New species of seaweed uncovered by genetic analyses

These discoveries were made by an international research collaboration group consisting of the following members from Kobe University; Assistant Professor Takeaki Hanyuda, Professor Hiroshi Kawai (both of the Research Center for Inland Seas) and Kensho Yamamura (2nd year Masters in Biology at the Graduate School of Science).

The results of this research were published in the following journals; 'Phycologia' (October 14, 2019) and 'Phycological Research' (October 29, 2019).

Research Findings

Gloiopeltisis a genus of seaweed that is reddish brown to dark yellow in color. Called 'funori' in Japanese, it has been utilized to make glue and binding since ancient times. It is also used as an ingredient in miso soup.

Until recently, there were five identified species worldwide, three of which were found in Japan- 'fukuro-funori' (Gloiopeltis furcata), 'ma-funori' (Gloiopeltis tenax) and 'hana-funori' (Gloiopeltis complanata). This research team revealed through genetic analyses that there are in fact over ten species of Gloiopeltis in Japan alone.

Analyses ofGloiopeltis furcata

Gloiopeltis furcatahas the widest distribution range amongGloiopeltisspecies. It is found in the inter-tidal zones of temperate to cold water regions covering most of the northern Pacific Coasts. The research team genetically analyzed specimens ofG. furcatacollected from many habitats across its wide distribution. They revealed that there are 4 to 5 unnamed species that have previously been misclassified asG. furcata. These are easily confused with each other unless genetically analyzed.

Genetic analysis also suggested that some populations ofG. furcatahad previously been miscategorized as separate species. It was shown thatGloiopeltis minutanative to California and so called due to its small size, was in factG. furcata. A 19th century sample from Kamchatka, Russia was classified asG. dura, however this species has not been reported since the name was introduced. Genetic analysis showed that this species was also synonymous withG. furcata.

The research group also genetically analyzed the type specimen ofG. furcatataken from Sitka in Alaska in the 19thcentury. This specimen is currently housed at the V. L. Komarov Botanical Institute in St. Petersburg, Russia. Analyses revealed that this specimen was very close genetically to the specimens found in the Hokkaido and Tohoku areas of Japan. It was determined that they are conspecific- they belong to the same species. AsG. furcatahas been reported over a much wider range of Japan, it is thought that there are several different species south of Tohoku- more research is required to illuminate this.

Analyses of theGloiopeltis complanatasubgenus

Gloiopeltis complanatais distinguishable fromG. furcataby its smaller size and greater number of branches.

To discover more about theG. complanataclade, genetic analyses were performed on historic and modern samples from the Okinawa region. This included 19th century specimens now held at Trinity College Herbarium in Ireland. These historical samples were taken by American botanist Charles Wright during the North Pacific Exploring Expedition of 1853-56.

The results confirmed that there is a separate species that was previously thought to be the same asG. complanata, which was very close genetically to a species which was described as Caulacanthus compressus in the 19th century. Therefore, this research group proposed the reinstatement of the speciesGloiopeltis compressa(new Japanese name: Ryukyu-funori). It is mainly found in Okinawa (formerly the Ryukyu kingdom) and is characterized by its smaller size.

Discovery of an unconfirmed species in Japan

This research also revealed that a species previously found in Korea --Gloiopeltis frutex-- also grows around Kyushu in southern Japan. Overall, this research has identified a new species, Ryukyu-funori (Gloiopeltis compressa), and has revealed that there is great variation in theGloiopeltis属在日本和世界各地。继续研究is hoped to illuminate this further.