Sightings and bycatch of small pelagic cetaceans, new information registered by volunteer fishermen off São Paulo, Brazil

Getting to know you: Identification of pygmy killer whales (Feresa attenuata) and melon-headed whales (Peponocephala electra) under challenging conditions

“…To aid in future identifications, we illustrate and describe some of the main differences between these two species of small cetaceans. The incident reported by MARIGO and GIFFONI (2010) might represent the 'tip of the iceberg' regarding the incidental catches of cetaceans by pelagic drift nets off Brazil. Offshore driftnetting operating along the south-southeastern coast of Brazil may threaten pygmy killer whales.…”

“…We examined in detail Figure 3 in MARIGO and GIFFONI (2010) who reported that two melon-headed whales were taken in a surface driftnet about 90 nm off Santos, Brazil. We concluded they were in fact pygmy killer whales and explain our reasoning.…”

“…MARIGO and GIFFONI (2010) reported on the incidental capture of one pygmy killer whale and two melon-headed whales by the Ubatuba-based pelagic fleet while operating surface driftnets some 90 nm off Santos. According to the authors, three of those 'black animals' were captured in the same set during the first trip on November 2005, close to the Merluza Gas Platform, in Santos Basin, southeastern Brazil (24º43'S-44º33'W).…”

“…As pointed out by BAIRD (2010), the distinctive features of these two species are: (a) Peponocephala generally only have white on the lips (except in some very large individuals), while Feresa often have white areas around the lips and extending on to the head around the mouth; (b) the head shape in Feresa tends to be more bulbous, except in large adults, while Peponocephala do not have a very bulbous head shape; and (c) Feresa have rounded pectoral flippers while Peponocephala have acutely pointed flipper tips. These three characters are easily recognized in the colour photograph in MARIGO and GIFFONI (2010): the two whales have light areas on the front of the head, chest and belly, bulbous heads, and rounded pectoral flippers. The greyish patch on the chest of the smaller dolphin, shown in their Figure 3, is conspicuous and can be seen on a pygmy killer whale landed in India (JEYABASKARAN et al, 2011).…”

“…Another important feature is the distinctive groove on the belly which begins anterior to the umbilicus and ends at the anus, as observed in CHANTRAPORNSYL (1996). All five of these morphological differences between the two species were overlooked and may have contributed to the misidentification of these dolphins as melon headed whales by MARIGO and GIFFONI (2010). Figures 1-8 provide some photographs of these characters which distinguish between P. electra and F. attenuata.…”