IDENTIFICATION (with reason) OF Branchiostoma 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. Body is divided into two parts, a trunk & a post anal tail.
2. Notochord extends through the entire length of the body.
3. Persistent numerous pharyngeal gill slits.

           Hence, the specimen belongs to Sub Phylum Cephalochordata

1. Elongated body, laterally compressed like a fish.
2. Series of myotomes are visible.
3. Presence of buccal cirri around the oral hood.
4. Dorsal, caudal & ventral fins are continuous.
5. Anterior ventrolateral edges of the body project as a pair of metapleural fold.
6. Presence of a ventral & median atriopore.
7. Anus is asymmetrically places on left side.

        Hence, the specimen seems to be Genus: Amphioxus /Branchiostoma

Systematic Position: (Young,1981)

Kingdom: Animalia

         Phylum: Chordata

             Sub Phylum: Cephalochordata

                              Genus: Branchiostoma