Description and phylogenetic position of Amphora aliformis (Bacillariophyta), a new species from Tokyo Bay

Abstract:

The genus Amphora is a large and widely distributed group of raphid diatoms, frequently found in fresh, brackish, and salt water environments from around the world. Presented here is the description and phylogenetic position of Amphora aliformis, a new species collected from the Banzu Flats, Tokyo Bay, Japan. This species has a unique morphology, with features seldom or never before observed within the genus Amphora, such as a dorsal marginal wing and ventral apical pores, as well as a unique phylogenetic position as an early diverging lineage within the genus. As with many large and diverse groups of diatoms, new evidence has called into question the validity of the long standing classification system for the genus Amphora. Within the previous system, A. aliformis would be prescribed to the subgenus Diplamphora based on morphological valve features. However, molecular phylogenetic analysis demonstrates that Diplamphora is not monophyletic and furthers evidence that Amphora classification is in need of revision. Included here is a description of A. aliformis based on light microscope, scanning electron microscope, and molecular phylogenetic data, as well as a re-examination and discussion of the current state of Amphora classification.

Key Words::

• Amphora
• Diplamphora
• Japan
• New species
• Phylogeny
• Tokyo Bay

ACKNOWLEDGEMENTS

This research was partially funded through a joint National Science Foundation and Japanese Society for the Promotion of Science East Asia and Pacific Summer Institute fellowship award No. 1316805 and a student research grant from the University of Colorado Boulder Department of Ecology and Evolutionary Biology. The authors would also like to thank Sarah Hamsher for helpful comments and discussion.