Terrestrial molluscs mucus trailing behavior of Taiwan slug snake, Pareas formosensis

[[abstract]]Chemosensory search is one of the most important foraging behaviors for snakes. The survival of snakes is directly influenced by the efficiency of chemosensory search. Taiwan slug snake, Pareas formosensis, is a dietary specialist feeding on land snails, especially the Pulmonata. The aim of this study is to investigate the trailing behavior of Taiwan slug snake on the terrestrial mollusks mucus. A Y-shaped observation area was used to exam the trailing behavior of Taiwan slug snake to the mucus of terrestrial slugs (Incilaria bilineata) and two snails (Nesiohelix swinhoei and Cyclophorus formosensis). The results showed that Taiwan slug snakes preferred to trail the mucus of I. bilineata and N. swinhoei; The trailing rate was 87.5% and 62.5%, respectively. Taiwan slug snakes showed no significant preference between the trailing rate of C. formosensis (4.2%) and distilled water (0%). Testing by three kinds of mucus Taiwan slug snakes showed the greatest preference of I. bilineata, then N. swinhoei, and C. formosensis. I exposed each mucus to the air for 0, 15, 30, and 60 minutes, the result showed that the mucus trailing rates declined according to the increase of mucus exposure time. Taiwan slug snakes could not discriminate the direction of prey by mucus trails. Two parts of terrestrial slugs’ mucus were separated by centrifugation, namely small-molecules and macro-molecules. Nevertheless, Taiwan slug snakes showed no significant difference in tracing either small-molecules or macro-molecules.