Classification of Sternaspis
The plump, white, barbell-shaped worm Sternaspis scutata can reach a length of roughly 3.5 cm (1.4 in). The second through fourth of the seven segments that make up the anterior region have lateral bundles of chaetae, or bristles. Compared to the posterior portion of the worm, which contains thirteen to fifteen segments, this portion is shorter and narrower. Bundles of long chaetae border the edges of two firm brown chitinous plates that form a shield on the underside of the posterior portion. The base of the shield gives rise to several long, semi-coiled gills that resemble threads.
Kingdom :- Animalia (Multicellular eukaryotic organisms)
Phylum :- Annelida (Segmented worms with true coelom and metamerism)
Class :- Polychaeta (Marine bristle worms with parapodia)
Order :- Terebellida (Tubicolous, sedentary and proboscis not-protrusible, without jaws or teeth)
Genus :- Sternaspis
Habit and habitat of Sternaspis
Sternaspis is a marine, tubicolous polychaete
Distribution
: It is found in U.S.A. (Florida).
Comments of Sternaspis
- Body is short and made up of about 30 segments.
- Head is formed by prostomium and peristomium. Prostomium is elongated and without any appendages.
- Peristomium is knob like and contains mouth.
- First three segments have incomplete bristles, segments 8 to 15 have setae while segments 5th, 6th, 7th and 16th to 24th are devoid of setae.
- Just below 7th segment is a pair of genital papilla.
- In Sternaspis spinosa, the prostomium is elongated and bifurcated like the proboscis of the Echiurida.
- Intestine is coiled and the anus is terminal and surrounded by gills.
- Below 7th segment body is durable shaped and posteriorly a cuticular thickening is present ventrally called as ventral shield.
- Ventral shield contains number of setae around its edge.
Identification
Since the animal has bifurcated proboscis like prostomium and all above features hence it is Sternaspis.
See other posts also
- Environmental Limiting Factors
- ROTIFERA – STRUCTURE,LIFE HISTORY AND AFFINITIES
- Holocephali – General organization and affinities
- ORGANIZATION OF COELOM
- Species Concept