This netsuke is of an ivory carp. The carp is a rather popular subject of Japanese art in general. This is an example of perfect netsuke in the sense that, instead of being shown in its full length, it is beautifully curved around with its tail joining back up with the body. This gives it a compact form, which is highly considered to be the ideal for a good netsuke. The reason for this is that the wearer does not wish to have anything sticking out which might be broken off while being worn.
This netsuke is carved from elephant ivory and has beautiful large inlays of dark buffalo horn for the eyes, something which is quite a typical feature of netsuke from this period (late 18th century probably before 1800). The scales of the fish are carved in considerable detail, and each scale is incised with little markings. All the incisions are then heightened in black ink, which again is quite typical of ivory netsuke of this period. The tail is pierced with two holes for the himotoshi, or cord attachments, and it is widely thought in the case of this netsuke that these holes were added later. Quite often, 18th century netsuke have what are called “natural himotoshi”, in other words, the object itself has some sort of hole in it which allows for the attachment of a cord, since the netsuke is attached to a hanging object, the sagemono: an inro containing medicines, a pouch of some sort for tobacco or other bits and pieces, or a money pouch. In this case, it is quite likely that the cord was simply attached around the body of the carp itself. This would have functioned very much like an early netsuke. There were early netsuke in the form of rings, so-called kuruma netsuke, and this netsuke would have likely functioned in exactly the same way.
There has been speculation that this carp might be by one of the greatest carvers of all, Masanao of Kyoto, who was active in the period that this netsuke was certainly carved. He is one of the artists mentioned in the Sōken Kishō, the notable publication of 1781 and the only real record of netsuke carvers over a period of around two hundred years in Japan, falling right in the middle of the netsuke carving period between 1700 and 1900. Having looked at the known models by Masanao, some signed, some not signed, it seems that they have a different sort of mouth. It is a very elongated mouth or face with a large open mouth. The other feature which seems to differ greatly from this netsuke is the way in which the dorsal fin on the back and the tail are carved. In the case of Masanao, he gives a lovely thinness to both the fin and the tail. The ivory is carved very thin. He also gives a beautiful undulation, a sort of frilliness to the whole length of the fin and to the tail, which actually is quite fan-shaped. In this netsuke from the Hermitage Museum, the fin is slightly thicker than Masanao’s. It is undulating but lacks the nice thin frilliness along the top ridge, and certainly when we come to the tail, instead of this furling fan shape, we have a rather salamander-like tail, much like the end of an oar. It is quite rounded and has no real movement to it. It is just a sort of flat piece of tail. For those reasons, it seems to not be the work of Masanao. It is still by a very good carver.
The other suggestion is that it could be somebody from the Yoshinawa Yoshitomu school of carvers, who were also working in Kyoto at exactly the same time as Masanao in the late 18th century. One of the reasons for thinking this is that there are well-known models by Yoshitomu of The Legend of Kinko, a Chinese literatus who went underwater on the back of a large carp. They are great carvings, and again they have such features as the very big inlay for the eyes, and artists of the Yoshinawa Yoshitomu school have a tendency to have incised decoration. An example of this is in their figure carvings where you find repeat patterns along the edges of garments, kimono or robes, and there seems to be a similarity in the way that the gills of this fish are carved. Therefore, there is good reason for making that attribution.