Digital Commons Network^™

Histology Of Dichromatic And Seasonal Color Change Of The Cranial Region Of Callagur Borneoensis, Kevin William Matson

Masters Theses

Male Callagur borneoensis exihibit sexual dichromatism and seasonal coloration which is rare among turtles. In the breeding season male's heads are colored white with a scarlet stripe from the occiput to the tip of the snout. After the breeding season they change to drab charcoal-gray to black with a dull orange-yellow stripe. Females and juveniles are a drab brown throughout the year.

This study was performed to determine the mechanisms of this color change at the histological level. Histological preparation of the head revealed a significant increase in vascular tissue just below the epidermis of the stripe area with increased …