The coevolution between telson morphology and venom glands in scorpions (Arachnida).

As in previous contributions to the , the aim of this note is to bring some general information on a particular aspect of the scorpion biology. An attempt is made to explain the possible coevolution of telson morphology and venom glands, which took place during several hundred million years and in particular since scorpions migrated from aquatic to terrestrial environments. Three components can be directly associated with predation and defensive behaviours: (1) morphology of the chelae and structure of the chelae fingers granulations; (2) morphology of the metasoma and in particular of the telson; (3) evolution of tegumentary glands in the telson toward different types of venom glands. Since a number of recent contributions already treated some of these aspects, I will limit my comments to the possible evolution of the telson in relation to the evolution of venom glands. As in previous contributions, the content of this article is basically addressed to non-specialists on scorpions whose research embraces scorpions in several fields such as venom toxins and public health.