Predation by non-bioluminescent firefly larvae on a tepui-summit endemic toad

Thriving in a hostile world: Insights from the dietary strategy of two allopatric, closely related tepui summit endemic amphibians

“…3 km 2 ). The species is reported to occur in high numbers on the summit of Roraima-tepui (Kok et al, 2019;Kok, unpublished), but is listed as Vulnerable (VU) by the IUCN Red List of Threatened Species since it notably has a very restricted range and is expected to be prone to decline due to global climate change (IUCN SSC Amphibian Specialist Group, 2020). These small toads (16.2-29.8 mm snoutvent length in adults) secrete a sticky yellow fluid when molested (Figure 3b).…”

“…We also illustrate for the first time the previously unknown larva of Rhantus elegans, a dytiscid reported to be endemic to the summit of Roraima-tepui (Figure 9l), and demonstrate Oreophrynella quelchii is probably an opportunistic feeder, a notable exception is the avoidance of predatory larvae as noted both through absence in stomach contents and observations. Oreophrynella quelchii is predated by venomous firefly larvae (Coleoptera, Lampyridae) on the summit of Roraima-tepui (Kok et al, 2019). Although early instars of these larvae are within the range of the prey sizes usually consumed, they were never found in the toad's gut contents.…”

“…These captive toads never attempted to feed on the firefly larvae, which suggests that they are able to differentiate between firefly larvae and other potential prey items, even at night and even if these larvae do not glow (Kok et al, 2019;Kok, pers. obs.…”

“…This is mainly due to the logistical difficulties in performing long-term field surveys in such extreme and isolated environments. Notable exceptions are a few reports on the reproductive ecology and behavior of tepui summit toads of the genus Oreophrynella (Mägdefrau & Mägdefrau, 1994McDiarmid & Gorzula, 1989), of Pristimantis yuruaniensis (Strabomantidae) and Stefania riveroi (Hemiphractidae) from the Eastern Tepui Chain (Mägdefrau & Mägdefrau, 1994), and a recent paper discussing the unexpected predation on Oreophrynella quelchii by firefly larvae (Kok et al, 2019). To date, there has been no published investigation on dietary patterns in any tepui summit amphibian species.…”

“…Toads of the genus Oreophrynella (nine species endemic to Pantepui; Kok et al, 2020) are particularly well adapted to the tepui top environment (Kok et al, 2019(Kok et al, , 2020McDiarmid & Gorzula, 1989). Current phylogenetic hypotheses based on molecular data indicate that Oreophrynella is placed near the base of the bufonid tree (e.g., Kok et al, 2012;Kok, Ratz, et al, 2018;Van Bocxlaer et al, 2010) in a paraphyletic group of taxa sometimes termed "atelopodid" (e.g., McDiarmid, 1971), with Atelopus recovered as its sister clade (Kok, Ratz, et al, 2018).…”