Juveniles of the Torpedo Scad, Megalaspis cordyla (Teleostei: Carangidae), schooling with venomous catfishes (Plotosidae): a new case of mimicry and an identification correction

Smith-Vaniz et al. (2018) reported a case of mimicry between juveniles of Caranx bucculentus Alleyne & Macleay (Carangidae) and Plotosus lineatus (Thunberg) (Plotosidae) in this volume of the Journal of the Ocean Science Foundation (p. 82). The identifications were based solely on photographs of schooling juveniles at Lembeh Strait, Indonesia. Soon after the on-line version of the paper became available, new information made it obvious that the carangid had been misidentified. A color image of an approximately 5 cm fork length juvenile of C. bucculentus from Western Australia was kindly sent to me by John Pogonoski. This specimen has a much deeper body than the mimic carangid and its coloration is very different. Subsequently, I received 4 color photographs of what was clearly the same carangid illustrated in Smith-Vaniz et al. (2018) in association with Plotosus schools. One of these photographs (Fig. 1) shows 17 individuals schooling with the venomous catfishes. The photographs were taken by Neville Ayliffe at Stringer Reef, Sodwana Bay, South Africa (-27.519°, 32.689° or 27° 31.14’S, 32° 41.34’ E). Because C. bucculentus does not occur in the western Indian Ocean, the identity of the mimic carangid cannot be that species. So what species is it?