Eptatretus wisneri (Kuo, Huang & Mok 1994)

Brachial length 4.58% of total length; six pairs of gill pouches and gill apertures, gill apertures closely spaced in straight line; external opening of pharyngocutaneous duct (PCD) confluent with the most posterior left gill aperture (51 of 59 specimens examined), and much larger than other apertures; fused unicuspid teeth; eye spots present but not clear (Ref. 31545).

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 ).

分布於臺灣的東南海域。

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，齒列式(7-10)+3/2+(7-9)。鰓孔每側6個，彼此間距大，呈縱線排列，左側最後一個大於其餘鰓孔。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(15-20)+(0-1)+(36-44)+(6-11)，總數為57-76。無鱗。肛門位於體後端。無背、臀、胸及腹鰭，僅有尾鰭。體色呈褐色，背部中央無白帶，腹面中央之皮褶具淡色緣。本種為1994年由郭建賢等人發表於台灣的新種。

棲息於近海泥沙底。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。