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Cited by 260Marine Invertebrate Physiology and EcologySleep and Wakefulness ResearchCircadian rhythm and melatonin

The Jellyfish Cassiopea Exhibits a Sleep-like State

Open access
Nath, Ravi D., Bedbrook, Claire N., Abrams, Michael J., Basinger, Ty, Bois, Justin S., Prober, David A., Sternberg, Paul W., Gradinaru, Viviana +1 more·2017·Current Biology
DOI 10.1016/j.cub.2017.08.014PMC PMC5653286
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Abstract

Do all animals sleep? Sleep has been observed in many vertebrates, and there is a growing body of evidence for sleep-like states in arthropods and nematodes [1-5]. Here we show that sleep is also present in Cnidaria [6-8], an earlier-branching metazoan lineage. Cnidaria and Ctenophora are the first metazoan phyla to evolve tissue-level organization and differentiated cell types, such as neurons and muscle [9-15]. In Cnidaria, neurons are organized into a non-centralized radially symmetric nerve net [11, 13, 15-17] that nevertheless shares fundamental properties with the vertebrate nervous system: action potentials, synaptic transmission, neuropeptides, and neurotransmitters [15-20]. It was reported that cnidarian soft corals [21] and box jellyfish [22, 23] exhibit periods of quiescence, a pre-requisite for sleep-like states, prompting us to ask whether sleep is present in Cnidaria. Within Cnidaria, the upside-down jellyfish Cassiopea spp. displays a quantifiable pulsing behavior, allowing us to perform long-term behavioral tracking. Monitoring of Cassiopea pulsing activity for consecutive days and nights revealed behavioral quiescence at night that is rapidly reversible, as well as a delayed response to stimulation in the quiescent state. When deprived of nighttime quiescence, Cassiopea exhibited decreased activity and reduced responsiveness to a sensory stimulus during the subsequent day, consistent with homeostatic regulation of the quiescent state. Together, these results indicate that Cassiopea has a sleep-like state, supporting the hypothesis that sleep arose early in the metazoan lineage, prior to the emergence of a centralized nervous system.

AI snapshot

Written from the paper’s full text.

TL;DR

The upside-down jellyfish Cassiopea shows a nighttime quiescent state with reduced responsiveness and rebound after deprivation, meeting behavioral criteria for a sleep-like state. This suggests sleep-like behavior may predate centralized nervous systems.

Key findings

  • Across 23 jellyfish tracked over six day-night cycles, nighttime pulsing dropped about 32% relative to daytime: 781 ± 199 vs 1155 ± 315 pulses per 20 min. A separate 16-jellyfish no-feeding cohort showed the same pattern.
  • During night, latency to first pulse after a drop was 5.9 ± 4.0 s vs 2.1 ± 0.9 s during day; time to reach bottom was 12.0 ± 3.2 s vs 8.6 ± 2.9 s during day (n = 23). A second drop within 30 s abolished the day-night difference, indicating rapid reversibility.
  • Depriving jellyfish of nighttime quiescence for the last 6 h reduced next-day first-4-h activity by ~12% (1146 ± 232 to 1008 ± 210 pulses/20 min, n = 30); 12-h deprivation reduced following-day activity by ~17% (1361 ± 254 to 1132 ± 263, n = 16). The same mechanical stimulation during the day produced no significant change.
  • Constant light did not produce circadian oscillation in activity, but constant dark did; melatonin and pyrilamine induced concentration-dependent daytime quiescence.

Methods

  • Behavioral tracking: individual Cassiopea in clear cubbies inside light-controlled tanks under 12:12 light/dark; overhead cameras at 15 fps recorded pulsing; pulse events and inter-pulse intervals were derived from pixel-intensity changes in manually selected regions of interest.
  • Samples/design: 23 jellyfish tracked for 6 consecutive day-night cycles; 16 tracked for 3 cycles without feeding; arousal assay n = 23; 6-h and 12-h deprivation experiments n = 30 and n = 16; additional clonal C. xamachana used for some pharmacology/circadian assays. Genotyping via COI sequencing and actin staining/confocal imaging were also performed.
  • Analysis: SciPy-based processing; paired/unpaired t-tests, two-way ANOVA with Bonferroni posttest; normality and equal-variance checks; log transformation for time-to-first-pulse data.

Limitations

  • Stated: the authors note that whether other cnidarians sleep remains untested, and the ancestral function/selective advantage of sleep is unresolved. They also state no sample-size predetermination, no blinding during experiments/outcome assessment, and no specific randomization method.
  • Evident: most experiments used a mixed collection of Cassiopea species/sizes/ages/sexes/morphologies, so species-level generalization is limited; some assays used a young clonal C. xamachana line.
  • Evident: the sleep-like state is inferred from behavioral proxies (pulsing, latency, rebound) under laboratory conditions; circadian regulation is ambiguous because activity cycled in constant dark but not under several constant-light conditions, and mechanistic evidence is limited to pharmacological responses.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1016/j.cub.2017.08.014

Cites

43 of 43 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 39 cited sources checked · 0 supported · 0 flagged

  • Findingown data

    Melatonin induces a reversible, concentration-dependent decrease in Cassiopea activity during the day.

    “We observed that melatonin induces a reversible decrease in activity in Cassiopea during the day in a concentration-dependent manner (Figure S4F–H), suggesting that melatonin has a conserved quiescence-inducing effect in Cassiopea.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.
  • Findingown data

    A 6-hour mechanical perturbation during the last 6 hours of night caused a significant ~12% decrease in Cassiopea activity during the first 4 hours of the following day compared with the pre-perturbation day.

    “When the perturbation was performed during the last 6 hours of the night (Figure 4A), we observed a significant decrease in activity (~12%) during the first 4 hours of the following day relative to the pre-perturbation day (mean of first 4 hours of pre-perturbation day: 1146 ± 232 pulses/20 min compared to post-perturbation day: 1008 ± 210 pulses/20 min, mean ± s.d.; n = 30 animals; Figure 4C).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.
  • Findingown data

    Pyrilamine induces concentration-dependent quiescence in Cassiopea.

    “Pyrilamine, a histamine H1 receptor antagonist that induces sleep in vertebrates [36], also induces concentration-dependent quiescence in Cassiopea (Figure S4F).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.
  • Findingown data

    During the decreased-activity periods after either 6-hour or 12-hour nighttime perturbation, Cassiopea showed increased response latency to a sensory stimulus.

    “During periods of decreased activity after either the 6-hour or 12-hour perturbation, we also observed increased response latency to a sensory stimulus (Figure S4A), indicating a sleep-like state.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.
  • Findingown data

    No circadian oscillation of Cassiopea activity was observed under constant light conditions of low, mid, or full intensity.

    “We observed no circadian oscillation of jellyfish activity under any of the constant light conditions (Figure S4D).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.
  • May combine two claims. 18
  • Classified as probably not a substantial claim. 15

  • May combine two claims.

    Findingown data

    Cassiopea show reduced responsiveness to a sensory stimulus at night, with longer time to first pulse and time to reach bottom compared with day.

    “At night, the jellyfish showed an increase in the time to first pulse and the time to reach bottom, compared to day (time to first pulse day: 2.1 ± 0.9 s versus night: 5.9 ± 4.0 s, and the time to reach bottom day: 8.6 ± 2.9 s versus night: 12.0 ± 3.2 s, mean ± s.d.; n = 23 animals) (Figure 3B,C).”
    • Also stated in: § RESULTS AND DISCUSSION · hedged
      “This increased latency in response to stimulus indicates that Cassiopea have reduced responsiveness to stimulus during the night.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • May combine two claims.

    Findingown data

    The nighttime quiescent state of Cassiopea is rapidly reversible, as a nighttime food stimulus transiently raised activity to daytime levels.

    “To test the reversibility of this nighttime quiescent state we introduced a food stimulus at night, which transiently increased activity to daytime levels (Figure S3E).”
    • Also stated in: § RESULTS AND DISCUSSION · plain
      “The nighttime quiescent state in Cassiopea is thus rapidly reversible, consistent with a sleep-like behavior.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • May combine two claims.

    Findingown data

    Daytime mechanical perturbation for 6 or 12 hours produced no significant pre- versus post-perturbation activity difference, indicating that the rebound response is specific to deprivation of nighttime quiescence rather than muscle fatigue.

    “To distinguish between sleep deprivation and muscle fatigue, we performed the 6- or 12-hour mechanical stimulus experiments during the day (Figure 4B,E). We observed no significant difference between pre- and post-perturbation activity levels (Figure 4C,F), indicating that the rebound response is specific to deprivation of nighttime quiescence.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • May combine two claims.

    Findingown data

    Cassiopea jellyfish pulse less at night than during the day, with mean nighttime activity about 32% lower than daytime activity (night 781 ± 199 vs day 1155 ± 315 pulses per 20 min).

    “We observed that Cassiopea pulse less at night than during the day (Figure 2; Data S1).”
    • Also stated in: § RESULTS AND DISCUSSION · plain
      “all showed a large decrease in mean activity (~32%) at night (781 ± 199 pulses/20 min, mean ± s.d.) compared to the day (1155 ± 315 pulses/20 min, mean ± s.d.; Figure 2C,E).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • May combine two claims.

    Findingown data

    The reduced nighttime responsiveness of Cassiopea is rapidly reversible: a second drop within 30 s decreased response latencies at night, and after the second drop day and night latencies were indistinguishable.

    “During the night, there is a large decrease in the time to first pulse and time to reach the bottom, after the second drop when compared to the first drop (Figure 3D,E).”
    • Also stated in: § RESULTS AND DISCUSSION · boosted
      “During the day and night, the time to first pulse and time to bottom after the second drop were indistinguishable, demonstrating that after perturbation, animals have similar arousal levels during the day and night.”
    • Also stated in: § RESULTS AND DISCUSSION · hedged
      “These results indicate that Cassiopea have rapidly reversible reduced responsiveness to a stimulus during the night.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • May combine two claims.

    Findingown data

    Daytime feeding does not cause the day-night behavioral difference; no-feeding recordings were consistent with feeding recordings.

    “To ensure that day feeding does not cause the day-night behavioral difference, we tracked the activity of 16 jellyfish over three consecutive days and nights without feeding and observed results consistent with those including feeding (Figure 2F,G; Figure S3D).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • May combine two claims.

    Findingown data

    Cassiopea activity decreased through the first 3-6 hours of night, with lowest activity 6-12 hours after the day-to-night transition.

    “Jellyfish activity decreased throughout the first 3–6 hours of the night, with the lowest activity occurring 6–12 hours after the day to night transition.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • Classified as probably not a substantial claim.

    Findingown data

    Cassiopea prefer staying on solid surfaces.

    “We observed in our nursery that Cassiopea prefer staying on solid surfaces as is found in nature.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    The 95th percentile of the night IPI frequency distribution is 13.9 s, whereas the day 95th percentile is 2.5 s.

    “These pauses are seen as a tail in the IPI frequency distribution (Figure 2B: 95th percentile of night IPI frequency distribution (gray) is 13.9 s). Such long pauses are rarely seen during the day (Figure 2B: 95th percentile of day IPI frequency distribution (yellow) is 2.5 s).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • May combine two claims.

    Findingown data

    The decreased activity after perturbation is due to both decreased pulsing frequency and increased pause length.

    “This period of decreased activity is due to both decreased pulsing frequency (increased mode of IPI-length) and increased pause length (increase in the IPI-length 95th percentile) (Figure S4B,C).”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • May combine two claims.

    Findingown data

    At night, the inter-pulse interval is typically longer than during the day, due to a longer mode of the IPI distribution and more frequent pauses.

    “During the night, the IPI is typically longer than during the day (Figure 2A,B; Data S1; Figure S3A). Two features contribute to this lengthening of the IPI: (1) the mode of the IPI distribution is longer at night than during the day, and (2) night pulsing is more often interrupted by pauses of variable length.”
    Quote in the paperSubstantial claim
    • Rests on an assumption: Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

  • May combine two claims.

    Premisecitation

    Cassiopea rarely swim and usually remain stationary with their bell on a surface.

    “They rarely swim and rather remain stationary with their bell on a surface, hence their name, the upside-down jellyfish (Figure 1B; Figure S1A; Movie S1; [25,26]).”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [25] Jantzen, 2010, Enhanced pore water nutrient fluxes by the upside-down jellyfish Cassiopea sp. in a Red Sea coral reef, Mar. Ecol. Prog. Ser. source

      Not checked in the free run.

    • cites [26] Holland, 2004, Global phylogeography of Cassiopea (Scyphozoa: Rhizostomeae): molecular evidence for cryptic species and multiple invasions of the Hawaiian Islands, Mar. Biol. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationown data

    The activity decrease after 12-hour nighttime perturbation was larger than after 6-hour perturbation, indicating that sleep rebound magnitude depends on the amount of sleep deprivation.

    “The decrease in activity caused by the 12-hour perturbation was larger than that of the 6-hour perturbation, indicating that the amount of sleep rebound is dependent on the level of sleep deprivation.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    A fully functioning circadian system is not essential for sleep; animals with null mutations in circadian rhythm genes still sleep, though sleep timing is altered.

    “A fully functioning circadian system is also not essential for sleep to occur; animals with null mutations of circadian rhythm genes still sleep, though sleep timing is altered [30].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [30] Zimmerman, 2008, Conservation of sleep: insights from non-mammalian model systems, Trends Neurosci. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductown data

    At least two laboratory replicates were performed within the recording setup, which holds up to 8 jellyfish.

    “For these experiments we performed at least two laboratory replicates within our recording setup, which is limited to 8 jellyfish.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Sleep has been hypothesized to have multiple functions, including synaptic homeostasis, neurotransmitter regulation, cellular damage repair, toxin removal, memory consolidation, and energy conservation.

    “It has been hypothesized that sleep has multiple functions, including synaptic homeostasis, regulation of neurotransmitters, repair of cellular damage, removal of toxins, memory consolidation and energy conservation [7], although the ancestral role and selective advantage of sleep remains elusive.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [7] Joiner, 2016, Unraveling the evolutionary determinants of sleep, Curr. Biol. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    In many animals sleep is regulated by both homeostatic and circadian systems, but this is not always the case.

    “In many animals sleep is regulated by both homeostatic and circadian systems [29], but this is not always the case [4–7,30].”
    Quote in the paperNot a substantial claim0 of 6 sources checked
    • cites [29] Borbély, 1999, Sleep homeostasis and models of sleep regulation, J. Biol. Rhythms

      Not checked in the free run.

    • cites [4] Hill, 2014, Cellular stress induces a protective sleep-like state in C. elegans, Curr. Biol. source

      Not checked in the free run.

    • cites [5] Trojanowski, 2016, Call it worm sleep, Trends Neurosci. source

      Not checked in the free run.

    • cites [6] Allada, 2008, Unearthing the phylogenetic roots of sleep, Curr. Biol. source

      Not checked in the free run.

    • cites [7] Joiner, 2016, Unraveling the evolutionary determinants of sleep, Curr. Biol. source

      Not checked in the free run.

    • cites [30] Zimmerman, 2008, Conservation of sleep: insights from non-mammalian model systems, Trends Neurosci. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    No specific randomization method was used.

    “No specific method for randomization was used.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Experimental animals were assigned to groups at random.

    “Animals were randomly assigned to experimental groups.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    C. elegans exhibits a developmentally regulated sleep state, and adult C. elegans show a non-circadian stress-induced sleep state.

    “For instance, the nematode C. elegans exhibits a developmentally regulated sleep state, and adult C. elegans show a non-circadian stress-induced-sleep state [4,5,31].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [4] Hill, 2014, Cellular stress induces a protective sleep-like state in C. elegans, Curr. Biol. source

      Not checked in the free run.

    • cites [5] Trojanowski, 2016, Call it worm sleep, Trends Neurosci. source

      Not checked in the free run.

    • cites [31] Nath, 2016, C. elegans stress-induced sleep emerges from the collective action of multiple neuropeptides, Curr. Biol. source

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    Log-transformed time-to-first-pulse data were approximately Gaussian distributed with equal variance between groups, validating standard two-way ANOVA and unpaired t-tests on the transformed data.

    “Tests of the log transformed time to first pulse data showed that the transformed data was approximately Gaussian distributed with equal variance between experimental groups, validating the use of standard two-way ANOVA and unpaired t-tests on the transformed data.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    No statistical method was used to predetermine sample size.

    “No statistical methods were used to predetermine sample size.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Experimental groups compared statistically were tested for equal variance.

    “Experimental groups that were statistically compared were tested for equal variance.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    Melatonin promotes sleep in diurnal vertebrates, including zebrafish and humans, and induces quiescence in invertebrates.

    “One such conserved molecule, melatonin [32], promotes sleep in diurnal vertebrates, including zebrafish [33] and humans [34], and induces quiescence in invertebrates [35].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [32] Peres, 2014, Developmental and light-entrained expression of melatonin and its relationship to the circadian clock in the sea anemone Nematostella vectensis, Evodevo source

      Not checked in the free run.

    • cites [33] Zhdanova, 2001, Melatonin promotes sleep-like state in zebrafish, Brain Res. source

      Not checked in the free run.

    • cites [34] Brzezinski, 2005, Effects of exogenous melatonin on sleep: a meta-analysis, Sleep Med. Rev. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductown data

    Normality tests indicated all datasets were approximately Gaussian distributed except the time-to-first-pulse arousal data.

    “The normality tests showed that all datasets were approximately Gaussian distributed with the exception of the time to first pulse arousal data.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductnone given

    Investigators were not blinded to allocation during experiments or outcome assessment.

    “Investigators were not blinded to allocation during experiments and outcome assessment.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Premisecitation

    At least 600 million years of evolution separate cnidarians from bilaterians.

    “Though at least 600 million years of evolution separate cnidarians from bilaterians [9–16], many aspects of the nervous system are conserved, including neuropeptides and neurotransmitters [15–20].”
    Quote in the paperSubstantial claim0 of 8 sources checked
    • cites [9] Dunn, 2014, Animal phylogeny and its evolutionary implications, Annu. Rev. Ecol. Evol. Syst. source

      Not checked in the free run.

    • cites [10] Arendt, 2016, From nerve net to nerve ring, nerve cord and brain--evolution of the nervous system, Nat. Rev. Neurosci. source

      Not checked in the free run.

    • cites [11] Katsuki, 2013, Jellyfish nervous systems, Curr. Biol. source

      Not checked in the free run.

    • cites [12] Erwin, 2002, The last common bilaterian ancestor, Development source

      Not checked in the free run.

    • cites [13] Hejnol, 2015, Neural nets, Curr. Biol. source

      Not checked in the free run.

    • cites [14] Kelava, 2015, Evolution of eumetazoan nervous systems: insights from cnidarians, Philos. Trans. R. Soc. Lond. B Biol. Sci. source

      Not checked in the free run.

    • cites [15] Bosch, 2017, Back to the basics: cnidarians start to fire, Trends Neurosci. source

      Not checked in the free run.

    • cites [16] Grimmelikhuijzen, 1995, The nervous systems of cnidarians, EXS

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Premisecitation

    Pyrilamine, a histamine H1 receptor antagonist, induces sleep in vertebrates.

    “Pyrilamine, a histamine H1 receptor antagonist that induces sleep in vertebrates [36], also induces concentration-dependent quiescence in Cassiopea (Figure S4F).”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [36] Gandhi, 2015, Melatonin is required for the circadian regulation of sleep, Neuron source

      Not checked in the free run.

28 of 28

  • The paper relies on this without support.

    Pulsing frequency is a valid measure of behavioral activity and quiescence in Cassiopea.

    “We define activity as the total number of pulses in the first 20 minutes of each hour.”
    “To monitor jellyfish activity, pulsing information was extracted from the individual frames of each recording.”

  • The paper relies on this without support.

    Laboratory-recorded pulsing behavior reflects the jellyfish's natural behavioral state.

    “Cassiopea were reared in artificial seawater (ASW, Instant Ocean, 30–34 ppt) at pH 8.1–8.3, 26–28°C with a 12-hour day/night cycle.”
    “Individual jellyfish were placed into 700 mL square clear plastic containers (cubbies), with white sand bottoms, in 35 L (10 gallon) glass tanks (Figure S1C–F).”
2 of 2

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Sleep has been identified in every animal that has been carefully studied.

    “Sleep has been recognized in each animal carefully scrutinized.”

    From The Biology of General Anesthesia from Paramecium to Primate (2019) · cites this paper as [29]

  • Behaviorally quiescent or sleep-like states may be as globally widespread as susceptibility to volatile anesthetics.

    “behaviorally quiescent or sleep-like states may be as globally penetrant as susceptibility to volatile anesthetics [22–29].”

    From The Biology of General Anesthesia from Paramecium to Primate (2019) · cites this paper as [29]

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. Folmer, 1994, DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates, Mol. Mar. Biol. Biotechnol., 3, 294

Cited by

Sorted by citations

Authors
Nath, R. D., Bedbrook, C. N., Abrams, M. J., Basinger, T., Bois, J. S., Prober, D. A., Sternberg, P. W., Gradinaru, V., & Goentoro, L.
Affiliations
California Institute of Technology (US)
Corresponding author
Goentoro, Lea
ORCID
Venue
Current Biology
Publisher
Elsevier BV
Published
2017-10
Volume
27
Issue
19
Pages
2984-2990.e3
ISSN
0960-9822 (ISSN-L)
DOI
10.1016/j.cub.2017.08.014
PMC
PMC5653286
OpenAlex
W2756734175
Cited by
260
References
43
Citations by year
2026: 26 · 2025: 28 · 2024: 32 · 2023: 22 · 2022: 38 · 2021: 28 · 2020: 27 · 2019: 31 · 2018: 21 · 2017: 7
FWCI
16.71
Type
journal article
Language
en
Open access
Licence
Locations
  • Current Biology (publishedVersion)
  • PubMed (publishedVersion)
  • Europe PMC (PubMed Central) (acceptedVersion)
  • PubMed Central (acceptedVersion)
  • CaltechAUTHORS (California Institute of Technology) (submittedVersion)
Funders
  • NIH Director’s New Innovator Award/PECASE (IDP20D017782-01)
  • James S. McDonnell Foundation for Complex Systems Science (220020365)
  • NIMH under a Ruth L. Kirschstein National Research Service Award (F31MH102913)
  • NINDS under a Ruth L. Kirschstein National Research Service Award (F31NS100519)
  • National Science Foundation Graduate Research Fellowship (1144469)
  • NIH (T32GM007616)
  • Heritage Medical Research Institute
  • HHMI (047-101)
Topics
  • Physical Sciences › Earth and Planetary Sciences › Paleontology › Marine Invertebrate Physiology and Ecology
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Sleep and Wakefulness Research
  • Life Sciences › Neuroscience › Endocrine and Autonomic Systems › Circadian rhythm and melatonin
Keywords
sleep, Cassiopea, box jellyfish, Cnidaria, sleep homeostasis, sleep evolution, animal evolution
MeSH terms
Animals, Biological Evolution, Sleep, Scyphozoa

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