Tiger shark predation on large ocean sunfishes

Tiger shark predation on large ocean sunfishes (Family Molidae) – two Australian observations

Marianne Nyegaard, Samantha Andrzejaczek, Curt S. Jenner, Micheline-Nicole M. Jenner

ABSTRACT:

Sharks are commonly listed as predators of the large ocean sunfishes (genera Mola and Masturus), yet documented shark predation events on adult sunfish are exceedingly infrequent in the literature. Here we recount two Australian observations of tiger shark (Galeocerdo cuvier) predation on sunfish of ca. 1.3 and 2 m total length, respectively. The attacks demonstrate that tiger sharks are both able and willing to predate on large sunfish; however, based on a paucity of sunfish remains in tiger shark stomach analyses, and a lack of reports of the common sunfish parasite Molicola horridus in tiger sharks, these observations likely represent opportunistic predation events. The seemingly limited interactions may reflect differing habitat use by sunfish and tiger sharks within their overlapping distribution ranges, alternatively, large sunfish may comprise low quality or undesired prey for tiger sharks. Further, despite indications of prey debilitation during both accounts, the attacks likely represent indiscriminate tiger shark feeding events with no particular prey handling strategy.

Environ Biol Fish (2019), DOI: 10.1007/s10641-019-00926-y

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