Wake-like skin patterning and neural activity during octopus sleep.

While sleeping, many vertebrate groups alternate between at least two sleep stages: rapid eye movement and slow wave sleep, in part characterized by wake-like and synchronous brain activity, respectively. Here we delineate neural and behavioural correlates of two stages of sleep in octopuses, marine invertebrates that evolutionarily diverged from vertebrates roughly 550 million years ago (ref. ) and have independently evolved large brains and behavioural sophistication.

Comparing the dietary niche overlap and ecomorphological differences between invasive geckos and a native gecko competitor.

is one of the most successful, widespread invasive reptile species and has become ubiquitous across tropical urban settings in the Western Hemisphere. Its ability to thrive in close proximity to humans has been linked to the rapid disappearance of native geckos. However, aspects of natural history and ecomorphology, often assumed to be linked with this effect on native populations, remain understudied or untested.

Cyclic nature of the REM sleep-like state in the cuttlefish .

Sleep is a state of immobility characterized by three key criteria: an increased threshold of arousal, rapid reversal to an alert state and evidence of homeostatic 'rebound sleep' in which there is an increase in the time spent in this quiescent state following sleep deprivation. Common European cuttlefish, , show states of quiescence during which they meet the last two of these three criteria, yet also show spontaneous bursts of arm and eye movements that accompany rapid changes in chromatophore patterns in the skin. Here, we report that this rapid eye movement sleep-like (REMS-like) state is cyclic in nature.

Eyes Wide Shut: the impact of dim-light vision on neural investment in marine teleosts.

Understanding how organismal design evolves in response to environmental challenges is a central goal of evolutionary biology. In particular, assessing the extent to which environmental requirements drive general design features among distantly related groups is a major research question. The visual system is a critical sensory apparatus that evolves in response to changing light regimes.

Testing ontogenetic patterns of sexual size dimorphism against expectations of the expensive tissue hypothesis, an intraspecific example using oyster toadfish ().

Trade-offs associated with sexual size dimorphism (SSD) are well documented across the Tree of Life. However, studies of SSD often do not consider potential investment trade-offs between metabolically expensive structures under sexual selection and other morphological modules. Based on the expectations of the expensive tissue hypothesis, investment in one metabolically expensive structure should come at the direct cost of investment in another.

Molecular phylogenetics of squirrelfishes and soldierfishes (Teleostei: Beryciformes: Holocentridae): reconciling more than 100 years of taxonomic confusion.

Squirrelfishes and soldierfishes (Holocentridae) are among the most conspicuous species in the nocturnal reef fish community. However, there is no clear consensus regarding their evolutionary relationships, which is reflected in a complicated taxonomic history. We collected DNA sequence data from multiple single copy nuclear genes and one mitochondrial gene sampled from over fifty percent of the recognized holocentrid species and infer the first species-level phylogeny of the Holocentridae.