Ethogram analysis reveals new body patterning behavior of the tropical arrow squid Doryteuthis plei off the São Paulo Coast

How do you do the things that you do? Ethological approach to the description of robot behaviour

The detailed description of behaviour of the interacting parties is becoming more and more important in human-robot interaction (HRI), especially in social robotics (SR). With the rise in the number of publications, there is a substantial need for the objective and comprehensive description of implemented robot behaviours to ensure comparability and reproducibility of the studies. Ethograms and the meticulous analysis of behaviour was introduced long ago in animal behaviour research (cf. ethology). The adoption of this method in SR and HRI can ensure the desired clarity over robot behaviours, while also providing added benefits during robot development, behaviour modelling and analysis of HRI experiments. We provide an overview of the possible uses and advantages of ethograms in HRI, and propose a general framework for describing behaviour which can be adapted to the requirements of specific studies.

Cataloging Body Patterning in the Dwarf Cuttlefish (Sepia bandensis)

AbstractCephalopods use dynamic camouflage to blend in with their environment, communicate with conspecifics, and mimic other animals by changing their skin's color, texture, pattern, and shape. Past studies have cataloged common body patterns presented by various cephalopod species to gain insight into the evolution and function of these patterns in the natural environment. The common (Sepia officinalis), pharaoh (Sepia pharaonis), and flamboyant (Metasepia pfefferi) cuttlefish are three of the previously studied species and demonstrate that differences in habitat, physical size, and evolutionary history may influence the capacity and usage of body patterning. We studied the body patterns of an additional cuttlefish species, the dwarf cuttlefish (Sepia bandensis), to investigate further what aspects of ecology or behavior may influence body patterning in cuttlefish. We captured still images and video recordings of individually housed dwarf cuttlefish and analyzed them to catalog the body pattern components displayed. We utilized a quantitative approach to determine body patterns through a maximum likelihood analysis program (AutoClass C). We identified 79 distinct body pattern components, including 8 newly described components, and 7 overall body patterns. Our findings on the body patterning behavior of the dwarf cuttlefish add to a growing database of cephalopod display patterns for future studies and provide insight into the ecological and evolutionary drivers of dynamic camouflage in cephalopods.

Dominance Hierarchies in Marine Invertebrates

AbstractDominance hierarchies have been well studied in myriad terrestrial animals, but surprisingly little is known about hierarchies in marine invertebrates; examples are limited to a few species of decapod crustaceans and cephalopods. Is the marine environment less conducive to the establishment of dominance hierarchy structures, or does this just underline the lack of detailed behavioral information about most marine invertebrates? In this review, we highlight the published information about marine invertebrate dominance hierarchies, which involve ranks established through fights or displays. We focus on the method of hierarchy formation, examine the ecological implications of this population structure, and compare the habitat and behavioral characteristics of species that exhibit this behavior. Because dominance hierarchies can influence habitat use, population distributions, energetics, mating, resource exploitation, and population genetic structure, it is crucial to understand how this trait evolves and which species are likely to exhibit it. A better understanding of marine invertebrate hierarchies could change the way we think about population dynamics of some species and could have important implications for fisheries, conservation, or even modeling of social and economic inequality.

Investigating body patterning in aquarium-raised flamboyant cuttlefish (Metasepia pfefferi)

Cuttlefish are known for their ability to quickly alter their total appearance, or body pattern, to camouflage or to communicate with predators, prey and conspecifics. The body patterns of some species have been extensively documented to gain a better understanding of their behaviors. However, the flamboyant cuttlefish (Metasepia pfefferi) is largely unstudied. Recently, aquarists have been able to breed, house and display M. pfefferi, giving researchers ample opportunities to study their behavior under those conditions. This study aimed to identify the dorsally-visible components of the body patterns used by 5 sexually-mature, freely-behaving, F5 generation M. pfefferi in their home aquarium at The Seas in Epcot at Walt Disney World Resorts^®, Lake Buena Vista, FL, USA. Furthermore, we aimed to determine the most probable patterns used by this population of animals and to create a database of components that can be used in future behavioral studies. We found that this population of M. pfefferi use a combination of 7 textural, 14 postural, 7 locomotor and between 42 and 75 chromatic components in their home aquarium. Using maximum likelihood analysis and AutoClass@IJM software, we found that these components combine to generate 11 distinct body patterns. The software was able to sort 98% of the live animal observations into one of the 11 patterns with 90% confidence and 88% of observations with 99% confidence. Unusually for cuttlefish, 8 of the 11 identified patterns contained at least one “traveling” component (i.e., traveling waves or blinking spots) in which the colors on the skin appeared to travel on the animal’s mantle. In other species, these components are generally seen during hunting or aggression, but this population of M. pfefferi uses them frequently during a variety of contexts in their home aquarium. With few published data on the behavior of M. pfefferi in their natural environment, we cannot compare the behavior of the tank-raised individuals in this study to animals in the wild. However, this study provides the groundwork necessary for future studies of M. pfefferi body patterning and behavior.