Cnidofest 2018: the Future Is Bright for Cnidarian Research

Total Page:16

File Type:pdf, Size:1020Kb

Cnidofest 2018: the Future Is Bright for Cnidarian Research UC Merced UC Merced Previously Published Works Title Cnidofest 2018: the future is bright for cnidarian research. Permalink https://escholarship.org/uc/item/5zw6g05s Journal EvoDevo, 10(1) ISSN 2041-9139 Authors He, Shuonan Grasis, Juris A Nicotra, Matthew L et al. Publication Date 2019 DOI 10.1186/s13227-019-0134-5 Peer reviewed eScholarship.org Powered by the California Digital Library University of California He et al. EvoDevo (2019) 10:20 https://doi.org/10.1186/s13227-019-0134-5 EvoDevo MEETING REPORT Open Access Cnidofest 2018: the future is bright for cnidarian research Shuonan He1, Juris A. Grasis2, Matthew L. Nicotra3,4,5, Celina E. Juliano6 and Christine E. Schnitzler7,8* Abstract The 2018 Cnidarian Model Systems Meeting (Cnidofest) was held September 6–9th at the University of Florida Whitney Laboratory for Marine Bioscience in St. Augustine, FL. Cnidofest 2018, which built upon the momentum of Hydroidfest 2016, brought together research communities working on a broad spectrum of cnidarian organisms from North America and around the world. Meeting talks covered diverse aspects of cnidarian biology, with sessions focused on genomics, development, neurobiology, immunology, symbiosis, ecology, and evolution. In addition to interesting biology, Cnidofest also emphasized the advancement of modern research techniques. Invited technology speakers showcased the power of microfuidics and single-cell transcriptomics and demonstrated their application in cnidarian models. In this report, we provide an overview of the exciting research that was presented at the meeting and discuss opportunities for future research. Keywords: Cnidarians, Hydra, Hydractinia, Nematostella, Aiptasia, Cassiopeia Introduction use of many diferent cnidarians to address a myriad of Cnidaria (corals, jellyfsh, sea anemones, and hydroids) biological questions. is a phylum of aquatic animals, unifed by the presence Cnidofest 2018 (http://www.cnida rianm odelm eetin of specialized stinging cells called cnidocytes [1]. Tese g.org) was organized to foster the expansion of the beautiful and exotic creatures have fascinated biologists cnidarian research community and emphasize the since the dawn of experimental biology [2, 3]. Teir phy- application of modern molecular tools to both clas- logenic position as the sister group to Bilateria makes sic and emerging cnidarian models. As a successor to them key to addressing long-standing questions regard- the Hydroidfest 2016 meeting [18], which emphasized ing animal relationships and evolution [4–7]. Until hydrozoan research, Cnidofest 2018 widened its focus to recently, cnidarian research has been hindered by the lack include representatives from many cnidarian taxa. Two of advanced molecular and genetic approaches. How- established model organisms, Hydra and Nematostella, ever, rapidly advancing technologies, including genome appeared in approximately 60% of the abstracts. How- sequencing and gene-editing tools, are now being applied ever, the overall meeting agenda was diverse, with 11 to many cnidarian species. Large collections of genomic cnidarian species featured during 44 oral presentation and transcriptomic data of diverse cnidarian species have sessions and a total of 22 species represented by the 85 now been generated [8–12] and single-cell sequencing submitted abstracts. Nearly all major cnidarian clades technologies are deepening our understanding of cnidar- were represented (Fig. 1), including traditionally under- ian development and evolution [13, 14]. Tese data, in represented groups, such as Cubozoa, Staurozoa, and combination with new gene-editing capabilities [15–17], Myxozoa. Newly sequenced genomes and transcriptomes are opening new experimental avenues and enabling the are giving these lesser known, yet fascinating animals a signifcant boost. A major goal of the Cnidofest 2018 meeting was to *Correspondence: [email protected] 7 Whitney Laboratory for Marine Bioscience, University of Florida, St. contribute to the career development of trainees in Augustine, FL 32080, USA the cnidarian research community. With funding sup- Full list of author information is available at the end of the article port from the National Science Foundation and the © The Author(s) 2019. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creat iveco mmons .org/licen ses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/ publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. He et al. EvoDevo (2019) 10:20 Page 2 of 11 the future is bright. In this report, we provide an over- view of the exciting research presented at Cnidofest 2018. Keynote address: cnidarian symbionts and the fate of coral reefs Virginia Weis (Oregon State University) is an inspir- ing fgure in the cnidarian research community. For more than two decades, she has pioneered and pro- moted coral symbiosis studies using Aiptasia, which is colonized by dinofagellates from the family Symbiod- iniaceae [19], as a model organism. Work from her lab and her collaborators successfully pushed forward our understanding of host–symbiont interactions on the molecular and cellular level. As the keynote speaker of Cnidofest 2018, Weis shared with the audience high- lights covering 22 years of research done by her labo- ratory, her success in promoting and connecting the Aiptasia community, her vision of the future of symbio- sis research, and her concern over global warming and the accelerating rate of coral extinction. Weis emphasized the importance of translating fndings in basic research into valuable tools for con- servation biology. Te lectin/glycan interaction and the complement pathway were identifed as key play- ers mediating host–symbiont recognition; disruption of these pathways blocks symbiont colonization in Aiptasia larvae. Based on these discoveries, Weis and her collaborators are currently testing symbionts with Fig. 1 Cnidarian model systems represented at Cnidofest. a A chemically modifed glycans as an attempt to increase hermaphroditic green Hydra polyp bearing a testes and an egg their colonizing abilities, with the ultimate goal of (courtesy of Stefan Siebert). b Gastrozooids and gonozooids of a rescuing bleached coral populations. Meanwhile, by Hydractinia symbiolongicarpus colony (courtesy of Steven Sanders). incubating Aiptasia with high concentrations of throm- c Nematostella vectensis adult polyp (courtesy of Shuonan He). d The bospondin type 1 repeat (TSR) peptides, a key compo- banded tube-dwelling anemone, Isarachnanthus nocturnes (courtesy of Sérgio Stampar). e A Cordylophora colony growing on eelgrass nent of the complement pathway, Weis and colleagues (courtesy of Nadine Folino Rorem and E. Sally Chang). f Medusa of turned normal symbionts into ‘super colonizers’. Tese Cassiopea spp. (courtesy of Casandra Newkirk) approaches, though preliminary, may help to alleviate challenges in coral conservation. Finally, Weis laid out her vision for a community-wide efort to develop gene manipulation techniques such as CRISPR/Cas9 in both University of Florida Ofce of Research, registration Aiptasia and their dinofagellate symbionts. Tanks to fees were waived for nearly all trainees and travel allow- the eforts of Weis, many well-established biologists ances were awarded to 16 domestic and 5 international such as John Pringle (Stanford) and Tomas Gilmore trainees. Tis allowed for trainees to make up nearly (Boston University) have adopted Aiptasia as a research 70% of the total attendance, and 68% of the oral pres- organism in their own labs. Meanwhile, a younger gen- entations (30/44) were given by students and postdocs. eration of Aiptasia biologists are emerging with talent Te environment provided at Cnidofest enabled stu- and dedication, highlighted by the exciting oral pres- dents and postdocs to showcase their work and interact entations and posters during this meeting. Emphasiz- directly with established researchers in this small, yet ing the need for multiple communities to unite around vibrant community. With these fantastic young scien- the complex issue of saving coral reefs, Weis stressed tists, new species, new technologies, and new ideas, the that “it takes a village to save corals…and we must take cnidarian research community is growing quickly and action before it’s too late.” He et al. EvoDevo (2019) 10:20 Page 3 of 11 Genomics: expanding genomic resources and then performed comparative analyses across four for cnidarian research Brown Hydra species and one Green Hydra species to ask Cnidarian genomes hold a key to understanding animal how the expansion of TEs increased the genome sizes of phylogenetic relationships and provide the framework Brown Hydra compared to Green Hydra [11, 24]. Wong for exploring the evolution of complex biological pro- found that one LINE family transposable element is sig- cesses from embryogenesis to aging. Te opening session nifcantly enriched in the Brown Hydra species as com- of Cnidofest 2018 included exciting advancements in pared to the Green Hydra. Wong hypothesized that this comparative genomics and the development of genome lineage-specifc LINE family TE expansion could partially engineering
Recommended publications
  • Toxin-Like Neuropeptides in the Sea Anemone Nematostella Unravel Recruitment from the Nervous System to Venom
    Toxin-like neuropeptides in the sea anemone Nematostella unravel recruitment from the nervous system to venom Maria Y. Sachkovaa,b,1, Morani Landaua,2, Joachim M. Surma,2, Jason Macranderc,d, Shir A. Singera, Adam M. Reitzelc, and Yehu Morana,1 aDepartment of Ecology, Evolution, and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, Hebrew University of Jerusalem, 9190401 Jerusalem, Israel; bSars International Centre for Marine Molecular Biology, University of Bergen, 5007 Bergen, Norway; cDepartment of Biological Sciences, University of North Carolina at Charlotte, Charlotte, NC 28223; and dBiology Department, Florida Southern College, Lakeland, FL 33801 Edited by Baldomero M. Olivera, University of Utah, Salt Lake City, UT, and approved September 14, 2020 (received for review May 31, 2020) The sea anemone Nematostella vectensis (Anthozoa, Cnidaria) is a to a target receptor in the nervous system of the prey or predator powerful model for characterizing the evolution of genes func- interfering with transmission of electric impulses. For example, tioning in venom and nervous systems. Although venom has Nv1 toxin from Nematostella inhibits inactivation of arthropod evolved independently numerous times in animals, the evolution- sodium channels (12), while ShK toxin from Stichodactyla heli- ary origin of many toxins remains unknown. In this work, we pin- anthus is a potassium channel blocker (13). Nematostella’snem- point an ancestral gene giving rise to a new toxin and functionally atocytes produce multiple toxins with a 6-cysteine pattern of the characterize both genes in the same species. Thus, we report a ShK toxin (7, 9). The ShKT superfamily is ubiquitous across sea case of protein recruitment from the cnidarian nervous to venom anemones (14); however, its evolutionary origin remains unknown.
    [Show full text]
  • Feeding-Dependent Tentacle Development in the Sea Anemone Nematostella Vectensis ✉ Aissam Ikmi 1,2 , Petrus J
    ARTICLE https://doi.org/10.1038/s41467-020-18133-0 OPEN Feeding-dependent tentacle development in the sea anemone Nematostella vectensis ✉ Aissam Ikmi 1,2 , Petrus J. Steenbergen1, Marie Anzo 1, Mason R. McMullen2,3, Anniek Stokkermans1, Lacey R. Ellington2 & Matthew C. Gibson2,4 In cnidarians, axial patterning is not restricted to embryogenesis but continues throughout a prolonged life history filled with unpredictable environmental changes. How this develop- 1234567890():,; mental capacity copes with fluctuations of food availability and whether it recapitulates embryonic mechanisms remain poorly understood. Here we utilize the tentacles of the sea anemone Nematostella vectensis as an experimental paradigm for developmental patterning across distinct life history stages. By analyzing over 1000 growing polyps, we find that tentacle progression is stereotyped and occurs in a feeding-dependent manner. Using a combination of genetic, cellular and molecular approaches, we demonstrate that the crosstalk between Target of Rapamycin (TOR) and Fibroblast growth factor receptor b (Fgfrb) signaling in ring muscles defines tentacle primordia in fed polyps. Interestingly, Fgfrb-dependent polarized growth is observed in polyp but not embryonic tentacle primordia. These findings show an unexpected plasticity of tentacle development, and link post-embryonic body patterning with food availability. 1 Developmental Biology Unit, European Molecular Biology Laboratory, 69117 Heidelberg, Germany. 2 Stowers Institute for Medical Research, Kansas City, MO 64110,
    [Show full text]
  • The Culture, Sexual and Asexual Reproduction, and Growth of the Sea Anemone Nematostella Vectensis
    Reference: BiD!. Bull. 182: 169-176. (April, 1992) The Culture, Sexual and Asexual Reproduction, and Growth of the Sea Anemone Nematostella vectensis CADET HAND AND KEVIN R. UHLINGER Bodega Marine Laboratory, P.O. Box 247, Bodega Bay, California 94923 Abstract. Nematostella vectensis, a widely distributed, water at room temperatures (Stephenson, 1928), and un­ burrowing sea anemone, was raised through successive der the latter conditions some species produce numerous sexual generations at room temperature in non-circulating asexual offspring by a variety of methods (Cary, 1911; seawater. It has separate sexes and also reproduces asex­ Stephenson, 1929). More recently this trait has been used ually by transverse fission. Cultures of animals were fed to produce clones ofgenetically identical individuals use­ Artemia sp. nauplii every second day. Every eight days ful for experimentation; i.e., Haliplanella luciae (by Min­ the culture water was changed, and the anemones were asian and Mariscal, 1979), Aiptasia pulchella (by Muller­ fed pieces of Mytilus spp. tissue. This led to regular Parker, 1984), and Aiptasia pallida (by Clayton and Las­ spawning by both sexes at eight-day intervals. The cultures ker, 1984). We now add one more species to this list, remained reproductive throughout the year. Upon namely Nematostella vectensis Stephenson (1935), a small, spawning, adults release either eggs embedded in a gelat­ burrowing athenarian sea anemone synonymous with N. inous mucoid mass, or free-swimming sperm. In one ex­ pellucida Crowell (1946) (see Hand, 1957). periment, 12 female isolated clonemates and 12 male iso­ Nematostella vectensis is an estuarine, euryhaline lated clonemates were maintained on the 8-day spawning member ofthe family Edwardsiidae and has been recorded schedule for almost 8 months.
    [Show full text]
  • Identification and Description of Chitin and Its Genes in Cnidaria
    Chitin the Good Fight – Identification and Description of Chitin and Its Genes in Cnidaria Lauren Elizabeth Vandepas A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy University of Washington 2018 Reading Committee: Chris T. Amemiya, Chair William E. Browne Adam Lacy-Hulbert Program Authorized to Offer Degree: Biology 1 | P a g e © Copyright 2018 Lauren E. Vandepas 2 | P a g e University of Washington Abstract Chitin the Good Fight – Identification and Description of Chitin and Its Genes in Cnidaria Lauren Elizabeth Vandepas Chair of the Supervisory Committee: Chris T. Amemiya Department of Biology This dissertation explores broad aspects of chitin biology in Cnidaria, with the aim of incorporating glycobiology with evolution and development. Chitin is the second-most abundant biological polymer on earth and is most commonly known in metazoans as a structural component of arthropod exoskeletons. This work seeks to determine whether chitin is more broadly distributed within early-diverging metazoans than previously believed, and whether it has novel non-structural applications in cnidarians. The Cnidaria (i.e., medusae, corals, sea anemones, cubomedusae, myxozoans) comprises over 11,000 described species exhibiting highly diverse morphologies, developmental programs, and ecological niches. Chapter 1 explores the distribution of chitin synthase (CHS) genes across Cnidaria. These genes are present in all classes and are expressed in life stages or taxa that do not have any reported chitinous structures. To further elucidate the biology of chitin in cnidarian soft tissues, in Chapters 2 and 3 I focus on the model sea anemone Nematostella vectensis, which has three chitin synthase genes – each with a unique suite of domains.
    [Show full text]
  • The Starlet Sea Anemone
    The Starlet Sea Anemone I. The starlet sea anemone (Nematostella vectensis)—an “emerging model system” A. The growing literature on Nematostella. A query of the Scientific Citation Index (conducted 06/26/07) identified 74 articles and reviews that contain “nematostella” in the title, keywords, or abstract. The number of such publications is increasing dramatically (Fig. 1a), as are the citations of these papers (Fig. 1b). Much of the Nematostella literature is not yet indexed; we identified another 66 published books, reviews, or articles published prior to the 1990’s that mention Nematostella. An annotated list is housed at http://nematostella.org/Resources_References. A B Figure 1. Nematostella publications (A) and citations (B) by year. B. Nematostella’s Merits as a Model System Nematostella is an estuarine sea anemone that is native to the Atlantic coast of North America. In the early 1990’s, its potential value as a model system for developmental biology was first explicitly recognized by Hand and Uhlinger [1]. Over the last 10 years, its utility has extended far beyond developmental biology due to its informative phylogenetic position, and its amenability to field studies, organismal studies, developmental studies, cellular studies, molecular and biochemical studies, genetic studies, and genomic studies [2]. 1. Phylogenetic relationships. Nematostella is a member of the Cnidaria, one of the oldest metazoan phyla. The Cnidaria is a closely related outgroup to the Bilateria, the evolutionary lineage that comprises >99% of all extant animals (Fig. 3). Comparisons between Nematostella and bilaterians have provided insights into the evolution of key animal innovations, including germ cell specification, bilateral symmetry, mesoderm, and the nervous system [3-7].
    [Show full text]
  • Zootaxa, First Record of the Sea Anemone Nematostella Vectensis
    Zootaxa 2343: 66–68 (2010) ISSN 1175-5326 (print edition) www.mapress.com/zootaxa/ Correspondence ZOOTAXA Copyright © 2010 · Magnolia Press ISSN 1175-5334 (online edition) First record of the sea anemone Nematostella vectensis (Actiniaria: Edwardsiidae) in Southern Hemisphere waters JANINE F. SILVA1,2, CARLOS A. C. LIMA1, CARLOS D. PEREZ2,3 & PAULA B. GOMES1,4 1G.P.A., Universidade Federal Rural de Pernambuco, Laboratório de Ecologia e Conservação de Ecossistemas Marinhos (LECEM), Av. Dom Manoel de Medeiros s/n, Dois Irmãos, Recife - PE, Brasil 2G.P.A., Mestrado em Biologia Animal, Universidade Federal de Pernambuco, Av. Prof. Moraes Rego, s/n, Cidade Universitária, Recife, PE, Brasil 3G.P.A., Universidade Federal de Pernambuco, Campus de Vitória de Santo Antão, Rua Alto do Reservatório, s/n, Centro, Vitória de Santo Antão, PE, Brasil. E-mail: [email protected] 4Corresponding author. E-mail: [email protected] This is the first record of the starlet sea anemone, Nematostella vectensis Stephenson, 1935, in Southern Hemisphere waters. Specimens of N. vectensis were collected in the surroundings of the Port of Recife, Pernambuco, Brazil. The species is native to the Atlantic coast of the United States of America; populations along the Pacific coast of the USA and the coasts of England are the result of anthropogenic introduction, probably associated with ships and boats used in oyster commerce (Sheader et al. 1997; Pearson et al. 2002; Reitzel et al. 2008). The present study extends the latitudinal distribution of this species, and we discuss the presence on the Brazilian coast of this exotic species. Nematostella vectensis is a small (typically less than 1 cm in column length), infaunal sea anemone inhabiting salt marshes, saline lagoons, and other sheltered estuarine environments (Hand and Uhlinger 1992, 1994; Reitzel et al.
    [Show full text]
  • The Marine Jellyfish Model Clytia Hemisphaerica. In: Boutet, A. & B
    The marine jellyfish model Clytia hemisphaerica. In: Boutet, A. & B. Schierwater, eds. Handbook of Established and Emerging Marine Model Organisms in Experimental Biology, CRC Press Sophie Peron, Evelyn Houliston, Lucas Leclère To cite this version: Sophie Peron, Evelyn Houliston, Lucas Leclère. The marine jellyfish model Clytia hemisphaerica. In: Boutet, A. & B. Schierwater, eds. Handbook of Established and Emerging Marine Model Organisms in Experimental Biology, CRC Press. 2021. hal-03173740 HAL Id: hal-03173740 https://hal.archives-ouvertes.fr/hal-03173740 Preprint submitted on 18 Mar 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. The marine jellyfish model Clytia hemisphaerica. Sophie Peron, Evelyn Houliston, Lucas Leclère Sorbonne Université, CNRS, Laboratoire de Biologie du Développement de Villefranche-sur- Mer (LBDV), 06320 Villefranche-sur-Mer, France. 8.1 History of the model 8.1.1 Early studies on Clytia hemisphaerica anatomy and development 8.1.1.1. First descriptions of Clytia embryonic development 8.1.1.2. Clytia as a model for experimental embryology 8.1.1.3. Clytia medusa regeneration 8.1.1.4. Sex determination and the origin of germ cells 8.1.2. Clytia as a model after 2000 8.2 Geographical location 8.3.
    [Show full text]
  • A Novel Regulatory Gene Promotes Novel Cell Fate by Suppressing Ancestral Fate In
    bioRxiv preprint doi: https://doi.org/10.1101/2021.08.29.458124; this version posted August 29, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. 1 Title: A novel regulatory gene promotes novel cell fate by suppressing ancestral fate in 2 the sea anemone Nematostella vectensis 3 4 Authors: Leslie S Babonis1,2, Camille Enjolras1, Joseph F Ryan1,3 and Mark Q Martindale1,3 5 6 Affiliations: 7 1. Whitney Laboratory for Marine Bioscience, University of Florida, St. Augustine, FL 32080 8 2. Department of Ecology and Evolutionary Biology, Cornell University, Ithaca NY 14853 9 (current address) 10 3. Department of Biology, University of Florida, Gainesville, FL 32611 11 12 Corresponding Author: Leslie S Babonis, Department of Ecology and Evolutionary Biology, 13 Cornell University, E145 Corson Hall, Ithaca NY 14853; [email protected]; (808) 347-6562 14 15 Authors Contributions: LSB, CE, JFR, and MQM collected data and performed analyses; LSB 16 conceived of the study and wrote the manuscript; CE, JFR, and MQM edited and approved the 17 manuscript. 18 19 Competing Interests: The authors declare no competing interests. 20 21 Classification: Biological Science, Developmental Biology 22 Keywords: cell identity, novelty, evolution 23 24 This PDF file includes: 25 Main Text 26 Figures 1 to 4 bioRxiv preprint doi: https://doi.org/10.1101/2021.08.29.458124; this version posted August 29, 2021.
    [Show full text]
  • Cellular Pathways During Spawning Induction in the Starlet Sea
    www.nature.com/scientificreports OPEN Cellular pathways during spawning induction in the starlet sea anemone Nematostella vectensis Shelly Reuven1,3, Mieka Rinsky2,3, Vera Brekhman1, Assaf Malik1, Oren Levy2* & Tamar Lotan1* In cnidarians, long-term ecological success relies on sexual reproduction. The sea anemone Nematostella vectensis, which has emerged as an important model organism for developmental studies, can be induced for spawning by temperature elevation and light exposure. To uncover molecular mechanisms and pathways underlying spawning, we characterized the transcriptome of Nematostella females before and during spawning induction. We identifed an array of processes involving numerous receptors, circadian clock components, cytoskeleton, and extracellular transcripts that are upregulated upon spawning induction. Concurrently, processes related to the cell cycle, fatty acid metabolism, and other housekeeping functions are downregulated. Real-time qPCR revealed that light exposure has a minor efect on expression levels of most examined transcripts, implying that temperature change is a stronger inducer for spawning in Nematostella. Our fndings reveal the potential mechanisms that may enable the mesenteries to serve as a gonad-like tissue for the developing oocytes and expand our understanding of sexual reproduction in cnidarians. Sexual reproduction is the predominant mode of procreation in almost all eukaryotes, from fungi and plants to fsh and mammals. It generates the conditions for sexual selection, which is a powerful evolutionary force driving morphological, physiological, and behavioral changes in many species 1,2. Sex is thought to have arisen once and to have been present in the last eukaryotic common ancestor 3–5; therefore, it is an important trait in evolutionary biology.
    [Show full text]
  • Nematostella Vectensis Class: Anthozoa, Hexacorallia
    Phylum: Cnidaria Nematostella vectensis Class: Anthozoa, Hexacorallia Order: Actiniaria, Nynantheae, Athenaria Starlet sea anemone Family: Edwardsiidae Taxonomy: Nematostella vectensis was 1975). There is a single ventral siphonoglyph described by Stephenson in 1935. (Williams 1975). Nematostella pellucida is a synonym (Hand Oral Disc: There is no inner 1957). In the larger taxonomic scale, the ring of tentacles, and there are no subclass Zoantharia has been synonymized siphonoglyphs, on the oral disc. with Hexacorallia (Hoeksema 2015). Tentacles: Tentacles are retractile, cylindrical, and tapered. They are Description not capitate, or knobbed. Though they can Medusa: No medusa stage in Anthozoans vary from 12-18, there are usually 16 Polyp: (Stephenson 1935; Fautin and Hand 2007). Size: The column (Fig. 1) can be up to There are 6-7 outer (exocoelic) tentacles that 15 mm long in the field, but can grow much are longer than inner (endocoelic) tentacles, longer (160 mm) when raised in the and are often reflexed down the column (they laboratory (Hand and Uhlinger 1992; Fautin can be longer than column). The inner and Hand 2007). The maximum diameter is 4 tentacles can be raised above the mouth (Fig. mm at the base near the bulb (physa) (Hand 1), and can have white spots on their inner 1957) and increases to 8 mm at the crown of edges (Crowell 1946). Nematosomes can be tentacles; the diameter is not often this large, seen moving inside the tentacles. and a more average diameter of the column is Mesenteries: Mesenteries are 2.5 mm. vertical partitions (eight in this species) below Color: The anemone is white and the gullet and visible through the column.
    [Show full text]
  • Six Major Steps in Animal Evolution: Are We Derived Sponge Larvae?
    EVOLUTION & DEVELOPMENT 10:2, 241–257 (2008) Six major steps in animal evolution: are we derived sponge larvae? Claus Nielsen Zoological Museum (The Natural History Museum of Denmark, University of Copenhagen), Universitetsparken 15, DK-2100 Copenhagen, Denmark Correspondence (email: [email protected]) SUMMARY A review of the old and new literature on animal became sexually mature, and the adult sponge-stage was morphology/embryology and molecular studies has led me to abandoned in an extreme progenesis. This eumetazoan the following scenario for the early evolution of the metazoans. ancestor, ‘‘gastraea,’’ corresponds to Haeckel’s gastraea. The metazoan ancestor, ‘‘choanoblastaea,’’ was a pelagic Trichoplax represents this stage, but with the blastopore spread sphere consisting of choanocytes. The evolution of multicellularity out so that the endoderm has become the underside of the enabled division of labor between cells, and an ‘‘advanced creeping animal. Another lineage developed a nervous system; choanoblastaea’’ consisted of choanocytes and nonfeeding cells. this ‘‘neurogastraea’’ is the ancestor of the Neuralia. Cnidarians Polarity became established, and an adult, sessile stage have retained this organization, whereas the Triploblastica developed. Choanocytes of the upper side became arranged in (Ctenophora1Bilateria), have developed the mesoderm. The a groove with the cilia pumping water along the groove. Cells bilaterians developed bilaterality in a primitive form in the overarched the groove so that a choanocyte chamber was Acoelomorpha and in an advanced form with tubular gut and formed, establishing the body plan of an adult sponge; the pelagic long Hox cluster in the Eubilateria (Protostomia1Deuterostomia). larval stage was retained but became lecithotrophic. The It is indicated that the major evolutionary steps are the result of sponges radiated into monophyletic Silicea, Calcarea, and suites of existing genes becoming co-opted into new networks Homoscleromorpha.
    [Show full text]
  • The Starlet Sea Anemone, Nematostella Vectensis John A
    My favorite animal Rising starlet: the starlet sea anemone, Nematostella vectensis John A. Darling, Adam R. Reitzel, Patrick M. Burton, Maureen E. Mazza, Joseph F. Ryan, James C. Sullivan, and John R. Finnerty* Summary were chosen primarily for their convenience to researchers in In recent years, a handful of model systems from the basal one particular discipline, the model organisms of tomorrow will metazoan phylum Cnidaria have emerged to challenge long-held views on the evolution of animal complexity. be selected for their ability to address questions that cut across The most-recent, and in many ways most-promising the boundaries of traditional disciplines, integrating molecular, addition to this group is the starlet sea anemone, organismal and ecological studies. A premium will also be Nematostella vectensis. The remarkable amenability of placed on choosing model systems for their phylogenetic this species to laboratory manipulation has already made informativeness, so that they might serve as a complement to it a productive system for exploring cnidarian develop- existing model systems in reconstructing evolutionary history. ment, and a proliferation of molecular and genomic tools, including the currently ongoing Nematostella genome One recent reflection of this strategic shift is the growing project, further enhances the promise of this species. In interest in outgroups to the Bilateria. If we are to understand addition, the facility with which Nematostella populations the origin of developmental processes and genetic architec- can be investigated within their natural ecological context ture that underlie the diversity and complexity of Bilaterian suggests that this model may be profitably expanded to address important questions in molecular and evolu- animals, then we must understand the ancestral Bilaterian tionary ecology.
    [Show full text]