Okinawa mejina - Okinawa mejina

A marine fish belonging to the order Perciformes and family Greninidae of the class Osteichthyes. It is found in the waters from Chiba Prefecture to the Pacific coast of the southern coast of Kyushu, the Sea of ​​Japan coast of Yamaguchi Prefecture, the Goto Islands, the Amami Islands, the Ryukyu Islands, the Ogasawara Islands, Taiwan, and other areas. It is called "Sukaace" in the Izu Seven Islands, "Ushigure" in southern Wakayama, and "Stew" in Okinawa. Its body is oval, moderately laterally compressed, and stocky. Its body height is high, about half its body length. The dorsal edge of the head slopes steeply in front of the eye. Its caudal peduncle is high and thick. Its mouth is small, with a thick upper lip and the rear end of the maxilla reaches almost below the front edge of the eye. The main maxilla is covered by the suborbital bone. The teeth on both the upper and lower jaws are tridentate-like at the tip, arranged in three or four rows, and are suitable for pecking at seaweed. The snout is round. The eyes are small and close to the dorsal edge of the head. The entire gill cover is covered with scales. There are 47 to 53 lateral line perforated scales, and the number of scales in the transverse row below the center of the dorsal fin spine is 5 to 7, but usually 6. The bases of the soft rays of the dorsal and anal fins are covered with small scales. The body, head, and each fin are greenish black, and there is a bright yellow transverse band on the side of the body, but this band becomes thinner as the fish grows. Also, if the fish dies after being fished out, the color becomes unclear. The iris is blue. Juvenile fish can be found in tide pools on rocky shorelines. Adult fish live alone in coastal reefs and on the outer edges of coral reefs, feeding on seaweed, lugworms, shrimp, crabs and other small animals. Although omnivorous, they are highly dependent on seaweed and form territories. They can reach a maximum length of about 45cm. They are used as sashimi, in hotpot dishes, and grilled with salt, but have a distinctive sea smell and are not very tasty.

This species belongs to the G. genus, which also includes the G. leonina and G. leonina, but these latter two species can be distinguished from this species by the lack of scales on the lower half of the gill cover, the thin upper lip, and the lack of a yellow horizontal band on the center of the side of the body.

[Kunio Amagaoka August 20, 2021]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

硬骨魚綱スズキ目メジナ科に属する海水魚。千葉県から九州南岸の太平洋沿岸、山口県の日本海沿岸、五島(ごとう)列島、奄美(あまみ)諸島、南西諸島、小笠原(おがさわら)諸島、台湾などの海域に分布する。伊豆七島ではスカエース、和歌山南部ではウシグレ、沖縄ではシチューとよばれている。体は楕円(だえん)形で中程度に側扁(そくへん)し、ずんぐりしている。体高は高く、体長のおよそ半分。頭部の背縁は目の前方で急傾斜する。尾柄(びへい)は高くて太い。口は小さくて、上唇は分厚く、上顎(じょうがく)の後端は目の前縁下近くに達する。主上顎骨は眼下骨で覆われる。上下両顎歯は先端で三叉(さんさ)した門歯状で、3～4列に並び、海藻をついばむのに適している。吻(ふん)は丸い。目は小さく、頭部背縁に近接する。鰓蓋(さいがい)の全域が鱗(うろこ)で覆わる。側線有孔鱗(ゆうこうりん)数は47～53枚、背びれ棘(きょく)部の中央下での横列鱗数は5～7枚であるが、普通は6枚。背びれと臀(しり)びれの軟条部の基部は小さい鱗で覆われる。体、頭部、各ひれは緑黒色で、体側に1本の鮮黄色の横帯があるが、この横帯は成長すると薄くなる。また、釣り上げられるなどして死ぬと不明瞭(ふめいりょう)になる。虹彩(こうさい)は青色。幼魚は磯(いそ)の潮だまり（タイドプール）で見られる。成魚は沿岸の岩礁域やサンゴ礁の外縁に単独で生息し、海藻やゴカイ、エビ、カニなどの小動物を食べる。雑食性であるが、海藻類への依存度が強く、縄張りをつくる。最大全長は約45センチメートル。刺身、鍋(なべ)料理、塩焼きなど総菜魚にされるが、特有の磯臭さがあり、それほどおいしくない。

　本種はメジナ属に属する。同属には本種以外にメジナおよびクロメジナG. leoninaがいるが、後2種は鰓蓋の下半分に鱗がないこと、上唇は薄いこと、体側中央部に黄色横帯がないことなどの特徴で本種と区別できる。

［尼岡邦夫　2021年8月20日］

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