From: PO2::"JOHANSEN@JCVAXA.JCU.EDU" 28-DEC-1995 17:22:48.97 To: Multiple recipients of list DIATOM-L CC: Subj: Should resting spores be recognized taxonomically? Dear colleagues, At the recent meeting at Lakeside Lab, I raised the question as to whether or not diatom resting spores should be recognized taxonomically as "forms" (forma). I received only a little feedback, and the opinions were split. I wanted to throw this question out for discussion. It sounds like a good idea to me for the following reasons: 1. The rank of "forma" is generally reserved for ecophenes, i.e. environmental variants that have no genetic basis for their separation. These forms demonstrate environmentally induced morphological differences from the typical forms. A resting spore would fit this definition. 2. Resting spores are inconsistently reported in the literature, and generally are not quantified separately. Yet because they are tied to environmental cues they possibly contain valuable ecological information that it is unfortunate to lose. If recognized as forms, they could be quantified, and ecological information would be preserved. 3. It is likely that some taxa recognized at higher taxonomic rank (species, varieties) are really resting forms of validly described species. If resting spores were given form names, the historical taxonomic and ecological information available in the literature could be preserved and added upon by transfering them to "forma" rank. 4. If one chose not to recognize the resting spores as forms, using the species name and saying there were resting spores in the population would still be valid. So, what does everbody have to say about this? Reply to the net or to me directly, depending upon how acerbic you are feeling. Jeff Johansen "JOHANSEN@JCVAXA.JCU.EDU" From: PO4::"kingston@usgs.gov" "John C Kingston, BIOLOGIST, Denver, CO (John Kingston)" 28-DEC-1995 18:09:04.95 To: Multiple recipients of list DIATOM-L CC: Subj: Re: Should resting spores be recognized taxonomically? Jeff wrote: > At the recent meeting at Lakeside Lab, I raised the question as to >whether or not diatom resting spores should be recognized taxonomically as >"forms" (forma). I received only a little feedback, and the opinions were >split. Quick response from a non-essential fed who has been told to stay home and not use this computer...especially to talk about blame for furloughs.... Jeff-- Added to your interesting concerns are the related ones stemming from Mark Edlund's talk at Lakeside Lab, after which he was posing the question: Should a probable resting stage be given a specific or a varietal designation, in a case where we cannot tell to which "real species" it may belong. (Did you get an answer Mark?). It must happen often, but Mark was wrestling with whether it should be avoided. I agree with you, Jeff, that resting spores are poorly reported, often either ignored or merged with vegetative cells - both cases are a loss of life history and environmental info. I like your choice #4 of saying species XXX, resting stage as follows.... Of course with the Chrysophyceae, the splitting of resting spores without knowing their species affinity has proven very valuable for ecological and other interpretations (Adam, Zeeb, Duff, Smol, etc.), and in most cases it is not possible to make them a form of a known taxon. A numbering system has served much better than saying only, "we found lots of little glass balls, and some of them looked pretty amazing." There are semi-official procedures for collating the new morphotypes internationally, under the guidance of a working group representing a research community that is much smaller than ours of several hundred (or thousand) diatomists. From an ecological perspective, some identifier to keep the information about the resting stage is desirable. And this would also be desireable for botanists who want to work with the taxonomy and life history, so they know that these spores are available for study. From a botanical perspective, using "forma" does not seem the best way to do it to me, but I can see why you are thinking that this might force more information to be reported. Reporting about auxospores suffers from a similar lack of standard procedures. It is a reporting problem, but how can we improve this? --John ================== John C. Kingston Biological QA Unit From: PO2::"stoermer@UMICH.EDU" "Gene Stoermer" 29-DEC-1995 09:46:05.85 To: Multiple recipients of list DIATOM-L CC: Subj: Re: Should resting spores be recognized taxonomically? I don't mean to plug up everyone's mailbox, but the notion of designating life cycle stages as formae strikes me as strange. I am doing this at home, and don't have the ICBN handy but, if I remember correctly, it is also contrary to the rules. One immediate problem I see is that some of the most effective "resting stages" don't have, to my knowledge, any morphological modifications (e.g. Aulacoseira granulata). I think Jeff's idea of somehow conveying information about spore occurrence is a really good one, but I think it would be best accomplished by text notes. ***************************************************************** Eugene Stoermer, University of Michigan Internet e-mail address: stoermer@umich.edu Voice Phone: 313-764-5238 Fax: 313-747-2748 ***************************************************************** From: PO4::"slcooper@ACPUB.DUKE.EDU" "Sherri Cooper" 2-JAN-1996 11:26:29.46 To: Multiple recipients of list DIATOM-L CC: Subj: Re: Should resting spores be recognized taxonomically? I second the opinions of John and Gene. Resting spores are important to quantify, and should be reported separately, but not sure about the form designation. I have given them numbers myself, finding it difficult to identify most resting spores to specific species. Sherri Cooper Duke Wetland Center Durham, NC 27708 From: PO3::"EYH@WPO.NERC.AC.UK" "Elizabeth Haworth" 2-JAN-1996 12:25:23.91 To: Multiple recipients of list DIATOM-L CC: Subj: spores A Happy New Year to All The subject of identifying spores/resting stages may be 'old news' but I'd like to add my comments. Gene is right in saying that this is a part of the life cycle of the 'taxon' and therefore merits no formal name differentiation, except in the case of unrecognized fossils. There is, however, nothing to stop one having a category of 'species x - spore' in analyses and this would be the most straightforward way to include this differentiation; they do, after all, represent a specimen. I have recorded spores and cysts regularly but haven't made much use of them since I see, or recognize, so few. Urosolenia spores are the most readily observable in my samples here and keep me alert for the valves which are so easily passed over. Can anyone provide useful references to spore recognition? I think that is what keeps most people from differentiating them even though they are certainly scattered around the various texts. It would be helpful if some of the papers with sections relating to spores could be collated. I will also go and inspect the Fritsch Collection of Algal Illustrations to see if many of the sheets include spore illustrations. Liz Haworth Institute of Freshwater Ecology, Ambleside, Cumbria, UK. E.Haworth@ife.nerc.ac.uk From: PO2::"Reed.Scherer@NATGEOG.UU.SE" "Reed Scherer" 5-JAN-1996 05:18:04.57 To: Multiple recipients of list DIATOM-L CC: Subj: Re: Should resting spores be recognized taxonomically? This topic is of great interest to me as well. So many of the fossil diatoms described, especially lower Paleogene (>~40 million years) and Mesozoic diatoms, are spores with generally unknown vegetative affinities. Rarely a spore will be found within a vegetative frustule. And it is often a surprise that may lead to a taxonomic dilemma, if one is to adhere strictly to ICBN. (e.g., If the spore was described before the vegetative, but as a totally different genus then..........your problems have just begun.) I haven't the time today to go into a discourse on this. [I SINCERELY WISH MORE OF MY COLLEAGUES SUBSCRIBED TO OR UTILIZED THIS SERVICE (PAT SIMS....JULIANNE FENNER...ARE YOU LISTENING???)] Those interested in the spore "problem" in the stratigraphic context should have a look at: Hargraves, P. 1987. The relationship of some fossil diatom genera to resting spores, 8th diatom symposium 67-80 also: Harwood and Gersonde, 1990. Lower Creataceous diatoms from ODP Leg 113 (parts 1 and 2). Proceedings of the Ocean Drilling Program, Scientific Results V. 120. I frankly don't know what the appropriate course of action should be on this particular taxonomic bugaboo. (I've avoided thinking it all the way through). I hope the discussion continues. Best wishes to all for a great new year Reed Scherer From: PO4::"dtakiba@RC.JAPEX.CO.JP" "akiba fumio" 7-JAN-1996 23:47:32.57 To: Multiple recipients of list DIATOM-L CC: Subj: Re: Should resting spore ....... Dear Reed, I am grad to read a series of talks on resting spores at the beginning of this new year. Among them, your comment on fossil ones was especially nice to me, since you called attention to another facet of the resting spores, possibly a way to their application to paleoenvironmental and biostratigraphic analyses, of course involving some serious troubles on their taxonomic treatments as well. I quite agree with you that more "fossil-diatom colleagues" are better to be involved with this topic. You mentioned about Paleogene and Mesozoic resting spores in particular, but of course there are a lot of Neogene resting spores, and it is very regretful that most of them have been almost both taxonomically and biostratigraphically neglected in the previous literatures with few exceptions, so far I understand, and then their probable high utilities remain untested properly. In my routine biostratigraphic analysis, I count resting spores (most probably those of Chaetoceros and its closely related genera, I suppose) collectively during a count of "normal" diatom valves, and once I noted and reported that their very high occurrence might reflect some significant paleoenvironmental change in a particular Latest Miocene interval of the Northwest Pacific (Akiba, 1986; in DSDP, Leg 87 Init. Repts.), but again I'm regretful that I have not recognized so far those spores individually, although I' pretty sure they are biostratigraphically useful as well (there should be so numerous unnamed fossil "resting spores"). At the coming 14th International Diatom Symposium '96 at Tokyo (Sept. 2 - Sept. 8), therefore, I hope somebody (yourself ?) will be a convener and organize a workshop on the various aspects of "Resting spores." I surely will help him or her. Very sincerely yours, Fumio Fumio Akiba Paleontology and Sedimentology Groups JAPEX Research Center, Japan Peteroleum Exploration Co., Ltd. 1-2-1, Hamada, Mihama-ku, Chiba, 261 Japan Voice;043-275-9311 Fax;043-275-9316 E-mail; dtakiba@rc.japex.co.jp