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Cephalopods have the potential to become useful experimental models in various fields of science, particularly in neuroscience, physiology, and behavior. Their complex nervous systems, intricate color- and texture-changing body patterns, and problem-solving abilities have attracted the attention of the biological research community, while the high growth rates and short life cycles of some species render them suitable for laboratory culture. Octopus chierchiae is a small octopus native to the central Pacific coast of North America whose predictable reproduction, short time to maturity, small adult size, and ability to lay multiple egg clutches (iteroparity) make this species ideally suited to laboratory culture. Here we describe novel methods for multigenerational culture of O. chierchiae, with emphasis on enclosure designs, feeding regimes, and breeding management. O. chierchiae bred in the laboratory grow from a 3.5 mm mantle length at hatching to an adult mantle length of approximately 20–30 mm in 250–300 days, with 15 and 14% survivorship to over 400 days of age in first and second generations, respectively. O. chierchiae sexually matures at around 6 months of age and, unlike most octopus species, can lay multiple clutches of large, direct-developing eggs every ∼30–90 days. Based on these results, we propose that O. chierchiae possesses both the practical and biological features needed for a model octopus that can be cultured repeatedly to address a wide range of biological questions.

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Our goal was to validate the use of dermal swabs to evaluate both reproductive and stress physiology in the California two-spot octopus, Octopus bimaculoides. Our objectives were to: 1. use a biological stressor to validate glucocorticoid analysis; 2. compare the concentration of reproductive hormones (estrogen and progesterone in females; testosterone in males) of reproductive (N = 4) and senescent (N = 8) individuals to determine the effect of age on hormonal patterns; and 3. determine the relationship between glucocorticoid and reproductive hormone production. For the stress test, individuals were first swabbed and then chased around the aquarium with a net for five minutes. Afterwards, individuals were swabbed for 2 hours at 15-minute intervals to compare to a pre-stress test swab. Reproductive individuals responded to the stressor with a 2-fold peak of cortisol at 15 and 90 minutes. Six of eight senescent individuals did not produce a 2-fold increase in cortisol. Reproductive females had significantly higher sex hormone concentrations (progesterone, estrogen, and testosterone) compared to senescent females. Reproductive males also had significantly higher levels of testosterone compared to their senescent counterparts. After the stressor, only reproductive males produced a 2-fold increase in testosterone concentrations, while sex hormones in females showed no change. Dermal swabs provide an effective and non-invasive means for evaluating octopus hormones, which can provide indicators of both reproductive state and perceptions of acute stressors.

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