DOCSLIB.ORG

Zoology Manual II

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Zoology Manual II Zoology II 6. Present the preserved cnidaria on a tray or the model/transparencies. Ask what the skin of the cnidaria is like. Have the children verbally describe their observations. Explain that there are two layers to the skin of the cnidaria, the ectoderm and the endoderm. 7. The skeleton is an outer layer of tough, transparent perisarc. It supports and protects the cnidaria. 8. Circulation occurs through the movement of fluid between two tissue layers (ectoderm and endoderm) that circulate the food to each cell. 9. Respiration has no structural specialization, but occurs through diffusion between cell and the water. 10. Reproduction is sophisticated. Labeled ‘alternation of generations’, the two generations are the hydroid and the medusa. The hydroid reproduces asexually; its offspring is the medusa. The medusa reproduces sexually; its offspring is the hydroid. 11. Lay out the pictures of the main characteristics / internal parts of the cnidaria. Distribute the labels for the children to read and to match to the appropriate pictures. Read the definitions and allow the children to match the definitions to the pictures and labels. 12. Present the booklet and display the wall chart. Montessori Research and Development © 2004 33 Zoology II Activities: 1. Allow the children to sit and observe the anemone. 2. Allow the children to dissect or examine the slide of the hydra under a microscope. 3. The children should make their own booklets, tracing or drawing the pictures and writing the definitions. 4. Visit an aquarium or marine biology museum to see anemones or hydra. NOTE: It is advised that the presentation be divided over several days: Days 1-5 Observe the live anemone Observe the preserved hydra Days 6-8 Dissect the hydra / view model and transparencies Days 9-10 Introduce the pictures and labels, the booklet and wall chart NOTE ALSO: Greek: knide - nettle koilos - hollow enteron - intestine Montessori Research and Development © 2004 34 Zoology II Presentation 2: Life Cycle of the Jellyfish 1. Show the life cycle of the jellyfish to the children. 2. Name the parts of the life cycle of the jellyfish: A. Sexual Reproduction: adult medusa, gamete (egg or sperm), blastula, planula larva, polyp, bud, immature medusa, adult medusa. B. Asexual Reproduction: polyp, bud, asexual larva, polyp. 3. Discuss the life cycle of the jellyfish: A. Sexual Reproduction - The adult jellyfish contains either eggs or sperm in gonads. Some species have both eggs and sperm in one individual. B. The Adult Medusa - The adult medusa releases eggs or sperm from the gonads into the water. The gonads are located along the radial canals. C. The Gamete - The gamete is the egg or sperm released by the adult medusa into the water. The egg and sperm unite to form the blastula. D. The Blastula - The blastula is the microscopic fertilized egg. E. The Planula Larva - The planula larva is free-swimming, using cilia to swim through the water. The planula larva is solid with no mouth. The planula larva metamorphoses into the polyp. F. The Polyp - The polyp settles on a hard surface and remains anchored to the hard surface through the winter. The polyp reproduces asexually by budding to produce a colony of polyps. In the spring, the polyps reproduce asexually to form stacks of tiny, swimming, immature medusae called ephyra. Montessori Research and Development © 2004 35 Zoology II G . The Immature Medusa - The immature medusa grows and develops into the adult medusa. 4. Discuss another life cycle of the jellyfish. A. Asexual Reproduction - The jellyfish polyp reproduces by itself without exchanging any genetic material with another polyp. B. The Polyp - The polyp settles on a hard surface and remains anchored to the hard surface through the winter. The polyp reproduces asexually by budding to produce a colony of polyps. C. The Bud - The bud forms on the side of the polyp and separates from the polyp to become the asexual larva. D. The Asexual Larva - The asexual larva grows and develops into a polyp. 5. Encourage each child to repeat the functions of the parts of the life cycle of the jellyfish. 6. Lay out the pictures of the life cycle of the jellyfish in a circle with the adult jellyfish at the top center and going clockwise. 7. Distribute the labels for the children to match to the pictures. 8. When the children know the definitions of the parts of the life cycle of the jellyfish, distribute the definitions for the children to read and to match to the pictures. 9. Display the chart of the life cycle. 10. Place The Jellyfish Life Cycle classified nomenclature material on the shelf. 11. Place The Jellyfish Life Cycle booklet on the shelf. Montessori Research and Development © 2004 36 Zoology II 12. Follow-up activities for the child: A. Match the picture and label. (simple nomenclature) B. Match the picture, label, and definition. (classified nomenclature) C. Make a booklet of The Jellyfish Life Cycle. D. Make a chart of The Jellyfish Life Cycle. E. Repeat the above procedure for the sea anemone and coral. Montessori Research and Development © 2004 37 Zoology II Presentation 3: Internal Parts of the Sea Anemone - Detailed 1. Show the picture of the internal parts of the sea anemone to the children. 2. Name the internal parts of the sea anemone: oral disk, siphonoglyphs, sphincter muscles, mouth, pharynx, gastrovascular cavity, ectoderm, mesoglea, endoderm, mesentery, retractor muscles, mesenteric filaments, gonads, and basal disk. 3. Discuss the internal parts of the sea anemone. A. The Internal Parts of the Sea Anemone - The internal parts of the sea anemone are oral disk, siphonoglyphs, sphincter muscles, mouth, pharynx, gastrovascular cavity, ectoderm, mesoglea, endoderm, mesentery, retractor muscles, mesenteric filaments, gonads, and basal disk. B. The Oral Disk - The oral disk is the disk around the mouth. The oral disk extends inwards to produce the tubular gullet or pharynx. The tentacles are attached to the oral disk. C. The Siphonoglyphs - The siphonoglyphs are two grooves located in the oral disk. The siphonoglyphs have many cilia which move water, oxygen, and food particles through the pharynx and gastrovascular cavity. D. The Sphincter Muscles - The sphincter muscles contract and expand the oral disk and the tentacles. E. The Mouth - The mouth is in the center of the oral disk and is surrounded by tentacles. Water, oxygen, and food particles enter the sea anemone through the mouth. The mouth also squirts out the waste material and acts as the anus in the sea anemone. Montessori Research and Development © 2004 38 Zoology II F. The Pharynx - The pharynx is the tubular connection between the mouth and the gastrovascular cavity of the sea anemone. The siphonoglyphs move water, oxygen, and food particles from the mouth, through the pharynx, and into the gastrovascular cavity. Internal fluid pressure in the pharynx and gastrovascular cavity help to keep the upright shape of the sea anemone. G . The Gastrovascular Cavity - The gastrovascular cavity is the digestive system of the sea anemone. The cilia of the siphonoglyphs move the water, oxygen, and food particles through the gastrovascular cavity. Radial canals distribute dissolved oxygen and carbon dioxide from the gastrovascular cavity to the outside layers of the sea anemone. H. The Ectoderm - The ectoderm is the outside layer of cells of the sea anemone. I. The Mesoglea - The mesoglea is the jelly-like substance between the ectoderm and the endoderm of the sea anemone. The mesoglea is a matrix of elastic collagen fibers that gives the shape to the sea anemone and cements the ectoderm and endoderm together. The mesoglea can also change the body shape. J. The Endoderm - The endoderm is the inside layer of cells of the sea anemone. The endoderm forms the lining of the gastrovascular cavity. K. The Mesentery - The mesentery forms internal partitions in the gastrovascular cavity. The mesentery usually occurs in arrays of multiples of six mesenteries. Montessori Research and Development © 2004 39 Zoology II L. The Retractor Muscles - The retractor muscles are longitudinal muscles that are anchored in the mesoglea. The retractor muscles retract the tentacles. The retractor muscles retract the mesoglea for movement from place to place. M. The Mesenteric Filaments - The mesenteric filaments are attached to the gonads. Sperm and fertilized eggs are released through the mesenteric filaments and out through the mouth. N. The Gonads - The gonads contain the eggs and sperm of the sea anemone. The sperm are released through the mesenteric filaments. The eggs are held in the gonads until fertilization occurs. Once the eggs are fertilized, they are released through the mesenteric filaments. Some sea anemones are hermaphrodites, containing both eggs and sperm, while others have separate sexes. Sea anemones do not fertilize their own eggs. O. The Basal Disk - The basal or pedal disk is the point of attachment of the sea anemone to a surface such as a rock or coral reef. The sea anemone can reproduce by splitting of the basal disk. 4. Encourage each child to repeat the function of the internal parts of the sea anemone. 5. Lay out the pictures of the internal parts of the sea anemone from left to right. 6. Distribute the labels for the children to match to the pictures. 7. When the children know the definitions of the internal parts of the sea anemone, distribute the definitions for the children to read and to match to the pictures. Montessori Research and Development © 2004 40 Zoology II 8. Display the wall chart. 9. Place The Internal Parts of the Sea Anemone classified nomenclature material on the shelf. 10. Place The Internal Parts of the Sea Anemone booklet on the shelf. 11. Follow-up activities for the child: A.
Load more

Recommended publications
  • The Polyp and the Medusa Life on the Move
    The Polyp and the Medusa Life on the Move Millions of years ago, unlikely pioneers sparked a revolution. Cnidarians set animal life in motion. So much of what we take for granted today began with Cnidarians. FROM SHAPE OF LIFE The Polyp and the Medusa Life on the Move Take a moment to follow these instructions: Raise your right hand in front of your eyes. Make a fist. Make the peace sign with your first and second fingers. Make a fist again. Open your hand. Read the next paragraph. What you just did was exhibit a trait we associate with all animals, a trait called, quite simply, movement. And not only did you just move your hand, but you moved it after passing the idea of movement through your brain and nerve cells to command the muscles in your hand to obey. To do this, your body needs muscles to move and nerves to transmit and coordinate movement, whether voluntary or involuntary. The bit of business involved in making fists and peace signs is pretty complex behavior, but it pales by comparison with the suites of thought and movement associated with throwing a curve ball, walking, swimming, dancing, breathing, landing an airplane, running down prey, or fleeing a predator. But whether by thought or instinct, you and all animals except sponges have the ability to move and to carry out complex sequences of movement called behavior. In fact, movement is such a basic part of being an animal that we tend to define animalness as having the ability to move and behave.
    [Show full text]
  • Cassiopea Xamachana (Upside-Down Jellyfish)
    UWI The Online Guide to the Animals of Trinidad and Tobago Ecology Cassiopea xamachana (Upside-down Jellyfish) Order: Rhizostomeae (Eight-armed Jellyfish) Class: Scyphozoa (Jellyfish) Phylum: Cnidaria (Corals, Sea Anemones and Jellyfish) Fig. 1. Upside-down jellyfish, Cassiopea xamachana. [http://images.fineartamerica.com/images-medium-large/upside-down-jellyfish-cassiopea-sp-pete-oxford.jpg, downloaded 9 March 2016] TRAITS. Cassiopea xamachana, also known as the upside-down jellyfish, is quite large with a dominant medusa (adult jellyfish phase) about 30cm in diameter (Encyclopaedia of Life, 2014), resembling more of a sea anemone than a typical jellyfish. The name is associated with the fact that the umbrella (bell-shaped part) settles on the bottom of the sea floor while its frilly tentacles face upwards (Fig. 1). The saucer-shaped umbrella is relatively flat with a well-defined central depression on the upper surface (exumbrella), the side opposite the tentacles (Berryman, 2016). This depression gives the jellyfish the ability to stick to the bottom of the sea floor while it pulsates gently, via a suction action. There are eight oral arms (tentacles) around the mouth, branched elaborately in four pairs. The most commonly seen colour is a greenish grey-blue, due to the presence of zooxanthellae (algae) embedded in the mesoglea (jelly) of the body, and especially the arms. The mobile medusa stage is dioecious, which means that there are separate males and females, although there are no features which distinguish the sexes. The polyp stage is sessile (fixed to the substrate) and small (Sterrer, 1986). UWI The Online Guide to the Animals of Trinidad and Tobago Ecology DISTRIBUTION.
    [Show full text]
  • PROGRAMME ABSTRACTS AGM Papers
    The Palaeontological Association 63rd Annual Meeting 15th–21st December 2019 University of Valencia, Spain PROGRAMME ABSTRACTS AGM papers Palaeontological Association 6 ANNUAL MEETING ANNUAL MEETING Palaeontological Association 1 The Palaeontological Association 63rd Annual Meeting 15th–21st December 2019 University of Valencia The programme and abstracts for the 63rd Annual Meeting of the Palaeontological Association are provided after the following information and summary of the meeting. An easy-to-navigate pocket guide to the Meeting is also available to delegates. Venue The Annual Meeting will take place in the faculties of Philosophy and Philology on the Blasco Ibañez Campus of the University of Valencia. The Symposium will take place in the Salon Actos Manuel Sanchis Guarner in the Faculty of Philology. The main meeting will take place in this and a nearby lecture theatre (Salon Actos, Faculty of Philosophy). There is a Metro stop just a few metres from the campus that connects with the centre of the city in 5-10 minutes (Line 3-Facultats). Alternatively, the campus is a 20-25 minute walk from the ‘old town’. Registration Registration will be possible before and during the Symposium at the entrance to the Salon Actos in the Faculty of Philosophy. During the main meeting the registration desk will continue to be available in the Faculty of Philosophy. Oral Presentations All speakers (apart from the symposium speakers) have been allocated 15 minutes. It is therefore expected that you prepare to speak for no more than 12 minutes to allow time for questions and switching between presenters. We have a number of parallel sessions in nearby lecture theatres so timing will be especially important.
    [Show full text]
  • Glossary - Zoology - Intro
    1 Glossary - Zoology - Intro Abdomen: Posterior part of an arthropoda’ body; in vertebrates: abdomen between thorax and pelvic girdle. Acoelous: See coelom. Amixia: A restriction that prevents general intercrossing in a species leading to inbreeding. Anabiosis: Resuscitation after apparent death. Archenteron: See coelom. Aulotomy: Capacity of separating a limb; followed by regeneration; used also for asexual reproduction; see also fissipary (in echinodermata and platyhelminthes). Basal Lamina: Basal plate of developing neural tube; the noncellular, collagenous layer that separates an epithelium from an underlying layer of tissue; also basal membrane. Benthic: Organisms that live on ocean bottoms. Blastocoel: See coelom. Blastula: Stage of embryonic development, at / near the end of cleavage, preceding gastrulation; generally consisting of a hollow ball of cells (coeloblastula); if no blastoceol is present it is termed stereoblastulae (arise from isolecithal and moderately telolecithal ova); in meroblastic cleavage (only the upper part of the zygote is divided), the blastula consists of a disc of cells lying on top of the yolk mass; the blastocoel is reduced to the space separating the cells from the yolk mass. Blastoporus: The opening into the archenteron (the primitive gastric cavity of the gastrula = gastrocoel) developed by the invagination of the blastula = protostoma. Cephalisation: (Gk. kephale, little head) A type of animal body plan or organization in which one end contains a nerve-rich region and functions as a head. Cilium: (pl. cilia, long eyelash) A short, centriole-based, hairlike organelle: Rows of cilia propel certain protista. Cilia also aid the movement of substances across epithelial surfaces of animal cells. Cleavage: The zygote undergoes a series of rapid, synchronous mitotic divisions; results in a ball of many cells.
    [Show full text]
  • FAU Institutional Repository
    FAU Institutional Repository http://purl.fcla.edu/fau/fauir This paper was submitted by the faculty of FAU’s Harbor Branch Oceanographic Institute. Notice: ©1999 Academic Press. This manuscript is an author version with the final publication available and may be cited as: Young, C. M. (1999). Marine invertebrate larvae. In E. Knobil & J. D. Neill (eds.), Encyclopedia of Reproduction, 3. (pp. 89-97). London, England, and San Diego, CA: Academic Press. --------1111------- Marine Invertebrate Larvae Craig M. Young Harbor Branch Oceanographic Institution 1. What Is a Larva? metamorphOSiS Morphological and physiological changes II. The Production of Larvae that occur during the transition from the larval phase to iII. Larval forms and Diversity the juvenile phase: often coincides with settlement in ben­ IV. Larval Feeding and Nutrition thic species. V. Larval Orientation, Locomotion, Dispersal, and mixed development A developmental mode that includes a Mortality brooded or encapsulated embryonic stage as well as a free­ VI. Larval Settlement and Metamorphosis swimming larval stage. VlI. Ecological and Evolutionary Significance of Larvae planktotrophic larva A feeding larva that obtains at least part VlIl. Economic and Medical Importance of Larvae of its nutritional needs from either particulate or dissolved exogenous sources. Planktotrophic larvae generally hatch from small, transparent eggs. GLOSSARY settlement The permanent transition of a larva from the plankton to the benthos. In sessile organisms, settlement atrochal larva A uniformly ciliated larva (cilia not arranged is marked by adhesion to the substratum. It is often closely in distinct bands). associated with metamorphosis and may involve habitat se­ competent larva A larva that is physiologically and morpho­ lection.
    [Show full text]
  • Coral Histopathology II
    INTRODUCTION The prevalence and severity of reef degradation due to coral disease has increased considerably over the last two decades. Emerging coral diseases have been linked to biotic and abiotic stressors and their synergistic interactions. Coral disease research is in its infancy and only beginning to take advantage of technologies and methodologies routinely used in epizootiology, clinical and diagnostic medicine, and pathology. This Coral Histopathology Workshop (and its predecessor) provided forums to begin adapting advances in biomedical and veterinary sciences, pathology, toxicology, and biotechnology to the study of coral disease and health; it also provided a foundation on which to build a framework for coral disease research that can interface with mainstream medical and veterinary research. The goals of this Workshop were to produce standards for (1) morphological descriptors based on accepted medical terminology, (2) consistent and concise descriptions of lesions in the field, as well as (3) clinical morphological diagnoses in the laboratory. Consensus reached during this workshop will be peer reviewed by the coral scientific community, both in public settings where the materials will be presented in workshop/discussion formats, directly soliciting review by others establishing terminology for the field, and through opinion papers in the peer-review literature to adopt specialized terminologies to facilitate communication among histopathologists. Once adopted, the terminology and microscopic descriptions will enable development of instructional materials and distance learning tools for coral histopathology. STUDY SETS OF HISTOLOGY SLIDES PROVIDED BY THE IRCP An important facet of this workshop was the use of study sets of slides with serial sections from the same sample for independent individual micro- E.
    [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]
  • OREGON ESTUARINE INVERTEBRATES an Illustrated Guide to the Common and Important Invertebrate Animals
    OREGON ESTUARINE INVERTEBRATES An Illustrated Guide to the Common and Important Invertebrate Animals By Paul Rudy, Jr. Lynn Hay Rudy Oregon Institute of Marine Biology University of Oregon Charleston, Oregon 97420 Contract No. 79-111 Project Officer Jay F. Watson U.S. Fish and Wildlife Service 500 N.E. Multnomah Street Portland, Oregon 97232 Performed for National Coastal Ecosystems Team Office of Biological Services Fish and Wildlife Service U.S. Department of Interior Washington, D.C. 20240 Table of Contents Introduction CNIDARIA Hydrozoa Aequorea aequorea ................................................................ 6 Obelia longissima .................................................................. 8 Polyorchis penicillatus 10 Tubularia crocea ................................................................. 12 Anthozoa Anthopleura artemisia ................................. 14 Anthopleura elegantissima .................................................. 16 Haliplanella luciae .................................................................. 18 Nematostella vectensis ......................................................... 20 Metridium senile .................................................................... 22 NEMERTEA Amphiporus imparispinosus ................................................ 24 Carinoma mutabilis ................................................................ 26 Cerebratulus californiensis .................................................. 28 Lineus ruber .........................................................................
    [Show full text]
  • Cnidarian Immunity and the Repertoire of Defense Mechanisms in Anthozoans
    biology Review Cnidarian Immunity and the Repertoire of Defense Mechanisms in Anthozoans Maria Giovanna Parisi 1,* , Daniela Parrinello 1, Loredana Stabili 2 and Matteo Cammarata 1,* 1 Department of Earth and Marine Sciences, University of Palermo, 90128 Palermo, Italy; [email protected] 2 Department of Biological and Environmental Sciences and Technologies, University of Salento, 73100 Lecce, Italy; [email protected] * Correspondence: [email protected] (M.G.P.); [email protected] (M.C.) Received: 10 August 2020; Accepted: 4 September 2020; Published: 11 September 2020 Abstract: Anthozoa is the most specious class of the phylum Cnidaria that is phylogenetically basal within the Metazoa. It is an interesting group for studying the evolution of mutualisms and immunity, for despite their morphological simplicity, Anthozoans are unexpectedly immunologically complex, with large genomes and gene families similar to those of the Bilateria. Evidence indicates that the Anthozoan innate immune system is not only involved in the disruption of harmful microorganisms, but is also crucial in structuring tissue-associated microbial communities that are essential components of the cnidarian holobiont and useful to the animal’s health for several functions including metabolism, immune defense, development, and behavior. Here, we report on the current state of the art of Anthozoan immunity. Like other invertebrates, Anthozoans possess immune mechanisms based on self/non-self-recognition. Although lacking adaptive immunity, they use a diverse repertoire of immune receptor signaling pathways (PRRs) to recognize a broad array of conserved microorganism-associated molecular patterns (MAMP). The intracellular signaling cascades lead to gene transcription up to endpoints of release of molecules that kill the pathogens, defend the self by maintaining homeostasis, and modulate the wound repair process.
    [Show full text]
  • Theor Biol Antho 2007.Pdf
    This article was originally published in a journal published by Elsevier, and the attached copy is provided by Elsevier for the author’s benefit and for the benefit of the author’s institution, for non-commercial research and educational use including without limitation use in instruction at your institution, sending it to specific colleagues that you know, and providing a copy to your institution’s administrator. All other uses, reproduction and distribution, including without limitation commercial reprints, selling or licensing copies or access, or posting on open internet sites, your personal or institution’s website or repository, are prohibited. For exceptions, permission may be sought for such use through Elsevier’s permissions site at: http://www.elsevier.com/locate/permissionusematerial ARTICLE IN PRESS Journal of Theoretical Biology 246 (2007) 477–490 www.elsevier.com/locate/yjtbi Generation of bilateral symmetry in Anthozoa: A model Stefan Berkingà Zoological Institute, University of Cologne, Weyertal 119, D-50923 Ko¨ln, Germany Received 4 August 2006; received in revised form 21 December 2006; accepted 8 January 2007 Available online 20 January 2007 Abstract Polyps of Anthozoa usually display bilateral symmetry with respect to their mouth opening, to their pharynx, and in particular to the arrangement of their mesenteries. Mesenteries, which are endodermal folds running from the apical to the basal end of the body, subdivide the gastric cavity into pouches. They form in a bilateral symmetric sequence. In this article I propose that early in polyp development the endoderm subdivides successively into three different types of compartments. A mesentery forms at the border between compartments.
    [Show full text]
  • Molecular Approaches Underlying the Oogenic Cycle of the Scleractinian
    www.nature.com/scientificreports OPEN Molecular approaches underlying the oogenic cycle of the scleractinian coral, Acropora tenuis Ee Suan Tan1, Ryotaro Izumi1, Yuki Takeuchi 2,3, Naoko Isomura4 & Akihiro Takemura2 ✉ This study aimed to elucidate the physiological processes of oogenesis in Acropora tenuis. Genes/ proteins related to oogenesis were investigated: Vasa, a germ cell marker, vitellogenin (VG), a major yolk protein precursor, and its receptor (LDLR). Coral branches were collected monthly from coral reefs around Sesoko Island (Okinawa, Japan) for histological observation by in situ hybridisation (ISH) of the Vasa (AtVasa) and Low Density Lipoprotein Receptor (AtLDLR) genes and immunohistochemistry (IHC) of AtVasa and AtVG. AtVasa immunoreactivity was detected in germline cells and ooplasm, whereas AtVG immunoreactivity was detected in ooplasm and putative ovarian tissues. AtVasa was localised in germline cells located in the retractor muscles of the mesentery, whereas AtLDLR was localised in the putative ovarian and mesentery tissues. AtLDLR was detected in coral tissues during the vitellogenic phase, whereas AtVG immunoreactivity was found in primary oocytes. Germline cells expressing AtVasa are present throughout the year. In conclusion, Vasa has physiological and molecular roles throughout the oogenic cycle, as it determines gonadal germline cells and ensures normal oocyte development, whereas the roles of VG and LDLR are limited to the vitellogenic stages because they act in coordination with lipoprotein transport, vitellogenin synthesis, and yolk incorporation into oocytes. Approximately 70% of scleractinian corals are hermaphroditic broadcast spawners and have both male and female gonads developing within the polyp of the same colony1. Tey engage in a multispecifc spawning event around the designated moon phase once a year2–4.
    [Show full text]
  • The Reproductive Biology of the Scleractinian Coral Plesiastrea Versipora in Sydney Harbour, Australia
    Vol. 1: 25–33, 2014 SEXUALITY AND EARLY DEVELOPMENT IN AQUATIC ORGANISMS Published online February 6 doi: 10.3354/sedao00004 Sex Early Dev Aquat Org OPEN ACCESS The reproductive biology of the scleractinian coral Plesiastrea versipora in Sydney Harbour, Australia Alisha Madsen1, Joshua S. Madin1, Chung-Hong Tan2, Andrew H. Baird2,* 1Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia 2ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, Queensland 4811, Australia ABSTRACT: The scleractinian coral Plesiastrea versipora occurs throughout most of the Indo- Pacific; however, the species is only abundant in temperate regions, including Sydney Harbour, in New South Wales, Australia, where it can be the dominant sessile organism over small spatial scales. Population genetics indicates that the Sydney Harbour population is highly isolated, sug- gesting long-term persistence will depend upon on the local production of recruits. To determine the potential role of sexual reproduction in population persistence, we examined a number of fea- tures of the reproductive biology of P. versipora for the first time, including the sexual system, the length of the gametogenetic cycles and size-specific fecundity. P. versipora was gonochoric, sup- porting recent molecular work removing the species from the Family Merulinidae, in which the species are exclusively hermaphroditic. The oogenic cycle was between 13 and 14 mo and the spermatogenetic cycle between 7 and 8 mo, with broadcast spawning inferred to occur in either January or February. Colony sex was strongly influenced by colony size: the probability of being male increased with colony area. The longer oogenic cycle suggests that females are investing energy in reproduction rather than growth, and consequently, males are on average larger for a given age.
    [Show full text]