IDENTIFICATION (with reason) OF Myxine sp. (B.Sc. ZOOLOGY_CCF- SEMESTER5_DSCC-9)

 Identifying features are:

1. Multicellular heterotroph.
2. embryonic development, preceded by heterogametic fertilization.

            Hence, the specimen belongs to the Kingdom Animalia.

1. Presence of hollow, dorsal, tubular nerve cord.
2. Presence of notochord, at any stage of their life or throughout the life.
3.  Presence of pharyngeal gill slits & post anal tail during some stage in the ontogeny.

            Hence, the specimen belongs to the Phylum Chordata.

1. Presence of Cranium.
2. Presence of vertebral column.
3. Presence of paired lateral appendages.
4. A post anal tail usually present.

           Hence, the specimen belongs to the Sub Phylum: Vertebrata

1. Functional jaws are absent.
2. Paired fins are absent.

          Hence, the specimen belongs to the Super Class: Agnatha

1. Circular & suctorial mouth.
2. Presence of 1-16 pairs of gill slits.
3. Nostril is single & median.

       Hence, the specimen belongs to the Class: Cyclostomata

1. Mouth is terminal with four pairs of tentacles.
2. Nostril is terminal.
3. 1-15 pairs of gill-slits.

      Hence, the specimen belongs to the Order: Myxinoidea

1. Mouth is surrounded by lips.
2. Scale-less cylindrical body is divided into head, trunk & tail.
3. Eyes are vestigeal.
4. Single external branchial aperture on each side.
5. Mucous pores are present on the down side of body.

     Hence, the specimen seems to be Myxine sp.

Systematic Position: (Young,1981)

Kingdom: Animalia

         Phylum: Chordata

             Sub Phylum: Vertebrata

                    Super Class: Agnatha

                         Class: Cyclostomata

                              Order: Myxinoidea

                                  Genus: Myxine