Daphnia lumholtzi (image) Society for Experimental Biology Share Print E-Mail Caption Undefended Daphnia lumholtzi (left) is compared with the defended phenotype (right). The defended phenotype has remarkably elongated head and tail-spines in response to chemical cues from the three-spined stickleback Gasterosteus aculeatus. Credit Dr Linda Weiss Usage Restrictions Freely available with attribution to Dr Linda Weiss. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.