Crested Gudgeon

Diagnosis: 11-15 scales in predorsal series; 25-29 ctenoid scales in longitudinal series (including 1-2 scales on caudal fin base); 9-12 scales in rearward transverse series; 1st dorsal fin: VI; second dorsal fin: I,8 (rarely 7); anal fin: I,7-9 (usually 8); pectoral fins: 19-22; pelvics relatively long, their tips almost, or just reaching level of anus; caudal fin rounded, with 11-16 segmented rays (Ref. 57413, 82489). 1st gill arch with 4-5 gill rakers on epibranchial, 6-8 on ceratobranchial (Ref. 82489), about 12 in total, that are narrow and spine-like (Ref. 57413). Dark brown, scales edged in dark brown (Ref. 5493). Body with 4-5 oblique bands (Ref. 5493, 82489), crossing dorsum at nape, 1st dorsal fin, 2nd dorsal fin and caudal peduncle (one or two)(Ref. 82489). Anterior part of 1st dorsal fin dark, 2nd dorsal and caudal fin with alternating dark brown and white spots, anal and pelvic fins dusky to black, pectorals clear; females with more distinct bands and lighter fins (Ref. 5493).Coloration: Preserved specimens: 2-3 longitudinal series of small dark spots above midline of flanks; broad, dark, crossbar running from each dorsal fin base towards belly, bifurcating on flanks into separate bands; 2 narrower crossbars on caudal peduncle; a lunate band on base of caudal fin; dark pre- and suborbital bands on head, confluent below eye; dark spot behind eye and light horizontal band running to posterior of operculum; snout marbled; 3 dark crossbars on nape preceding a light area in front of 1st dorsal-fin base; ventral area of head speckled; both dorsal fins with a dark proximal band; 1st dorsal fin more or less entirely dark to distal margin; 2nd dorsal fin with dark distal margin; anal and pelvic fins black, except distal area of pelvic fins lighter; pectoral fins with a dark spot at base (edged red in life) and an upper, smaller, dark spot sometimes evident (Ref. 57413).

Distinct pairing (Ref. 205).

Amphidromous. Refers to fishes that regularly migrate between freshwater and the sea (in both directions), but not for the purpose of breeding, as in anadromous and catadromous species. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.Characteristic elements in amphidromy are: reproduction in fresh water, passage to sea by newly hatched larvae, a period of feeding and growing at sea usually a few months long, return to fresh water of well-grown juveniles, a further period of feeding and growing in fresh water, followed by reproduction there (Ref. 82692).

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

Inhabits rivers, estuaries (Ref. 4967) and mangrove creeks (Ref. 10812).

Inhabits rivers, estuaries (Ref. 4967) and mangrove creeks (Ref. 10812). Feeds on crustaceans and small fishes. Marketed fresh (Ref. 12693). Maximum size recorded in West Africa was 8.3 cm TL (Ref. 57413).

fisheries:

分布於印度-太平洋區海域，由莫三比克的 Delagoa 灣與馬達加斯加，西至中國與菲律賓、臺灣及澳洲等。 臺灣分布於西部、北部及西南部九等海域。

小型魚類，不具食用經濟性。

第1背鰭：Ⅵ；第2背鰭：Ⅰ/ 8~9。臀鰭：Ⅰ/7~8；胸鰭：20~22；腹鰭：Ⅰ/5；尾鰭：15~16。縱列鱗 28~31；橫列鱗 8~9；背鰭前鱗 12~13。鰓耙 4~5+7。體長為體高的3.4~3.7倍；為頭長的3.3~3.5倍。頭長為吻長的3.5~4.7倍；為眼徑的4.5~4.9倍；眼間距的4.6~5.1倍。尾柄長為尾柄高的2.2~2.6倍。體延長，身體前部呈圓筒形，後側扁。背緣、腹緣微微隆起，尾柄較長且高。頭中大，較短且圓，前端略為平扁；頭後高而側扁，其頭寬小於頭高。吻短，圓鈍，吻背面圓凸，吻端稍低於眼睛下緣。吻長約等於、稍小於眼徑，約為眼徑的0.9倍。吻側各具有2行骨質棘。眼中大，上位，稍微突出，眼睛上緣鄰近頭緣。兩眼間隔甚窄，中間微凹，間距稍小於眼徑，約為眼徑的0.9倍。眼睛的上緣和後緣具有半環形的鋸齒狀骨棘。鼻孔每側兩個，分離：前鼻孔圓形，具有短管，接近上唇；後鼻孔小，無鼻管，在眼前方。口中大，前上位，口裂向後延伸至對應於眼睛中位。上、下頜齒狀細尖，多行，上頜外列齒較大；鋤骨無齒。唇厚。舌窄，游離。鰓孔寬大，向前向下延伸至對應於眼位。前鰓蓋骨後緣光滑無棘。鰓蓋骨上方具有一橫溝。鰓被架6根。魚體具大型櫛鱗；臉頰、鰓蓋部位以及眼後背側的櫛鱗較小。胸部與腹部則披有圓鱗。而吻部和下顎面則無鱗片。無側線。背鰭2個：第1背鰭起於胸鰭基部稍後上方，後端不延伸至第2背鰭；第2背鰭較長，平放時不延伸至尾鰭基部。臀鰭起點與第2背鰭相對。胸鰭呈寬圓、扇形，中側位，胸鰭長約等於頭長。左、右腹鰭靠近，但不相連、癒合，腹鰭末端不會至肛門。尾鰭長圓形。頭部及體測為黃褐色，腹側淺色，體側有6條暗色橫帶，有時橫帶會不明顯；眼下方及眼後下方常具有2~3條輻射狀灰黑色的條紋。背鰭及臀鰭為灰黑色，具淺色條紋；腹鰭黑色；尾鰭深灰色。(林上智、林沛立編寫 2012/10)

暖水性近岸小型底棲性魚類，多半棲息於河口、紅樹林濕地或沙岸沿海的泥沙底質的棲地中，同時也被發現於棲息於海濱礁石或退潮後殘存的小水窪中。通常行穴居生活，屬於底棲性魚類，多半在夜間出來覓食，以攝食小魚及甲殼類等為生。

Butis koilomatodon, commonly known as the mudsleeper, is a species of fish in the family Butidae native to fresh, brackish and salt water of the Indo-Pacific region, ranging from Madagascar and Mozambique to the Philippines, China and Australia. It has been introduced to the Atlantic region where considered invasive and known from Panama, Venezuela and Brazil as well as Nigeria. This predatory species mainly lives in rivers, estuaries and mangroves, and reaches up to 10.7 cm (4.2 in) in total length.

Inhabits rivers, estuaries (Ref. 4967) and mangrove creeks (Ref. 10812)..