I= FORM AND FUNCTIONAL EVOLUTION OF MANDIBLES IN CRUSTACEA
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Title of Thesis
FORM AND FUNCTIONAL EVOLUTION OF MANDIBLES IN CRUSTACEA

Author(s)
Anees Ahmad Ghauri,
Institute/University/Department Details
Department of Zoology/ University of the Punjab
Session
1983
Subject
Zoology
Number of Pages
275
Keywords (Extracted from title, table of contents and abstract of thesis)
mandibles, crustacea, metanauplius stage, mandibular structure, copepods, calanus, podocop ostracods, heterocypris, branchiopod mandible, branchiopoda, ostracoda, eucopepoda, branchiura, cirripedia, malacostraca, leptostraca, eumalacostraca

Abstract
In a comparative study of various parts of the mandible it was found that the mandible as found in the metanauplius stage represent the most primitive and generalized condition of mandibular structure.

Mandibles of copepods e.g. Calanus and podocop ostracods e.g. Heterocypris resemble with the above plan with certain modification. Branchiopod mandible loose palp. On either side (dorsal and ventral ) of the original gnathal edge with tubercle mastricatory surfaces are formed tubercles appear as pore bristles on the right masticatory surface of Chirocephalus and are retained as such on the left. On the left masticatory surface only the dorsal half is retained. In artemia the tubercles are absent and only the ventral halves are retained. In Triops there replaced by teeth.

In conchostraca either the dorsal or the ventral half of masticatory surface is represented.

In Moydocopa, the leg-like mandible is composed of two podomeres of protopodite and three of endopodite. The exopodite is reduced. The scythe-shaped process is the gnathal edge with tubercle; and represent the coxal endite. In Cypridina the coxal lobe is a coxal endite or a gnathobase.

In cirripeds lepas & Balanus the mandibular blade is coxal endite of mandible of metanauplis larva.

In Malacostraca, the original gnathal edge of the mandible of metanauplius larva divides into two dorsal and ventral parts. The dorsal part divides again to form molar process and the setose lobe. Likewise with the division of lower part, lacinia mobilis and incisor process are differentiated. Such an ideal condition is seen in the mandibles of peracaridan orustaceans e.g. Mysis and Gammarus.

The mandibles of Nebalia is a case of degeneration of mandibular parts. In other, in addition to the usual incisor and the molar process setose lobe in present e.g. Diatylis and in Gnathophausia and Lophogaster only lacinia mobilis is present.

In Meganyctiphanes the gnathal edge foreshadow the differentiation of lacinia mobilis. The mandibles of Meganyctiphanes are simpler than Lophogaster. In Anaspidacea the left gnathal edge has a setose lobe and the right has lacinia mobilis.

In the mandibles of Squilla the original gnathal edge of the mandibles of metanauplius larva are retained as such with the molar shifting at an angle of 90o from the incisor process.

Download Full Thesis
3284.44 KB
S. No. Chapter Title of the Chapters Page Size (KB)
1 0 Contents
52.77 KB
2 1 Introduction 1
39.38 KB
3 2 Materials And Method 7
20.3 KB
4 3 Results 10
911.63 KB
  3.1 Sub Class Branchiopoda 10
  3.2 Order Lipostraca 10
  3.3 Order Anostraca 15
  3.4 Order Notostraca 41
5 4 Sub Class Ostracoda 77
349.68 KB
  4.1 Order Myodocopa 77
  4.2 Order Podocopa 91
6 5 Sub Eucopepoda 102
146.46 KB
  5.1 Order Eucopepoda 102
7 6 Sub Class Branchiura 115
19.61 KB
  6.1 Argulus Sp. 115
8 7 Sub Class Cirripedia 118
109.56 KB
  7.1 Order Thoracica 118
9 8 Sub Class Malacostraca 126
1220.99 KB
  8.1 Series Leptostraca 126
  8.2 Series Eumalacostraca 133
10 9 Discussion 204
279.98 KB
11 10 Summary 233
40.34 KB
12 11 References 238
65.88 KB