Short Communication |
Corresponding author: Josef Juráň ( juran.josef@seznam.cz ) Academic editor: Endymion Cooper
© 2016 Josef Juráň.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Juráň J (2016) Trachelomonas bituricensis var. lotharingia M.L. Poucques 1952, a morphologically interesting, rare euglenoid new to the algal flora of the Czech Republic. PhytoKeys 61: 81-91. https://doi.org/10.3897/phytokeys.61.7408
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This report describes the discovery of the rare euglenoid taxon Trachelomonas bituricensis var. lotharingia in a small mesotrophic pond in the Czech Republic. Only limited data are available on the distribution of this taxon as same as for typical variety of Trachelomonas bituricensis, even though this taxon is morphologically very well defined. I provide a brief discussion of the taxonomic validity of this taxon based only on morphological features, which are characteristic for the taxonomy of the genus Trachelomonas. This finding is completely new for the algal flora of the Czech Republic. This report provides new information about the worldwide distribution of this taxon and its ecology.
Czech Republic, floristics, microalgae, Trachelomonas
Floristics studies have had a long tradition in the Czech Republic beginning in the second half of the 19th century, when several works about alga flora in this country were published. Since the publication of pioneering works by
I performed a nearly 5 year survey during my bachelors and masters studies investigating the diversity of photosynthetic euglenophytes (
The genus Trachelomonas includes euglenoids with their cells enclosed in envelopes (loricas) comprising polysaccharides with a content of iron and several inorganic compounds (
Trachelomonas bituricensis was originally described by
The aim of this study was to survey the algal flora of the small mesotrophic pond Ďáblík (South Bohemia region, Czech Republic, 48°49'41.0"N, 14°35'49.6"E, see Figs
Visualisation of the morphology of Trachelomonas bituricensis var. lotharingia by optical and electron scanning microscopy. A Overall appearance of lorica under an optical microscope, with a short collar with undulated edge (marked with arrow) B Detailed image of the lorica surface with three types of spines: long, curved spines at the antapical part of the lorica; shorter spines on the lorica’s body; and several straight spines near the apical pore (marked with arrows). Note the numerous disc-like chloroplasts in the cell C, D Loricas viewed by scanning electron microscopy, with clearly visible punctuation at the surface, and short collar with undulated edge (marked with arrow). Scale bars = 10 μm.
In 2012 and 2013, a pilot survey was taken, and in 2014, a more detailed survey with monthly sampling at five chosen locations was performed. The aim of this survey was to record algal diversity, especially for loricate euglenoid genera Trachelomonas and Strombomonas. Samples were taken using a 20 µm plankton net, and the material was fixed in formaldehyde solution and Lugol’s iodine solution. Samples were examined microscopically under an Olympus BX51 microscope and photographed with an Olympus DP-71 camera with DP Controller 3.1.267 software. Samples fixed in iodine solution were used for scanning electron microscopy. Materials for scanning electron microscopy were prepared as described by
The algal flora of the Ďáblík pond is dominated by dinophytes (Peridinium spp.), together with desmids and metaphytic communities of Spirogyra spp. steril., as well as diatoms (especially Gomphonema species). Taxon-rich flora of the loricate euglenoids will be studied in detail using optical and scanning electron microscopy in conjunction with comparisons of the chemical and physical parameters of pond water. Based on the preliminary results, some of the taxa appear to represent new algal flora of the Czech Republic, but these taxa require further study. The most interesting finding is the discovery of Trachelomonas bituricensis var. lotharingia, a newly recorded variety of algal flora in the Czech Republic. This variety is quite common in Ďáblík pond, which contains a stable population of this alga. This finding represents the first record of this taxon among algal flora of the Czech Republic based on a detailed literature review and the floristic survey across the Czech Republic that I performed during my bachelors and masters studies (
The loricas in this species are (41 –)45–46 µm in length and (30 –)33–35 µm wide. The cell contains numerous disc-like chloroplasts, probably without pyrenoids. The surface of the lorica in this taxon from Ďáblík pond is punctate and covered with well-developed hollow, sharp spines (see Fig.
A comparison of a typical variety of Trachelomonas bituricensis, the variety described by
Feature |
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|
This study |
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Shape | ellipsoidal to ovoid | ellipsoidal | |
Length
|
40 µm | 40 µm | (41 –)45–46 µm |
Width
|
20 µm | 30 µm | (30 –)33–35 |
Spine length | |||
- conical spines | N/A | 4–6 µm | 4–5 µm |
- posterior part | N/A | 12–14 µm | 8–13 µm |
Collar | slightly enlarged, with thickening at the base | short, large, regular undulated edge | short collar with undulated edge |
Chloroplasts | N/A | N/A | numerous, discoid |
Ecology | fishpond; plankton | wetland; plankton | mesotrophic pond; benthos, metaphyton |
These two taxa (Trachelomonas bituricensis and Trachelomonas bituricensis var. lotharingia) are commonly mentioned in works about euglenophytes (e.g.,
Several species of Trachelomonas have the similar morphology as Trachelomonas bituricensis. The most resembling taxa are Trachelomonas horrida, which was first described by
The high morphological variability of the genus Trachelomonas makes classification based only on morphology (e.g., shape, surface, absence or presence of various forms of collar and sometimes colour of the lorica) quite difficult and has led to the description of morphologically similar forms as separate taxa. As a result of morphological variability, the traditional taxonomy of Trachelomonas based only on a description of lorica characters is problematic for several reasons. First, there are several examples of the morphology of euglenoids changing depending on environmental conditions. This variability in shape was observed in several euglenoid genera in culture (
Many reports about euglenoid taxonomy based on morphological and molecular data (e.g.,
This report describes what is likely the third record of Trachelomonas bituricensis var. lotharingia in Europe and the first record of this taxon in the Czech Republic. The description of this taxon is morphologically and ecologically similar to the original description. The taxonomic validity of this taxon remains to be validated, as it may represent part of a complex of morphologically similar species together with T. spinosa and T. horrida. Nonetheless, the discovery of this taxon sheds light on the distribution of algae of the Czech Republic and European algal flora in general.