Mc Cosker'S Hagfish

This species is distinguished from its congeners, except Eptatretus poicilus by the following characters: gill apertures 8 pairs (7 in one specimen), well-spaced and arranged in a near straight line; a 3/3 multicusp pattern of teeth; differs from Eptatretus poicilus by its number of trunk pores 38-43 (vs. 45-50), by the number of total pores 69-75 (vs. 78-86) and by its colour pattern, with body purple to purplish brown (vs. body strongly mottled with pale brown, dark brown and white-beige) (Ref. 123790). Description: Eight gill pouches and apertures each side, last gill aperture confluent with the pharyngocutaneous duct on the left side; 12 multicusps (3 fused cusps in each row), unicusps 36-39 (9,9 to 10,10 unicusps in each anterior and 9,9 to 9,10 in each posterior row), total cusps 48-51; prebranchial 14-15, branchial 7, tail 10-12. Ventral finfold absent or vestigial; caudal finfold with white margin; head slightly lighter than body color, face dark except for small white area around mouth; barbels all white (Ref. 31788).

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 ).