DOCSLIB.ORG

Population Biology and Grazing Processes of the Sea Urchin Centrostephanus Tenuispinus (Clark, 1914) Inhabiting Coral and Macroalgal Dominated Reefs

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Population Biology and Grazing Processes of the Sea Urchin Centrostephanus Tenuispinus (Clark, 1914) Inhabiting Coral and Macroalgal Dominated Reefs Population biology and grazing processes of the sea urchin Centrostephanus tenuispinus (Clark, 1914) inhabiting coral and macroalgal dominated reefs Rathnayaka Mudiyanselage Gayani Nilupika Thilakarathna, BSc This thesis is presented for the degree of Doctor of Philosophy of Murdoch University 2017 i Declaration I declare that this thesis is my own account of my research and contains as its main content work which has not previously been submitted for a degree at any tertiary education institution. .................................... (Gayani N. T. Rathnayaka Mudiyanselage) December 2017 ii Abstract Sea urchins play a key role as herbivores and bio-eroders, impacting the organization and structure in many marine benthic habitats. Hall Bank reef (32°2.002´S and 115°42.957´E) off Western Australia is unique having high coral cover, which is unusual for high latitude reefs. Although the high density of Centrostephanus tenuispinus is believed to be the reason for the absence of macroalgae, lack of knowledge on the biology and ecology of this species hampers our understanding of the functioning these reefs. The main objective of this study was to evaluate the role of C. tenuispinus in structuring and functioning of Hall Bank reef with respect to macroalgae- dominated Minden Reef. Benthic surveys and monthly sample collections were carried out at two sites, to assess temporal variation of substrate cover, urchin density, reproductive patterns, feeding habits and bio-erosion. Higher density (2.94 ± 0.14 m-2) of C. tenuispinus with small tests at Hall Bank reef indicated low food availability, while lower densities (0.14 ± 0.01 m-2) of larger urchins at Minden Reef indicated high productivity in the habitat. A clear synchronised annual reproductive cycle was recorded. The gametogenic cycle was initiated by decreasing seawater temperature and day length in March, leading to spawning in winter. Minden Reef urchins had a higher Gonadosomatic Index, coinciding with high food availability. Less seasonal variability in substrate composition influenced the reduced variability in diet at Hall Bank reef while pronounced seasonal variation in the diet of Minden Reef urchins coincided with seasonal changes of substrate cover. Bio-erosion rates were positively correlated with sea water temperature. The annual bio-erosion rate in Hall Bank reef was 1017.69 g -2 -1 CaCO3 m y . Changes in the population of Centrostephanus tenuispinus, being the dominant grazer and bio-eroder in Hall Bank reef, can greatly influence the structure and species composition of the reef, and could lead to ecological phase shifts in this reef system at extremes. The comprehensive knowledge acquired through this study on Centrostephanus tenuispinus provides baseline data for the region on this particular species which could be used in monitoring and managing reefs with current trends in climate change. iii Acknowledgements While I alone am responsible for this thesis, it is nonetheless at least as much a product of years of interaction with, and inspiration by, a larger number of colleagues and peers as it is my own work. For this reason, I humbly take this opportunity to acknowledge debt to all those people whose comments, questions, criticism, support and encouragement, personal and academic, have left a mark on this work. The first gratitude goes to my supervisors Dr. Mike van Keulen and Dr. John Keesing. I am very grateful for your encouragement and for not giving up on me with my limited underwater experience. Your ideas and passions in the field of marine sciences have exceptionally inspired and enriched my growth as a student, a researcher and a budding scientist. Your understanding, encouraging and personal guidance have provided a good basis for the present thesis. My appreciation is also extended to the Murdoch University for providing me the Murdoch International Scholarship (MIPS). I am very grateful for generous support with field work from Steven Goynich, Michael Taylor, Ian Dapson, Claudia Muller, Amy Kirke, Peter Howie, Phillip Good, Mark Thiele, Brodee Elsdon and Justine Arnold. You all have been a source of inspiration through your tremendous support in an extraordinary manner to move my field work forward, also in encouraging me to pursue ideas. I would like to express my deep and sincere gratitude, to Dr. John Huisman, Director West Australian Herbarium, for his tremendous help in identification of algae. Also I would like to thank Dr. James Tweedley for his generous help with Primer. My deepest gratitude goes Gordon Thomson for his generous support and advice with histology work. I owe my sincere gratitude for Dr. Damian Thomson, CSIRO for providing water temperature data, Department of Water and Environmental Regulation for providing water quality data, Department of Biodiversity, Conservation and Attractions, WA and Department of Fisheries, WA for providing permission for the sample collections. iv My deepest gratitude goes to Dr. Dileepa de Croos for being my mentor in most of my carrier and for his encouragement and guidance during my PhD career. I am grateful for my uncle Dr. Thilak Gunattilake, aunty Mrs. Chandra Guantillake and my friends Piyumi Fonseka and Nadhe Fonseka for being my family and being there for me whenever I needed for last four years. I also owe my thanks to Shashikala, Shanika, Thusitha, Aurelie and all of my colleagues for their immense encouragement and support for last four years. I cannot forget my cousin Sajith Udayanga, uncle Mr. PA Dayarathna and aunties Mrs. Sriyani Manage and Ms. Chandra Rathnayaka for taking care of my mother in my absence in Sri Lanka. Finally, I owe my loving thanks to my mother and late father. It is my father who made me enthusiastic for the world of science since my childhood. I have learned so much from my parents and I appreciate all of the sacrifices that they have made for me. My mother in particular, sacrificed everything for my studies and was the guardian angel of my life. Without her encouragement and understanding it would have been impossible for me to be where I am today. Therefore, I dedicate this dissertation to her with my affection and my never-ending appreciation for all she has done for me. v Table of Contents Declaration .......................................................................................................................... ii Abstract ......................................................................................................................... iii Acknowledgements ............................................................................................................ iv List of Tables .................................................................................................................... xiii Chapter 1 - Literature Review and Introduction .................................................................. 1 1.1 General Introduction ............................................................................................................1 1.2 Impact of climate change on urchin habitats ......................................................................1 1.2.1 Global warming and latitudinal shifts of species ..........................................................2 1.2.2 Impact of Ocean Acidification .......................................................................................3 1.3 Ecology of temperate reefs ..................................................................................................4 1.3.1 Tropical reefs Vs Temperate reefs ................................................................................4 1.3.2 Ecological interactions in temperate latitude reefs ......................................................4 1.3.3 Keystone species ...........................................................................................................5 1.3.4 Drivers of coral-macroalgae phase shifts ......................................................................5 1.3.5 Predicting ecological interactions- food web analysis ..................................................9 1.4 Ecological role of sea urchins on coral reefs ..................................................................... 10 1.5 Sea urchin Biology ............................................................................................................. 12 1.5.1 Sea urchin feeding ...................................................................................................... 12 1.5.2 Sea urchin population size regulation ........................................................................ 13 1.5.3 Sea urchin reproduction ............................................................................................ 15 1.6 Temperate sea urchins ...................................................................................................... 16 1.7 Centrostephanus spp. ....................................................................................................... 16 1.7.1 Centrostephanus tenuispinus in Western Australia ................................................... 18 1.7.2 Centrostephanus tenuispinus population in Hall Bank reef ....................................... 19 1.8 Thesis Aims:....................................................................................................................... 19 Chapter 2 – Population status and size distribution of Centrostephanus tenuispinus: Hall Bank reef vs Minden Reef .............................................................................
Load more

Recommended publications
  • Society of Japan
    Sessile Organisms 21 (1): 1-6 (2004) The Sessile Organisms Society of Japan Combination of macroalgae-conditioned water and periphytic diatom Navicula ramosissima as an inducer of larval metamorphosis in the sea urchins Anthocidaris crassispina and Pseudocentrotus depressus Jing-Yu Li1)*, Siti Akmar Khadijah Ab Rahimi1), Cyril Glenn Satuito 1)and Hitoshi Kitamura2)* 1) Graduate School of Science and Technology, Nagasaki University, 1-14 Bunkyo, Nagasaki 852-8521, Japan 2) Faculty of Fisheries, Nagasaki University, 1-14 Bunkyo, Nagasaki 852-8521, Japan *correspondingauthor (JYL) e-mail:[email protected] (Received June 10, 2003; Accepted August 7, 2003) Abstract The induction of larval metamorphosis in the sea urchins Anthocidaris crassispina and Pseudocentrotus depressus was investigated in the laboratory, using waters conditioned by 15 different macroalgae com- bined with the periphytic diatom Navicula ramosissima. Larvae of P. depressus did not metamorphose, but larvae of A. crassispina showed a high incidence of metamorphosis, especially in waters conditioned by coralline red algae or brown algae. High inductive activity for larval metamorphosis was detected in Corallina pilulifera-conditioned water during a 2.5-year investigation, but the activity was relatively low in February or March and in September, the off growth seasons of the alga. By contrast, Ulva pertusa-con- ditioned water did not show metamorphosis-inducing activity except in spring or early summer. These re- sults indicate that during their growth phase, red and brown
    [Show full text]
  • Bacillus Crassostreae Sp. Nov., Isolated from an Oyster (Crassostrea Hongkongensis)
    International Journal of Systematic and Evolutionary Microbiology (2015), 65, 1561–1566 DOI 10.1099/ijs.0.000139 Bacillus crassostreae sp. nov., isolated from an oyster (Crassostrea hongkongensis) Jin-Hua Chen,1,2 Xiang-Rong Tian,2 Ying Ruan,1 Ling-Ling Yang,3 Ze-Qiang He,2 Shu-Kun Tang,3 Wen-Jun Li,3 Huazhong Shi4 and Yi-Guang Chen2 Correspondence 1Pre-National Laboratory for Crop Germplasm Innovation and Resource Utilization, Yi-Guang Chen Hunan Agricultural University, 410128 Changsha, PR China [email protected] 2College of Biology and Environmental Sciences, Jishou University, 416000 Jishou, PR China 3The Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan Institute of Microbiology, Yunnan University, 650091 Kunming, PR China 4Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409, USA A novel Gram-stain-positive, motile, catalase- and oxidase-positive, endospore-forming, facultatively anaerobic rod, designated strain JSM 100118T, was isolated from an oyster (Crassostrea hongkongensis) collected from the tidal flat of Naozhou Island in the South China Sea. Strain JSM 100118T was able to grow with 0–13 % (w/v) NaCl (optimum 2–5 %), at pH 5.5–10.0 (optimum pH 7.5) and at 5–50 6C (optimum 30–35 6C). The cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant respiratory quinone was menaquinone-7 and the major cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0,C16 : 0 and C16 : 1v11c. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, an unknown glycolipid and an unknown phospholipid. The genomic DNA G+C content was 35.9 mol%.
    [Show full text]
  • Beach Treasures
    BEACH TREASURES – HAVE YOU SEEN THEM? … Peter Crowcroft, Eco-Logic Education and Environment Services … Drawings by Kaye Traynor As the weather warms, and walking on the beach becomes much more appealing, keep a lookout along the high tide line for these two interesting, but rarely seen, beach treasures. Argonauta nodosa: Known as the Knobby Argonaut, or often, mistakenly, called the Paper Nautilus, this animal is actually a species of octopus that freely swims in the open ocean, in what is known as the pelagic zone – i.e. neither close to the bottom nor near the shore. It is in the family Argonautidae. Females of this species grow significantly larger than males, and secrete their paper-thin egg casing, that is such a rare and special find along our southern Australian beaches. To find a specimen in pristine condition, without any breakages, is considered by many as the pinnacle of beach combing fortune. Although this fragile structure acts as a shell, protecting and housing the female argonaut, it is unlike other cephalopod, true shells, and is regarded as an evolutionary novelty, unique to this family. The egg casing is typically around 150 mm in length, though some extraordinary Argonauta nodosa Knobby Argonaut specimens at 250 mm, or even larger, are known to grace some mantelpieces. Due to the radical dimorphism between male and females, not much was known about male Argonauts until relatively recently. Unlike the females, they do not secrete and live in an egg case, they reach only a fraction of the female size, and live a much shorter lifespans – only mating once, unlike the females that produce numerous broods of eggs throughout their lives.
    [Show full text]
  • «Etude De La Diversité Biologique Et De La Santé Des Récifs Coralliens Des
    Gough, C., Harris, A., Humber, F. and Roy, R. «Etude de la diversité biologique et de la santé des récifs coralliens des sites pilotes du projet Gestion des Ressources Naturelles Marines du Sud de Toliara» (Projet MG0910.01) Biodiversity and health of coral reefs at pilot sites south of Toliara WWF Southern Toliara Marine Natural Resource Management project MG 0910.01 2D Aberdeen Studios, 22-24 Highbury Grove, London N5 2EA, UK. [email protected] Tel: +44 (0)20 3176 0548 Fax: +44 (0)800 066 4032 Blue Ventures Conservation Report Acknowledgements: The authors would like to thank the WWF teams in Toliara and Antananarivo and the Blue Ventures London staff for logistical support. Thanks to Vola Ramahery and Gaetan Tovondrainy from WWF Toliara for their support in the field and Mathieu Sebastien Raharilala and Soalahatse for their technical assistance. Thanks also go to the Blue Ventures dive team for their hard work and scientific expertise. Many thanks also to each of the village communities for their kind help and hospitality. Our sincere thanks also to Geo-Eye for their kind donation of the high-resolution satellite imagery. Recommended citation: Gough, C., Harris, A., Humber, F. and Roy, R. (2009). Biodiversity and health of coral reefs at pilot sites south of Toliara WWF Marine resource management project MG 0910.01 Author’s contact details: Charlotte Gough ([email protected]); Alasdair Harris ([email protected]); Frances Humber ([email protected]); Raj Roy ([email protected]) ii Blue Ventures Conservation Report Table of Contents List of Abbreviations ............................................ 2 Zone C – Itampolo (commune Itampolo)...........
    [Show full text]
  • Research on Indian Echinoderms - a Review
    J. mar. biol Ass. India, 1983, 25 (1 & 2):91 -108 RESEARCH ON INDIAN ECHINODERMS - A REVIEW D. B. JAMES* Central Marine fisheries Research Institute, Cochin -682031 In the present paper research work so far done on Indian Echinoderms is reviewed. Various aspects such as history, taxonomy, anatomy, reproductive physiology, development and larval forms, ecology, animal associations, parasites, utility, distribution and zoogeography, toxicology and bibliography are reviewed in detail. Corrections to misidentifications in earlier papers have been made wherever possible and presented in the Appendix at the end of the paper. and help at every stage. He thanks Dr. INTRODUCTION P.S.B.R. James, Director, C.M.F.R. Institute for kindly suggesting to write this review and ECHINODERMS being common and conspicuous also for his kind interest and encouragement. organisms of the sea shore have attracted the He also thanks Miss A.M. Clark, British Museum attention of the naturalists since very early (Natural History), London for commenting times. Their btauty, more so their symmetry on the correct identity of some of the echino­ have attracted the attention of many a natura­ derms presented here. list. Although the first paper on Indian Echino- <jlerms was published as early as 1743 by Plan- HISTORY cus and Gaultire from Goa there was not much progress in the field except in the late nineteenth Most of the research work on Indian echino­ and early twentieth centuries when echinoderms derms relate only to taxonomy with little or no collected mostly by R.I.M.S. Investigator were information on the ecology and other aspects reported by several authors.
    [Show full text]
  • DEEP SEA LEBANON RESULTS of the 2016 EXPEDITION EXPLORING SUBMARINE CANYONS Towards Deep-Sea Conservation in Lebanon Project
    DEEP SEA LEBANON RESULTS OF THE 2016 EXPEDITION EXPLORING SUBMARINE CANYONS Towards Deep-Sea Conservation in Lebanon Project March 2018 DEEP SEA LEBANON RESULTS OF THE 2016 EXPEDITION EXPLORING SUBMARINE CANYONS Towards Deep-Sea Conservation in Lebanon Project Citation: Aguilar, R., García, S., Perry, A.L., Alvarez, H., Blanco, J., Bitar, G. 2018. 2016 Deep-sea Lebanon Expedition: Exploring Submarine Canyons. Oceana, Madrid. 94 p. DOI: 10.31230/osf.io/34cb9 Based on an official request from Lebanon’s Ministry of Environment back in 2013, Oceana has planned and carried out an expedition to survey Lebanese deep-sea canyons and escarpments. Cover: Cerianthus membranaceus © OCEANA All photos are © OCEANA Index 06 Introduction 11 Methods 16 Results 44 Areas 12 Rov surveys 16 Habitat types 44 Tarablus/Batroun 14 Infaunal surveys 16 Coralligenous habitat 44 Jounieh 14 Oceanographic and rhodolith/maërl 45 St. George beds measurements 46 Beirut 19 Sandy bottoms 15 Data analyses 46 Sayniq 15 Collaborations 20 Sandy-muddy bottoms 20 Rocky bottoms 22 Canyon heads 22 Bathyal muds 24 Species 27 Fishes 29 Crustaceans 30 Echinoderms 31 Cnidarians 36 Sponges 38 Molluscs 40 Bryozoans 40 Brachiopods 42 Tunicates 42 Annelids 42 Foraminifera 42 Algae | Deep sea Lebanon OCEANA 47 Human 50 Discussion and 68 Annex 1 85 Annex 2 impacts conclusions 68 Table A1. List of 85 Methodology for 47 Marine litter 51 Main expedition species identified assesing relative 49 Fisheries findings 84 Table A2. List conservation interest of 49 Other observations 52 Key community of threatened types and their species identified survey areas ecological importanc 84 Figure A1.
    [Show full text]
  • Evolutionary Background Entities at the Cellular and Subcellular Levels in Bodies of Invertebrate Animals
    The Journal of Theoretical Fimpology Volume 2, Issue 4: e-20081017-2-4-14 December 28, 2014 www.fimpology.com Evolutionary Background Entities at the Cellular and Subcellular Levels in Bodies of Invertebrate Animals Shu-dong Yin Cory H. E. R. & C. Inc. Burnaby, British Columbia, Canada Email: [email protected] ________________________________________________________________________ Abstract The novel recognition that individual bodies of normal animals are actually inhabited by subcellular viral entities and membrane-enclosed microentities, prokaryotic bacterial and archaeal cells and unicellular eukaryotes such as fungi and protists has been supported by increasing evidences since the emergence of culture-independent approaches. However, how to understand the relationship between animal hosts including human beings and those non-host microentities or microorganisms is challenging our traditional understanding of pathogenic relationship in human medicine and veterinary medicine. In recent novel evolution theories, the relationship between animals and their environments has been deciphered to be the interaction between animals and their environmental evolutionary entities at the same and/or different evolutionary levels;[1-3] and evolutionary entities of the lower evolutionary levels are hypothesized to be the evolutionary background entities of entities at the higher evolutionary levels.[1,2] Therefore, to understand the normal existence of microentities or microorganisms in multicellular animal bodies is becoming the first priority for elucidating the ecological and evolutiological relationships between microorganisms and nonhuman macroorganisms. The evolutionary background entities at the cellular and subcellular levels in bodies of nonhuman vertebrate animals have been summarized recently.[4] In this paper, the author tries to briefly review the evolutionary background entities (EBE) at the cellular and subcellular levels for several selected invertebrate animal species.
    [Show full text]
  • In Situ Observations Increase the Diversity Records of Rocky-Reef Inhabiting Echinoderms Along the South West Coast of India
    Indian Journal of Geo Marine Sciences Vol. 48 (10), October 2019, pp. 1528-1533 In situ observations increase the diversity records of Rocky-reef inhabiting Echinoderms along the South West Coast of India Surendar Chandrasekar1*, Singarayan Lazarus2, Rethnaraj Chandran3, Jayasingh Chellama Nisha3, Gigi Chandra Rajan4 and Chowdula Satyanarayana1 1Marine Biology Regional Centre, Zoological Survey of India, Chennai 600 028, Tamil Nadu, India 2Institute for Environmental Research and Social Education, No.150, Nesamony Nagar, Nagercoil 629001, Tamil Nadu, India 3GoK-Coral Transplantation/Restoration Project, Zoological Survey of India - Field Station, Jamnagar 361 001, Gujrat, India 4Department of Zoology, All Saints College, Trivandrum 695 008, Kerala, India *[Email: [email protected]] Received 19 January 2018; revised 23 April 2018 Diversity of Echinoderms was studied in situ in rocky reefs areas of the south west coast of India from Goa (Lat. N 15°21.071’; Long. E 073°47.069’) to Kanyakumari (Lat. N 08°06.570’; Long. E 077°18.120’) via Karnataka and Kerala. The underwater visual census to assess the biodiversity was carried out by SCUBA diving. This study reveals 11 new records to Goa, 7 to Karnataka, 5 to Kerala and 7 to the west coast of Tamil Nadu. A total of 15 species representing 12 genera, 10 families, 8 orders and 5 Classes were recorded namely Holothuria atra, H. difficilis, H. leucospilota, Actinopyga mauritiana, Linckia laevigata, Temnopleurus toreumaticus, Salmacis bicolor, Echinothrix diadema, Stomopneustes variolaris, Macrophiothrix nereidina, Tropiometra carinata, Linckia multifora, Fromia milleporella and Ophiocoma scolopendrina. Among these, the last three are new records to the west coast of India.
    [Show full text]
  • Climate Change and Coral Reef Bleaching: an Ecological Assessment of Long-Term Impacts, Recovery Trends and Future Outlook
    Estuarine, Coastal and Shelf Science 80 (2008) 435–471 Contents lists available at ScienceDirect Estuarine, Coastal and Shelf Science journal homepage: www.elsevier.com/locate/ecss Climate change and coral reef bleaching: An ecological assessment of long-term impacts, recovery trends and future outlook Andrew C. Baker a,b,1, Peter W. Glynn a,*,1, Bernhard Riegl c,1 a Division of Marine Biology and Fisheries, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, USA b Wildlife Conservation Society, Marine Program, 2300 Southern Boulevard, Bronx, NY 10460, USA c National Coral Reef Institute, Oceanographic Center, Nova Southeastern University, 8000 North Ocean Drive, Dania, FL 33004, USA article info abstract Article history: Since the early 1980s, episodes of coral reef bleaching and mortality, due primarily to climate-induced Received 18 July 2008 ocean warming, have occurred almost annually in one or more of the world’s tropical or subtropical seas. Accepted 4 September 2008 Available online 17 September 2008 Bleaching is episodic, with the most severe events typically accompanying coupled ocean–atmosphere phenomena, such as the El Nin˜o-Southern Oscillation (ENSO), which result in sustained regional elevations of ocean temperature. Using this extended dataset (25 years), we review the short- and long- Keywords: þ coral bleaching term ecological impacts of coral bleaching on reef ecosystems, and quantitatively synthesize recovery reefs data worldwide. Bleaching episodes have resulted in catastrophic loss of coral cover in some locations, zooxanthellae and have changed coral community structure in many others, with a potentially critical influence on the Symbiodinium maintenance of biodiversity in the marine tropics.
    [Show full text]
  • The Status of Mariculture in Northern China
    271 The status of mariculture in northern China Chang Yaqing1 and Chen Jiaxin2 1Dalian Fisheries University Dalian, Liaoning, People’s Republic of China E-mail: [email protected] 2Yellow Sea Fisheries Research Institute Chinese Academy of Fisheries Sciences Qingdao, Shandong, People’s Republic of China Chang, Y. and Chen, J. 2008. The status of mariculture in northern China. In A. Lovatelli, M.J. Phillips, J.R. Arthur and K. Yamamoto (eds). FAO/NACA Regional Workshop on the Future of Mariculture: a Regional Approach for Responsible Development in the Asia- Pacific Region. Guangzhou, China, 7–11 March 2006. FAO Fisheries Proceedings. No. 11. Rome, FAO. 2008. pp. 271–284. INTRODUCTION The People’s Republic of China has a long history of mariculture production. The mariculture industry in China has achieved breakthroughs in the hatchery, nursery and culture techniques of shrimp, molluscs and fish of high commercial value since the 1950s. The first major development was seaweed culture during the 1950s, made possible by breakthroughs in breeding technology. By the end of the 1970s, annual seaweed production had reached 250 000 tonnes in dry weight (approximately 1.5 million tonnes of fresh seaweed). Shrimp culture developed during the 1980s because of advances in hatchery technology and economic reform policies. Annual shrimp production reached 210 000 tonnes in 1992. Disease outbreaks since 1993, however, have reduced shrimp production by about two-thirds. Mariculture production increased steadily between 1954 and 1985, but has been growing exponentially since 1986, mostly driven by mollusc culture. Mollusc culture in China began to expand beyond the four traditional species (oyster, cockle, razor clam and ruditapes clam) in the 1970s.
    [Show full text]
  • (Mollusca: Euthyneura) Biodiversity in Mauritius Lisa Ah-Shee-Tee1
    An assessment of nudibranchs (Mollusca: Euthyneura) biodiversity in Mauritius Lisa Ah-Shee-Tee1 ([email protected] ), Daneshwar Puchooa1 ([email protected] ), Vishwakalyan Bhoyroo1 ([email protected] ), Chandani Appadoo2 ([email protected] ) 1Department of Agricultural & Food Science, Faculty of Agriculture, University of Mauritius, Mauritius 2Department of Biosciences & Ocean Studies, Faculty of Science, University of Mauritius, Mauritius Presenting author is a PhD student: Lisa Ah Shee Tee. Species form the basic unit of biodiversity. They provide economic, pharmacological and public health importance while some can be used as bio-indicators of either environmental quality or climate change. Cataloguing a list of species is also an element of biodiversity. Without prior knowledge of the different species present in the same environment, it is difficult to move towards a sustainable management. Nudibranchs constitute one of the most diverse group of opisthobranchs. They are also known as “butterflies of the sea” as a result of their spectacular coloration. Nudibranchs are recognised to possess important pharmacological potency such as cytotoxicity to a number of tumor cell lines. They can also be used to detect and monitor fine-scale climate change along the coast. They are able to forecast ups and downs in the populations of other species with long pelagic larval periods. Reports of nudibranchs occurrence from Mauritius Island date back from 1832 arising from expedition and systematic records. The most recent review of the biodiversity of opisthobranchs in Mauritius date back to 1991 whereby 23 nudibranchs species belonging to eight families were identified. The present study aims to provide an inventory of nudibranchs species from the lagoon of Mauritius.
    [Show full text]
  • From the Yellow Sea, Korea
    Anim. Syst. Evol. Divers. Vol. 29, No. 4: 312-315, October 2013 http://dx.doi.org/10.5635/ASED.2013.29.4.312 Short communication A New Record of Sea Urchin (Echinoidea: Stomopneustoida: Glyptocidaridae) from the Yellow Sea, Korea Taekjun Lee1, Sook Shin2,* 1College of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea 2Department of Life Science, Sahmyook University, Seoul 139-742, Korea ABSTRACT Sea urchins were collected from waters adjacent to Daludo Island and Mohang harbor in the Yellow Sea, and were identified into Glyptocidaris crenularis A. Agassiz, 1864, of the family Stomopneustidae within the order Stomopneustoida, based on morphological characteristics. This species has two unique morphological characteristics: the ambulacral plate is composed of three primary plates and two demi-plates, and a valve of globiferous pedicellaria consists of with a well-developed long terminal hook and a unique stalk equipped with one to six long lateral processes covering membranes, resembling fins. It is newly recorded in Korea and is described with photographs. This brings the total number of sea urchins reported from the Yellow Sea, Korea, to seven. Keywords: Glyptocidaris crenularis, sea urchin, taxonomy, morphology, Yellow Sea, Korea INTRODUCTION ethyl alcohol and their important morphological characters were photographed using a digital camera (D7000; Nikon, Sea urchins are familiar marine benthic species which are Tokyo, Japan), stereo- and light-microscopes (Nikon SMZ classified into two subclasses: Cidaroidea and Euechinoidea. 1000; Nikon Eclipse 80i) and scanning electron microscope Euechinoidea includes 11 orders (Kroh and Mooi, 2013). Of (JSM-6510; JEOL, Tokyo, Japan). The specimens were iden- them, the order Stomopneustoida comprises only two species tified on the basis of morphological chracters and described of two families: Glyptocidaris crenularis A.
    [Show full text]