Sneaky egg-eating in Telmatherina sarasinorum, an endemic fish from Sulawesi

The Malili Lakes of south-central Sulawesi, Indonesia, recently hailed as ‘Wallace’s Dreamponds’ (Herder et al., 2006a), are gaining recognition as a powerful model system for studying adaptive radiation in a variety of organisms, including crabs, snails (von Rintelen et al., 2004; von Rintelen & Glaubrecht, 2005) and fishes (Roy et al., 2004; Gray & McKinnon, 2006; Herder et al., 2006a). Included in this group of endemic animals are the telmatherinid fishes (Atheriniformes: Telmatherinidae). The telmatherinids or sailfin silversides (Kottelat, 1991), are small, often brightly coloured fishes found throughout four of the lakes and numerous streams of the Malili Lakes drainage. All of the telmatherinids found in Lake Matano, the most isolated lake, are endemic, while Lakes Towuti and Mahalona share several species, and Lake Wawontoa only contains one confirmed telmatherinid. Several stream forms are found throughout the system, collectively called Telmatherina bonti (Weber & de Beaufort) [although this taxonomy may change as more thorough genetic analyses are conducted (Herder et al., 2006b)]. Until recently almost nothing was known about the behavioural ecology of this group of fishes, other than brief behavioural notes included in Kottelat’s (1990, 1991) taxonomic descriptions. Given the recent interest in these fishes,