Feeding Preferences of Nipa-Obligate Crab Labuanium politum (de Man, 1887) in Captivity; Herbivorous Shift to Opportunistic Omnivores

Labuanium politum is a sesarmid crab that inhabit at nipa palm (Nypa fruticans) forest and known as herbivorous animal. The feeding ecology of this crab are literally scarce. Therefore, this study was carried out to investigate the feeding behaviour of L. politum towards different type of nipa leaf condition and various food materials through a series of laboratory feeding-preference experiments; leaf preference and multiple-choice feeding experiment. Total of 16 crabs (male=8, female=8) were placed individually in glass aquarium. Leaf preferences of L. politum were determined on three choices of nipa leaf condition (fresh=green, senescent=yellow and decayed=brown) in which the choices were given for each crabs. Results showed that this crab significantly preferred green leaf over yellow and brown leaf. Meanwhile, for multiple-choice feeding experiment, the crabs were given other choices of food materials: mangrove slug, cricket, bee and green nipa leaf. Consequently, L. politum preferred animal materials over green leaf, thus provides evidence that even though in the natural habitats they are herbivorous, this crab can be shifted towards opportunistic omnivores with strong preferences for animal food. These results suggest that this crab play a greater role in nutrient cycling in the nipa forest