FISHERIES AND MARINE SERVICE Translation Series No. 3076 Some new terms in seston research by Einar. Naumann. Original title: Ueber einige neue Begriffe der Sestonkunde. Lunds Universitets Arsskrift From: Acta Universitatis Lundensis 20(3) . 3-]5, 1924 Translated by the Translation Bureau(HC'C:) Multilingual Services Division Departmènt of the Secretary of.State of Canada Department of the Environment Fisheriès and Marine Service Canada Centre for Inland Waters Burlington, Ont. 1974 20 pages typescript D.EPARTMENT OF THE SECRETARY OF STATE eM11 SECRÉTARIAT D'ÉTAT TRANSLATION BUREAU BUREAU DES TRADUCTIONS „<suiyil-A MULTILINGUAL SERVICES dge.Zat DIVISION DES SERVICES DIVISION CANADA MULTILINGUES Fe-A4 30 7 • CLIENT'S NO. ' DEPARTMENT DIVISION/BRANCH CITY N 0 DU CLIEnr MINISTRE DIVISION/DIRECTION VILLE 534609 Ezwironment Inland Waters Branch Burlington BUREAU NO. LANGUAGE TRANSLATOR (INITIALS) NO DU BUREAU LANGUE • • TRADUCTEUR (INITIALES) . 4 - ' • • .German . • 1. - (. ./ ' 1 . HGC . .1!Yi ... SOME NEW TERMS IN SESTON RESEARCH •• By Einar Naumann (Ueber einige neue Begriffe der Sestonkunde. Lunds Universitets Arsskrift. N.F. Avd. 2 Bd 20. Nr. 3. Acta Universitatis Lundensis. 1924.) . • e?* The term** esSestonn was introduced into limnology by R. • Kolkwit z (1912). Under- s est on - we- understand-. the- t otality- of bodies contained in water, whether in suSpension or floating in its surface • fi2m. • . • • Thus seston embraces several formation classes of animals and plants. In addition, it includes every kind of inanimate matter contained in free water -- detritus or tripton 1916). • The following . formation classes comprise seston: plankton (Hensen,.1887)„ nekton (Haeckel, 1891), pleuston (Schrdter and Kirchner, 1896), and neuston (Naumann, 1917). • * Figures in the margin give page nuMbers in the original. —1. TRANSL. ** IlBegriffil may mean both nterm” and ?concept." Both words are used in .. this translation, according to apparent context. • -- TRANSL. • UNEDITM TRANSLAT;ON For Informeion only • • TRADUC..TION NON REVISEE Aon—zoo. 0-31 • Informan soulemon• , As regards a more deta iled definition of these terms, we shall .confine ourselves to the following remarks. 1. In accordance with Kolkwitz (1912), plankton is defined as the organism formation of free mater. The initial term, as defined by Hensen, was extremely broad and could even be compared to the current term seston. Modern researchers e however, view plankton as a component part] of seston... 2. Nekton s according to Haeckel (1891) embracesienerally the larger water fauna that is relatively unaffected by external influences, divide nekton into planktonekton and neustonekton. The latter includes above all the insects of the mater surface studied by Brocher. 3. In accordance with SchrUter and Kirchner (1896), pleuston means the higher floating flora of the water. 4. Neuston. Organisms belonging thereto, in accordance with E. Naumann (1917), are defined as micro—organic formations found in the surface film of the water. Neuston, of course, also embraces all in- animate bodies found 'suspended in the surface film. The introduction of these definitions of the main term seston and its component terms has been very useful for the further treatment of limnological problems. This is especially true of certain branches of applied limnology. A further study of these matters, however, will probably lead to the need for a more detailed definition of the above noted mainl •• terms. This paper May be seen as a contribution in that direction. H • . 'I. ! . i . I. SIZE CLASSES OF SESTON Initially, seston may simply be divided into the Size classes of . .megâ10—, macro—, meso—, micro— and nannotypes. These are terms which have found wide application in plankton research for some time, through the witingn SchUtt (1892) and Lehmann (1911). The lable that follows Provides. information as to the current size relationships and technical characteristics denoted by these terms. 1 %.. To these terms 1 should now like toadd \the new term ultra- seston„ which is also included in the Table. By it 1 understand that part of the seston ranging in size from a fee microns to microscopie it is characterized by the fact that with invisibility. Technically the present state of technology it cannot be quantified completely. The term ultraseston is..based pr. imarilyi on technical considerations. Its purpose is, first of all, to indicate that this size class is outside . the research possibilities of modern investigational techniques, whose Units are defined by the bacteria and the finer detritus. Partly, however, ultraseston is also composed of bodies that are genuinely ultramicroscopic, i.e.: that are situated on or beyond the borderline of direct microscopic Observation. 1 This is easily demonstrated with dark—field illumination of water samples from waters with abundant seston. however, knowle%e on the ultramicroscopic conditions of natural bodies of water is still incomplete. .1 Ultraseston is composed of a highly heterogeneous material. The following elements predominate: • .(Text cont. on page 5) gze class Characteristics Technical Data Megaloseston Minimum size several centimeters Maybe caught with coarse nets and , Eacroseston and other filters • • Mesoseston Minimum size apprOx. 500-1,000 May be caught with coarse nets and nierons. (Tissue-building animDls et.) other filters Microseston Minimum size apprôx. 60 microns • May be caught r1..th finer nets and (The larger Protista; detritus flakes, other filters etc.) Nannoseston Minimum size approx, 5 microns Cannot be,calight with nets. Complete (Smaller Protista; finer detritus, etc.) quantitative determination possible 'only with centrifuge methods or with. chadber. • Ultraseston Size ranging from 5 microns at most to At besé, qualitatively determinable :microscopic invisibility. (Bacteria; with centrifuge or. chamheï-=---quantitatively the finest detritus, .etc.) . not fully determinable. .,,.,..v..^ • Aquatic bacteria • Peritripton resulting from the call.aborAtion of limnic organisms Colloidal f7.occula,tes of assimilates that Autochthonous I have entered the water elements Other colloidal flocculates Colloidal solutions a Allochthonous ^ Bacteria, peritripton and colloidal flocculates elements introduced from the outside None of these elements can be deter-mined quantitative77 i-r3,th present limnological methodology. We have as yet very few details con- cerning their h ature. This is especially true of bacteria. Although bacteriology of water has become tremendously important in' practical tezms, in theoretical terms it carries little weight. This is a disadvan- tage,'tahich results from the fact that bacteriolog<y is confined largely- -to the method of obtaining its material by concentration. ' Given Ithe present state of li.mnologg, we are.almost cer"in7y justified in characterizing ultraseston as one of.the most important factors in the total metabolism of freshwater bodies. 1 This element lof the total seston is the Unk in the total budget that represents the transition between dissolved nutrients and I the higher production of the water. It is here that the bacterial processing of expired vorganisms takes place, and it is also here that we find the source of colloidal flocculates. From this point, two paths diverge; one leads-vialthe further separation of organic substances ,1 into the realm of solutions; the other leads directly to a reincarnation in the 13.fe of the xoop:Lankton. In pure:y schematic terms, the position of ultraseston in the total spectrum of aquatic life may be represented appro^dm.ate],y as fol.l.o^rs. Y.^^►ldnuki^^s► (4,1641%. \i{Ihrnlnf(p Dïssolved ..nutrients 6 In advancing this scheme,.1 base myself primarily on the . resurks of ;vLy- investigations of the nutritive biology of ara_.?ma1 limno- plankton, on which I have reported in greater detail in several special publipations (1910, 1421,' y92.31). As described thereiln,, the productive biol4gy of the entire zooplankton of the filtrating and sedimentatinR .type. is dependent primarily on the nanno- and ûltraseston.in the water. This is true above all for the non-predatory Cladocera, where ultrasest^on is of the greatest importance, as wexl as for Diaptomidsa and, thirdly,- for the Rotifera. The important ro1,e thus being played by ultraseston in the total metabolism of freshwater makes more detailed investigationsof this subject highly desirable. Thus far, study of ultraseston has been confined to hygieniç bacteriology. Theoretical ^ interest must now focus I on biological bacteriology and tr3.pton research in the area of ultraseston. • • . II DETAILED GROUPING OF NEUSTON The . term neuston was introduced by me for the firet time in 1917. I used it to refer to the organism formation of the surface fila of water, in distinction to plankton, which defines the organisms of free water. The term has found wide acceptance. The further differentiation of the old plankton concept resulting therefrom should contribute to a continued development of various concepts and terms in the field of theoretical and applied limnology. A grouping of this formation class within the systematics of plant sociology,which I believe is not quite. correct, has been undertaken • y Gams (1918). He compares neuston with pleuston e and even classifies thu former as a subseries of the actual pleuston e which he terms micropleuston. This, hogever, is misleading. Pleuston is e after all, a Tr/holly different - formation ) since e according to the original definition