False Killer Whale – Pseudorca crassidens
Habitat: Deep offshore waters.
Description: Long slender body, small tapered head; underslung lower jaw holds 7 – 12 pairs of large teeth, circular in cross-section; 6 – 10 pairs in upper jaw. Colouration all black except for variable throat patch which ranges from indistinct grey to nearly white on belly between flippers. Sometimes also a light grey blaze on side of face. Flippers are black, narrow, tapered, about 1/10th of body length, with distinct ‘elbow’ appearance. Dorsal fin is tall (to 40 cm), sickle-shaped, just behind midpoint of back.
Size: 4.5 – 5.4 m, males larger (up to 6.1 m).
Weight: 1200 – 2000 kg.
Lifespan: 30 – 40 years, oldest known individuals 63 years (female) and 58 years (male).
Distribution: Worldwide, mainly in tropical and warm temperate waters. A few mass strandings in British Isles prior to 1935. 5 sightings snce 1976, 5 – 54 km from land, mainly in July and August.
Diet & Feeding: Primarily squid and large fish, known to prey on dolphins and has been reported attacking sperm whales.
Breeding: Females are spontaneous ovulators. No obvious calving peak. Gestation period lasts 15.5 months (possibly down to 11). Lactation period 18 – 24 months. Calving interval reported in one population almost 7 years. Sexual maturity at 8 – 14 years in both sexes. Known to hybridise with bottlenose dolphin.
Conservation Status & Population: No population estimates in the Atlantic. Has been actively hunted off Japan and St Vincent, West Indies, in the 1970s. Caught off Florida for dolphinaria. Accidental bycatch reported off Australia. High levels of PCB, DDT, DDE, mercury pollutants reported.
Almost all black, slender form. No beak. Head is small and slender with rounded snout. Dorsal fin is tall, sickle-shaped, central.
Vocalisations: Comprise whistles ranging 5.3 – 8.2 Hz (significantly higher than for pilot whales, killer whales) and echolocation clicks with peak frequencies around 100 kHz. Can discriminate between complex harmonic whistles and simpler ones, suggesting it is able to understand complex vocalisations.