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Santillo S, De Petrocellis L, Musio C. Diurnal and circadian regulation of opsin-like transcripts in the eyeless cnidarian Hydra. Biomol Concepts 2024; 15:bmc-2022-0044. [PMID: 38502542 DOI: 10.1515/bmc-2022-0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Accepted: 02/28/2024] [Indexed: 03/21/2024] Open
Abstract
Opsins play a key role in the ability to sense light both in image-forming vision and in non-visual photoreception (NVP). These modalities, in most animal phyla, share the photoreceptor protein: an opsin-based protein binding a light-sensitive chromophore by a lysine (Lys) residue. So far, visual and non-visual opsins have been discovered throughout the Metazoa phyla, including the photoresponsive Hydra, an eyeless cnidarian considered the evolutionary sister species to bilaterians. To verify whether light influences and modulates opsin gene expression in Hydra, we utilized four expression sequence tags, similar to two classic opsins (SW rhodopsin and SW blue-sensitive opsin) and two non-visual opsins (melanopsin and peropsin), in investigating the expression patterns during both diurnal and circadian time, by means of a quantitative RT-PCR. The expression levels of all four genes fluctuated along the light hours of diurnal cycle with respect to the darkness one and, in constant dark condition of the circadian cycle, they increased. The monophasic behavior in the L12:D12 cycle turned into a triphasic expression profile during the continuous darkness condition. Consequently, while the diurnal opsin-like expression revealed a close dependence on light hours, the highest transcript levels were found in darkness, leading us to novel hypothesis that in Hydra, an "internal" biological rhythm autonomously supplies the opsins expression during the circadian time. In conclusion, in Hydra, both diurnal and circadian rhythms apparently regulate the expression of the so-called visual and non-visual opsins, as already demonstrated in higher invertebrate and vertebrate species. Our data confirm that Hydra is a suitable model for studying ancestral precursor of both visual and NVP, providing useful hints on the evolution of visual and photosensory systems.
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Affiliation(s)
- Silvia Santillo
- Institute of Applied Sciences and Intelligent Systems "Eduardo Caianiello" (ISASI), National Research Council (CNR), Via Campi Flegrei 34, 80078 Pozzuoli (Naples), Italy
| | - Luciano De Petrocellis
- Institute of Biomolecular Chemistry (ICB), National Research Council (CNR), 80078 Pozzuoli (Naples), Italy
| | - Carlo Musio
- Institute of Biophysics (IBF), Trento Unit, National Research Council (CNR), Via Sommarive 18, 38123 Trento, Italy
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2
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Bielecki J, Dam Nielsen SK, Nachman G, Garm A. Associative learning in the box jellyfish Tripedalia cystophora. Curr Biol 2023; 33:4150-4159.e5. [PMID: 37741280 DOI: 10.1016/j.cub.2023.08.056] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Revised: 07/17/2023] [Accepted: 08/18/2023] [Indexed: 09/25/2023]
Abstract
Associative learning, such as classical or operant conditioning, has never been unequivocally associated with animals outside bilatarians, e.g., vertebrates, arthropods, or mollusks. Learning modulates behavior and is imperative for survival in the vast majority of animals. Obstacle avoidance is one of several visually guided behaviors in the box jellyfish, Tripedalia cystophora Conant, 1897 (Cnidaria: Cubozoa), and it is intimately associated with foraging between prop roots in their mangrove habitat. The obstacle avoidance behavior (OAB) is a species-specific defense reaction (SSDR) for T. cystophora, so identifying such SSDR is essential for testing the learning capacity of a given animal. Using the OAB, we show that box jellyfish performed associative learning (operant conditioning). We found that the rhopalial nervous system is the learning center and that T. cystophora combines visual and mechanical stimuli during operant conditioning. Since T. cystophora has a dispersed central nervous system lacking a conventional centralized brain, our work challenges the notion that associative learning requires complex neuronal circuitry. Moreover, since Cnidaria is the sister group to Bilateria, it suggests the intriguing possibility that advanced neuronal processes, like operant conditioning, are a fundamental property of all nervous systems.
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Affiliation(s)
- Jan Bielecki
- Institute of Physiology, Kiel University, 24118 Kiel, Germany.
| | | | - Gösta Nachman
- Section of Ecology and Evolution, University of Copenhagen, 2100 Copenhagen, Denmark
| | - Anders Garm
- Marine Biological Section, University of Copenhagen, 2100 Copenhagen, Denmark.
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3
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Halkjær Wiisbye S, Garm A. Unique horizontal gaze control in the box jellyfish, Tripedalia cystophora. Vision Res 2023; 203:108159. [PMID: 36516604 DOI: 10.1016/j.visres.2022.108159] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/23/2022] [Accepted: 11/26/2022] [Indexed: 12/14/2022]
Abstract
All known cubozoans, box jellyfish, have a similar visual system. They possess four sensory structures called rhopalia, which carry-six eyes each. Two of these six eyes are true image-forming camera type eyes in several ways similar to vertebrate eyes. The rhopalia hang by a thin flexible stalk and in the distal end, there is a high-density crystal. In an earlier study of the Caribbean species Tripedalia cystophora, we showed that the crystals act as weights ensuring that the rhopalia are always upright no matter the orientation of the medusa and the vertical part of the visual field of the eyes thus kept relatively constant. Here we have examined the horizontal part of the visual field under different experimental conditions including different visual environments. We find that the horizontal gaze direction is largely controlled by the anatomy of the rhopalium and rhopalial stalk, similar to what has previously been shown for the vertical gaze direction. In a vertically oriented medusa, the rhopalia are kept with a 90° angle between them with the lower lens eyes (LLE) pointing inwards. This 90° shift is kept in horizontally swimming medusa, resulting in the left LLE gazing right, the right gazing left, the bottom gazing orally (backwards compared to swimming direction), and the top LLE gazing aborally (forwards compared to swimming direction). The light environment was manipulated to test if the visual input influences this seemingly strict horizontal gaze direction but even in complete darkness there is tight mechanistic control.
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Affiliation(s)
| | - Anders Garm
- Marine Biological Section, University of Copenhagen, Denmark.
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Flensburg SB, Garm A, Funch P. The contraction-expansion behaviour in the demosponge Tethya wilhelma is light controlled and follows a diurnal rhythm. J Exp Biol 2022; 225:286159. [PMID: 36546534 DOI: 10.1242/jeb.244751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022]
Abstract
Sponges (phylum Porifera) are metazoans which lack muscles and nerve cells, yet perform coordinated behaviours such as whole-body contractions. Previous studies indicate diurnal variability in both the number of contractions and the expression of circadian clock genes. Here, we show that diurnal patterns are present in the contraction-expansion behaviour of the demosponge Tethya wilhelma, by using infrared videography and a simulated night/day cycle including sunrise and sunset mimics. In addition, we show that this behaviour is at least strongly influenced by ambient light intensity and therefore indicates light-sensing capabilities in this sponge species. This is supported by our finding that T. wilhelma consistently contracts at sunrise, and that this pattern disappears both when the sponge is kept in constant darkness and when it is in constant light.
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Affiliation(s)
- Sarah B Flensburg
- Department of Biology, Aarhus University, Ny Munkegade 114-116, 8000 Aarhus C, Denmark
| | - Anders Garm
- Marine Biological Section, University of Copenhagen, Universitetsparken 4, 2100 Copenhagen Ø, Denmark
| | - Peter Funch
- Department of Biology, Aarhus University, Ny Munkegade 114-116, 8000 Aarhus C, Denmark
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5
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Garm A, Svaerke JE, Pontieri D, Oakley TH. Expression of Opsins of the Box Jellyfish Tripedalia cystophora Reveals the First Photopigment in Cnidarian Ocelli and Supports the Presence of Photoisomerases. Front Neuroanat 2022; 16:916510. [PMID: 35991966 PMCID: PMC9389615 DOI: 10.3389/fnana.2022.916510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Accepted: 06/24/2022] [Indexed: 11/13/2022] Open
Abstract
Cubomedusae, or box jellyfish, have a complex visual system comprising 24 eyes of four types. Like other cnidarians, their photoreceptor cells are ciliary in morphology, and a range of different techniques together show that at least two of the eye types—the image-forming upper and lower lens eyes—express opsin as the photopigment. The photoreceptors of these two eye types express the same opsin (Tc LEO), which belongs to the cnidarian-specific clade cnidops. Interestingly, molecular work has found a high number of opsin genes in box jellyfish, especially in the Caribbean species Tripedalia cystophora, most of which are of unknown function. In the current study, we raised antibodies against three out of five opsins identified from transcriptomic data from T. cystophora and used them to map the expression patterns. These expression patterns suggest one opsin as the photopigment in the slit eyes and another as a putative photoisomerase found in photoreceptors of all four eyes types. The last antibody stained nerve-like cells in the tentacles, in connection with nematocytes, and the radial nerve, in connection with the gonads. This is the first time photopigment expression has been localized to the outer segments of the photoreceptors in a cnidarian ocellus (simple eye). The potential presence of a photoisomerase could be another interesting convergence between box jellyfish and vertebrate photoreceptors, but it awaits final experimental proof.
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Affiliation(s)
- Anders Garm
- Marine Biological Section, University of Copenhagen, Copenhagen, Denmark
- *Correspondence: Anders Garm
| | - Jens-Erik Svaerke
- Marine Biological Section, University of Copenhagen, Copenhagen, Denmark
| | - Daniela Pontieri
- Marine Biological Section, University of Copenhagen, Copenhagen, Denmark
| | - Todd H. Oakley
- Department of Biology, University of California, Santa Barbara, Santa Barbara, CA, United States
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Abstract
Neurons are the fundamental building blocks of nervous systems. It appears intuitive that the human brain is made up of hundreds, if not thousands different types of neurons. Conversely, the seemingly diffuse nerve net of Cnidaria is often assumed to be simple. However, evidence that the Cnidaria nervous system is indeed simple is sparse. Recent technical advances make it possible to assess the diversity and function of neurons with unprecedented resolution. Transgenic animals expressing genetically encoded Calcium sensors allow direct physiological assessments of neural responses within the nerve net and provide insight into the spatial organization of the nervous system. Moreover, response and activity patterns allow the characterization of cell types on a functional level. Molecular and genetic identities on the other hand can be assessed combining single-cell transcriptomic analysis with correlations of gene expression in defined neurons. Here I review recent advances on these two experimental strategies focusing on Hydra, Nematostella, and Clytia.
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Affiliation(s)
- Simon G Sprecher
- Department of Biology, University of Fribourg, Fribourg, Switzerland
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Gornik SG, Bergheim BG, Morel B, Stamatakis A, Foulkes NS, Guse A. Photoreceptor Diversification Accompanies the Evolution of Anthozoa. Mol Biol Evol 2021; 38:1744-1760. [PMID: 33226083 PMCID: PMC8097283 DOI: 10.1093/molbev/msaa304] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Anthozoan corals are an ecologically important group of cnidarians, which power the productivity of reef ecosystems. They are sessile, inhabit shallow, tropical oceans and are highly dependent on sun- and moonlight to regulate sexual reproduction, phototaxis, and photosymbiosis. However, their exposure to high levels of sunlight also imposes an increased risk of UV-induced DNA damage. How have these challenging photic environments influenced photoreceptor evolution and function in these animals? To address this question, we initially screened the cnidarian photoreceptor repertoire for Anthozoa-specific signatures by a broad-scale evolutionary analysis. We compared transcriptomic data of more than 36 cnidarian species and revealed a more diverse photoreceptor repertoire in the anthozoan subphylum than in the subphylum Medusozoa. We classified the three principle opsin classes into distinct subtypes and showed that Anthozoa retained all three classes, which diversified into at least six subtypes. In contrast, in Medusozoa, only one class with a single subtype persists. Similarly, in Anthozoa, we documented three photolyase classes and two cryptochrome (CRY) classes, whereas CRYs are entirely absent in Medusozoa. Interestingly, we also identified one anthozoan CRY class, which exhibited unique tandem duplications of the core functional domains. We next explored the functionality of anthozoan photoreceptors in the model species Exaiptasia diaphana (Aiptasia), which recapitulates key photo-behaviors of corals. We show that the diverse opsin genes are differentially expressed in important life stages common to reef-building corals and Aiptasia and that CRY expression is light regulated. We thereby provide important clues linking coral evolution with photoreceptor diversification.
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Affiliation(s)
- Sebastian G Gornik
- Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
| | | | - Benoit Morel
- Computational Molecular Evolution Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany
| | - Alexandros Stamatakis
- Computational Molecular Evolution Group, Heidelberg Institute for Theoretical Studies, Heidelberg, Germany.,Institute for Theoretical Informatics, Karlsruhe Institute of Technology, Karlsruhe, Germany
| | - Nicholas S Foulkes
- Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany.,Institute of Biological and Chemical Systems, Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Annika Guse
- Centre for Organismal Studies, Heidelberg University, Heidelberg, Germany
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Schlaefer JA, Wolanski E, Lambrechts J, Kingsford MJ. Behavioural and oceanographic isolation of an island-based jellyfish (Copula sivickisi, Class Cubozoa) population. Sci Rep 2021; 11:10280. [PMID: 33986430 PMCID: PMC8119444 DOI: 10.1038/s41598-021-89755-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 04/27/2021] [Indexed: 11/09/2022] Open
Abstract
Cubozoan jellyfish are classified as plankton despite the strong swimming and orientation abilities of cubomedusae. How these capabilities could affect cubozoan population structures is poorly understood. Medusae of the cubozoan Copula sivickisi can uniquely attach to surfaces with the sticky pads on their bells. Biophysical modelling was used to investigate the spatial scales of connectivity in a C. sivickisi population. When the medusae were active at night they could maintain their observed distribution on fringing reef if they attached to the reef when the current speed exceeded a moderate threshold. This behaviour facilitated the isolation of a C. sivickisi population on reefs fringing Magnetic Island, Queensland, Australia. Within this distribution, there was considerable within bay retention and medusae rarely travelled > 3 km. The few (< 0.1%) medusae lost from the island habitat were largely advected into open water and away from the mainland coast which lies 8 km from the island. Given that successful emigration is unlikely, the island population probably represents a stock that is ecologically distinct from any mainland populations. The cosmopolitan distribution of C. sivickisi could contain incipient or cryptic species given the small scales of connectivity demonstrated here.
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Affiliation(s)
- Jodie A Schlaefer
- Research Hub for Coral Reef Ecosystem Functions, James Cook University, Townsville, QLD, 4811, Australia. .,College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia. .,ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.
| | - Eric Wolanski
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.,TropWATER, James Cook University, Townsville, QLD, 4811, Australia
| | - Jonathan Lambrechts
- Institute of Mechanics, Materials and Civil Engineering, Université de Louvain, 1348, Louvain-La-Neuve, Belgium
| | - Michael J Kingsford
- College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.,ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia
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9
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Kanaya HJ, Park S, Kim JH, Kusumi J, Krenenou S, Sawatari E, Sato A, Lee J, Bang H, Kobayakawa Y, Lim C, Itoh TQ. A sleep-like state in Hydra unravels conserved sleep mechanisms during the evolutionary development of the central nervous system. SCIENCE ADVANCES 2020; 6:6/41/eabb9415. [PMID: 33028524 PMCID: PMC7541080 DOI: 10.1126/sciadv.abb9415] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 08/19/2020] [Indexed: 06/08/2023]
Abstract
Sleep behaviors are observed even in nematodes and arthropods, yet little is known about how sleep-regulatory mechanisms have emerged during evolution. Here, we report a sleep-like state in the cnidarian Hydra vulgaris with a primitive nervous organization. Hydra sleep was shaped by homeostasis and necessary for cell proliferation, but it lacked free-running circadian rhythms. Instead, we detected 4-hour rhythms that might be generated by ultradian oscillators underlying Hydra sleep. Microarray analysis in sleep-deprived Hydra revealed sleep-dependent expression of 212 genes, including cGMP-dependent protein kinase 1 (PRKG1) and ornithine aminotransferase. Sleep-promoting effects of melatonin, GABA, and PRKG1 were conserved in Hydra However, arousing dopamine unexpectedly induced Hydra sleep. Opposing effects of ornithine metabolism on sleep were also evident between Hydra and Drosophila, suggesting the evolutionary switch of their sleep-regulatory functions. Thus, sleep-relevant physiology and sleep-regulatory components may have already been acquired at molecular levels in a brain-less metazoan phylum and reprogrammed accordingly.
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Affiliation(s)
- Hiroyuki J Kanaya
- Department of Biology, School of Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Sungeon Park
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Ji-Hyung Kim
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Junko Kusumi
- Department of Environmental Changes, Faculty of Social and Cultural Studies, Kyushu University, Fukuoka 819-0395, Japan
| | | | - Etsuko Sawatari
- Faculty of Arts and Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Aya Sato
- Faculty of Arts and Science, Kyushu University, Fukuoka 819-0395, Japan
| | - Jongbin Lee
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Hyunwoo Bang
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | | | - Chunghun Lim
- School of Life Sciences, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea.
| | - Taichi Q Itoh
- Faculty of Arts and Science, Kyushu University, Fukuoka 819-0395, Japan.
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10
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Helmark S, Garm A. Gonadal cnidocytes in the cubozoan Tripedalia cystophora Conant, 1897 (Cnidaria: Cubozoa). J Morphol 2019; 280:1530-1536. [PMID: 31334880 DOI: 10.1002/jmor.21046] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/21/2019] [Accepted: 07/07/2019] [Indexed: 11/09/2022]
Abstract
Cubozoans have a complex lifecycle in many ways similar to the scyphozoan lifecycle. The sexual reproduction within cubozoans varies between species with one clade having copulation and internal fertilization and the release of planula larvae. This cubozoan clade, the family Tripedaliidae, includes three species, Copula sivickisi, Tripedalia cystophora, and Tripedalia binata. In a recent study, it was suggested that in C. sivickisi cnidocytes play a new and important role during the sexual reproduction. Male derived cnidocytes anchor sperm packages to the female gonads and female derived cnidocytes protect the externalized embryo strand. Here, we have examined the gonads and gametes of T. cystophora and our results reveal that the male produced spermatozeugmata have a high number of isorhiza type cnidocytes, which are transferred along with the sperm during copulation. This adds further support to our hypothesis that they are important for sperm anchorage. The female gonads are lacking cnidocytes all together showing that cnidocyte production is not just a default state of the epithelium in these animals.
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Affiliation(s)
- Sandra Helmark
- Marine Biological Section, University of Copenhagen, Copenhagen, Denmark
| | - Anders Garm
- Marine Biological Section, University of Copenhagen, Copenhagen, Denmark
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11
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Abstract
What is the 'simplest' animal that sleeps? When did sleep first evolve? Do all animals sleep? Tantalizing hints to answers come from new research showing that jellyfish, one of the earliest evolving groups of animals, have a sleep-like restful state.
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Affiliation(s)
- John A Lesku
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia.
| | - Linh M T Ly
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia
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12
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Omond S, Ly LMT, Beaton R, Storm JJ, Hale MW, Lesku JA. Inactivity Is Nycthemeral, Endogenously Generated, Homeostatically Regulated, and Melatonin Modulated in a Free-Living Platyhelminth Flatworm. Sleep 2018; 40:4091373. [PMID: 28958003 DOI: 10.1093/sleep/zsx124] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Introduction Sleep either appeared once early in the evolution of animals, or at multiple instances over evolutionary time. Understanding whether sleep is a diagnostic trait for members of the kingdom Animalia has important implications for our understanding of the evolution of sleep and sleep functions. Unfortunately, knowledge on the phylogenetic breadth of sleep is restricted to vertebrates, a few arthropods and molluscs, and one species of nematode. There is a dearth of information on the other 30 or so animal phyla. Aims and Methods Here, we provide original data on a previously unstudied group of animals with respect to sleep: platyhelminth flatworms. These free-living animals are relatively simple, with a rudimentary central nervous system and absence of many other specialized physiological systems. Results Despite this simplicity, inactive flatworms appeared to be sleeping. Specifically, quiescence was organized in a circadian manner, occurring largely during the daytime. This basic rhythm persisted under constant darkness, suggesting that it was endogenously generated. Active flatworms responded more readily to stimulation, and flatworms recovered lost sleep by sleeping longer after a 3-hour period of inactivity deprivation. We were also able to increase inactivity in a dose-dependent manner with exposure to melatonin, a hormone that increases sleep in diurnal animals. Conclusions Taken together, these data expand our understanding of the phylogenetic extent of sleep and reinforce the idea that sleep evolved early in the evolutionary history of animals. However, additional studies on other types of animals are required for a comprehensive understanding of the origin(s) and evolution of sleep.
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Affiliation(s)
- Shauni Omond
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia
| | - Linh M T Ly
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia
| | - Russell Beaton
- School of Psychology and Public Health, La Trobe University, Melbourne 3086, Australia
| | - Jonathan J Storm
- Division of Natural Sciences & Engineering, University of South Carolina Upstate, Spartanburg 29301, SC
| | - Matthew W Hale
- School of Psychology and Public Health, La Trobe University, Melbourne 3086, Australia
| | - John A Lesku
- School of Life Sciences, La Trobe University, Melbourne 3086, Australia
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13
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Bielecki J, Garm A. Vision Made Easy: Cubozoans Can Advance Our Understanding of Systems-Level Visual Information Processing. Results Probl Cell Differ 2018; 65:599-624. [PMID: 30083938 DOI: 10.1007/978-3-319-92486-1_27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Animals relying on vision as their main sensory modality reserve a large part of their central nervous system to appropriately navigate their environment. In general, neural involvement correlates to the complexity of the visual system and behavioural repertoire. In humans, one third of the available neural capacity supports our single-chambered general-purpose eyes, whereas animals with less elaborate visual systems need less computational power, and generally have smaller brains, and thereby lack in visual behaviour. As a consequence, both traditional model animals (mice, zebrafish, and flies) and more experimentally tractable animals (Hydra, Planaria, and C. elegans) cannot contribute to our understanding of systems-level visual information processing-a Goldilocks case of too big and too small.However, one animal, the box jellyfish Tripedalia cystophora, possesses a rather complex visual system, displays multiple visual behaviours, yet processes visual information by means of a relatively simple central nervous system. This-just right-model system could not only provide information on how visual stimuli are processed through distinct combinations of neural circuitry but also provide a processing algorithm for extracting specific information from a complex visual scene.
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Affiliation(s)
- Jan Bielecki
- GEOMAR - Helmholtz Centre for Ocean Research, Kiel, Germany.
- Institute of Physiology, Christian Albrechts University, Kiel, Germany.
| | - Anders Garm
- Marine Biological Section, University of Copenhagen, Copenhagen, Denmark
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14
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Nath RD, Bedbrook CN, Abrams MJ, Basinger T, Bois JS, Prober DA, Sternberg PW, Gradinaru V, Goentoro L. The Jellyfish Cassiopea Exhibits a Sleep-like State. Curr Biol 2017; 27:2984-2990.e3. [PMID: 28943083 DOI: 10.1016/j.cub.2017.08.014] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2017] [Revised: 07/17/2017] [Accepted: 08/04/2017] [Indexed: 12/28/2022]
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.
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Affiliation(s)
- Ravi D Nath
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA; Howard Hughes Medical Institute
| | - Claire N Bedbrook
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Michael J Abrams
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Ty Basinger
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Justin S Bois
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - David A Prober
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Paul W Sternberg
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA; Howard Hughes Medical Institute
| | - Viviana Gradinaru
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Lea Goentoro
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
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15
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Canepa A, Fuentes V, Bosch-Belmar M, Acevedo M, Toledo-Guedes K, Ortiz A, Durá E, Bordehore C, Gili JM. Environmental factors influencing the spatio-temporal distribution of Carybdea marsupialis (Lineo, 1978, Cubozoa) in South-Western Mediterranean coasts. PLoS One 2017; 12:e0181611. [PMID: 28746410 PMCID: PMC5528890 DOI: 10.1371/journal.pone.0181611] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 07/05/2017] [Indexed: 11/25/2022] Open
Abstract
Jellyfish blooms cause important ecological and socio-economic problems. Among jellyfish, cubozoans are infamous for their painful, sometimes deadly, stings and are a major public concern in tropical to subtropical areas; however, there is little information about the possible causes of their outbreaks. After a bloom of the cubomedusa Carybdea marsupialis (Carybdeidae) along the coast of Denia (SW Mediterranean, Spain) in 2008 with negative consequences for local tourism, the necessity to understand the ecological restrictions on medusae abundance was evident. Here we use different models (GAM and zero-inflated models) to understand the environmental and human related factors influencing the abundance and distribution of C. marsupialis along the coast of Denia. Selected variables differed among medusae size classes, showing different environmental restriction associated to the developmental stages of the species. Variables implicated with dispersion (e.g. wind and current) affected mostly small and medium size classes. Sea surface temperature, salinity and proxies of primary production (chl a, phosphates, nitrates) were related to the abundances of small and large size classes, highlighting the roles of springtime salinity changes and increased primary production that may promote and maintain high densities of this species. The increased primary (and secondary) production due to anthropogenic impact is implicated as the factor enabling high numbers of C. marsupialis to thrive. Recommendations for monitoring blooms of this species along the study area and applicable to Mediterranean Sea include focus effort in coastal waters where productivity have been enriched by anthropogenic activities.
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Affiliation(s)
- Antonio Canepa
- Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile.,Marine Biology and Oceanography Department, Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
| | - Verónica Fuentes
- Marine Biology and Oceanography Department, Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
| | - Mar Bosch-Belmar
- Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, Lecce, Italy
| | - Melissa Acevedo
- Marine Biology and Oceanography Department, Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
| | - Kilian Toledo-Guedes
- Department of Marine Sciences and Applied Biology, University of Alicante, Alicante, Spain
| | - Antonio Ortiz
- Departamento de Ecología e Instituto Multidisciplinar para el Estudio del Medio "Ramon Margalef" IMEM, Universidad de Alicante, Alicante, Spain
| | - Elia Durá
- Departamento de Ecología e Instituto Multidisciplinar para el Estudio del Medio "Ramon Margalef" IMEM, Universidad de Alicante, Alicante, Spain
| | - César Bordehore
- Departamento de Ecología e Instituto Multidisciplinar para el Estudio del Medio "Ramon Margalef" IMEM, Universidad de Alicante, Alicante, Spain
| | - Josep-Maria Gili
- Marine Biology and Oceanography Department, Institut de Ciències del Mar, Consejo Superior de Investigaciones Científicas, Barcelona, Spain
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16
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Bozman A, Titelman J, Kaartvedt S, Eiane K, Aksnes DL. Jellyfish distribute vertically according to irradiance. JOURNAL OF PLANKTON RESEARCH 2017; 39:280-289. [PMID: 29731527 PMCID: PMC5914403 DOI: 10.1093/plankt/fbw097] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/25/2016] [Revised: 12/07/2016] [Accepted: 12/19/2016] [Indexed: 06/08/2023]
Abstract
We tested the hypothesis that the coronate jellyfish Periphylla periphylla distributes vertically according to a preferential range of absolute light intensities. The study was carried out in Lurefjorden, Norway, a fjord characterized by mass occurrences of this jellyfish. We collected data on the vertical distribution of P. periphylla medusa during day, dusk and night periods from video observations by a remotely operated vehicle in relation to estimated ambient light levels. Our results suggest that large P. periphylla (average size in catches ~9 cm diameter) avoided total irradiance levels above 5×10-3 µmol quanta m-2 s-1. Nearly two-thirds of the population stayed above irradiance of 10-7 µmol quanta m-2 s-1 during daytime, while some individuals occupied much darker water. Thus, part of the population appeared to distribute vertically and undertake diel vertical migration (DVM) according to a preferential range of light intensities.
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Affiliation(s)
- Andrea Bozman
- Faculty of Biosciences and Aquaculture, Nord University, Po Box 1490, 8049 Bodø, Norway
| | - Josefin Titelman
- Department of Biosciences, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway
| | - Stein Kaartvedt
- Department of Biosciences, University of Oslo, PO Box 1066 Blindern, 0316 Oslo, Norway
| | - Ketil Eiane
- Faculty of Biosciences and Aquaculture, Nord University, Po Box 1490, 8049 Bodø, Norway
| | - Dag L. Aksnes
- Department of Biology, University of Bergen, Thormøhlensgt 53 A/B, 5020 Bergen, Norway
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17
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Lasley RM, Ames CL, Erdman R, Parks S, Collins AG. First record of the box jellyfishTripedalia cystophora(Cnidaria: Cubozoa: Tripedaliidae) in the Gulf of Mexico. P BIOL SOC WASH 2016. [DOI: 10.2988/0006-324x-129.q2.164] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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18
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Garm A, Bielecki J, Petie R, Nilsson DE. Hunting in Bioluminescent Light: Vision in the Nocturnal Box Jellyfish Copula sivickisi. Front Physiol 2016; 7:99. [PMID: 27065877 PMCID: PMC4812875 DOI: 10.3389/fphys.2016.00099] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2015] [Accepted: 03/01/2016] [Indexed: 11/13/2022] Open
Abstract
Cubomedusae all have a similar set of six eyes on each of their four rhopalia. Still, there is a great variation in activity patterns with some species being strictly day active while others are strictly night active. Here we have examined the visual ecology of the medusa of the night active Copula sivickisi from Okinawa using optics, morphology, electrophysiology, and behavioral experiments. We found the lenses of both the upper and the lower lens eyes to be image forming but under-focused, resulting in low spatial resolution in the order of 10-15°. The photoreceptor physiology is similar in the two lens eyes and they have a single opsin peaking around 460 nm and low temporal resolution with a flicker fusion frequency (fff) of 2.5 Hz indicating adaptions to vision in low light intensities. Further, the outer segments have fluid filled swellings, which may concentrate the light in the photoreceptor membrane by total internal reflections, and thus enhance the signal to noise ratio in the eyes. Finally our behavioral experiments confirmed that the animals use vision when hunting. When they are active at night they seek out high prey-concentration by visual attraction to areas with abundant bioluminescent flashes triggered by their prey.
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Affiliation(s)
- Anders Garm
- Marine Biological Section, Department of Biology, University of Copenhagen Copenhagen, Denmark
| | - Jan Bielecki
- Department of Ecology evolution and Marin Biology, University of California, Santa Barbara Santa Barbara, CA, USA
| | - Ronald Petie
- Marine Biological Section, Department of Biology, University of Copenhagen Copenhagen, Denmark
| | - Dan-Eric Nilsson
- Vision Group, Department of Biology, Lund University Lund, Sweden
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19
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Cleary DFR, Becking LE, Polónia ARM, Freitas RM, Gomes NCM. Jellyfish-associated bacterial communities and bacterioplankton in Indonesian Marine lakes. FEMS Microbiol Ecol 2016; 92:fiw064. [PMID: 27004797 DOI: 10.1093/femsec/fiw064] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/15/2016] [Indexed: 01/08/2023] Open
Abstract
In the present study, we compared communities of bacteria in two jellyfish species (the 'golden' jellyfish Mastigias cf.papua and the box jellyfish Tripedalia cf.cystophora) and water in three marine lakes located in the Berau region of northeastern Borneo, Indonesia. Jellyfish-associated bacterial communities were compositionally distinct and less diverse than bacterioplankton communities. Alphaproteobacteria, Gammaproteobacteria, Synechococcophycidae and Flavobacteriia were the most abundant classes in water. Jellyfish-associated bacterial communities were dominated by OTUs assigned to the Gammaproteobacteria (family Endozoicimonaceae), Mollicutes, Spirochaetes and Alphaproteobacteria (orders Kiloniellales and Rhodobacterales). Mollicutes were mainly restricted to Mastigias whereas Spirochaetes and the order Kiloniellales were most abundant in Tripedalia hosts. The most abundant OTU overall in jellyfish hosts was assigned to the family Endozoicimonaceae and was highly similar to organisms in Genbank obtained from various hosts including an octocoral, bivalve and fish species. Other abundant OTUs included an OTU assigned to the order Entomoplasmatales and mainly found in Mastigias hosts and OTUs assigned to the Spirochaetes and order Kiloniellales and mainly found in Tripedalia hosts. The low sequence similarity of the Entomoplasmatales OTU to sequences in Genbank suggests that it may be a novel lineage inhabiting Mastigias and possibly restricted to marine lakes.
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Affiliation(s)
- Daniel F R Cleary
- Department of Biology, CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Leontine E Becking
- Department of Marine Zoology, Naturalis Biodiversity Center, Darwinweg 2, 2333 CR Leiden, the Netherlands Wageningen University and Research Centre, Marine Animal Ecology Group, PO Box 338, 6700 AH Wageningen, the Netherlands Department of Environmental Science, Policy, and Management, University of California Berkeley, 130 Mulford Hall, Berkeley CA 94720-3114, USA
| | - Ana R M Polónia
- Department of Biology, CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Rossana M Freitas
- Department of Biology, CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
| | - Newton C M Gomes
- Department of Biology, CESAM, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal
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20
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Courtney R, Sachlikidis N, Jones R, Seymour J. Prey Capture Ecology of the Cubozoan Carukia barnesi. PLoS One 2015; 10:e0124256. [PMID: 25970583 PMCID: PMC4429964 DOI: 10.1371/journal.pone.0124256] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Accepted: 03/11/2015] [Indexed: 12/16/2022] Open
Abstract
Adult Carukia barnesi medusae feed predominantly on larval fish; however, their mode of prey capture seems more complex than previously described. Our findings revealed that during light conditions, this species extends its tentacles and ‘twitches’ them frequently. This highlights the lure-like nematocyst clusters in the water column, which actively attract larval fish that are consequently stung and consumed. This fishing behavior was not observed during dark conditions, presumably to reduce energy expenditure when they are not luring visually oriented prey. We found that larger medusae have longer tentacles; however, the spacing between the nematocyst clusters is not dependent on size, suggesting that the spacing of the nematocyst clusters is important for prey capture. Additionally, larger specimens twitch their tentacles more frequently than small specimens, which correlate with their recent ontogenetic prey shift from plankton to larval fish. These results indicate that adult medusae of C. barnesi are not opportunistically grazing in the water column, but instead utilize sophisticated prey capture techniques to specifically target larval fish.
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Affiliation(s)
- Robert Courtney
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
- * E-mail:
| | | | - Rhondda Jones
- College of Marine & Environmental Sciences, James Cook University, Townsville, Queensland, Australia
| | - Jamie Seymour
- Australian Institute of Tropical Health and Medicine, James Cook University, Cairns, Queensland, Australia
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21
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Gurska D, Garm A. Cell proliferation in cubozoan jellyfish Tripedalia cystophora and Alatina moseri. PLoS One 2014; 9:e102628. [PMID: 25047715 PMCID: PMC4105575 DOI: 10.1371/journal.pone.0102628] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 06/22/2014] [Indexed: 11/19/2022] Open
Abstract
Cubozoans (box jellyfish) undergo remarkable body reorganization throughout their life cycle when, first, they metamorphose from swimming larvae to sessile polyps, and second, through the metamorphosis from sessile polyps to free swimming medusae. In the latter they develop complex structures like the central nervous system (CNS) and visual organs. In the present study several aspects of cell proliferation at different stages of the life cycle of the box jellyfish Tripedalia cystophora and Alatina moseri have been examined through in vivo labeling of cells in the synthetic phase (S phase) of the cell cycle. Proliferation zones were found in metamorphosing polyps, as well as in juvenile medusae, where both the rhopalia and pedalia have enhanced rates of proliferation. The results also indicate a rather fast cell turnover in the rhopalia including the rhopalial nervous system (RNS). Moreover, T. cystophora showed diurnal pattern of cell proliferation in certain body parts of the medusa, with higher proliferation rates at nighttime. This is true for two areas in close connection with the CNS: the stalk base and the rhopalia.
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Affiliation(s)
- Daniela Gurska
- Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Anders Garm
- Marine Biological Section, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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22
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Bielecki J, Zaharoff AK, Leung NY, Garm A, Oakley TH. Ocular and extraocular expression of opsins in the rhopalium of Tripedalia cystophora (Cnidaria: Cubozoa). PLoS One 2014; 9:e98870. [PMID: 24901369 PMCID: PMC4047050 DOI: 10.1371/journal.pone.0098870] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 05/07/2014] [Indexed: 11/18/2022] Open
Abstract
A growing body of work on the neuroethology of cubozoans is based largely on the capabilities of the photoreceptive tissues, and it is important to determine the molecular basis of their light sensitivity. The cubozoans rely on 24 special purpose eyes to extract specific information from a complex visual scene to guide their behavior in the habitat. The lens eyes are the most studied photoreceptive structures, and the phototransduction in the photoreceptor cells is based on light sensitive opsin molecules. Opsins are photosensitive transmembrane proteins associated with photoreceptors in eyes, and the amino acid sequence of the opsins determines the spectral properties of the photoreceptors. Here we show that two distinct opsins (Tripedalia cystophora-lens eye expressed opsin and Tripedalia cystophora-neuropil expressed opsin, or Tc-leo and Tc-neo) are expressed in the Tripedalia cystophora rhopalium. Quantitative PCR determined the level of expression of the two opsins, and we found Tc-leo to have a higher amount of expression than Tc-neo. In situ hybridization located Tc-leo expression in the retinal photoreceptors of the lens eyes where the opsin is involved in image formation. Tc-neo is expressed in a confined part of the neuropil and is probably involved in extraocular light sensation, presumably in relation to diurnal activity.
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Affiliation(s)
- Jan Bielecki
- Ecology, Evolution and Marine Biology, University of California at Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
| | - Alexander K. Zaharoff
- Ecology, Evolution and Marine Biology, University of California at Santa Barbara, Santa Barbara, California, United States of America
| | - Nicole Y. Leung
- Ecology, Evolution and Marine Biology, University of California at Santa Barbara, Santa Barbara, California, United States of America
| | - Anders Garm
- Marine Biological Section, University of Copenhagen, Copenhagen, Denmark
| | - Todd H. Oakley
- Ecology, Evolution and Marine Biology, University of California at Santa Barbara, Santa Barbara, California, United States of America
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23
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Chiaverano LM, Holland BS, Crow GL, Blair L, Yanagihara AA. Long-term fluctuations in circalunar Beach aggregations of the box jellyfish Alatina moseri in Hawaii, with links to environmental variability. PLoS One 2013; 8:e77039. [PMID: 24194856 PMCID: PMC3806728 DOI: 10.1371/journal.pone.0077039] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 09/06/2013] [Indexed: 01/22/2023] Open
Abstract
The box jellyfish Alatina moseri forms monthly aggregations at Waikiki Beach 8-12 days after each full moon, posing a recurrent hazard to swimmers due to painful stings. We present an analysis of long-term (14 years: Jan 1998- Dec 2011) changes in box jellyfish abundance at Waikiki Beach. We tested the relationship of beach counts to climate and biogeochemical variables over time in the North Pacific Sub-tropical Gyre (NPSG). Generalized Additive Models (GAM), Change-Point Analysis (CPA), and General Regression Models (GRM) were used to characterize patterns in box jellyfish arrival at Waikiki Beach 8-12 days following 173 consecutive full moons. Variation in box jellyfish abundance lacked seasonality, but exhibited dramatic differences among months and among years, and followed an oscillating pattern with significant periods of increase (1998-2001; 2006-2011) and decrease (2001-2006). Of three climatic and 12 biogeochemical variables examined, box jellyfish showed a strong, positive relationship with primary production, >2 mm zooplankton biomass, and the North Pacific Gyre Oscillation (NPGO) index. It is clear that that the moon cycle plays a key role in synchronizing timing of the arrival of Alatina moseri medusae to shore. We propose that bottom-up processes, likely initiated by inter-annual regional climatic fluctuations influence primary production, secondary production, and ultimately regulate food availability, and are therefore important in controlling the inter-annual changes in box jellyfish abundance observed at Waikiki Beach.
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Affiliation(s)
- Luciano M. Chiaverano
- Kewalo Marine Laboratory, Pacific Biosciences Research Center, University of Hawaii at Mānoa, Honolulu, Hawaii, United States of America
- * E-mail:
| | - Brenden S. Holland
- Center for Conservation Research & Training, Pacific Biosciences Research Center, University of Hawaii at Mānoa, Honolulu, Hawaii, United States of America
| | - Gerald L. Crow
- Waikiki Aquarium, University of Hawaii at Mānoa, Honolulu, Hawaii, United States of America
| | - Landy Blair
- Ocean Safety and Lifeguard Services, City and County of Honolulu, Honolulu, Hawaii, United States of America
| | - Angel A. Yanagihara
- Bekesy Laboratory, Pacific Biosciences Research Center, and Department of Tropical Medicine, John A. Burns School of Medicine, University of Hawaii at Mānoa, Honolulu, Hawaii, United States of America
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24
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Garm A, Hedal I, Islin M, Gurska D. Pattern- and contrast-dependent visual response in the box jellyfish Tripedalia cystophora. ACTA ACUST UNITED AC 2013; 216:4520-9. [PMID: 24031055 DOI: 10.1242/jeb.091934] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cubomedusae possess a total of 24 eyes, some of which are structurally similar to vertebrate eyes. Accordingly, the medusae also display a range of light-guided behaviours including obstacle avoidance, diurnal activity patterns and navigation. Navigation is supported by spatial resolution and image formation in the so-called upper lens eye. Further, there are indications that obstacle avoidance requires image information from the lower lens eye. Here we use a behavioural assay to examine the obstacle avoidance behaviour of the Caribbean cubomedusa Tripedalia cystophora and test whether it requires spatial resolution. The possible influence of the contrast and orientation of the obstacles is also examined. We show that the medusae can only perform the behaviour when spatial information is present, and fail to avoid a uniformly dark wall, directly proving the use of spatial vision. We also show that the medusae respond stronger to high contrast lines than to low contrast lines in a graded fashion, and propose that the medusae use contrast as a semi-reliable measure of distance to the obstacle.
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Affiliation(s)
- Anders Garm
- Section of Marine Biology, University of Copenhagen, DK-2100 Copenhagen Ø, Denmark
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25
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Swim pacemaker response to bath applied neurotransmitters in the cubozoan Tripedalia cystophora. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2013; 199:785-97. [PMID: 23893247 DOI: 10.1007/s00359-013-0839-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 07/05/2013] [Accepted: 07/11/2013] [Indexed: 10/26/2022]
Abstract
The four rhopalia of cubomedusae are integrated parts of the central nervous system carrying their many eyes and thought to be the centres of visual information processing. Rhopalial pacemakers control locomotion through a complex neural signal transmitted to the ring nerve and the signal frequency is modulated by the visual input. Since electrical synapses have never been found in the cubozoan nervous system all signals are thought to be transmitted across chemical synapses, and so far information about the neurotransmitters involved are based on immunocytochemical or behavioural data. Here we present the first direct physiological evidence for the types of neurotransmitters involved in sensory information processing in the rhopalial nervous system. FMRFamide, serotonin and dopamine are shown to have inhibitory effect on the pacemaker frequency. There are some indications that the fast acting acetylcholine and glycine have an initial effect and then rapidly desensitise. Other tested neuroactive compounds (GABA, glutamate, and taurine) could not be shown to have a significant effect.
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26
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Gershwin LA, Richardson AJ, Winkel KD, Fenner PJ, Lippmann J, Hore R, Avila-Soria G, Brewer D, Kloser RJ, Steven A, Condie S. Biology and ecology of Irukandji jellyfish (Cnidaria: Cubozoa). ADVANCES IN MARINE BIOLOGY 2013; 66:1-85. [PMID: 24182899 DOI: 10.1016/b978-0-12-408096-6.00001-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Irukandji stings are a leading occupational health and safety issue for marine industries in tropical Australia and an emerging problem elsewhere in the Indo-Pacific and Caribbean. Their mild initial sting frequently results in debilitating illness, involving signs of sympathetic excess including excruciating pain, sweating, nausea and vomiting, hypertension and a feeling of impending doom; some cases also experience acute heart failure and pulmonary oedema. These jellyfish are typically small and nearly invisible, and their infestations are generally mysterious, making them scary to the general public, irresistible to the media, and disastrous for tourism. Research into these fascinating species has been largely driven by the medical profession and focused on treatment. Biological and ecological information is surprisingly sparse, and is scattered through grey literature or buried in dispersed publications, hampering understanding. Given that long-term climate forecasts tend toward conditions favourable to jellyfish ecology, that long-term legal forecasts tend toward increasing duty-of-care obligations, and that bioprospecting opportunities exist in the powerful Irukandji toxins, there is a clear need for information to help inform global research and robust management solutions. We synthesise and contextualise available information on Irukandji taxonomy, phylogeny, reproduction, vision, behaviour, feeding, distribution, seasonality, toxins, and safety. Despite Australia dominating the research in this area, there are probably well over 25 species worldwide that cause the syndrome and it is an understudied problem in the developing world. Major gaps in knowledge are identified for future research: our lack of clarity on the socio-economic impacts, and our need for time series and spatial surveys of the species, make this field particularly enticing.
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Affiliation(s)
- Lisa-ann Gershwin
- CSIRO Marine and Atmospheric Research, Castray Esplanade, Hobart, Tasmania, Australia.
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