The digestive and ingestive system of Sirians is similar to that of terrestrial snakes, including a highly developed stomach. Sirians prefer live prey or freshly-killed meat. Sometimes by choice but often due to lack of meat, Sirians consume raw, mineral-rich vegetables as a dietary supplement. Fried or prepared foods cause gastric upset. The excretory system makes provision for solid and liquid waste through a single large kidney organ.
Sirian lungs are both functional and operate best in low-altitude topography and damp climates.
Sirian skin is covered by dermal plates, or scales, and is extremely osmotic. To keep their dermal from drying and cracking, Sirians bathe regularly in oil-rich water. This skin is devoid of feeling, but is thin enough to allow some sensory transmittal and gas permeability. The optical arrangement of Sirians is purely reptilian, with a single vertical slit instead of a round pupil. The Sirian eye possesses sufficient cones to allow pale color vision, and it is extremely sensitive to light due to the density of rod neurons.