The Light Microscopist’s Diatom Glossary 2nd Ed. The Light Microscopist's Diatom Glossary by D. S. Gill 1st Ed. August 2006 2nd Ed. June 2011 All rights reserved Preface to 2nd Edition The previous Edition of this publication contained a number of formatting errors for which I apologise. Most, if not all, of these have been corrected in this edition. It has been determined that two new term categories should be introduced – Hydrological terms and Oceanographic terms - as references to both these disciplines are frequently found in publications and also associated with samples. There is also a growing tendency in papers to include words or terms under the banner of Ecology. These terms have been included where it is felt appropriate. Some readers have also pointed out that the plethora of older texts in languages other than English cause some problems to those of us who are monolingual. Thus, a section relating to German and French terms is to be included in later editions, but will not be as extensive as the current English Glossary. It has become increasingly clear that whilst many of the the relatively older terms have fallen into disuse they were used more or less consistently throughout texts of their time. The same, however, cannot be said for more modern terms where usage and interpretation are sometimes at significant variance one with another. This being the case I have included the disparate descriptions where such seems appropriate. Modern academic papers relating to the Diatomaceae use less of the older terms but have introduced other ‘vogue’ terms, equally confusing to those outside academia or not steeped in a specific discipline. Many of these are now included in this edition, though some of the explanations of their meaning are complex and need further effort to simplify. Many of these modern papers use the Harvard Method of referencing in the body of the text which may make the bulk of the paper hard to read and interrupts the flow, but if you can discipline yourself to ignore the references everything becomes easier to follow. Don’t be put off by verbose titles. With the wealth of published material now available the title has become an important mechanism for academics to quickly identify what will lie within their sphere of interest. Thus the title will likely contrive to include as many key words as possible relating to the subject under investigation. Also appended to this edition is a categorised listing of the all the terms. What may be surprising to some is the sheer quantity of literature pertaining to diatoms that is now published. The evidence of such a plethora of papers confirms the importance of the diatoms and often, despite their numbers, their fragility and how easily we might tip the balance of nature with unforeseen, and perhaps catastrophic, results. Page 1 The Light Microscopist’s Diatom Glossary 2nd Ed. Introduction The intention of this glossary is to provide a reference that will enable readers of both old and new tracts to understand the terms used. In my experience each publication has a tendency to provide information relating to its own references and methods, and anyone using a number of publications at any one time has the utmost difficulty in determining the references, having to flick back and forth in multiple volumes and then having to consult the plates to confirm the meaning. Having stated this aim, it was also my intention to provide as comprehensive a coverage as possible. To this end I have expended considerable effort to locate examples and derivations. However, were I to continue to do this in an effort to complete all entries, then, the publication would never see the light of day. It is therefore my intention to continue with the work and publish an extended version as and when the volume of new or amended entries dictates. The glossary contains those references that I, and colleagues, have encountered. No doubt, this is not all terms that have been utilised in the many hundreds of published works. Where appropriate the word or term has associated with it a published example of its use. All the entries used to describe frustule or valve features have an F in braces {F} following the word or term. All the entries used as geometric descriptions have a G in braces {G} following the word or term. All the entries used to describe a habitat, an era, or a mode of living have an H in braces {H} following the word or term. All the entries used to describe a microscopic technique or view have an M in braces {M} following the word or term. All the entries used to describe a process or state, chemical or physical, have a P in braces {P} following the word or term. All the entries used as a Hydrological term have Hy in braces {Hy} following the word or term. All the entries used as an Oceanographical term have an O in braces {O} following the word or term. All the entries that might be used in an Ecological context have an E in braces {E} following the word or term. Many of the Geometric terms are combined in descriptions e.g. lanceolate-elliptic. As there are far too many of these combinations to enumerate the reader should refer to the constituent parts separately and remember that the description implies something between the two, with the former term being predominant. In the example above then, the shape would be more lanceolate than elliptic whereas ellipto-lanceolate would be more elliptic than lanceolate. Many descriptive items can and have been prefixed by 'sub'. This implies a tendency towards a particular feature without actually being sufficiently like it to warrant the actual term. These 'sub...' words and terms have been omitted as full entries. However, the following are some that have been encountered:- Subacute, Page 2 The Light Microscopist’s Diatom Glossary 2nd Ed. Subapiculate, Subcapitate, Subcircular, Subconical, Subcordate, Subcruciform, Subcuneate, Subcylindrical, Subdistant, Subelliptical, Subglobose, Sublanceolate, Sublinear, Submarginal, Submedian, Subnavicular, Suborbicular, Suboval, Subparallel, Subquadrangular, Subradiate, Subrhomboidal, Subrostrate, Subsessil rings, Subspherical, Subsymmetrical, Subtriangular, Subtruncate. These entries in original publications may be hyphenated e.g. sub-triangular. The entry structure is as follows:- Word or term {Category of use} Origin of the word or term. (Etymology) An explanation of the word or term in the context of its category and where possible in relation to the diatoms. Example: Publication name (Species if present) An extract from the publication containing the word or term with the term underlined. A word or two about derivatives of words describing stuctures or features. In general one may consider a word that is constructed of a feature name with 'ate' appended e.g. Papilla - Papillate, to mean that the feature being described is in nature similar or likened to a papilla though not the same. The same word with 'ose' appended e.g. Papilla - Papillose to mean that it contains Papilla. Though this is not always true and sometimes the terms are interchangeable one should always consider the context in which the word is used. Notes:- The term 'Cell' is usually given to a living diatom individual. The term 'Frustule' is a complete skeleton, composed of valves and connecting bands. A Abbreviate {F} In combination. Latin. Ad – to, Latin. brevis - short. Contracted or shortened. Example: Diatoms from the West Indian Archipelago by P.T. Cleve. (Navicula regula) Striae coarse, radiate, reaching to the median line, abbreviate in the middle... Ablation {Hy}{E} The process by which ice and snow dissipate owing to melting and evaporation. Example: Diatoms of the McMurdo ice shelf, Antarctica... (Davida E. Kellogg & Thomas B. Kellogg) [1986] These observations may pertain to oher present and former antarctic ice shelves that are characterized by surface ablation and basal freezing. Page 3 The Light Microscopist’s Diatom Glossary 2nd Ed. Absorption {Hy}{O}{E} Latin. absorbere - to suck in. The process by which substances in gaseous, liquid, or solid form are assimilated or taken up by other substances. Also the utilisation og light energy sources. Example: Spectral photosynthesis, quantum yield and bluegreen light enhancement of productivity rates in the diatom Chaetoceros gracile and the prymnesiophyte Emiliania huxleyi (Oscar Schofield et al) [1990] While the absorption spectra for the chromophytes were similar, E. huxleyi exhibited a higher quantum efficiency and hence a higher photosynthetic rate, than C. gracile. Abutment {P} The proximity of one feature to another, as in adjacent to. Example: The Cytoplasmic Fine Structure of the Diatom, Nitzschia palea (R. W. Drum) [1963] Each chloroplast extends from the points of mutual abutment in the center of the cell, to within 2 or 3 microns of the respective end of the cell. Abutment {Hy} The part of a valley or canyon wall against which a dam is constructed. Right and left abutments are those on respective sides of an observer looking downstream. Example: Algal communities near Cape Maclear, southern Lake Malawi, Africa (K.A. Haberyan) [1991] ...long filaments of a reddish-black form of Oscillatoria, which seemed confined to rock abutments... Abutment Seepage {Hy} Reservoir water that moves through seams or pores in the natural abutment material and exits as seepage. Example: Abyssal {H} Greek. abyssos - bottomless (1) Pertaining to the zone of modal ocean basin depth, below 2000 m, lying seaward to and deeper than the bathyal (qv) zone. (2) Encompassing the ocean floor at depths between 2 and 6 km. Example: Diatoms in the Ocean Deeps (E. J. F. Wood) [1956] There is a great deal to support the theory enunciated in this paper that the diatoms found in abyssal mud samples Abyssal Fan {O} Greek.