Johnston Island Damsel

Description: Identified by the yellowish color and broad black rounded bar, but black sometimes reduced to a trace (Ref. 48636). Body depth 2.1-2.4 in SL (Ref. 90102)

Oviparous, distinct pairing during breeding (Ref. 205). Eggs are demersal and adhere to the substrate (Ref. 205). Males guard and aerate the eggs (Ref. 205).

Dorsal spines (total): 12; Dorsal soft rays (total): 17 - 19; Analspines: 2; Analsoft rays: 16 - 18

Common in outer reefs and passages, frequently associated with Acropora, Stylophora, or Pocillopora coral heads or a single head of Pocillopora eydouxi. Feeds on benthic algae and probably coral polyps. Diurnal species (Ref. 13550).

Adults are found clear water, inner to outer reef crests in rich coral habitat (Ref. 48636). Benthopelagic (Ref. 58302). Common in passages, frequently associated with Acropora, Stylophora, or Pocillopora coral heads or a single head of Pocillopora eydouxi (= Pocillopora grandis). Usually seen solitary (Ref. 48636). Feed on benthic algae and probably coral polyps. Oviparous, distinct pairing during breeding (Ref. 205). Eggs are demersal and adhere to the substrate (Ref. 205). Males guard and aerate the eggs (Ref. 205). Diurnal species (Ref. 13550).

fisheries: of no interest; aquarium: commercial

分布於印度-太平洋區，由東非到夏威夷、馬貴斯與皮特凱恩群島，北至琉球與博寧群島， 南至羅得豪島與拉帕島。台灣發現於南部及蘭嶼等沿岸。

本身體色豔麗，是受歡迎之水族觀賞魚。

體呈卵圓形而側扁，標準體長為體高之1.7-1.9倍。吻短而略尖。眼中大，上側位。口小，上頜骨末端不及眼前緣；齒單列，且較長。眶下骨具鱗，後緣則平滑；眶前骨與眶下骨間無缺刻；前鰓蓋骨後緣平滑。體被櫛鱗；側線之有孔鱗片21-22個。背鰭單一，軟條部不延長而呈角形，硬棘XII，軟條18-19；臀鰭硬棘II，軟條16-18；胸鰭鰭條19；尾鰭叉形，末端呈尖形，上下葉外側鰭條不延長呈絲狀。體呈淡黃色體，側後半部具一寬約8個鱗片之黑色橫帶，但是黑色橫帶有時縮小成痕跡，橫帶後方體側和尾鰭為黃色。背鰭前部無黑斑；胸鰭黃色。

主要發現於清澈的水域且是珊瑚繁生的棲息地，通常在礁石頂冠的內側或外側，亦常見於通道。常棲息的珊瑚，包括/Acropora/ 、 /Stylophora/ 或 /Pocillopora/等珊瑚的頂部，或棲息於一整叢的/ Pocillopora eydouxi/內。 通常單獨的被看到。以底藻或可能是珊瑚蟲為食。

Plectroglyphidodon johnstonianus, commonly known as the Johnstone Island damselfish, is a species of damselfish from the Indo-Pacific. It occasionally makes its way into the aquarium trade. It grows to a size of 14 cm in length.

Common in outer reefs and passages, frequently associated with @Acropora@, @Stylophora@, or @Pocillopora@ coral heads or a single head of @Pocillopora eydouxi@. Feeds on benthic algae and probably coral polyps.