Embryonic development of the camouflaging dwarf cuttlefish, Sepia bandensis

Abstract

Background: 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 4 months, they lay dozens of eggs over their 9-month lifespan, and the embryos develop to hatching in 1 month. Results: Here, we describe methods to culture dwarf cuttlefish embryos in vitro and define 25 stages of cuttlefish development. Conclusion: This staging series serves as a foundation for future technologies that can be used to address a myriad of developmental, neurobiological, and evolutionary questions.

Morphological Variation and New Description of the Subcutaneous Gland of Sepiella inermis (Van Hasselt, 1835) in Thai Waters

“…The two ink glands are present in a single individual. The development of the ink sac spans from embryogenesis to the adult stage [3]. The process 2 of 21 of ink release from the sac begins with stimulation originating from the latero-ventral palliovisceral lobe located within the posterior subesophageal mass of the central mantle cavity.…”

A brain atlas of the camouflaging dwarf cuttlefish,Sepia bandensis

“…We study the dwarf cuttlefish, Sepia bandensis, a tropical species from the Indo-Pacific (Figure 1A-D, Video 1). Dwarf cuttlefish are small (<6 cm mantle length), embryonic development is relatively fast (1 month) and they reach sexual maturity in only 4 months (Montague et al, 2021). Dwarf cuttlefish can be bred at relatively high density in the lab, each animal produces dozens of embryos over its lifetime, and the embryos can be cultured in vitro to hatching (Montague et al, 2021).…”

“…Dwarf cuttlefish are small (<6 cm mantle length), embryonic development is relatively fast (1 month) and they reach sexual maturity in only 4 months (Montague et al, 2021). Dwarf cuttlefish can be bred at relatively high density in the lab, each animal produces dozens of embryos over its lifetime, and the embryos can be cultured in vitro to hatching (Montague et al, 2021). These features may permit the introduction of genetically-encoded calcium indicators and light-activated channels that may facilitate an understanding of the relationship between neural activity and behavior.…”

Developmental staging and future research directions of the model marine tubewormHydroides elegans

“…Despite its utility as a developmental model [12][13][14][15][16][17] , characterizations of the growth and development of Hydroides remains fragmented, and the community has yet to establish a standardized staging scheme that spans the entirety of development. Staging schemes have become a commonplace tool across all major developmental model systems including frog 18 , chick 19 , zebrafish 20 , and sea urchin [21][22][23] , and are fundamental for the development and utility of non-traditional model organisms [24][25][26][27][28] . Staging schemes provide a unified narrative of development under tightly controlled environmental conditions, and offer accuracy and consistency in describing the progression of key developmental events.…”