Dragonet

Ground coloration dark brown, ventral parts of body light brown or white. Back with some darker saddles, sides of body with a row of black blotches. First dorsal fin with an ocellate black blotch on third membrane. Anal fin with a broad distal black streak. Second dorsal fin, caudal fin, pectoral and pelvic fins with brownish spots and blotches (Ref 42832).

Dorsal spines (total): 4; Dorsal soft rays (total): 9; Analsoft rays: 8

Inhabits shallow to deep waters (Ref. 559), on sandy mud bottoms (Ref. 11230). Rarely seen by divers but more commonly encountered in shallow waters (Ref. 90102). Feeds mainly on amphipods, polychaetes, bivalves, gastropods and ophiuroids (Ref. 13374). Minimum depth of 5 m reported from Ref. 90102.

分布於西太平洋區，包括台灣、日本、巴布亞新幾內亞、印尼、澳洲西北部及赤斯特菲群島等。台灣分布於西部、北部及澎湖海域。

小型魚類，僅具學術研究價值。

體延長，縱扁。枕骨區具二個高骨質突起，通常在突起間另具一骨質崚脊。鰓孔背位。前鰓蓋骨強棘為頭長之0.23-0.45倍，強棘末端平直或稍下彎曲，腹緣平滑而直，基部具一強倒棘，背緣具六至十三個鋸齒狀之小倒棘。側線從眼延伸至尾鰭第3或第4分支鰭條的末端，具一眼下分支及一分叉之頜、前鰓蓋骨分支，枕骨區具一條橫向側線及尾柄背部具二條橫向側線，連接體側二側線。雄魚第一背鰭高，第I及第II棘延長成絲狀，約等長，雌魚第一背鰭低，背棘不延長成絲狀；雌、雄魚第二背鰭鰭緣平直，背鰭與臀鰭除最後一鰭條外，其餘鰭條均不分叉；胸鰭延伸至臀鰭第2鰭條基部；雌雄魚尾鰭均延長，茅狀尾，雌魚尾鰭稍短。保存標本體呈棕色，背部具白斑及深棕色底，腹部白色，體側具一列深棕斑及黑點；雄魚喉部具一棕斑或黑斑，且無線紋圍繞，雌魚喉部稍白；眼深灰或深藍色；雌、雄魚第一背鰭色淡，均具不規則之棕斑及棕線，但數目及分佈位置多變，第III棘膜具一白底黑斑，此黑斑延伸至第II棘膜，第II棘膜亦具白紋；雌雄魚第二背鰭透明，鰭條具棕點，鰭膜具水平之短棕紋及棕點；臀鰭鰭緣2/3處黑色， 鰭條尖端白色，鰭基白色；尾鰭具6-12列排成垂列之深棕斑，下葉緣黑或深棕色。

主要棲息於於淺水區到深水域的砂泥底上。以片腳類動物、多毛類動物、二枚貝、腹足動物與陽燧足等為食。

Callionymus japonicus, the Japanese longtail dragonet, is a species of dragonet native to the western Pacific Ocean where it is found at a depth of around 208 metres (682 ft). This species grows to a length of 20 centimetres (7.9 in) SL.