Fifteenth NAWQA Workshop on Harmonization. of Algal Taxonomy. April 28-May 1, 2005

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1 Fifteenth NAWQA Workshop on Harmonization of Algal Taxonomy April 28-May 1, 2005 Report No Phycology Section/Diatom Analysis Laboratory Patrick Center for Environmental Research The Academy of Natural Sciences of Philadelphia 1900 Benjamin Franklin Parkway Philadelphia, PA Edited by Eduardo A. Morales August 2006

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3 Table of Contents Page Introduction... 1 Criteria for Adopting New Names... 2 Procedure for Evaluating Names... 4 Workshop Outcomes... 5 Adopted Genera Names... 6 Genus Names that were not Adopted or that were Deleted from List... 8 Additional Workshop Outcomes Summary of the Discussion on Gyrosigma Taxonomy at the Fifteenth NAWQA Workshop on Harmonization of Algal Taxonomy Conclusions Current Status of the Monoraphid GeneraKarayevia and Kolbesia Summary Problem Background Current status of Kolbesia Current status of Karayevia Recommendations List of names within or related to Karayevia recommended for use in NAWQA Taxonomy and Nomenclature of Two Species within the Genus Nitzschia Hassall Summary Review of valid taxa Review of invalid taxa Review of new species found in NAWQA material Conclusions and recommendations General References Appendix Appendix Appendix i

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5 Introduction The Fifteenth NAWQA Diatom Taxonomy Workshop was held at the Academy of Natural Sciences of Philadelphia on April 28-May 1, Specialists participating in the workshop were Kalina Manoylov from Michigan State University, MI; Nadezhda Slavchova and Rosalina Topalova from Portland State University, OR; Diane M. Winter from University of Nebraska, NB; Dr. Rex L. Lowe from Bowling Green State University, OH; Dr. Mark B. Edlund from the Science Museum of Minnesota, MN; Paul B. Hamilton from the Canadian Museum of Nature, Ottawa; and Dr. Sarah Spaulding from University of Colorado, Boulder, CO. Dr. Marina G. Potapova, Dr. Eduardo A. Morales, Dr. Donald F. Charles, Karin C. Ponader, Sarah Hamsher, Erin Hagan, Frank W. Acker, Mark Schadler and Kathleen Sprouffske from the Patrick Center for Environmental Research s Phycology Section at the Academy of Natural Sciences of Philadelphia also participated in the workshop and/or collaborated in its organization. The First, Second, and Third NAWQA taxonomy workshops had the overall objectives of harmonizing taxa names used in the ANSP and University of Louisville/University of Michigan laboratories, identifying reference images for each taxon, and agreeing on up-to-date nomenclature to use when analyzing NAWQA 1994 and 1997-Start samples (See Clason and Charles, 1999; 2000; Morales and Potapova, 2000). The Fourth Workshop dealt with the taxonomy of some problematic Navicula and Gomphonema species (Morales, 2001a), the Fifth Workshop with additional problematic species in the genus Navicula (Morales, 2001b), and the Sixth Workshop with many problematic taxa in the genus Gomphonema (Morales, 2002a). The Seventh Workshop concentrated on problematic species of the genus Nitzschia (Morales and Hamilton, 2002). The Eighth Workshop focused on the production of an updated taxonomic list, 1

6 the 2001-Start Taxa List (Morales, 2003a). The Ninth Workshop dealt with the taxonomic review of lists and some groups of soft algae, including a review of taxa lists and consideration of cyanobacteria and red-algae groups (in prep.). The Tenth Workshop focused on the taxonomy of Achnanthes-like taxa that are difficult to identify under the light microscope (Morales and Charles, 2005). The Eleventh Workshop dealt with the taxonomy of the blue-green algae (in prep.). The Twelfth Workshop dealt with fragilarioid problematic taxa (in prep.). The Thirteenth Workshop dealt with the taxonomy of taxa related to Synedra ulna (Nitzsch) Ehrenberg (in prep.). The Fourteenth Workshop concentrated on the taxonomy of various soft algal groups and continued with the review of the soft algae taxa list (in prep). The Fifteenth Workshop, subject of this report, focused on the revision of the 2001-Start diatom taxa list to produce the 2004-Start list to be used in the analysis of samples collected in 2004 and subsequent years. This revision was based on discussions of recent transfers of taxa and the review of recent concepts of taxa at the family, genus and species levels. Criteria for Adopting New Names Taxonomic lists used for the analysis of NAWQA samples are regularly updated at threeyear intervals. In order to achieve this, a workshop is organized and an extensive literature review is performed in search of new changes and advances in algal taxonomy (see Procedure for Evaluating Names, p. 4). Taxonomic names used for 2004-Start samples should reflect recent taxonomic trends, but any changes to the existing list should be made conservatively. Similar to the Third Workshop, the majority of new taxonomic names proposed in the literature pertain to the genus level. The majority of the newly erected genera are the result of discovery (mainly by SEM analysis) of a wide morphological variability within previously 2

7 established genera. These new genera tend to reflect more restricted groupings in which the morphological variability is limited, thus resulting in a more concise classification system. Some changes at the species and variety levels were also considered. Current literature reflects a tendency to work with morphologically restricted groups at the species level, restricting the use of the variety and form ranks. Therefore, many of these subspecific taxa became species of their own. Three main criteria were used in deciding whether to adopt a new name for the Start list. First, the validity of the proposed transfer was considered. Workshop participants determined whether creation of a new genus and/or species had a solid justification. Frequently, references with protologues were consulted and type material was observed, when available, from the ANSP Diatom Collection. To be accepted as a valid transfer, the new taxon had to be sufficiently supported by light microscopy (LM) and scanning electron microscopy (SEM), and/or ecological evidence. Second, the taxon had to be generally accepted by other diatom researchers. Participants relied on the frequency with which the new taxon was used in recent ecological and/or taxonomic literature, on the publication of arguments against or in favor of a given taxon, and on their own personal experience (i.e., does one consider that the taxon is sufficiently distinct?). During the Third Workshop, taxa changes may have been rejected because of their lack of distinguishable characters at the LM level. Due to the increasing use of SEM technology in published literature and by NAWQA analysts, this lack of LM characters was a minor criterion. Third, in cases in which a new genus had been accepted during the Third Workshop, additional transfers of species were done. In a few cases, workshop participants did reconsider the validity or reliability of a genus based on additional information presented in the literature. 3

8 The 2001-Start Diatom Taxa List currently contains groups of taxa for which some species have been transferred validly, but others remain under previous nomenclature. This is because the latter have not been transferred validly from one genus to another. Although participants recognize that some species should be transferred to new genera, they have followed the rules of the International Code of Botanical Nomenclature. In two cases, two of the genera that had been adopted during the Third Workshop were reevaluated based on newly published information. Names of species within these two genera, adopted during the workshop, follow suggestions in the literature. Procedure for Evaluating Names Prior to the workshop, K. Sprouffske and E. Morales prepared an Excel list of the taxa that have been reported to the BIO-TDB (the central biological database for NAWQA). E. Morales split the list into several parts and distributed them among workshop participants. Then, each participant listed all new transfers from the literature using the same spreadsheet and returned it to ANSP. All the parts were recombined, additional changes added, and this constituted the annotated list to be used during the workshop. During this workshop not only changes at the genus, species and infraspecific ranks were evaluated, but also family designations following two of the most influential works that are currently used in diatom research (i.e., Krammer and Lange-, and Round et al., 1990). During the workshop, participants went through the list and rated the proposed transfers. During an initial review of the list, taxa were assigned to four different categories: 1 when the new name for a taxon was approved; 2 when a given new name needed to be reviewed more thoroughly; 3 when the new name was not thoroughly supported in the literature or a name for 4

9 which sufficient information is not yet available; and 4 in the case of incorrect identifications. A particular identification was determined to be incorrect in three instances: the taxon is known only from fossil material, the taxon is known only from marine environments, or original slides from which a taxon had been reported were checked by M. Potapova or E. Morales. Next, literature was consulted, some material (including types from the ANSP Diatom Herbarium) was examined under LM, and the list of taxa was reviewed a second time to make a final decision about category 2 names. Workshop Outcomes All the new genera published in the literature and pertinent to updating the 2001-Start NAWQA Diatom Taxa List were reviewed by workshop participants. The updated list, known as the 2004-Start list, records the consensus of participants decisions as to whether to adopt proposed changes, and includes annotations with justifications and/or helpful comments. This list is presented in Appendix 1. A complete list of official names to be used by NAWQA analysts appears in Appendix 2. Names will be added to this list from time to time as new species are encountered during sample analysis, but they must first be approved by the Taxonomic Coordinator (E. Morales) following procedures and criteria in Appendix 1 of the Fifth NAWQA Report (Morales, 2001b). Both Appendices 1 and 2 are presented at the end of this report. Appendix 3 contains changes additional to those presented in Appendix 1 and that were compiled after the workshop. Some comments on the adopted/rejected new genus names follow. The name of the most common species from NAWQA within each new genus is presented in parentheses. 5

10 Adopted Genus Names Discostella Houk et Klee (Cyclotella stelligera species group) This taxon is based on Cyclotella stelligera (Houk and Klee, 2004). One of the main features distinguishing this taxon from related genera such as Punticulata and Cyclotella is the position of the strutted and labiate processes (fulto and rimoportulae, respectively). One of the main characteristics of this genus is the valve face composed of two distinct parts. The central area has an asterisk-shaped formation where each of the branches is an alveolus occluded toward the external valve surface by one to several rows of poroids. The rest of the valve face has radial striae of variable length (in some species the striae are restricted to the margins). The striae are composed of a variable number of areolae and thick costae are present between these striae. Many species show heterovalvy. In this case, one of the valves would possess the morphology described above and the other valve would have a concave central area in which the alveoli may or may not be visible under LM or SEM. In some cases even the areolae are occluded by excessive silicification. Platessa Lange- [Translation from German description in Krammer and Lange- (2004) by K. C. Ponader and D. M. Winter] Differential diagnosis of the genus Platessa in comparison with other genera split from Achnanthes sensu lato. The name Platessa was derived from the epithet of the scientific name of the Flounder Pleuronectes platessa. Frustules heterovalvar, monoraphid, according to the diagnosis of the family Achnanthidiaceae Mann in Round et al. (1990). The frustules of the species belonging to Platessa are similar in their habit and appearance to most of the species in the genus Cocconeis; 6

11 some have therefore been described originally as species in the latter genus. However, the construction of the raphe valve is different and the fimbriate valvocopula, which appears as a hyaline ring at the periphery of a Cocconeis raphe valve under LM, is missing. In their habitat, the cells can facultatively form short chain-like aggregates. The valve mantle and girdle bands together are only two microns wide in girdle view and are nearly straight with a very weak curvature along the apical and transapical axes. The cells are therefore very flat and disk-like. In the SEM, the raphe valve is concave and the pseudoraphe valve is convex; therefore, the opposite of the species with similar appearance under the LM and that are placed in the genus Psammothidium. The 3-4 copulae of each valve are very narrow and not perforated. The valvocopula does not have a different structure than that of other girdle elements. Externally, the distal raphe ends are nearly straight and end, as is the case of the proximal raphe ends, in very distinct pores. The bent distal ends of Planothidium that extend into the valve mantle are missing. Internally, the distal raphe ends have weakly developed helictoglossae. The proximal ends are bent in opposite directions. The areolae are internally occluded by hymens, have the same structure on both valves, and are generally arranged in biseriate rows in a quincunx arrangement. These rows of areolae do not show a tendency to become three or multiple rows, but rather a tendency to become single rows. The openings of the areoale do not show a tendency to transapical stretching, contrary to what happens in species of the genus Achnanthidium, but a tendency to stretch apically, especially when only one row of areolae is present. In addition, the valves of Achnanthidium are usually characterized by a linear, linearelliptical, or linear-lanceolate outline and are generally bent more strongly along the transapical axis (compare Fig. 90:3), and do not resemble species of Cocconeis. The monotypical genus Lemnicola also contains double rows of areolae, but possesses a stauros and curved distal raphe 7

12 ends. The rest of the genera that have been split from Achnanthes sensu lato are, in their combination of features, even less similar to Platessa. General discussion of the new genus. When the diverse species groups were still combined under Achnanthes subgenus Achnanthidium, which are now split at the rank of genera, there was no urgent need for a search for different criteria. Now that narrow and partly unclearly formulated genera diagnoses have been presented, a big heterogeneous group of taxa is left in Achnanthes. The search for criteria of further differentiation and structuring is a necessary consequence of these narrow genera concepts. The taxa that are here combined within Platessa were examined in the SEM and seem morphologically very homogeneous. Other taxa, as for example, Achnanthes lacunarum and A. lutherii, could, after examination under the SEM, also be part of this group. The latter however is heterovalvar regarding the areolae arrangement into different striae patterns. It is still in question if other species that have constant biseriate striae should be put into Planothidium or Platessa or into a new genus that has not yet been defined. Surely, there are reasons why the authors of the other new monoraphid genera did not define a placement for these species although their fine structures are known in the SEM. In the future, genera that have been defined in an imprecise manner will have to be considered at the time of placement of the species whose affinities remain doubtful. For a comparison of Platessa with other achnanthoid genera see Table 1. Genus Names that were not Adopted or that were Deleted from List Desmogonium Ehrenberg Species in this genus have been already transferred to the genus Eunotia. Therefore, there is no need to use this older homonym and it should be erased from the NAWQA list. 8

13 Kolbesia () Round et Bukhtiyarova (Achnanthes kolbei species group). This genus has been collapsed into Karayevia based on additional information gathered using SEM (Bukhtiyarova, 1999). M. Edlund and S. Spaulding explain the reasons for these taxonomic changes in more detail below. 9

14 Table 1. Comparison of selected morphological features of some recently erected Achnanthes-like genera. (Prepared by R. Lowe and P. Hamilton). Genus Character Achnanthidium Psammothidium Planothidium Rossithidium Karayevia Platessa Lemnicola Fine, not expanded at Raphe straight, central Raphe ends bent to one Raphe straight, central Axial area lanceolate Raphe straight, fissures Deflected in opposite center, terminal ends pores and terminal side proximal ends ends slightly swollen, hardly expanded toward not hooked directions proximate ends straight or slightly curved fissures variable apically expanded terminal ends turned to center filiform straight flexed to one side, Rhape internally, situated on rib, central pores bent toward one side externally running between parallel grooves proximal ends teardroplike and enclosed by opposite sides curved to one side at apex distinct groove apical ends on valve face turn to one side Valve form Raphe valve concave Raphe valve convex along both axes Raphe valve slightly concave Slightly concave raphe valve Stauros absent on Pseudoraphe valve Linear Coccoid, linear elliptical, Elliptic to elliptic- Linear to linear-lanceolate Elliptical to lanceolate, Concave Linear to linear elliptical, Valve shape ends always rounded lanceolate sometimes apices drawn narrowing to rounded out apex Uniseriate and often Similarly arranged on Bi to multiseriate, radiate Unbroken in central area, Radial on raphe valve, Pores biseriate and Biseriate to uniseriate transapically stretched both valves, poroid, small, to transverse interrupted striae on raphe valve can some shorter than others, apically stretched radial striae, interrupted Areolae closed on inner side by a cribrum on one side on the pseudoraphe valve be continuous, slightly separated or with a elongated more so toward margins. Areolae simple at valve center by wide slightly asymmetric central stauros outside, covered by a stauros on raphe valve cribrum internally With usually slightly 10 to 30 long, usually twice Inconspicuous ring of Mantle areolae present Mantle elongated areolae, that as long as wide (3 to 4) mantle pores extend around valve apex Cells small (less than 30µ Pseudoraphe valve with Narrow pseudoraphe long), often 3 to 6 times parallel striae and narrow stauros in center and Comments longer than wide axial area and circular areolae with a different raised central rib costae thickened on inside form than raphe valve (attached to sand grains)

15 Additional Workshop Outcomes Some problems encountered during the revision of the 2001-Start Taxa List required special attention and further work after the workshop. Chapters by participants working on these problems are presented in the following pages.

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17 Summary of the Discussion on Gyrosigma Taxonomy at the Fifteenth NAWQA Workshop on Harmonization of Algal Taxonomy By M. Potapova 1, photographs by D. Winter 2. 1 Patrick Center for Environmental Research The Academy of Natural Sciences of Philadelphia Philadelphia, PA Department of Geosciences University of Nebraska-Lincoln Lincoln, NE Identification of Gyrosigma taxa on the ANSP Algae Image Website was questioned by F.A.S. Sterrenburg in an message to D. Charles, September 10, Sterrenburg noted that he had critically revised Gyrosigma taxonomy using materials from various continents including those housed in the Diatom Herbarium of the Academy of Natural Sciences of Philadelphia (ANSP). He recommended that diatom analysts take into account his corrections to the existing taxonomic keys and floras. Participants of the Fifteenth Workshop reviewed Sterrenburg s publications, and based on his revisions and their own experience, made some changes in the existing NAWQA diatom taxa list. They also made recommendations for identification of Gyrosigma species in NAWQA material. There are 16 Gyrosigma taxa in the NAWQA 2001-Start list (unknowns excluded). According to Sterrenburg (1994; 1995), four of these taxa names must be excluded from the list because they are considered superfluous synonyms of other taxa. These are: G. spenceri (Smith) Griffith et Henfrey (synonym of G. acuminatum (Kützing) Rabenhorst), G. scalproides (Rabenhorst) Cleve (synonym of G. obtusatum (Sullivant et Wormley) Boyer), G. nodiferum 13

18 (Grunow) Reimer (synonym of G. sciotoense (Sullivant et Wormley) Cleve), and G. parkeri (Harrison) Elmore (synonym of G. wormley (Sullivant) Boyer). One taxon, G. reimeri Sterrenburg, has to be added to the list because it is present in U.S. rivers, but it is often misidentified as G. nodiferum. Additionally, G. obscurum (W. Smith) Griffith et Henrey is a Pleurosigma according to Sterrenburg (1993). Each proposed change is considered here in more detail. G. spenceri (Smith) Griffith et Henfrey and G. acuminatum (Kützing) Rabenhorst Sterrenburg (1995) studied type material of G. spenceri (ANSP G.C. 3174) from the Croton River, NY and of G. acuminatum (ANSP G.C a) from Germany, as well as many other populations of Gyrosigma that could be identified as these two taxa. He concluded that G. spenceri and G. acuminatum are conspecific because there are no differences in their morphological characters. Specimens from type populations differ, however, in shape: G. spenceri has lower width-to-length ratio than G. acuminatum, but Sterrenburg considered these differences non-essential and representing a continuum of variation. Workshop participants felt, however, that they can distinguish G. spenceri and G. acuminatum and usually do not observe intermediate shapes. The considerable difference between shapes of G. spenceri and G. acuminatum in type populations (Figs. 1, 2) convinced workshop participants that these two names might represent two different species, even if all morphological features except shape are the same. However, distinctions between G. spenceri and G. acuminatum were not consistent between different NAWQA analysts, with some clearly preferring the name G. spenceri, and others favoring G. acuminatum. This inconsistency was partly due to inadequate coverage of Gyrosigma in the flora most commonly used in routine identifications (Krammer and Lange- 14

19 , 1986). The final decision was to retain both names in the NAWQA species list, and recommend following Patrick and Reimer s (1966) key to identify these taxa. Due to the inconsistent use of these names in the past, and because so far there are no indications of ecological differences between these taxa, they can be lumped into G. acuminatum sensu Sterrenburg (1995) for large-scale analyses of NAWQA data. G. scalproides (Rabenhorst) Cleve and G. obtusatum (Sullivant et Wormley) Boyer Sterrenburg (1994) studied type material of G. obtusatum from Ohio (ANSP Boyer W-6-20) and G. scalproides from Europe (ANSP G.C ) and concluded that these names are synonyms. Both names are used for a Gyrosigma species with slightly sigmoid valve outline and T-shaped central external raphe endings. Workshop participants felt, however, that shape differences between Gyrosigma specimens in the type slides of G. obtusatum and G. scalproides (Figs. 3-6) are marked and cannot be dismissed until there is clear proof of a continuous variation between these two shapes. They agreed that NAWQA analysts should use both names, and that Patrick and Reimer s (1966) key should be used for identification. Some records of G. scalproides in the NAWQA data may be erroneous, because G. obtusatum is not listed in Krammer and Lange- (1986) and analysts using this flora might have identified G. obtusatum as G. scalproides. Records of both taxa could be lumped for large-scale analyses of NAWQA data under the name of G. obtusatum sensu Sterrenburg (1994). G. parkeri (Harrison) Elmore and G. wormley (Sullivant) Boyer Reimer (Patrick and Reimer, 1966) established that Gyrosigma parkeri is a synonym of G. wormley, and the latter name has priority. The name G. parkeri nevertheless appeared in 15

20 NAWQA records because it is used in a widely utilized flora, Krammer and Lange- (1986). Sterrenburg (1994) pointed out again that Reimer was correct in his conclusion about nomenclatural history of this taxon, and its name should be G. wormley. The workshop participants decided that all records of G. parkeri in the NAWQA counts must be changed to G. wormley. G. nodiferum (Grunow) Reimer, G. sciotoense (Sullivant et Wormley) Cleve), and G. reimeri Sterrenburg Sterrenburg s (1994) examination of type materials of Pleurosigma sciotoense Sullivant et Wormley (synonym of Gyrosigma sciotoense) from Columbus, OH and of Pleurosigma spencerii W. Smith var. nodiferum Grunow (synonym of G. spenceri var. nodiferum (Grunow) Cleve and G. nodiferum) from Europe showed that they are conspecific. G. sciotoense is an earlier and valid name. This species has a characteristically rotated central area and double raphe curvature (Figs. 7-9). The records of G. nodiferum in the NAWQA counts must be changed to G. sciotoense. It is important to note, however, that many of those records are erroneous, because taxonomic treatment of G. sciotoense and similar species in diatom floras was inadequate. A brief examination of NAWQA slides showed that the name G. nodiferum has been applied to at least three species: G. sciotoense, G. reimeri, and G. acuminatum (Figs. 7-15). The analysts that used Krammer and Lange- (1996) diatom flora for identifications applied the name G. nodiferum either to G. sciotoense that was illustrated as G. nodiferum, or to G. acuminatum (possibly because the illustration of G. nodiferum does not show clearly the characteristic features of this species). Those who used Patrick and Reimer (1966) applied the name G. nodiferum for G. reimeri, the species being yet unknown in G. reimeri can be most easily 16

21 distinguished from G. sciotoense by several (versus one in G. sciotoense) rows of areolae running around the valve apex (Figs. 13, 15). The name G. reimeri must be added to the NAWQA list, and Sterrenburg (1994) should be used for identification. Gyrosigma obscurum (W. Smith) Griffith et Henfrey and Pleurosigma obscurum W. Smith. Although Sterrenburg (1993, 2003) argued for the placement of Gyrosigma obscurum in the genus Pleurosigma, counterarguments by Reid (2002, 2004) were strong enough to convince workshop participants to retain this taxon in Gyrosigma. Conclusions Workshop participants decided to make the following changes to the NAWQA species list: to remove G. nodiferum (Grunow) Reimer and G. parkeri (Harrison) Elmore, and to add G. reimeri Sterrenburg. Records of G. nodiferum must be changed to G. sciotoense, and records of G. parkeri need to be changed to G. wormley. The other changes proposed by Sterrenburg were rejected. We think that Sterrenburg might be correct in concluding that G. acuminatum - G. spenceri, and G. obtusatum- G. scalproides are conspecific, but at present we are not entirely convinced that there is a continuum of variation between shapes corresponding to type populations of these diatoms. We decided to keep all four names to be able in the future to test hypotheses that there are ecological differences between populations with different valve outlines. 17

22 Figures 1-6. Micrographs of Gyrosigma specimens from type slides housed at the ANSP Diatom Herbarium. Scale bar = 10 μm. 1. G. acuminatum, ANSP G.C b, slide made from the type material, Herb. Kützing, Dec.9, No G. spenceri, ANSP G.C. 3174, Croton R., NY. 3. G. obtusatum, circled specimen from the lectotype slide ANSP W-6-20 Boyer, Columbus, OH G. scalproides, ANSP G.C , slide made from the type material, Rabenhorst, Alg. Eur. #

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24 Figures Representatives of Gyrosigma identified as G. nodiferum in NAWQA counts. Scale bar = 10 μm G. sciotoense. Cottonwood Creek, CO, South Platte River Basin study unit (ANSP Phycology Section GS116061, ANSP G.C. GS116061) G. spenceri (= G. acuminatum sensu Sterrenburg 1995), March Run, MD, Potomac River Basin study unit (ANSP Phycology Section GS ANSP G.C a) G. reimeri. Orestimba Creek, CA, San Joaquin-Tulare Basins study unit (ANSP Phycology Section GS119944, ANSP G.C a). 20

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27 Current Status of the Monoraphid Genera Karayevia and Kolbesia By Mark Edlund 1 and Sarah Spaulding 2 1 St. Croix Watershed Research Station Science Museum of Minnesota nd St. N. Marine on St. Croix, MN 55047, USA. 2 U.S. Geological Survey National Wetlands Research Center U.S. E.P.A., Region 8 EPA Mail Code EPR-EP th Street Denver, CO , USA Summary The genera Karayevia and Kolbesia were poorly and invalidly described by Round and Bukhtiyarova in Validation of the genera occurred under questionable circumstances by Round in Recent proposals by Bukhtiyarova (1999, personal communication in Lange- 2004) have disregarded the genus Kolbesia as a superfluous synonym of Karayevia, although little rationale has been offered. Because the co-author of Kolbesia no longer recognizes the genus and because it has not been well circumscribed since its inception, it is recommended that NAWQA analysts also disregard Kolbesia and use the species names and combinations in the genus Karayevia. Problem Background In 1996, Round and Bukhtiyarova erected four new achnanthoid genera to accommodate several groups of taxa that they felt warranted recognition separate from Achnanthes sensu stricto or Achnanthidium sensu stricto. Two of the new genera, Karayevia Round et 23

28 Bukhtiyarova and Kolbesia Round et Bukhtiyarova, were invalid at the time of description, because the generitype was not specifically designated. Round (1998) attempted to validate the two genera, proposing Achnanthes clevei Grunow in Cleve and Grunow as the generitype of Karayevia and erroneously proposing Achnanthes clevei (1930, a nom. nud.) as the generitype for Kolbesia. However, Fourtanier and Kociolek (1999) felt that the two genera were valid following Round (1998) as Karayevia Round et Bukhtiyarova ex Round and Kolbesia Round et Bukhtiyarova ex Round, citing that Round's error in typifying Kolbesia with A. clevei was a "lapsus" for Achnanthes kolbei (1930) and thus represented valid publication and typification under Art of ICBN (Greuter et al., 2000). Fourtanier and Kociolek (1999) further noted that as of Round's (1998) publication, no species combinations within Karayevia (and we suggest the same for Kolbesia) had been validly published (such as those proposed in Round and Bukhtiyarova 1996). As summarized by Kingston (2003) Karayevia is characterized by linear-lanceolate to lanceolate valves with various ends, valves of dissimilar structure, raphe filiform in a channel, terminal ends curved unilaterally, sternum present on pseudoraphe-valve, striae radiate on raphevalve and with oblong areolae near the raphe and margin, striae parallel to slightly radiate on pseudoraphe-valve, areolae closed internally by cribra on raphe-valve and externally by pegged cribra on pseudoraphe-valve, and cingulum of plain bands. Karayevia taxa grow adnate on sand and prefer alkaline water. Kolbesia also has dissimilar valves with a single elongate areola making up each stria on the raphe-valve and 2-3 elongate areolae separated by longitudinal hyaline areas in each stria on the pseudoraphe-valve. Areolae closings of Kolbesia are not defined in original description or by Kingston (2003). The raphe in Kolbesia is not in a channel, proximal raphe ends are expanded externally, distal ends are hooked, and a sternum is present on 24

29 the pseudoraphe-valve. Similar to Karayevia, Kolbesia taxa grow adnate on sand in alkaline water. Current status of Kolbesia To date, the generitype of Kolbesia, Achnanthes kolbei, has not been validly transferred to Kolbesia. Kingston (2000) provided valid transfers of three Kolbesia species, K. amoena () Kingston, K. ploenensis () Kingston, and K. suchlandtii () Kingston. Bukhtiyarova (personal communications in Lange- 2004) expressed her concern with the recognition of the genus Kolbesia, indicating that Dr. Round had penned the description of Kolbesia in Round et Bukhtiyarova (1996) without her consult. In response, Bukhtiyarova (1999) had transferred the type of Kolbesia, Achnanthes kolbei to the genus Karayevia; thus, in her opinion, the genus Kolbesia was obsolete. She followed by transferring other "Kolbesia" taxa to the genus Karayevia including: Karayevia kolbei () Bukhtiyarova Karayevia amoena () Bukhtiyarova (not validly published) Karayevia suchtlandtii () Bukhtiyarova Karayevia ploenensis () Bukhtiyarova Karayevia ploenensis var. gessneri () Bukhtiyarova (not validly published) Karayevia ploenensis var. woldstedtii () Bukhtiyarova (not validly published) Refer to the discussion under Karayevia for clarification on why several of these names are not validly published. 25

30 Current status of Karayevia The generitype of Karayevia, Achnanthes clevei Grunow, was validly transferred in 1999 as K. clevei (Grunow) Bukhtiyarova (Buktiyarova 1999, p 94). Bukhtiyarova (1999, p. 94) concurrently proposed these transfers into Karayevia: Karayevia clevei (Grunow) Bukhtiyarova Karayevia amoena () Bukhtiyarova (not validly published) Karayevia carissima (Lange-) Bukhtiyarova (not validly published) Karayevia clevei var. rostrata () Bukhtiyarova Karayevia clevei var. bottnica (Cleve) Bukhtiyarova (not validly published) Karayevia dornii (Lange-) Bukhtiyarova (not validly published) Karayevia kolbei () Bukhtiyarova Karayevia laterostrata () Bukhtiyarova Karayevia suchtlandtii () Bukhtiyarova Karayevia ploenensis () Bukhtiyarova Karayevia ploenensis var. gessneri () Bukhtiyarova (not validly published) Karayevia ploenensis var. woldstedtii () Bukhtiyarova (not validly published) Karayevia submarina () Bukhtiyarova (not validly published) A review of these transfers indicates that Karayevia carissima is not a valid transfer because a full and direct citation of the basionym reference is not presented ( Lange- et al., Bibliotheca Diatomologica 18.). Likewise, the transfer of Karayevia dornii is not valid because the taxon Achnanthes dornii was never formally published and was only included as a manuscript name by Lange- et al. (1989). Karayevia submarina is not validly 26

31 published because a full and direct citation of the basionym is not provided, i.e.,, F Diatomeen aus dem Lago de Maracaibo in Venezuela. Ergebnisse der deutschen limnologischen Venezuela-Expedition Deutscher Verlag der Wissenschaften, Berlin., Vol: 1, , with specific reference to p. 110 and Figs is not fully cited in Bukhtiyarova (1999). Karayevia clevei var. bottnica (Cleve) Bukhtiyarova is not validly published as Bukhtiyarova (1999) cites Achnanthes bottnica Cleve as the basionym when it should be Achnanthes clevei var. bottnica Cleve (Cleve, P The diatoms of Finland. Acta Societas Fauna et Flora Fennica 8(2): 1-68, specifically referring to p 52, Figs 3:4-5). Karayevia amoena is also not validly published because a full and direct citation of the basionym is not not listed in the literature section of Bukhtiyarova (1999) (, F Neue und wenig bekannte Diatomeen. IV. Bot Notiser 4(1952): , must specifically cite p. 386, and Figs ). The transfer of Karayevia ploenensis var. gessneri is also not validly published because a full and direct citation of the basionym is lacking; (1953) (, F Diatomeen aus der Oase Gafsa in Südtunesien. Arch. f. Hydrobiol. 48: , specifically referring to p. 148, Figs ) is not fully cited in Bukhtiyarova (1999). The transfer of Karayevia ploenensis var. woldstedtii is also not validly published because a full and direct citation of the basionym is lacking; (1954) (, F Die Diatomeenflora von Oberohe in der Lüneburger Heide. Abh. Naturw. Ver. Bremen 33: , with specific reference to p. 453 and Figs. 7-10) is not fully cited in Bukhtiyarova (1999). Lange- (2004) provided a validly published proposal of the new combination, Karayevia bottnica (P.T. Cleve) Lange-, in the supplemental text of the re-issue of Krammer and Lange-'s Süsswasserflora von Mitteleuropa 2/4 (Krammer and Lange- 27

32 , 2004). Lange- (2004) also proposed a new species, Karayevia obtusa Lange-, based on Achnanthes laterostrata fo. lanceolata Cleve Kingston (2000), unaware of Buktiyarova (1999), erroneously proposed the transfers Karayevia laterostrata () Kingston and Karayevia clevei var. rostrata () Kingston. Those two combinations are later homonyms of Bukhtiyarova's (1999) names; thus, they are illegitimate. Recommendations Because the co-author (Bukhtiyarova) of Kolbesia no longer recognizes the genus and because it has not been well circumscribed since its inception, it is recommended that NAWQA analysts also disregard the genus Kolbesia and use the species names and combinations for these taxa as provided in the genus Karayevia. A list of recommended (following ICBN rules, Greuter et al., 2000). Karayevia names and their synonyms follows. I (MBE) have contacted Bukhtiyarova and made her aware of the need to correct the transfers of the five Karayevia taxa that have not been validly published. Workshop participants agreed to use the Karayevia combinations in anticipation of Bukhtiyarova s valid publication of these names. List of names within or related to Karayevia recommended for use in NAWQA (in bolds) Karayevia amoena () Bukhtiyarova (nom. nud.) Achnanthes amoena Kolbesia amoena () Kingston 28

33 Karayevia carissima (Lange-) Bukhtiyarova (nom. nud.) Achnanthes carissima Lange- Karayevia clevei (Grunow) Bukhtiyarova Achnanthes clevei Grunow in Cleve et Grunow Achnanthidium clevei (Grunow) Czarnecki Karayevia clevei var. rostrata () Bukhtiyarova Karayevia clevei var. rostrata () Kingston (nom. illegit.) Achnanthidium clevei var. rostratum () Edlund Achnanthes clevei var. rostratum Karayevia bottnica (Cleve) Lange- Karayevia clevei var. bottnica (Cleve) Bukhtiyarova (nom. nud.) Achnanthes clevei var. bottnica Cleve Achnanthes bottnica (Cleve) Cleve Karayevia dornii (Lange-) Bukhtiyarova (nom. nud.) Achnanthes dornii Lange- (nom. illegit.) Karayevia kolbei () Bukhtiyarova Achnanthes kolbei Kolbesia kolbei () Round et Bukhtiyarova (nom. nud.) Karayevia laterostrata () Bukhtiyarova Karayevia laterostrata () Kingston (nom. illegit.) Karayevia laterostrata () Round et Bukhtiyarova (nom. nud.) Achnanthes laterostrata 29

34 Karayevia suchtlandtii () Bukhtiyarova Achnanthes suchtlandii Kolbesia suchlandtii () Kingston Karayevia ploenensis () Bukhtiyarova Achnanthes ploenensis Kolbesia ploenensis () Round et Bukhtiyarova (nom. nud.) Kolbesia ploenensis () Kingston Karayevia ploenensis var. gessneri () Bukhtiyarova (nom. nud.) Achnanthes ploenensis var. gessneri Karayevia ploenensis var. woldstedtii () Bukhtiyarova (nom. nud.) Achnanthes ploenensis var. woldstedtii Karayevia submarina () Bukhtiyarova (nom. nud.) Achnanthes submarina 30

35 Taxonomy and Nomenclature of Two Species within the Genus Nitzschia Hassall By Sarah Spaulding 1 and Sarah Hamsher 2 1 United States Geological Survey Fort Collins Science Center 2150 Centre Avenue, Bldg. C Fort Collins, CO Patrick Center for Environmental Research The Academy of Natural Sciences of Philadelphia Philadelphia, PA Summary Nitzschia obtusa var. kurzii Rabenhorst ex Cleve & Möller was reported as part of the 2001-Start NAWQA diatom taxa list. We recognized that a similar name, Nitzschia kurzeana, was recently mentioned in Kociolek (2004) as part of a review of the Rabenhorst exsiccate. Due to the inconsistency in the use of these names, we decided to investigate further. In order to accomplish this we reviewed type material of Nitzschia kurzeana Rabenhorst and Nitzschia obtusa W. Smith as well as NAWQA material. In conclusion, Nitzschia obtusa var. kurzii, Nitzschia obtusa var. kurziana Rabenhorst 1873, and Nitzschia kurzii Rabenhorst ex Cleve & Möller are invalid names. Records listing Nitzschia obtusa var. kurzii Rabenhorst ex Cleve & Möller in NAWQA should be changed to Nitzschia kurzeana Rabenhorst. While reviewing the material we also discovered four potentially new species (Nitzschia sp. 1, N. sp. 2, N. sp 37 NAWQA HAMSHER, and N. sp. 38 NAWQA HAMSHER) that did not fit the current description of Nitzschia kurzeana Rabenhorst or Nitzschia obtusa W. Smith. Nitschia sp. 1 and 31

36 sp. 2 are not present in NAWQA material and were found in H. L. Smith and Cleve and Möller collections, respectively currently housed in the ANSP Diatom Herbarium. Nitzschia sp. 37 and 38, as denoted by their unknown designation, have been found in NAWQA material. These new taxa should be added to the 2004-Start list and the corresponding changes added to the change systems devised to produce such a list. Review of valid taxa Nitzschia kurzeana Rabenhorst (Figs. 1-8) Type Material: Rabenhorst 2312 Slide examined: ANSP GC # Location: India (West Bengal) Calcutta Collector: Wilhelm Sulpiz Kurz Original description: N. magna, leviter sigmoidea, utroque polo obtusa, nodulis lateralibus magnis. 1 in 0,0001 m. m; valvis late linearibus, ad polos rotundato subcapitatos cuneatis, striis transversalibus subtilissimis. Observations: Valve margin is linear elongate with distal ends curved to opposite sides. Valve length ranges from 66.7 to 95.2 µm; valve width at the central valve ranges from 6.8 to 8.3. Valve width at the widest point ranges from 7.4 to 8.5 µm. Striae are difficult to resolve because of apparent degradation of the mounting medium, but we estimate that striae number in 10 µm. Fibulae are 6.5 to 8 in 10 µm. Striae are not resolvable in the slides we examined, because of the great thickness of the coverslip. Comments: Our observations are based on specimens prepared from isotype material of Rabenhorst. Collections from North America that fall within the original description of N. 32

37 kurzeana include populations found in (ANSP GC103574a) from Hillsboro Canal, Southern Florida, NAWQA Sample GS (Figs. 9-13). Kociolek (2004) notes that this name is not included in VanLandingham s (1978) catalog, and that reference is given to N. kurzii Rabenhorst ex Cleve & Möller #78 (see later). Based on the ICBN (Greuter et al., 2000), the name N. kurzeana is validly published. According to Edgar ( names presented in boldface in his catalog reflect those that Rabenhorst bolded on his specimen labels as the focus of the sample. The name N. kurzeana, appears in boldface in this catalog. Nitzschia obtusa W. Smith (Figs ) Type Material: W. Smith 109 Slide examined: W. Smith 109 (ANSP 78) Location: Shagalieu Marsh, Poole Bay, June 1849 Collector: W. Smith Original description: F. of F.V. linear, with rounded extremities; V. linear, obtuse; puncta double; striae 56 in 001. Length 0042 to v.v. Observations: Valve margin is extremely narrow and elongate. Valve length ranges from 221 to 300 µm; valve width ranges from µm. Fibulae number 4-6 in 10 µm. Striae are not resolvable in the slides we examined, because of the great thickness of the coverslip. Nitzschia kurzii Rabenhorst in Grunow Description (translation): Closely related to N. obtusa, valves linear, slightly bent with wedge shaped and crooked (not straight/bent) ends. Sometimes in the middle slightly thinner (also 33

38 found in N. obtusa). Fibulae approximately 7 in 10 µm. Striae in 10 µm. Length µm, width 9 µm. Bengal, very common in slightly salty water. Comments: This taxon is valid according to Silva (Index Nominum Algarum, ), and the original description appears in German. VanLandingham s Catalog (1978) lists this taxon as an alternate to N. kurzeana, implying that VanLandingham considered it a synonym. The species was described from Bengal. Both N. kurzeana and N. kurzii are described from the Indian subcontinent and it would be reasonable to compare these two taxa to determine if they are, indeed, distinct species. We have yet to determine if this taxon is synonymous with Nitzschia kurzii Rabenhorst ex Cleve & Möller. This is only a description; no pictures or slides exist at ANSP. Review of invalid taxa Nitzschia obtusa var. kurziana Rabenhorst 1873, No This taxon is invalid because it lacks a description. As a note, it is not listed in VanLandingham s Catalog (1978). The species was described from Calcutta, from a separate sample from N. kurzeana. Besides the similar type localities, the close spellings of the specific epithet (kurzeana) and variety (kurziana) lead us to believe that an orthographic error accounts for the difference in spelling. However, because the names are of different rank (species and variety) and by the same author (Rabenhorst), we cannot confirm that Rabenhorst made such an error. 34

39 Nitzschia kurzii Rabenhorst ex Cleve & Möller, This taxon is invalid because it lacks a description. It appears in VanLandingham s Catalog (1978). Nitzschia obtusa var. kurzii Rabenhorst ex Cleve & Möller, 1878, No. 78. This taxon is invalid because it lacks a description as a variety of the species obtusa. It appears in VanLandingham s Catalog as a species (see above), but not as a variety. Review of new species found in NAWQA material Nitzschia sp. 37 NAWQA HAMSHER (Figs ) Description: Valve margin is linear and elongate, with sigmoid symmetry in relation to apical axis. Central margin of valve is slightly constricted (more narrow) than the remainder of the valve. Length ranges from µm and width ranges from 6.5 to 9.1µm. Fibulae number 5-8 in 10 µm. The mounting medium in the Cleve & Möller 78 slide was degraded, which results in an abnormal appearance of the fibulae. Striae were not resolvable. This taxon differs from N. kurzeana by its more elongate valve margin that is the valve smaller in width compared to the valve length.comments: This taxon was found on the following slides: 1) Cleve & Möller 78 (Thaca Choung, East Indies collected by Kurz.) 2) ANSP GC b (from Tamiami Canal, Florida from NAWQA Sample GS027353) 3) ANSP GC a (from Salado Creek, Texas from NAWQA Sample GSN97121) 35

40 Nitzschia sp. 1 (Figs ) Description: Valve margin linear, with apiculate ends. Slight sigmoid symmetry. Central margin of valve is slightly constricted (more narrow) than the remainder of the valve. Length ranges from 50 to 74 µm and width ranges from 6 to 8 µm. Fibulae number 6-8 in 10 µm. Striae were not resolvable. Comments: This taxon was found on H.L. Smith 351 (Oakland, CA) (Smith, ). Nitzschia sp. 38 NAWQA HAMSHER (Figs ) Description: Valve margin extremely elongated and narrow, with bluntly rounded ends. Sigmoid symmetry in relation to apical axis. Length ranges from 182 to 346 µm, width ranges from 7 to 10 µm. Fibulae number 5-6 in 10 µm. Striae number in 10 µm. Comments: This taxon was found on ANSP GC a (Bayou Castine, LA from NAWQA Sample GSN01107) Nitzschia sp. 2 (Figs ) Description: Valve margin elongated and apiculate ends. Valve outline nearly symmetrical in relation to apical axis. Length ranges from 125 to 182 µm, width ranges from 6.3 to 9.2 µm. Fibulae number 5-7 in 10 µm. Striae were not resolveable. Comments: This taxon was found on Cleve & Möller #77 (Villerville, Normandie collected by A. de Brébisson). Conclusions and recommendations Diatom collections from the NAWQA program include at least five taxa from within the brackish water, sigmoid group of nitzschioid diatoms. Of these five taxa, we could confirm the identification of only one taxon, Nitzschia kurzeana Rabenhorst using type material. At least 36

41 four other taxa within this group of diatoms occur in NAWQA samples. Although we have not resolved if these taxa have been validly described, we documented here their morphological range. Further studies to determine the identity of these four entities are required. As identities are better established, appropriate changes to NAWQA data must be made. The unknown names provided here should be used if specimens are encountered in future NAWQA work. There are inconsistencies within the existing literature, which have led to a large number invalid taxa. Some of these inconsistencies appear to be orthographic errors, although we are not able to confirm this hypothesis. 37

42 Figures 1-8. Isotype specimens of N. kurzeana Rabenhorst Scale bars = 10 µm. 38

43 39

44 Figures Specimens identified as N. kurzeana from ANSP GC a (NAWQA GS027503). Scale bar = 10 µm. 40

45 41

46 Figures Isotype specimens of N. obtusa W. Smith 109 (ANSP 78). Figures 15 and 18 are of circled specimens, although there is no indication if the specimens were designated by W. Smith. 19. Type illustration of N. obtusa (Pg. 39, Pl. XIII, Fig. 109, 1853). Scale bar = 10 µm. 42

47 43

48 Figures Nitzschia sp. 37 NAWQA HAMSHER. Specimens are from ANSP Cleve & Möller #78. The slides are labeled as N. kurzii, a taxon which is not validly described. Sample from Thaca Choung, East Indies. Scale bar = 10 µm. 44

49 45

50 Figures Nitzschia sp. 37 NAWQA HAMSHER. Specimens are from ANSP GC b (NAWQA GS027353). Sample from Tamiami Canal, FL. Scale bar = 10 µm. 46

51 47

52 Figures Nitzschia sp. 37 NAWQA HAMSHER. Specimens are from ANSP GC a (NAWQA GSN97121). Sample from Salado Creek, TX. Scale bar = 10 µm. 48

53 49

54 Figures Nitzschia sp. 1. Specimens are from ANSP H.L. Smith (351). Sample from Oakland, CA. Scale bar = 10 µm. 50

55 51

56 Figures Nitzschia sp. 38 NAWQA HAMSHER. Specimens are from ANSP GC a (NAWQA GSN01107). Sample from Bayou Castine, LA. Scale bar = 10 µm. 52

57 53

58 Figures Nitzschia sp. 2. Specimens are from ANSP Cleve & Möller #77. The slides are labeled as N. obtusa, but these specimens are not of the type. Sample from Villerville, Normandie. Scale bar = 10 µm. 54

59 55