Rhabdophis callistus

Boettger's keelback is a Sulawesi natricine currently recognised as Rhabdophis callistus. Juveniles have a greenish-olive stripe along the spine, a yellow lengthwise band beneath the darker flank band and two dark lines along the belly. Twenty-one scale rows at midbody help separate it from several related snakes. Adult appearance remains poorly documented in accessible photographs (de Lang and Vogel 2006; Reptile Database).

The species is endemic to Sulawesi in verified accounts; reports from Sangihe lack cited voucher specimens and need confirmation. It lays eggs, although clutch size is unreported. Its identity has long been confused with Rhabdophis chrysargoides, and a recent gland study combined Sulawesi samples provisionally because their morphological characters overlap. Consequently, colour alone should not be used to identify adults, and this account preserves that taxonomic caution (Mori et al. 2025; RepFocus).