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.

 ISSN 0268-0130

2020 Impact Factor for the Herpetological Journal is 0.862


pdf 01. Growth and energetics of embryos of the gecko, Phyllodactylus marmoratus, a species with hard shelled eggs

510 downloads

Open Access

pp.37-42

Authors: Michael B. Thompson And Kylie J. Russell

Abstract: We measured water contents, gro wth of embryos and metaboli c rates in hard-shelled eggs of the Australian gecko, Phyllodactylus marmoratus, throughout incubation to make comparisons between (I) the proportional water content at oviposition of eggs of P. marmoratus and flexible-shelled eggs of lizards; and (2) the dry-mass specific energy consumption during development in P. marmoratus and lizards with flexible-shelled eggs. Egg contents (i.e. excluding eggshell) contained nearly 80% water, higher than reported for any other squamate reptile. Eggs were laid at embryonic stages 26/27-29, which is slightly earlier than for most other lizards. Incubation lasted 79-84 days at 25 °C and net water loss averaged just under 3 mg. Metabolism reflected the size of embryos, with little growth and lo w rates of oxygen consumption during the first third of incubation. Thereafter, growth and oxygen consumption in creased, with oxygen consumption slowing after day 70. This pattern is similar to that of other species of lizard. Water content of embryos fell from above 90% early in incubation to around 70% at hatching. Thus, the embryonic metabolic scaling factor was different when based on embryonic wet and dry mass. The dry-mass specific energetic cost of development in P. marmoratus was lower than other lizards, but this result was not related to having a hard-shelled egg. The respiratory exchange ratio suggests that embryonic metabolism is based on mixed protein and lipid, a pattern similar to that in flexible-shelled eggs of lizards, but different from birds.

Keywords: Phyllodactylus, gecko, embryonic development.

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.