The British Herpetological Society

The Herpetological Journal is the Society's prestigious quarterly scientific journal. Articles are listed in Biological Abstracts, Current Awareness in Biological Sciences,Current Contents, Science Citation Index, and Zoological Record.

The 2017/18  impact factor of The Herpetological Journal is 1.268

ISSN 0268-0130


pdf 05. Structural changes in olive ridley turtle eggshells during embryonic development

1122 downloads

Open Access

pp. 143-149
Authors: Sahoo, Gunanidhi; Mohapatra, Birendra K. & Dutta, Sushil K.

Abstract: We examined the chemical composition and ultrastructure of the eggshells of olive ridley turtles, Lepidochelys olivacea , at various stages of embryonic development (freshly laid, 42 days developed and hatched). The eggshell is mainly composed of calcium carbonate present in its aragonite morph, and serves as a source of calcium for the developing embryo. Gradual utilization of eggshell calcium by the developing embryo was reflected by sequential reduction of calcium content from the fresh eggshell (191±32 mg), through 42 days into development (151±36 mg), to hatching (69±11 mg). Structurally, the shells of olive ridley turtle eggs were composed of an outer inorganic calcareous layer, an inner organic fibrous layer and a thin boundary layer that enclosed the egg contents. Calcium resorption by the developing embryo also brought about remarkable modifications in the structure of the eggshell. Fresh eggshells were composed of closely spaced, organized nodular shell units, disoriented spicules and a dense mat of membrane fibres. After 42 days of incubation, these nodules changed to polygonal units with large inter-spaces and loose fibrilliar membranes, whereas the hatched eggshell appeared amorphous and homogenous with disoriented membrane fibres. A 37% decrease in shell thickness (150±11 m in fresh to about 100±6 m in hatched) was observed between laying and hatching. This decrease in shell thickness and structural modifications, with respect to compositional changes, were the effect of calcium resorption from the eggshell by the embryo during its development.

Keywords: SHELL UNITS, LEPIDOCHELYS OLIVACEA, MEMBRANE LAYER, ARAGONITE, CALCIUM

Download Access:

The latest 8 issues can be downloaded when logged in with a Herpetological Journal subscription membership.

Individual articles can be purchased for download.

Older issues and occasional Open Access articles are available for public download

Submissions:

For further information and submission guidelines please see our Journal Instructions to Authors

pdfBHS Ethics Policy

IMPORTANT NOTE - JUNE 2020

Please note that as from Volume 31 Number 1 (January 2021) on, the Herpetological Journal will be available as an online publication only - the last print edition will be Volume 30 Number 4.   

Aligning with this change, it is now no longer possible to purchase a subscription that includes a print copy of the HJ.  All members who have existing HJ print subscriptions that remain active as at end June 2020 will receive the full four 2020 print editions.  New subscribers or renewals after this time will only have option to subscribe to the online only subscription package.  Subscription pricing has been amended to reflect the content changes.