Brachysomophis porphyreus (Temminck & Schlegel 1846)

This species is distinguished by the following characters: tail 52% and head 11-14% of TL; body cylindrical for most of its length; dorsal fin arising well behind pectoral-fin tips; pectoral fins moderately elongate, about 3-6 times in HL; snout moderate; about 3.0 in jaw; jaws elongate, about 2.1-3.0 in head; lower jaw extending beyond snout tip; nostrils in very short tubes in upper lip and closely associated; cirri of labial fringe minute on lips of subadults, absent in large adults; center of eye behind anterior 30% of jaw; interorbital space narrow, less than orbit width; dorsal head profile nearly flat from level of midjaw to snout tip; nape and cheeks swollen, narrowing anteriorly from level of midjaw; cephalic pores inconspicuous; free sensory neuromasts not visible on nape; teeth conical; purplish brown when alive; lateral-line and cephalic pores (except mandibular) surrounded by fine dark punctations.

Vertebrae: 137 - 148

Observed nearly fully buried within a muddy bottom at a depth of 20 m (Ref. 42180).

分布於西北太平洋區，包括台灣、中國與日本的南部海岸。

極罕見蛇鰻類。

體延長而呈圓柱狀，尾長為全長(TL)之52%；頭長為全長(TL) 之之11-14%。背鰭起點遠在胸鰭之後。上下頜具有相當多的唇鬚，較為細小。胸鰭略延長，頭長約為其3-6倍。下頜較上頜突出。鼻短，吻長為其3倍。吻延長，頭長約為其2.1-3倍。眼部位於上頜前30%處。兩眼間具相對較窄，小於眼徑。鼻孔為短管狀，位於上頜前端，前後開孔緊靠在一起。頭部上方前方平坦，但後方及頸項部相當膨脹，向前漸漸變窄。頸項部感覺神經結小，不易見。頭部感覺孔及側線孔外圍為黑色細斑。牙齒呈錐狀，上頜齒前方具3游離齒，離後方外排牙齒甚遠；鋤骨齒前一列具5顆大牙齒；下頜齒一列，前方具3顆較小牙齒，中間具5-6較大且寬之牙齒，後方具5-6較小且密集之牙齒。脊椎骨137-148。背部呈紫色或深色，頭前方為棕色，具有細斑點。口內黑色。吻前端為白色。各鰭為白色。

主要棲息於淺的沙泥地區域，棲息深度在1-200公尺。通常將身體埋於沙內，僅露出頭部，等候埋伏突襲魚類及章魚等。

Brachysomophis porphyreus is an eel in the family Ophichthidae (worm/snake eels). It was described by Coenraad Jacob Temminck and Hermann Schlegel in 1846. It is a marine, temperate water-dwelling eel which is known from the northwestern Pacific Ocean, including Taiwan, China, Japan, and Korea. It is known to dwell at a depth of 20 metres, and makes burrows in mud, nearly deep enough to cover itself completely. Males can reach a maximum total length of 130 centimetres.

The species epithet "porphyreus" refers to the purple colouring of living specimens.