Nghiên cứu rươi (nereididae tylorrhynchus) trong hệ sinh thái đất vùng ven biển miền bắc việt nam tt tiếng anh

1 MINISTRY OF VIETNAM ACADEMY EDUCATION AND OF SCIENCE AND TRAINING TECHNOLOGY GRADUATE UNIVERSITY SCIENCE AND TECHNOLOGY NGUYEN THI HA RESEARCH ON RAGWORM (NEREIDIDAE: TYLORRHYNCHUS) IN SOIL ECOSYSTEM IN THE NORTHERN COASTAL AREA OF VIETNAM Major: Theory of Zoology Major code: 42 01 03 SUMMARY OF BIOLOGY DOCTORAL THESIS Ha Noi - 2020 The work was completed at: Academy of Science and Technology - Vietnam Academy of Science and Technology Science of supervisor 1: Prof.Dr of science Vu Quang Manh Science of supervisor 2: PhD Le Hung Anh Science reviewer 1: Science reviewer 2: Science reviewer 3: The thesis will be defended in front of the Institute's doctoral thesis evaluation council, meeting at the Academy of Science and Technology - Vietnam Academy of Science and Technology at … hour, date… month…year 2020 The thesis can be found at: - Library of Academy of Science and Technology - Vietnam National Library INTRODUCTION Reasons to choose a topic With a coastline of more than 3,200 km, along with dense estuary systems and monsoon tropical climate created for Vietnam in general and northern Vietnam in particular has estuary coastal ecosystem speciality and have the highest biological productivity Groups include Mollusca, Arthropoda, Annelida and are component soil macrofauna community structure in the northern coastal area of Vietnam In particular, in phylum Annelida, it is impossible not to mention genus Tylorrhynchus of the familia Nereidida, ordo Phyllodocida, class Polychaeta which has important role in the estuarine and marine ecosystems In the world, polychaeta are found in Japan, South China, Singapore, Indonesia with the number of discovered species of more than 5000 species divided into 86 families This group have important role in the food chain and net, additional ragworm are also considered as an indicator group of organisms to assess the quality of the water and bottom environment In our country, the appearance of ragworm has been mentioned by Nguyen Cong Tieu and Nguyen Cong Tru from the seventeenth and eighteenth centuries, many authors have published a list of hundreds of polychaeta species which appeared in Vietnam, especially there are species that have the ability to go deep into the mainland However, questions about the Ragworm that are favored by the Vietnamese people as a nutritious food source have not been studied: i) Are they in the list of published polychaeta in Vietnam? ii) In addition, with the change of time, space, climate changes, and living environment, the Ragworm in different provinces of Northern Vietnam have differences, morphological changes or is not? additional, during the their life cycle, the ragworm has a time to live in the soil but there has not been any research to consider the Ragworm as a component in soil macrofauna community structure in the northern coastal area of Vietnam With the above scientific and practical basis, a basic survey of the research on the Ragworm as a component in soil macrofauna community structure in ecosystem is necessary On that basis, we choose to research topic " Research on ragworm (Nereididae: Tylorrhynchus) in soil ecosystem in the northern coastal area of Vietnam” The purpose of the thesis The objective of the thesis is to research Ragworm (Nereididae: Tylorrhynchus) in soil macrofauna community structure in the northern coastal area of Vietnam and identify some living environment conditions of the Ragworm in the study area Ruoi habitats in the study area to provide scientific and practical basic for their conservation and development Research content 1/ Taxonomy of ragworm (Nereididae: Tylorrhynchus) by the traditional morphological combined DNA molecular biotechnology, in soil ecosystems in the coastal areas of Northern Vietnam 2/ Research Ragworm in soil macrofauna community structure according to five types of habitats, the five vertical deep layers in the soil and the four seasons in the study area 3/ Surveying some characteristics of the Ragworm habitat, contributing to their development and conservation in the study area The meaning of the thesis Scientific significance: For the first time, Ragworm (Nereididae: Tylorrhynchus) has been studied as a component in soil macrofauna community structure in the northern coastal area of Vietnam The results of the thesis provide the taxonomic position of the ragworm, new data on the relationship of the Ragworm with other Macrofauna groups s in soil in terms of composition, density, biomass and some elements of the habitat of the Ragworm in the study area Practical significance: The practical significance of the thesis is that the data obtained on taxonomy, biological characteristics, ecology of the ragworm in soil macrofauna community structure in the northern coastal area of Vietnam are the basis for further studies to propose a number of conservations and special to properly use, develop and exploit the resources of the Ragworm in the northern Vietnam in general and Hai Duong in particular In addition, these data contribute to build books, related curricula and teaching topics at undergraduate and postgraduate level Chapter 1: Overview 1.1 Situation of research on polychaeta worms in the world Study on classification of polychaete by morphological characteristics and DNA molecular genetic methods Taxonomy is the first stage in biodiversity research Studies on the taxonomy of polychaeta worms have been carried out quite early in the world and include some typical works such as the study of Uschakov (1955) in the Far East that recorded 400 species, study in the Japanese of Imajima & Hartman (1964) with 467 species, Indian waters with Fauvel (1953), Chinese waters with Wubaoling (1986) or South African waters studied Day's rescue (1967) In the world, classification of organisms by DNA molecular genetic methods was conducted from the late nineteenth century However, if the group of polychaeta alone had 225794 sequences solved In particular, the Nereididae family has 15418 sequences and is implemented in many countries around the world such as the US, Germany, Sweden and China vv Research on the biology and ecology of polychaete (Polychaeta) Research on the biology and ecology of polychaeta in the world can include the work of some authors such as: Zenkevich (1965), Gidholm (1969), Pearson & Rosenberg (1987), Alogi (1989, 1990) ) These authors have raised a number of characteristics on the growth, development and reproduction of polychaete, the relationship between polychaete with other organisms, their habitats and vice versa Other studies on polychaetes According to Giangrande et al (2005), Castrol & Micheal (1997): Most polychaeta are a source of protein food, an indicator for assessing environmental quality, besides they have important role in the chain and food wed Therefore, according to Uschakov (1955), some polychaeta have been raised and exploited as protein-rich food for shrimps and crabs, as bait for export for sea tourists 1.2 Situation of research on the ragworm (Nereididae: Tylorrhynchus) in the world Research on the taxonomy of ragworm (Nereididae: Tylorrhynchus) by morphological characteristics and DNA molecular genetic methods In the world, the study on taxonomy of ragworm (Nereididae: Tylorrhynchus) by morphological characteristics has been done by some authors such as Fauvel (1953), Day (1967), Uschakov (1955) or Imajima (1972), the authors gave some morphological characteristics of the head, limb and silk of ragworm In addition, only China in the world that has conducted ragworm ( Nereididae: Tylorrhynchus) classification by molecular biology technique, with the sequencing of the mitochondrial genomic DNA sequence of the Tylorrhynchus heterochaetus has been published on Genbank Research on the biology and ecology of the ragworm (Nereididae: Tylorrhynchus) In the world, research on the biology and ecology of ragworm has been conducted and can be referred to as research by Kent (2016) and Imajima et al (1964, 1972) These authors have given the nutritional characteristics, reproductive properties, reproductive forms and sexism of ragworm 1.3 Situation of research on Polychaeta in Vietnam Study on classification of polychaete by morphological characteristics and molecular biology techniques (DNA) The study has summarized the studies on polychaeta taxonomy by morphological characteristics in ecosystems: coral reefs, seagrass beds, soft-bottom tidal areas, mangrove forests, aquaculture ponds In Vietnam, for ragworm, the classification using DNA molecular biology techniques has not been implemented Research on the biology and ecology of polychaete In Vietnam, research on the biology and ecology of polychaete has been carried out by some authors such as works of Pham Dinh Trong (1999, 2003, 2018), Do Van Nhuong et al (2007), Phan Thi Kim Hong (2009, 2012) The majority of studies refer biomass and density fluctuation of ragworm in different seasons and ecosystems Other studies on polychaetes Research on the role and importance of polychaete has been done by a number of authors such as Theo Nguyen Van Chung (1994), Pham Dinh Trong and Do Van Nhuong (2001, 2003, 2004) Studies show that polychaete make an important contribution to biodiversity, which is an indicator group for assessing aquatic environment quality and the bottom layer Besides, this group is an important role in the chain and food wed According to Pham Dinh Trong (1997, 2018), the current marine resources in general as well as their food sources are benthos, 10 Body (Metastomium): Consists a lot of segments with a relatively homogeneous structure, each segment has limbs The limb (Parapodia) is a special appendage that is transformed from the wall of the body used for swimming and cows The limb included notopodium neuropodium) Dorsal branches of lateral limbs are flattened lobes Branches of the ventral surface forming a sickle shape Each side has silk tufts (silk threads include many different small hard hairs): back silk, belly silk, in each silk has strong buttress (aciculum) clear; cirri: back cirri and belly cirri in which the cirri belly is slender, thin, short, the back cirri has a round lobe and a crown at the tip The posterior part of the body of the lateral limbs is larger than the front, the dorsal silk and the belly are denser Limb is not transformed into gill In this study, by observing the limb of the body from the anterior to the posterior part of the body, it shows the appearance of types of silk, including: 1/ aciculum ; 2/ sickle-shape; 3/paddleshaped silk (oar-shape); 4/dorsal homogomph falciger dorsal; homogomph spiniger bristle; 6/ heterogomph falciger and 7/ lyriform Thus, compared with previous studies on the morphology of Tylorrhynchus heterochaetus in Northern Vietnam by previous authors such as Fauvel (1953), Dang Ngoc Thanh et al (1980), in this study, at the lateral part of Ragworm have been described, adding a picture of a lyre in the middle of the body The reason of the study of the previous authors only discovered types of silk on the limb because the authors only observed the anterior and posterior parts of the body, and the middle part of the body with the presence of the lyriform are not mentioned by the authors The morphological characteristics of adult (Nereididae: Tylorrhynchus) male and female of ragworm 16 To distinguish the sex of normal Ragworm based on color Visually, the male Ragworm are milky white and the females are blue or light blue However, the analytical results in the thesis distinguishes the sexes by observing the genital organs on a microscope Table 3.1: Results of some measurement criteria of ragworm (Nereididae: Tylorrhynchus) in coastal provinces in Northern Vietnam Province Targets Max Min Mas (g) Avera ge (g/indi vidual ) Max Min Len gth (m m) Wid th( mm Avera ge(g/i ndivid ual) Max Min Avera Province Quang Ninh ♂ ♀ n=2 n=3 2,3 0,2 1,0 ± 3,36 0,25 1,17 ± 0,57 0,4 1,13±0,54b 95 96 38 35 68, 68,7 64 ± ± 14, 15,7 68,69±15,3 9a 10 10 5,8 5,85 Hai Duong ♂ ♀ n=1 n=4 1,6 4,11 0,4 0,48 1,0 1,57 ± ± 0,93 0,3 1,44±0,87c 105 135 65 58 85, 92,9 87 ± ± 11, 22,1 59 91,28±20,6 c 4,8 10 5,6 17 0,7 0,1 ♀ n=5 2,9 0,0 Nam Đinh ♀ ♂ n=5 n=4 0,5 1,9 0,3 0,1 0,5 ± 0,2 0,8 ± 0,5 0,4 ± 0,0 Hai Phong Thai Binh ♂ n=2 ♀ n=3 ♂ n=4 2,62 4,51 0,49 0,46 1,27 ± 0,53 1,43 ± 0,72 0,7 ± 0,3 1,36±0,66c 0,79±0,53 0,73±0,34 115 129 50 48 79,3 80,0 ± ± 15,4 17,6 79,75±16,9b 80 60 65 48 4,4 4,14 a 125 40 69, 68 86 ± ± 8,5 16, 69,73±16, 66a 10 3 4,2 5,1 a 120 40 70, 58, 45 75 ± ± 14, 6,5 69,67±14, 4a 4,7 5,2 ) Seg men t num ber (Seg men t) ge(m m/ indivi dual) Max Min Avera ge(Se gment / Indivi dual) ± 2,1 ± 2,06 5,85±2,09c 71 44 57, 77 ± ± 1,3 5,48±1,37b c ± 1,06 ± 1,02 ± 0,8 ± 1,4 4,25±1,05a 5,12±1,44 ± ± 0,4 1,1 5,18±1,14 b b 72 40 65 52 74 48 72 48 64 44 51 43 57 29 53 36 62 23 55,7 ± 7,24 58,2 ± 3,53 59, 84 ± 5,3 56,8 ± 5,66 55,4 ± 5,7 47, 25 ± 2,8 43, ± 7,4 43, 75 ± 6,0 43, 88 ± 9,1 6,9 56,49±7,26 b ± 1,11 59,45±5,06 c 56,03±5,77b 43,47±7,3 4a 1/14 43,47±9a Male/female 1/1,8 1/3,3 1/1,4 1/14 ratio (Note: In the same row of different letters in the same row, there is a statistically significant difference (p