ESTIMATING BODY LENGTH OF PYGMY RIGHT WHALES (CAPEREA MARGINATA) FROM MEASUREMENTS OF THE SKELETON AND BALEEN

Abstract

AB5TRACTVarious parts of the skeleton and/or the longest baleen plate of 46 specimens of Caperea marginata from Australia and New Zealand were measured and related to body length. Of the 32 skull, postcranial and baleen-plate measurements available, eight were analysed and seven found to be good predictors of body length, by using a curvilinear model describing their relationship with body length. Greatest skull width, suptaoccipital length and mandible length had the smallest prediction limits (kO.28-0.33 m in small animals, kO.44-0.58 m in large animals) when compared with postcranial measurements (scapula length, vertebra 7 centrum width). Baleen-plate length was also a useful predictor of body length (50.32-0.77 m). There was a substantial increase in the arch of the skull as body length increased. Bulla length was not a good predictor of body length, because measurements were highly variable and because the bulla grew little during postnatal life. Physical maturity occurred at body lengths of at least 5.9 m, also the shortest length at which both epiphyses of the humerus and proximal epiphyses of the radius and ulna were fused. Weaning appears to occur at about 3-3.5 m.The following approximate relative agellength classes were erected: dependent calves, c3.6 m; subadults, 3.6-5.5 m; adults, >5.5 m. Females were significantly longer than males in the sample of 22 animals greater than 5.9 m, length of the smallest recorded physically mature animal.

Pygmy right whaleCaperea marginatarecords from Namibia

“…The specimen was eventually forwarded to the Naturhistorisches Museum, Wien, Austria, where it was compared with the 16th dorsal vertebra from a near-complete juvenile C. marginata skeleton from New Zealand, and the identification confirmed. The sizes of the two vertebrae were also similar, and as the New Zealand specimen had a maximum skull width of 370 mm, equivalent to a predicted body length of about 2.9 m (Kemper and Leppard 1999), this confirmed that the vertebra came from a juvenile. The bone has been retained by the finder as a souvenir (K Bauer, Naturhis torisches Museum, Wien, pers.…”

“…The cranium and some post crania were moved to Walvis Bay and were later transferred to the Rotterdam Museum of Natural History (see Table 1). The measurements of this cranium ( Figure 7, Table 2), indicate that the individual was a juvenile with a total body length of 3.3-3.4 m (Kemper and Leppard 1999).…”

“…The individual was measured, photographed and successfully refloated. The length of the individual (Figure 2b) suggests the animal was a juvenile (Kemper and Leppard 1999).…”

“…Skeletons were identified from the skull profile and shape, characteristic mandible, number and flattened shape of ribs, and rounded shape of lateral processes of vertebrae. Animals classified as juvenile were those immediately post-weaning, believed to occur at 3-3.5 m, and those as adults were animals >5.5 m in length; equivalent skull measurements were a supraoccipital length of <350 mm and >550 mm respectively (based on Kemper and Leppard 1999).…”

Dolphins, whales and porpoises : 2002-2010 conservation action plan for the world's cetaceans

“…It is one of the least known cetacean species, although recently completed anatomical studies (Kemper and Leppard 1999) and observations at sea (e.g., Matsuoka et al 1996) have begun to reveal basic information. There are no known conservation problems (Kemper 2002).…”