Bathygobius cocosensis (Bleeker 1854)

Characterized by mottled brown overall color, with five alternating irregular whitish and brown blotches or saddles dorsally on body; lower half of side with 5-7 rectangular brown blotches; white spots and blotches on cheek and operculum; upper 4-5 pectoral rays branched to base, tips membrane-free; rounded caudal fin; longitudinal scale series 37-38; predorsal scales 10-12, nearly reaching to above rear margin of preopercle; scales absent on cheek and operculum; ctenoid body scales, becoming cycloid on abdomen, breast and nape; depressed head, width greater than depth; depth of body 5.0 in SL (Ref. 90102).

Dorsal spines (total): 7; Dorsal soft rays (total): 9; Analspines: 1; Analsoft rays: 8

Lives among rubble, in sand pockets, or on reef rock and is abundant on silty intertidal reef flats (Ref. 9360, 58302). Benthic (Ref. 58302). Gut analysis composed of polychaetes, isopods, amphipods, and brachyurans (Ref. 9360, 48637).

aquarium: commercial

分布於印度-太平洋區海域，由東非到詹斯頓島、馬可薩斯島與 土木土島，北至臺灣、日本沖繩，南至大堡礁的南方與拉帕群島；以及馬里亞納群島與密克羅尼西亞的馬紹爾群島。臺灣分布於南部及東部海域。

小型魚類，不具漁業價值。

第一背鰭：Ⅵ；第二背鰭：Ⅰ/ 9；臀鰭：Ⅰ/ 7。胸鰭：19。縱列鱗36~38。橫列鱗13~14。背鰭前鱗2~5。體延長，側扁，尾柄略長。頭部稍扁，吻短。眼大，上側位。口斜裂，口裂向後延伸至對應於眼中部的下方；下頜腹面的頦瓣後緣內凹，兩端突起。鰓蓋骨上方有3個感覺孔(H', K', L')其中H', K'兩孔相分離。前鼻孔下方有一小形的皮瓣。頰部中央列感覺乳突線呈分叉狀。鰓裂小。向腹側延伸僅達鰓蓋中部的下方。體被有中大型的櫛鱗。頭部無鱗。第一背鰭無絲狀鰭條；胸鰭上方的鰭條末端游離呈細絲狀；腹鰭相連癒合呈吸盤狀，膜蓋中央凹入，無突起；尾鰭長圓形。體呈黃棕色，體側中央具1縱列暗色小斑塊，上方隱具若干條褐色橫帶；腹部無任何暗色斑點。眼後方具1深褐色斑點，鰓蓋部具1個黑斑，上方及胸鰭基上方各具1個黑斑。背鰭深褐色，具3行不明顯縱列斑；臀鰭邊緣深褐色，基部色淺；胸鰭、腹鰭為淺色；尾鰭具數行不規則的橫紋。(林上智、林沛立編寫 2012/10)

暖水性底層小型魚類，棲息於潮間帶石礫海域。雜食性，以藻類及底棲動物為食。