymbiosis in Aphids: Nutrients from Symbiotic Bacteria Help Greenfly Survive on Plant Sap


The humble aphid may appear unremarkable, but it is cleverly adapted to its plant-sucking way of life. Symbiotic bacteria greatly increase the ability of plant lice, also known as greenflies, to grow and reproduce, causing annoyance to gardeners and damage to crops worldwide. Plant Sap Provides Insufficient Nutrients In general, aphids disregard the flowers, fruits […]