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Vannier J, Aria C, Taylor RS, Caron JB. Waptia fieldensis Walcott, a mandibulate arthropod from the middle Cambrian Burgess Shale. ROYAL SOCIETY OPEN SCIENCE 2018; 5:172206. [PMID: 30110460 PMCID: PMC6030330 DOI: 10.1098/rsos.172206] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 05/04/2018] [Indexed: 05/12/2023]
Abstract
Waptia fieldensis Walcott, 1912 is one of the iconic animals from the middle Cambrian Burgess Shale biota that had lacked a formal description since its discovery at the beginning of the twentieth century. This study, based on over 1800 specimens, finds that W. fieldensis shares general characteristics with pancrustaceans, as previous authors had suggested based mostly on its overall aspect. The cephalothorax is covered by a flexible, bivalved carapace and houses a pair of long multisegmented antennules, palp-bearing mandibles, maxillules, and four pairs of appendages with five-segmented endopods-the anterior three pairs with long and robust enditic basipods, the fourth pair with proximal annulations and lamellae. The post-cephalothorax has six pairs of lamellate and fully annulated appendages which appear to be extensively modified basipods rather than exopods. The front part of the body bears a pair of stalked eyes with the first ommatidia preserved in a Burgess Shale arthropod, and a median 'labral' complex flanked by lobate projections with possible affinities to hemi-ellipsoid bodies. Waptia confirms the mandibulate affinity of hymenocarines, retrieved here as part of an expanded Pancrustacea, thereby providing a novel perspective on the evolutionary history of this hyperdiverse group. We construe that Waptia was an active swimming predator of soft prey items, using its anterior appendages for food capture and manipulation, and also potentially for clinging to epibenthic substrates.
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Affiliation(s)
- Jean Vannier
- Université de Lyon, Université Lyon 1, ENS de Lyon, CNRS, UMR 5276 LGL-TPE, Bâtiment Géode, 2, rue Raphaël Dubois, Villeurbanne 69622, France
| | - Cédric Aria
- State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, 39, East Beijing Road, Nanjing 210008, People's Republic of China
- Department of Natural History (Palaeobiology Section), Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, CanadaM5S 2C6
| | - Rod S. Taylor
- Manuels River Hibernia Interpretation Centre, 7 Conception Bay South Highway, CBS, Newfoundland, CanadaA1W 3A2
- Department of Earth Sciences, Memorial University of Newfoundland, St John's, Newfoundland, CanadaA1B 3X5
| | - Jean-Bernard Caron
- Department of Natural History (Palaeobiology Section), Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, CanadaM5S 2C6
- Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, CanadaM5S 3B2, Toronto, Ontario, CanadaM5S 3B2
- Department of Earth Sciences, University of Toronto, Toronto, Ontario, CanadaM5S 3B1
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Braun K, Stach T. Structure and ultrastructure of eyes and brains of Thalia democratica (Thaliacea, Tunicata, Chordata). J Morphol 2017; 278:1421-1437. [PMID: 28691238 DOI: 10.1002/jmor.20722] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 05/23/2017] [Accepted: 06/12/2017] [Indexed: 12/18/2022]
Abstract
Salps are marine planktonic chordates that possess an obligatory alternation of reproductive modes in subsequent generations. Within tunicates, salps represent a derived life cycle and are of interest in considerations of the evolutionary origin of complex anatomical structures and life history strategies. In the present study, the eyes and brains of both the sexual, aggregate blastozooid and the asexual, solitary oozooid stage of Thalia democratica (Forskål, ) were digitally reconstructed in detail based on serial sectioning for light and transmission electron microscopy. The blastozooid stage of T. democratica possesses three pigment cup eyes, situated in the anterior ventral part of the brain. The eyes are arranged in a way that the optical axes of each eye point toward different directions. Each eye is an inverse eye that consists of two different cell types: pigment cells (pigc) and rhabdomeric photoreceptor cells (prcs). The oozooid stage of T. democratica is equipped with a single horseshoe-shaped eye, positioned in the anterior dorsal part of the brain. The opening of the horseshoe-shaped eye points anteriorly. Similar to the eyes of the blastozooid, the eye of the oozooid consists of pigment cells and rhabdomeric photoreceptor cells. The rhabdomeric photoreceptor cells possess apical microvilli that form a densely packed presumably photosensitive receptor part adjacent to the concave side of the pigc. We suggest correspondences of the individual eyes in the blastozooid stage to respective parts of the single horseshoe-shaped eye in the oozooid stage and hypothesize that the differences in visual structures and brain anatomies evolved as a result of the aggregate life style of the blastozooid as opposed to the solitary life style of the oozooid.
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Affiliation(s)
- Katrin Braun
- Humboldt-Universität zu Berlin, Institut für Biologie, Vergleichende Zoologie, Philippstrasse 13, Haus 2, Berlin, 10115, Germany
| | - Thomas Stach
- Humboldt-Universität zu Berlin, Institut für Biologie, Molekulare Parasitologie, Philippstrasse 13, Haus 14, Berlin, 10115, Germany
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Frase T, Richter S. Nervous system development in the fairy shrimpBranchinellasp. (Crustacea: Branchiopoda: Anostraca): Insights into the development and evolution of the branchiopod brain and its sensory organs. J Morphol 2016; 277:1423-1446. [DOI: 10.1002/jmor.20585] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 07/22/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Thomas Frase
- Universität Rostock, Institut für Biowissensschaften, Allgemeine und Spezielle Zoologie, Universitätsplatz 2; D-18055 Rostock Germany
| | - Stefan Richter
- Universität Rostock, Institut für Biowissensschaften, Allgemeine und Spezielle Zoologie, Universitätsplatz 2; D-18055 Rostock Germany
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Böhm A, Pass G. The ocelli of Archaeognatha (Hexapoda): Functional morphology, pigment migration and chemical nature of the reflective tapetum. J Exp Biol 2016; 219:3039-3048. [DOI: 10.1242/jeb.141275] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/18/2016] [Indexed: 01/03/2023]
Abstract
The ocelli of Archaeognatha, or jumping bristletails, differ from typical insect ocelli in shape and field of view. While the shape of the lateral ocelli is highly variable among species, most Machiloidea have sole shaped lateral ocelli beneath the compound eyes and a median ocellus that is oriented downward. This study investigated morphological and physiological aspects of the ocelli of Machilis hrabei and Lepismachilis spp.
The light reflecting ocellar tapetum in Machilis hrabei is made up by xanthine nanocrystals, as demonstrated by confocal Raman spectroscopy. Pigment granules in the photoreceptor cells move behind the tapetum in the dark adapted state. Such a vertical pigment migration in combination with a tapetum has not been described for any insect ocellus so far. The pigment migration has a dynamic range of around 4 log units and is maximally sensitive to green light. Adaptation from darkness to bright light lasts over an hour, which is slow compared to the radial pupil mechanism in some dragonflies and locusts.
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Fritsch M, Kaji T, Olesen J, Richter S. The development of the nervous system in Laevicaudata (Crustacea, Branchiopoda): insights into the evolution and homologies of branchiopod limbs and ‘frontal organs’. ZOOMORPHOLOGY 2012. [DOI: 10.1007/s00435-012-0173-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Ma X, Hou X, Aldridge RJ, Siveter DJ, Siveter DJ, Gabbott SE, Purnell MA, Parker AR, Edgecombe GD. Morphology of Cambrian lobopodian eyes from the Chengjiang Lagerstätte and their evolutionary significance. ARTHROPOD STRUCTURE & DEVELOPMENT 2012; 41:495-504. [PMID: 22484085 DOI: 10.1016/j.asd.2012.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/21/2012] [Accepted: 03/22/2012] [Indexed: 05/31/2023]
Abstract
Visual organs are widely distributed throughout the animal kingdom and exhibit a great diversity of morphologies. Compound eyes consisting of numerous visual units (ommatidia) are the oldest preserved visual systems of arthropods, but their origins are obscure and hypothetical models for their evolution have been difficult to test in the absence of unequivocal fossil evidence. Here we reveal the detailed eye structures of well-preserved Early Cambrian lobopodians Luolishania longicruris and Hallucigenia fortis from the Chengjiang Lagerstätte, China. These animals possess a pair of eyes composed of at least two visual units, interpreted as pigment cups. Contrary to previous suggestions that Cambrian lobopodians possessed ocellus-like eyes comparable to those of extant onychophorans, this multi-component structure is more similar to the lateral eyes of arthropods. Morphological comparison and phylogenetic analyses indicate that these lobopodian eyes may represent an early stage in the evolution of the ancestral visual system of euarthropods.
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Affiliation(s)
- Xiaoya Ma
- Yunnan Key Laboratory for Palaeobiology, Yunnan University, 2 North Cuihu Road, Kunming 650091, China.
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Weiss LC, Tollrian R, Herbert Z, Laforsch C. Morphology of theDaphnianervous system: A comparative study onDaphnia pulex,Daphnia lumholtzi, andDaphnia longicephala. J Morphol 2012; 273:1392-405. [DOI: 10.1002/jmor.20068] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 06/25/2012] [Accepted: 06/26/2012] [Indexed: 11/10/2022]
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Fritsch M, Richter S. Nervous system development in Spinicaudata and Cyclestherida (Crustacea, Branchiopoda)--comparing two different modes of indirect development by using an event pairing approach. J Morphol 2012; 273:672-95. [PMID: 22460765 DOI: 10.1002/jmor.20014] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2011] [Revised: 12/15/2011] [Accepted: 01/29/2012] [Indexed: 11/09/2022]
Abstract
Cladocera are the ecologically most important group within the Branchiopoda. They are unquestionably branchiopods but their evolutionary origin remains unclear. One favored explanation of their origin is that they evolved from a reproductive larva of a clam shrimp-like ancestor. To reveal a transformation and identify (potential) changes in chronology (heterochrony), we investigated and compared the development of representatives of two clam shrimp taxa, one of the Spinicaudata (Leptestheria dahalacensis) and one of the Cyclestherida (Cyclestheria hislopi), the sister group of Cladocera. Both taxa develop indirectly although the exact modes are quite different. The development of the nervous system, labeled and analyzed using immunohistochemical techniques and confocal microscopy, and that of the external morphology, scanned with an electron microscope, was investigated. L. dahalacensis hatch as a free-swimming nauplius and the nervous system and external morphology develop gradually. In C. hislopi, on the other hand, several internal and external structures develop before the hatching of a nonswimming embryo-like larva which is still carried in a dorsal brood pouch. The development in L. dahalacensis is directed from anterior to posterior, whereas in C. hislopi a more synchronous anterior and posterior differentiation is present. A comparison of both developmental sequences gives us the first indications of the evolutionary transformation which the Cladocera may have undergone from a clam shrimp-like ancestor.
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Affiliation(s)
- Martin Fritsch
- Universitaet Rostock, Institut für Biowissensschaften, Allgemeine und Spezielle Zoologie, Universitaetsplatz 2, D-18055 Rostock, Germany.
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Richter S, Loesel R, Purschke G, Schmidt-Rhaesa A, Scholtz G, Stach T, Vogt L, Wanninger A, Brenneis G, Döring C, Faller S, Fritsch M, Grobe P, Heuer CM, Kaul S, Møller OS, Müller CHG, Rieger V, Rothe BH, Stegner MEJ, Harzsch S. Invertebrate neurophylogeny: suggested terms and definitions for a neuroanatomical glossary. Front Zool 2010; 7:29. [PMID: 21062451 PMCID: PMC2996375 DOI: 10.1186/1742-9994-7-29] [Citation(s) in RCA: 232] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2010] [Accepted: 11/09/2010] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Invertebrate nervous systems are highly disparate between different taxa. This is reflected in the terminology used to describe them, which is very rich and often confusing. Even very general terms such as 'brain', 'nerve', and 'eye' have been used in various ways in the different animal groups, but no consensus on the exact meaning exists. This impedes our understanding of the architecture of the invertebrate nervous system in general and of evolutionary transformations of nervous system characters between different taxa. RESULTS We provide a glossary of invertebrate neuroanatomical terms with a precise and consistent terminology, taxon-independent and free of homology assumptions. This terminology is intended to form a basis for new morphological descriptions. A total of 47 terms are defined. Each entry consists of a definition, discouraged terms, and a background/comment section. CONCLUSIONS The use of our revised neuroanatomical terminology in any new descriptions of the anatomy of invertebrate nervous systems will improve the comparability of this organ system and its substructures between the various taxa, and finally even lead to better and more robust homology hypotheses.
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Affiliation(s)
- Stefan Richter
- Universität Rostock, Institut für Biowissenschaften, Abteilung für Allgemeine und Spezielle Zoologie, Universitätsplatz 2, D-18055 Rostock, Germany
| | - Rudi Loesel
- RWTH Aachen, Institute of Biology II, Department of Developmental Biology and Morphology of Animals, Mies-van-der-Rohe-Straße 15, D-52056 Aachen, Germany
| | - Günter Purschke
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Zoologie, Barbarastraße 11,, D-49069 Osnabrück, Germany
| | - Andreas Schmidt-Rhaesa
- Biozentrum Grindel/Zoological Museum, Martin-Luther-King-Platz 3, D-20146 Hamburg, Germany
| | - Gerhard Scholtz
- Humboldt-Universität zu Berlin, Institut für Biologie - Vergleichende Zoologie, Philippstraße 13, D-10115 Berlin, Germany
| | - Thomas Stach
- Freie Universität Berlin, Zoologie - Systematik und Evolutionsforschung, Königin-Luise-Straße 1-3, D-14195 Berlin, Germany
| | - Lars Vogt
- Universität Bonn, Institut für Evolutionsbiologie und Ökologie, An der Immenburg 1, D-53121 Bonn, Germany
| | - Andreas Wanninger
- University of Copenhagen, Department of Biology, Research Group for Comparative Zoology, Universitetsparken 15, DK-2100 Copenhagen, Denmark
| | - Georg Brenneis
- Universität Rostock, Institut für Biowissenschaften, Abteilung für Allgemeine und Spezielle Zoologie, Universitätsplatz 2, D-18055 Rostock, Germany
- Humboldt-Universität zu Berlin, Institut für Biologie - Vergleichende Zoologie, Philippstraße 13, D-10115 Berlin, Germany
| | - Carmen Döring
- Universität Osnabrück, Fachbereich Biologie/Chemie, AG Zoologie, Barbarastraße 11,, D-49069 Osnabrück, Germany
| | - Simone Faller
- RWTH Aachen, Institute of Biology II, Department of Developmental Biology and Morphology of Animals, Mies-van-der-Rohe-Straße 15, D-52056 Aachen, Germany
| | - Martin Fritsch
- Universität Rostock, Institut für Biowissenschaften, Abteilung für Allgemeine und Spezielle Zoologie, Universitätsplatz 2, D-18055 Rostock, Germany
| | - Peter Grobe
- Universität Bonn, Institut für Evolutionsbiologie und Ökologie, An der Immenburg 1, D-53121 Bonn, Germany
| | - Carsten M Heuer
- RWTH Aachen, Institute of Biology II, Department of Developmental Biology and Morphology of Animals, Mies-van-der-Rohe-Straße 15, D-52056 Aachen, Germany
| | - Sabrina Kaul
- Freie Universität Berlin, Zoologie - Systematik und Evolutionsforschung, Königin-Luise-Straße 1-3, D-14195 Berlin, Germany
| | - Ole S Møller
- Universität Rostock, Institut für Biowissenschaften, Abteilung für Allgemeine und Spezielle Zoologie, Universitätsplatz 2, D-18055 Rostock, Germany
| | - Carsten HG Müller
- Ernst-Moritz-Arndt-Universität Greifswald, Zoologisches Institut, Cytologie und Evolutionsbiologie, Johann-Sebastian-Bach-Straße 11/12, D-17487 Greifswald, Germany
| | - Verena Rieger
- Ernst-Moritz-Arndt-Universität Greifswald, Zoologisches Institut, Cytologie und Evolutionsbiologie, Johann-Sebastian-Bach-Straße 11/12, D-17487 Greifswald, Germany
| | - Birgen H Rothe
- Biozentrum Grindel/Zoological Museum, Martin-Luther-King-Platz 3, D-20146 Hamburg, Germany
| | - Martin EJ Stegner
- Universität Rostock, Institut für Biowissenschaften, Abteilung für Allgemeine und Spezielle Zoologie, Universitätsplatz 2, D-18055 Rostock, Germany
| | - Steffen Harzsch
- Ernst-Moritz-Arndt-Universität Greifswald, Zoologisches Institut, Cytologie und Evolutionsbiologie, Johann-Sebastian-Bach-Straße 11/12, D-17487 Greifswald, Germany
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Schwentner M, Timms BV, Bastrop R, Richter S. Phylogeny of Spinicaudata (Branchiopoda, Crustacea) based on three molecular markers – An Australian origin for Limnadopsis. Mol Phylogenet Evol 2009; 53:716-25. [DOI: 10.1016/j.ympev.2009.07.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2009] [Revised: 06/16/2009] [Accepted: 07/23/2009] [Indexed: 11/16/2022]
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Lacalli TC. Serial EM analysis of a copepod larval nervous system: Naupliar eye, optic circuitry, and prospects for full CNS reconstruction. ARTHROPOD STRUCTURE & DEVELOPMENT 2009; 38:361-375. [PMID: 19376268 DOI: 10.1016/j.asd.2009.04.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2009] [Revised: 04/07/2009] [Accepted: 04/08/2009] [Indexed: 05/27/2023]
Abstract
The medial eye and optic center of the first nauplius of Dactylopusia (=Dactylopodia) tisboides, a harpacticoid copepod, were reconstructed from serial EM micrographs. Axons from the eye project to a set of matching cartridges defined by glial cells processes, and input is then processed in sequence through two synaptic fields. A single class of local relay neurons provides the main pathway between these, subject to modulatory input from a class of densely stained neurons with distinctive dense terminals. The importance of other outside sources of synaptic input to the second synaptic field indicates that the latter is a major site for integrating the optic input with signals originating elsewhere in the CNS. This accords with physiological data on the shadow response in barnacles, whose visual system is also derived from a naupliar eye. With a body length of ca. 80microns, copepod larvae like that of Dactylopusia are arguably among the smallest functional metazoans with a complex nervous system. Hence they are promising subjects for full reconstruction of neural circuitry at the EM level that could, in principle, reveal where key decision-making functions are localized.
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