Language: English
The genus Cyclotella (Kützing) Brébisson is one of the most well-known genera among diatomists who study centric diatoms. It is commonly known in Japan as “taiko—keiso”, “taiko” meaning drum and “keiso” meaning diatom in Japanese respectively. Most recently Hakansson (2002) established the genus Puncticulata, moving 9 taxa from Cyclotella while Houk & Klee (2004) established the genus Discostella, transferring 15 of the so called “stelligeroid taxa” from Cyclotella.
This work provides information on the taxonomical characteristics of the species of these three genera found in Japan along with a practical guide to help in their correct identification.
Abstract 5
Introduction 6
Materials and methods 7
Samples 7
Cleaning of samples 7
Types of diatom preparations 9
Microscopy 10
Taxonomical background 11
Morphological characters and terminology 12
Descriptions and notes of the taxa 15
Cyclotella (Kützing) Brébisson 15
C. atomus Hustedt var. atomus 15
C. atomus var. gracilis Genkal et Kiss 17
C. baltica (Grunow) Håkansson 18
C. cryptica Reimann, Lewin et Guillard 19
C. cyclopuncta Håkansson et Carter 21
C. kohsakaensis H. Tanaka et H. Kobayasi 22
C. litoralis C.B. Lange et Syvertsen 24
C. meduanae Germain 25
C. meneghiniana Kützing 26
C. ocellata Pantocsek 28
C. shanxiensis Xie et Qi 30
Discostella Houk et Klee 32
D. asterocostata (Lin, Xie et Cai) Houk et Klee 32
D. pliostelligera (H. Tanaka et Nagumo) Houk et Klee 32
D. pseudostelligera (Hustedt) Houk et Klee 33
D. stelligera (Cleve et Grunow) Houk et Klee var. tenuis (Hustedt) Houk et Klee 35
D. woltereckii (Hustedt) Houk et Klee 37
Puncticulata Håkansson 41
P. ozensis H. Tanaka et Nagumo 41
P. praetermissa (Lund) Håkansson 43
P. radiosa (Grunow) Håkansson 45
P. rhomboideo-elliptica (Skuja) H. Tanaka var. rhomboideo-elliptica comb. nov. 47
P. rhomboideo-elliptica var. rounda (Qi et Yang) H. Tanaka comb. nov. 48
General discussion 50
Preliminary key to the species identification of genera Cyclotella, Discostella and Puncticulata in Japan 53
1. Key to three cyclotelloid genera 53
2. Key to Cyclotella in Japan 53
3. Key to Discostella in Japan 53
4. Key to Puncticulata in Japan 54
Acknowledgements 54
Literature cited 55
List of materials examined 63
Plates 170 65