Carla Avolio


Position: Honours
Year: 2004
Phone: 02 9351 4543
Fax: 02 9351 4771
Location: Room 125, A12 - Macleay, The University of Sydney, NSW 2006

Current Research

Ecomorphology of rough scales in sea snakes


Over the years, researchers studying various aspects of sea snake biology have made a common observation of unique scale ornamentation in certain species of Hydrophiidae. These scale ornaments, or rugosities, can take the form of keels, tubercles or spines. Most authors have also observed that when the rugosities occur, they occur mostly in males and are significantly less developed in females. However, no empirical data exists to say for certain if these rugosities are sexually dimorphic and little more is known about this interesting phenomenon.

In the course of my Honours study, I have examined the occurrence of rugosities in sea snakes, looking at where they occur on the body and if there is any pattern seasonally or geographically. The main aim of my study has been to shed some light on the functional significance of these structures.

My study animal is Emydocephalus annulatus, the turtle-headed sea snake. This species is distributed from the tropical waters of the Timor Sea (Australia) to the temperate waters of the southwest Pacific Ocean (New Caledonia). Sexually dimorphic rugosities do occur in males of E. annulatus. Interestingly, in the New Caledonian males, the rugosities are sharply seasonal being strongly visible in winter and almost non-existent in summer. This seasonality makes E. annulatus an excellent study animal for my investigation into rugose scales in sea snakes. They are also blessed with an incredibly gentle nature and have been ideal in introducing me to this addictive world of snakes.