Emperor Akihito likes nothing better than to play detective when it comes to furthering his knowledge of the goby fish family, his passion since he was a youngster.

This little-known aspect of 85-year-old Akihito's character offers a charming, quirky and intimate picture of the man who will relinquish the Chrysanthemum Throne on April 30 in favor of his eldest son, Crown Prince Naruhito.

Akihito's down-to-earth and painstaking approach to scientific research, reflected in the more than 30 articles he has authored on goby fish, in many ways mirrors the importance he attached to his interactions with the general public during the three decades of his reign that started in 1989.

Goby account for more than 10 percent of the 4,500 or so fish species that inhabit Japan, according to Koichi Shibukawa, a professor of goby and classification of fish at the Museum of Natural and Environmental History, Shizuoka.

He noted that goby is the common name for many species of the small to midsize ray-finned fish, which cannot be easily distinguished from each other by appearance because they all look so similar.

As crown prince in 1966, Akihito penned an academic paper titled, “On the scientific name of a gobiid fish named ‘urohaze.’”

This was where Akihito displayed traits of Sherlock Holmes in arguing that a particular scientific name should be used to refer to a species of goby that is known as “urohaze” in Japanese. His detective work centered on the fact that scholars in the 19th century gave different scientific names to the goby species.

In his article, Akihito explained which of the names had the earliest publication date and thus priority of use.

He combed through old books and other manuscripts to make his case, finally stumbling on an illustrated work that referred to urohaze and proved his point.

However, it was bundled together with two other volumes with a possibly different publication year. Not only that, pages were out of order and disorganized.

On closer examination, he found that letters on one page in the bundle had been transferred onto the adjacent page because the book had been bound before the ink dried after printing.

That allowed Akihito to figure out the initial order of the pages and conclude the entry on urohaze was part of an illustrated volume issued in 1845.

His paper, complete with a photo taken at the National Research Institute of Police Science, argues that the scientific name of the urohaze should be “Glossogobius olivaceus,” which incorporates the name under which the fish species appears in the illustrated book.

“He investigated the matter absolutely thoroughly, and even studied documents that were extremely difficult to access at the time,” Shibukawa said. “It was said that his efforts were like those used in a detective story.”

In subsequent years, Akihito branched out in his taxonomical research on goby fish and focused on morphological differences in sensory organs in the head and scapulae, among other things.

His 1986 paper, titled “Some morphological characters considered to be important in gobiid phylogeny,” stands out as one of his scholarly summations.

In 2000, Akihito worked with experts, including his youngest son, Prince Fumihito, to publish an article in an international journal, in which the authors used a new DNA analysis method to infer the evolution process of goby fish. They argued that their earlier, morphologically based taxonomy had largely been accurate.

TOO BUSY CHATTING

Akihito's interest in sea creatures is undoubtedly due to the influence of his father Hirohito, posthumously known as Emperor Showa, who made a lifelong study of a group of jellyfish-like creatures called hydrozoa that won him scientific renown. The late emperor indulged in his studies at his laboratory in the Imperial Palace in Tokyo, as well as at imperial villas in Shizuoka and Kanagawa prefectures.

Shigeharu Senoo, a professor of fishery science at Kindai University, is well-acquainted with the emperor’s passion for fish studies.

Senoo was a Japan Overseas Cooperation Volunteer working in Zambia when Akihito, then crown prince, visited in 1983.

Senoo was assigned to explain the characteristics of tilapia fish, which were being farmed in Zambia, to Akihito. But Senoo became so nervous, he could not recall the scientific name for the fish, whereupon Akihito, who was supposed to be only listening, rattled off the name and other features of the tilapia.

From that point, the two men got on famously.

“You have to go to a banquet,” an aide informed the crown prince in hopes of hurrying him along. Akihito was having none of it, however, telling the aide, “Don’t worry.” He then continued his conversation with Senoo.

“He listened to me so attentively, despite his tight schedule that was organized down to the last minute," the marine biologist added.

A former chamberlain who assisted Akihito in his scientific studies over more than four decades said the emperor used to potter away in a small lab tucked inside the Crown Prince’s Residence, where he lived before ascending the throne.

The agency official said steel shelves in the room were packed with specimens and documents, adding that Akihito could often be found peering into his microscope during his free time, at night and on other occasions.

After he became emperor, Akihito often visited the Biological Laboratory in the grounds of the imperial palace when he could spare time from his official duties, which included visits around Japan and to communities affected by the Great Hanshin Earthquake in 1995 and the 2011 earthquake and tsunami disaster that triggered a triple meltdown at the Fukushima No. 1 nuclear power plant.

Akihito’s no-nonsense approach to research evokes the way he faces up to his official duties, according to the former chamberlain.

“Perhaps he was preparing for his future as emperor by means of his studies, whereby he checked up on things with his own eyes even at the cost of more time that it took him to do so,” the onetime aide said.

The National Museum of Nature and Science in Tokyo’s Ueno district is hosting a special exhibition titled, “Biological Researches by His Majesty the Emperor, and the Organisms Living in the Imperial Palace, Tokyo,” through March 31. Among the exhibits is a specimen of a goby species that Akihito studied.