Embryonic development of the camouflaging dwarf cuttlefish, Sepia bandensis.

Abstract

The dwarf cuttlefish Sepia bandensis, a camouflaging cephalopod from the Indo-Pacific, is a promising new model organism for neuroscience, developmental biology, and evolutionary studies. Cuttlefish dynamically camouflage to their surroundings by altering the color, pattern, and texture of their skin. The skin's "pixels" (chromatophores) are controlled by motor neurons projecting from the brain. Thus, camouflage is a visible representation of neural activity. In addition to camouflage, the dwarf cuttlefish uses dynamic skin patterns for social communication. Despite more than 500 million years of evolutionary separation, cuttlefish and vertebrates converged to form limbs, camera-type eyes and a closed circulatory system. Moreover, cuttlefish have a striking ability to regenerate their limbs. Interrogation of these unique biological features will benefit from the development of a new set of tools. Dwarf cuttlefish reach sexual maturity in 4months, they lay dozens of eggs over their 9-month lifespan, and the embryos develop to hatching in 1month. Here, we describe methods to culture dwarf cuttlefish embryos in vitro and define 25 stages of cuttlefish development. This staging series serves as a foundation for future technologies that can be used to address a myriad of developmental, neurobiological, and evolutionary questions.