Isistius triangulus (Probst, 1879)

Höltke, Olaf, Salvador, Rodrigo B. & Rasser, Michael W., 2023, Trophic relationships in the Early Miocene Upper Marine Molasse of Baden-Württemberg, Southwest Germany, with special emphasis on the elasmobranch fauna, Palaeontologia Electronica (a 46) 26 (3), pp. 1-38 : 31

Isistius triangulus (Probst, 1879)

Tooth type: Cutting-clutching.

There are only two extant species within this genus: I. brasiliensis (Quoy and Gaimard, 1824) and I. plutodus Garrick and Springer, 1964 . According to de Figueiredo Petean and de Carvalho (2018), members of this genus may not be good swimmers, given that they are ectoparasites of large fishes and cetaceans. Wounds made by Isistius spp. have been found on marlins, mackerels, tunas, sharks, rays, seals, whales, and dolphins (de Figueiredo Petean and de Carvalho, 2018). Strasburg (1963) also described squid retrieved from stomach contents and Cortés (1999) listed cephalopods as staple prey of I. brasiliensis . Extant I. brasiliensis has a TL of. 4.3 (Cortés, 1999), whereas I. plutodus has a TL of 4.2 ±0.4 (Froese and Pauly, 2019). Isistius spp. live in the oceanic realm, from epipelagic to bathypelagic regions (Ebert et al., 2021). For details on the feeding apparatus of the recent I. brasilianensis see Shirai and Nakaya (1992).