Takuto Ando , Karin Zonneveld , Gerard J.M. Versteegh , Mika Ishigaki , Tatsuyuki Yamamoto , Kazumi Matsuoka
{"title":"Why cysts of Alexandrium catenella and/or A. pacificum (Gonyaulacales, Dinophyceae) do not remain in sediments as fossils?","authors":"Takuto Ando , Karin Zonneveld , Gerard J.M. Versteegh , Mika Ishigaki , Tatsuyuki Yamamoto , Kazumi Matsuoka","doi":"10.1016/j.revpalbo.2024.105161","DOIUrl":null,"url":null,"abstract":"<div><p>The dinoflagellate genus <em>Alexandrium</em> contains a number of species that produce paralytic shellfish toxins and have been the focus of attention as toxic plankton for harmless algal studies. Among <em>Alexandrium</em> species, <em>A. catenella</em> and <em>A. pacificum</em> form ellipsoidal-shaped resting cysts, which are preserved in marine sediments, and have attracted attention as potential seeds for future proliferation after favorable environmental conditions <del>environmental improvement.</del> However, although these cysts are preserved in surface of marine sediments, there is no record of their occurrence from solidified sediments as fossils. In order to clarify the reason for this, we investigated the differences in the chemical composition of cyst walls between colorless cyst of <em>Alexandrium catenella/pacificum</em> and <em>Lingulodinium machaerophorum, Polysphaeridium zoharyi, Spiniferites</em> spp. by measuring the thickness of cyst walls and using Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy. The results showed that the cyst wall of <em>A. catenella/pacificum</em> and <em>L. machaerophorum</em> were all composed of cellulosic organic matter. However, <em>A. catenella/pacificum</em> have the higher percentage of α<!--> <!-->−/β-glucosidic linkages and that the thickness of their cyst walls is about one-third of that of <em>L. machaerophorum</em>. Therefore, these are reasons for the cysts of <em>A. catenella</em>/<em>pacificum</em> being more easily degraded in the sediment.</p></div>","PeriodicalId":54488,"journal":{"name":"Review of Palaeobotany and Palynology","volume":"329 ","pages":"Article 105161"},"PeriodicalIF":1.7000,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Review of Palaeobotany and Palynology","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S003466672400112X","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PALEONTOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The dinoflagellate genus Alexandrium contains a number of species that produce paralytic shellfish toxins and have been the focus of attention as toxic plankton for harmless algal studies. Among Alexandrium species, A. catenella and A. pacificum form ellipsoidal-shaped resting cysts, which are preserved in marine sediments, and have attracted attention as potential seeds for future proliferation after favorable environmental conditions environmental improvement. However, although these cysts are preserved in surface of marine sediments, there is no record of their occurrence from solidified sediments as fossils. In order to clarify the reason for this, we investigated the differences in the chemical composition of cyst walls between colorless cyst of Alexandrium catenella/pacificum and Lingulodinium machaerophorum, Polysphaeridium zoharyi, Spiniferites spp. by measuring the thickness of cyst walls and using Fourier Transform Infrared Spectroscopy (FTIR) and Raman Spectroscopy. The results showed that the cyst wall of A. catenella/pacificum and L. machaerophorum were all composed of cellulosic organic matter. However, A. catenella/pacificum have the higher percentage of α −/β-glucosidic linkages and that the thickness of their cyst walls is about one-third of that of L. machaerophorum. Therefore, these are reasons for the cysts of A. catenella/pacificum being more easily degraded in the sediment.
期刊介绍:
The Review of Palaeobotany and Palynology is an international journal for articles in all fields of palaeobotany and palynology dealing with all groups, ranging from marine palynomorphs to higher land plants. Original contributions and comprehensive review papers should appeal to an international audience. Typical topics include but are not restricted to systematics, evolution, palaeobiology, palaeoecology, biostratigraphy, biochronology, palaeoclimatology, paleogeography, taphonomy, palaeoenvironmental reconstructions, vegetation history, and practical applications of palaeobotany and palynology, e.g. in coal and petroleum geology and archaeology. The journal especially encourages the publication of articles in which palaeobotany and palynology are applied for solving fundamental geological and biological problems as well as innovative and interdisciplinary approaches.