 In this presentation, Phylum Mesozoa is described. After watching this you will learn the characteristics and Examples Dicyema spp., Pseudicyema spp., and Dicyemennea The brief description of Phylum Mesozoa along with reproduction and fertilization also described. Its relationship with Phylum Rhombozoa and Orthonectida. It is part of BS Zoology Course, Animal diversity.

1. Phylum Mesozoa Dr. Muhammad Moosa Abro
@Zoology by Miler and Harley

2. Examples Dicyema spp., Pseudicyema spp., and
Dicyemennea spp.
Approximately 50 species.
The mesozoans are enigmatic, minuscule, worm-like
endoparasites of marine invertebrates.
They are bilaterally symmetrical and lack tissues and
organs.
Phylum Mesozoa Dr. Muhammad Moosa Abro

3. The body is only two cell layers thick in most places, and it
consists of fewer than 50 cells.
Reproduction is both sexual and asexual.
No fossil mesozoans are known.
Molecular data and contrasting morphologies suggest that
“Mesozoa” may be polyphyletic—composed of two phyla:
Rhombozoa and
Orthonectida.
 “Mesozoa” is now often applied informally.
Phylum Mesozoa Dr. Muhammad Moosa Abro

4. References
4
1. Miller, A.S. and Harley, J.B. ; 1999 , 2002., 2007, 2009, 2012 & 2016 Zoology, 4th , 5th, 6th, 7th,
8th , 9th& 10th Edition (International), Singapore : McGraw Hill.
2. Hickman, C.P., Roberts, L.C/, AND Larson, A., 2018. INTEGRATED PRINCIPLES OF ZOOLOGY,
15th Edition (International), Singapore: McGRAW-Hill

5. References
5
1. Miller, A.S. and Harley, J.B. ; 1999 , 2002., 2007, 2009, 2012 & 2016 Zoology, 4th , 5th, 6th, 7th,
8th , 9th& 10th Edition (International), Singapore : McGraw Hill.
2. Hickman, C.P., Roberts, L.C/, AND Larson, A., 2018. INTEGRATED PRINCIPLES OF ZOOLOGY,
15th Edition (International), Singapore: McGRAW-Hill