Hyalotheca javanica (Gutwinski) Coesel

Araújo, Camila Barbosa de, Bicudo, Carlos Eduardo de Mattos, Takiyama, Luís Roberto & Melo, Sérgio de, 2020, Pseudofilamentous desmids (Zygnematophyceae) from an Amazonian floodplain lake (Macapá, AP, Brazil), Iheringia, Série Botânica (e 2020010) 75, pp. 1-14 : 8-9

Hyalotheca javanica (Gutwinski) Coesel , Nordic Journal of Botany 20(3): 379, fig. 39-40. 2000.

Hyalotheca indica Turner var. javanica Gutwinski , Bulletin International de l’Academie des Sciences de Cracovie 39: 579, pl. 36, fig. 2. 1902.

( Figs. 17 A-B)

The filament is not twisted. Cells 2 times longer than broad, 18-27 × 11-14 μm and 10-12 μm broad at the apex. Semicells barrel-shaped, joined by their apex; parallel lateral margins; slight elevation in the mid region; truncated apical margins; shallow median constriction.

Material examined: BRAZIL, AMAPÁ, Macapá, Curralinho Lake , 02.VI.2007, C.B. Araújo (SP469217), 03.VII.2007, C.B. Araújo (SP469218), 14.I.2008, C.B. Araújo (SP469223), 12.II.2008, C.B. Araújo (SP469224), 26.III.2008, C.B. Araújo (SP469225), 13.V.2008, C.B. Araújo (SP469227), 15.VII.2008, C.B. Araújo (SP469228) .

Comments: Hyalotheca indica var. javanica Gutwinski was proposed by Gutwinski (1902). This variety was reported in Brazil for the first time from material collected by Grönblad (1945) in the state of Pará. In 1965, Scott et al. (1965) proposed f. maior Grönblad & Croasdale based on specimens that presented cells relatively longer than those of the typical form and a punctated cell wall arranged in less regular horizontal rows. However, those authors did not publish the measurements of the specimens they studied. Coesel (2000) reclassified H. indica var. javanica to species level: Hyalotheca javanica (Gutwinski) Coesel. This was based on comments by West & West (1902), and they also considered that var. javanica specimens are relatively broader with a shallow median sinus that is difficult to notice, as well as less-rounded apical angles. Considering the literature, var. javanica and f. maior include a clear, obvious overlap of measurements. Thus, it was decided by Coesel (2000) that this taxon be maintained at the species level, and H. indica var. javanica be considered a basionym. The measurements range, including the both taxa, is as follows: cell 11-22 µm long, 9-16 µm broad, and apex 11-13 µm broad. Also, the f. maior proposed in Scott et al. (1965) should be considered a heterotypic (taxonomic) synonym of H. indica var. javanica .

Distribution in Brazil: Pará state ( Grönblad 1945, Scott et al. 1965, Förster 1969).

Figures

Figs. 16-23. Pseudofilamentous desmids of Curralinho Lake, Macapá,Amapá, Brazil. 16 A-B. Hyalotheca dissiliens var. dissiliens. A. fungi in the cell wall of the algae, B. detailed cells; 17 A-B. H. javanica. A. detailed pseudofilament, B. detailed cells; 18. Mateola curvata; 19 A-B. Phymatodocis nordstedtiana var. nordstedtiana f. minor. A. pseudofilament frontal view, B. pseudofilament lateral view; 20. Spondylosium desmidiiforme; 21. S. pulchrum var. pulchrum; 22. S. rectangulare var. rectangulare; 23 A-B. S. rectangulare var. goyazense, detailed cells and pseudofilaments. Scale bars = 10 µm.