Critical criteria for identification of the genus Chaetoceros (Bacillariophyta) based on setae ultrastructure. II. Subgenus Hyalochaete

Abstract:

Our objective was to select setae ultrastructure characteristics as identification criteria for Chaetoceros subgenus Hyalochaete. We sampled 53 Korean coastal water locations and three Chukchi Sea, Arctic Ocean sites, and we studied 22 species using light microscopy and scanning electron microscopy. We selected 12 criteria for species-specific identification: (1) point of fusion of the sibling setae, (2) spine form, (3) poroid shape, (4) spine arrangement, (5) poroid arrangement, (6) number of poroid rows per μm along the setae, (7) special intercalary setae, (8) connecting bridge-like structure on the basal part of the intercalary setae, (9) siliceous capilli on the basal part of the setae, (10) setae cross-sectional shape, (11) silicification of the setae wall and (12) direction of setae to the chain axis. Using these criteria, we constructed a dichotomous key to aid species-specific identification in the subgenus Hyalochaete.

Key Words::

• Chaetoceros
• Diatom
• Hyalochaete
• Identification
• Key
• Morphological Characteristic
• Poroid
• Seta
• Spine
• Ultrastructure

ACKNOWLEDGEMENTS

We are grateful to anonymous reviewers for critical comments on the manuscript. We thank Dr Sung-Ho Kang of the Korea Polar Research Institute, Korea Institute of Ocean Science & Technology, South Korea; Prof. Joon-Baek Lee of Jeju National University, South Korea; and Dr Seung Won Jung of the South Sea Research Institute, Korea Institute of Ocean Science & Technology, South Korea, for help with sample collection. We also thank Joon Sang Park of Sangmyung University for commenting on the manuscript. This work was supported by a grant from the Ministry of Environment of the Republic of Korea (Grant no. 416-111-008, Development of Biosensor Technology Using Microalgal Resources of the Eco-Innovation Project in 2014) and a 2014 Research Grant from Sangmyung University under grant no. 2014A0000172.

SUPPLEMENTARY DATA

Supplementary data associated with this article can be found online at http://dx.doi.org/10.2216/14-51.1.s1.