Peridinium willei Huitfeldt-Kaas (1900:5)
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publication ID |
https://doi.org/ 10.11646/phytotaxa.509.2.1 |
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persistent identifier |
https://treatment.plazi.org/id/03D587FF-D202-9D21-3AD4-DB64EA3EFD4F |
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treatment provided by |
Marcus |
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scientific name |
Peridinium willei Huitfeldt-Kaas (1900:5) |
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Peridinium willei Huitfeldt-Kaas (1900:5) . Figure 16 View FIGURE 16
Synonyms:
Peridinium alatum in Garbini (1902: 122)
Peridinium willei var. carinthiacum in Beck-Mannagetta (1931: 229)
Dimensions: L: 49–74 µm, Td: 32–67 µm.
Cell shape: Highly variable, from sub-spherical to deflated ball shape, that is, with a strong sinking in the ventral part of the epitheca as in P. willeli f. lineatum ( Fig. 16 View FIGURE 16 ).
Thecal characteristics: Tabulation, 4ʹ, 3a, 7ʹʹ, 5C, 6S, 5ʹʹʹ, 2ʹʹʹʹ. Without apical pore. In the spherical specimens, the plates are more uniform in the term of development of their axis. Plate 1ʹ very variable, from an almost rhombic shape ( Fig. 16B View FIGURE 16 ) to fan-shaped ( Fig. 16C View FIGURE 16 ). Plate 2a is of hexa symmetrical type ( Figs. 16D and 16E View FIGURE 16 ). The adcingular plates form cingular lists typical for the genus.
Cingulum and sulcus: Descendent cingulum. The sulcus penetrates slightly into the epitheca and reaches the antapex, being narrower in the anterior part and wider posteriorly.
Ecdysial opening: As in most of the species of the genus ( Boltovskoy 1973b) the opening is a result of the detachment of the seven dorsal plates of the epitheca.
Ornamentation: The main thecal plates have a relief reticulum formed by solid cords and nodules, with pores inside the alveolus. Tabular margins bordered by slightly prominent marginal ridges. A remarkable difference with the other species of the genus, except with P. limbatum , is the development of three hyaline lists arisen from the marginal ridges of the anterior edges of the plates 2ʹ+4ʹ, 1a+3ʹ+3a and 2a. ( Fig. 16 View FIGURE 16 C-F). These lists are continuous strips situated perpendicularly to the sagittal plane. At the antapex there are also lists, located on eiher side of the posterior end of the sulcus ( Fig. 16G View FIGURE 16 ).
Localities: Riogrande II reservoir in North-west, De La Regadera reservoir, Chisacá, La Cristalina, Media, and El Pozo lakes in central Colombia.
Commentaries: Two forms of this species were found in the analyzed samples, the willei form with 1ʹ plate expands laterally in an extraordinary way ( Fig. 16C View FIGURE 16 ) and the lateral epithecal plates and especially those of the apical region are tapered, forming two strips that run the epitheca from side to side ( Figs. 16E and 16F View FIGURE 16 ). In this case, 1ʹʹ plate is three times shorter than 7ʹʹ plate ( Fig. 16C View FIGURE 16 ) and cingular lists are more prominent. These specimens were found in Chisacá and El Pozo (lakes) and were larger than those of Boltovskoy (1999a). The lineatum form ( Fig. 16A View FIGURE 16 ) with 1ʹ plate rhombic shape ( Fig. 16B View FIGURE 16 ), these were found in Riogrande II and De La Regadera (reservoirs), La Cristalina and Media (lakes), was in the range of the measures cited by the same author ( Table 9) and larger than those reported in previous taxonomic studies ( Hansen & Flaim 2007; Huitfeld-Kaas 1900; Ling et al. 1989; Moestrup & Calado 2018).
World distribution: This species has a wide distribution in Europe, Asia and USA ( Moestrup & Calado 2018). In Central and South America in Argentina ( Boltovskoy 2003), Bolivia ( Iltis & Couté 1984), Brazil ( Fonseca & Bicudo 2008; Cardoso et al. 2010), Colombia ( Cardozo et al. 2005; Donato-R 2001), and México ( Löffler 1972).
Locality L (µm) Td (µm)
De La Regadera 55–74 43–62
Riogrande II 53–63 47–52
La Cristalina 60–70 51–67
Media 53–59 39–48
El Pozo 49–61 32–53
Total Variation 49–74 32–67
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