Diatoms, which are reported to have over 18,000 species worldwide and approximately 2,400 species in Korea, can be found in various environments including freshwater, seawater, and wetlands. They are particularly valuable for understanding global environmental changes throughout history due to their ability to maintain their shape for extended periods of time. Instead of collecting floating diatoms using nets, low-layer substrates such as gravel and leaves, as well as sedimentary surface layers, were gathered in order to identify attached diatom species. This is because attached diatoms demonstrate higher species diversity compared to floating diatoms. In this study, seven previously unrecorded diatoms were discovered in various domestic freshwater environments. Two species were found in reservoirs (Eunotia yanomami, Gomphonella pseudookunoi), two in parasitic cones (Eunotia carverenensis, Luticola minor), two in rivers (Cavinula maculata and Prestauroneis integra), and one (Surirella brebissonii var. kuetzingii) in a lagoon. The shapes, structures, and morphological characteristics of each diatom were identified using electron microscopy.

1. INTRODUCTION
2. MATERIALS AND METHODS
    2.1. Sampling sites and methods
    2.2. Pretreatment for specific identification
    2.3. Shape and microstructure analysis ofunrecorded diatoms
3. RESULTS
    3.1. Phylum Heterokontophyta
    3.2. Phylum Heterokontophyta
    3.3. Phylum Heterokontophyta
    3.4. Phylum Heterokontophyta
    3.5. Phylum Heterokontophyta
    3.6. Phylum Heterokontophyta
    3.7. Phylum Heterokontophyta
4. DISCUSSION
CRediT authorship contribution statement
Declaration of Competing Interest
ACKNOWLEDGEMENTS
REFERENCES

• Daeryul Kwon(Nakdonggang National Institute of Biological Resources, Sangju 37242, Republic of Korea)
• Kyeong-Eun Yoo(Department of Environmental Health Science, Sanghuh Life Science College, Konkuk University, Seoul 05029, Republic of Korea)
• Hyunjin Jo(Encountter the Ecology, Suwon 16512, Republic of Korea)
• Chaehong Park(Encountter the Ecology, Suwon 16512, Republic of Korea) Corresponding author