Early temperamental traits in an octopus (Octopus bimaculoides)

Area of Science:

• Behavioral Ecology
• Marine Biology
• Invertebrate Zoology

Background:

• Temperament research has primarily focused on vertebrates.
• Understanding temperament in invertebrates like octopuses offers insights into adaptive individuality.

Purpose of the Study:

• To investigate if discrete behaviors in Octopus bimaculoides can be reliably grouped to reflect temperament dimensions.
• To examine the developmental trajectory of octopus temperament across the first nine weeks of life.
• To determine the influence of relatedness on temperament development in this species.

Main Methods:

• Principal-components analysis (PCA) was used to group behavioral frequencies from 73 Octopus bimaculoides at 3 weeks old.
• Composite scores were calculated to evaluate temperamental trait levels at three time points (Weeks 3, 6, and 9) for 37 octopuses.
• Profile analysis was employed to assess changes in trait expression and the effect of relatedness.

Main Results:

• PCA identified four key temperament components: active engagement, arousal/readiness, aggression, and avoidance/disinterest, explaining 53% of behavioral variance.
• Significant changes in overall trait expression levels were observed between Week 3 and Week 6.
• Relatedness was found to significantly impact the development of individual temperamental profiles.

Conclusions:

• Octopus bimaculoides display quantifiable dimensions of temperament that evolve during early development.
• Temperament in octopuses is influenced by both developmental stage and genetic relatedness.
• These findings contribute to understanding adaptive individuality and life history in protostomes.