Myxine formosana Mok & Kuo 2001

Head white; body and tail grayish-black to dark purple. A 3-cusp multicusp on the anterior set of cusps and 2-cusp multicusp on the posterior set. Gill pouches, generally 5 pairs (rarely 4). Slime pores 0 - 4 (mostly 2) above the area between the anterior and posterior ends of the cloaca. Anterior unicusps 10 (8-12) on each side. Anterior part of ventral finfold (VFF) higher than posterior part (mostly vestigial). Caudal finfold (CFF) low to vestigial (Ref. 40969).

Copulatory organ absent. The gonads of hagfishes are situated in the peritoneal cavity. The ovary is found in the anterior portion of the gonad, and the testis is found in the posterior part. The animal becomes female if the cranial part of the gonad develops or male if the caudal part undergoes differentiation. If none develops, then the animal becomes sterile. If both anterior and posterior parts develop, then the animal becomes a functional hermaphrodite. However, hermaphroditism being characterised as functional needs to be validated by more reproduction studies (Ref. 51361 ).

Caught using shrimp traps (Ref. 40969).

分布於臺灣的西南海域。

主要為底拖網捕獲。棲息地較深，故較為罕見。

體延長呈圓柱狀，體後方側扁。眼退化為皮膚所覆蓋。無上下頜。口腔外緣具四對鬚；口腔外側左右各有兩列齒，其內列齒之2-3顆齒之基部愈合，因此齒列式為10(8-12)+3/2+10(8-12)。鰓囊5對，但每側所有的出鰓囊管(efferent gill pouch ducts)的開口集中於一處，因此外鰓孔只有一對，其中左側鰓孔與咽皮管(pharyngocutaneous duct)開口相癒合。體側各有一列黏液孔，可依位置區分為鰓前區、鰓區、鰓肛區及肛後區等四區，黏液孔數分別為(26-32)+0+(54-58)+14，總數為80-117。無鱗。肛門位於體後端。前腹面皮褶高於後腹面皮褶(一般為退化)；尾部皮褶低，甚至退化。體色呈灰黑至暗紫色，前頭部白色；頭部之第一黏液孔白色，而其後至鰓孔處之所有黏液孔暗色。

棲息於深海泥沙底。活動力較弱，主要以死魚或其它無脊椎動物的屍體為食。捕獲時，全身會分泌許多黏液並捲成一團，藉以爭扎以利脫困。