IDENTIFICATION (with reason) OF Wallago 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. Mouth is covered by functional jaws.
2. Presence of paired appendages.

       Hence, the specimen belongs to the Super Class Gnathostomata

1. Operculum is present to cover the gills.
2. Homocercal type of tail is present.
3. Presence of bony endoskeleton.
4. Presence of terminal mouth.

      Hence, the specimen belongs to the Class: Osteichthyes

1. Fins are  supported by lepidotrichia—thin, bony, or horny spines that radiate from the body.
2. Fin rays attach directly to the internal skeletal elements (radials).
3. Rays are connected by a thin layer of skin (webbing), acting like a folding fan. 

   Hence, the specimen belongs to the Sub Class: Actinopterygii

1. Scales are absent or covered by epidermis.
2. Presence of fully filamentous gills.
3. Presence of swim bladder.

Hence, the specimen belongs to the Super Order Teleostei

1. Naked skin or with bony scutes or plates but never with scales.
2. Barbels 1 to 4 pairs.
3. Reduced maxillary support the barbels.
4. Ramified lateral line is present.
5. Abdominal pelvic fin is present.
6. First fin ray of dorsal & pectoral fins modified as hard spines or thick rays.

Hence, the specimen belongs to the  Order Siluriformes

1. Very short dorsal fin, spineless, with 4 or 5 rays.
2. Pectoral fin with a spine & with 10-15 rays.
3. Ventral fin with 9-10 rays.
4. Anal fin long with 65-95 rays.
5. Presence of four barbels. One pair maxillary & one pair mandibular.
6. Deep mouth cleft, extending to behind the eyes.

          Hence, the specimen seems to be 

Tenualosa sp

Systematic Position: (Young,1981)

Kingdom: Animalia

         Phylum: Chordata

             Sub Phylum: Vertebrata

                    Super Class: Gnathostomata

                         Class: Osteichthyes

                               Sub Class: Actinopterygii

                                  Super Order: Teleostei

                                              Order:  Siluriformes

                                                  Genus: Tenualosa