Fish remains were found in 50% of males in this study in comparison to only 10% of females, and may be indicative of differences in foraging habitats between sexes as suggested in other studies (Clarke et al., 1988). Among those beaks within the family Histioteuthidae that could not be resolved to the species level, beaks were separated into those of Types A and B (as per Clarke, 1986) and where possible classified into species groups as described by Clarke (1980, 1986). The authors thank all of the volunteers who helped with the necropsy of whales and collection of samples, particularly Deborah Thiele and Margie Morrice for their help in the co-ordination of the collection and archive of samples. Three of the stomachs were empty. 15 of these species were deep-sea squids, which are not presently targeted by fisheries. Given that the samples studied here represent only a few days to at most a few weeks of prey consumed, the amount of these commercial species consumed by sperm whales far exceeds that of the current fishery operations in the area. Patrick, Miller J.O. Madsen, P. T. and and Søiland, H. The fact that the Sperm Whale can dive so deep helps tremendously when it comes to feeding. Immature animals contained higher abundances of subtropical and Antarctic species. Hickmott, L. As stated earlier most of what is known about the sperm whales squid diet has been studied from the contents found inside the sperm whales stomach. Slooten, Elisabeth While researchers haven’t really been able to witness any battles between a sperm whale and colossal squid (which can measure in at over 45 ft and weigh more than 1, 000 pounds) the markings found on the sperm whales head indicate struggles they’ve had while trying to consume this species of squid. Not all animals measured for dorsal total length were aged. Members of the histioteuthid family dominated samples by number and by frequency of occurrence. While a comprehensive assessment on the calorific content of cephalopod species is lacking, those assessments that have been undertaken demonstrate cephalopods to be an appreciably lower source of energy to top predators than fish or crustaceans (Croxall and Prince, 1982). Evidence of at least eight species of fish and 22 species of cephalopod was found, together with an assortment of foreign bodies including rock fragments and fishing nets. and If it is assumed that the wet weight of nematodes and the estimated total wet weight of cephalopods in each sample is largely representative of the total wet weight of each stomach sample, nematodes in the stomach of the sperm whales in this study comprise 0.3 ± 0.9% (range: 0.01–5.7%) of the total wet weight of stomach contents. The most important prey species, both in terms of numerical abundance (%N) and abundance by weight (%W), was the oceanic squid Histioteuthis bonnellii (%N = 48.4, %W = 66.3) followed by H. reversa (%N = 28.4, %W = 13.8) and Octopoteuthis sicula (%N = 8.5, %W = 17.2). Faecal studies are limited as they can only ever report on partial samples. Differences in the species composition of the diet of males and females may be reflective of different foraging habitats between sexes. Species diversity within diet samples is likely to reflect that of the prey diversity within a given foraging region. The diet of individuals in age groups 2 and 3 did not appear to reflect a predominance of either large or small cephalopod species. Oblique and lateral illustrations of the lower beaks are given, as well as sections of the rostrum, jaw angle, shoulder and lateral wall, to show the major identifying features for each of the species.Squid are an important component of food chains in the Southern Ocean and they act as both high-level predators and prey for apex predators. Olsen, E. Teloni, Valeria Similarity percentages (SIMPER) were determined in order to ascertain those cephalopod species responsible for any statistically significant differences observed between groups with ANOSIM. Cephalopods of the world. The diet of sperm whales observed in this study was predominantly composed of muscular cephalopods. However, on leaving their natal groups males associate with others of a similar size rather than age group, with groups observed to contain 12–15 individuals (or multiples thereof) 10–29 years old (Best, 1979). Some features of this site may not work without it. x��YKo$7�����"Qo`a��n�-�rr��$�x�K�~H��T�垌3����*=(>?R�7���G ��h��z� ���h�)1����rzz9}���i����Wo��RM&8Bl��j^^͏�p���'l��\��˃��ਿb�3�`��2z�'�r�����,O�5� ϲ�cK�1������9�1�{�e����g��iK����y�nQKh63'`��ъK"�"�5l��A��`�#M�k��J08z�^����4�� TE37Z��-�*�O|�4xm�t}�]�ח���_���;'��p&���Q��z�Z+��hh�o�d�鷟n~����W���'g]� 7�>&�*��T+D��oN?��t�c��qr��,;���l`ki����M8��z��,��߾zs�?�Z�� �""�&b�nw���W%"�K/��r&�pڂ Guerra, M. Generally most cephalopod species display ontogenic migration to deeper waters and it is likely therefore, that larger and older members of cephalopods species range to deeper depths (M. R. Clarke, pers. The Parks and Wildlife Service, Tasmania, particularly Hans Wapstra kindly helped with logistics. Full text views reflects the number of PDF downloads, PDFs sent to Google Drive, Dropbox and Kindle and HTML full text views. 4 0 obj This data will be updated every 24 hours. The Sperm Whale's diet consists almost exclusively of cephalopods (squid and octopus), especially the deep water and ocean bed species. The amount of local cephalopod beaks in the stomachs suggests some of the stranded sperm whales did not feed much within New Zealand waters in the days prior to stranding.The beaks of Taningia danae, Octopoteuthis megaptera, Octopoteuthis sp. Distribution of the dorsal mantle lengths of cephalopod prey in the diet of southern Australian sperm whales. Fishery effort has varied temporally, with foreign fishing vessels taking up to 7914 tonnes during the 1970s, and domestic catches much lower increasing from 439 to 1673 tonnes between 1995/1996 and 1997/1998 (AFMA, 2001). Johnson, M. P. opportunity to evaluate current diet and contrast it with historical accounts for the sperm whale, and offer new means to investigate sperm whale migrations in the region. Members of the family Histioteuthidae were the most important numerically, and were also important in terms of estimated reconstituted mass, although members of the Onychoteuthidae were the most dominant species in samples in terms of estimated reconstituted mass. In all cases the relative proportion of contents collected was estimated. This study expands the available knowledge using analysis of the stomach contents from nine individuals stranded in Greece between 2005 and 2014. Víkingsson, G. and The abundances of M. hamiltoni, M. robsoni, H. bonnellii, Histioteuthis B2, and Galiteuthis glacialis were most important in contributing to the differences observed between sexes (Table 4). Cephalopod species for which LRLs differed significantly between stranding site and age groups. The number of cephalopod species observed in the stomachs of sperm whales in this study is higher than that recorded elsewhere (Gaskin and Cawthorn, 1967; Clarke and MacLeod, 1974; Clarke and MacLeod, 1976; Clarke et al., 1976; Clarke, 1980; Clarke and MacLeod, 1982; Fiscus et al., 1989; Pascoe et al., 1990; Smith, 1992; González et al., 1994; Clarke and Roeleveld, 1998; Clarke and Roper, 1998; Clarke and Young, 1998; Smith and Whitehead, 2000) and encompasses tropical to Antarctic, muscular and gelatinous, pelagic, mesopelagic, bathypelagic, and mesobathypelagic species. Law, R.J. The presence of cephalopod species described from tropical and Antarctic regions in the diet of individual sperm whales suggests that cephalopod beaks may be retained for longer periods than previously thought. Sperm whales in the Greek part of the Mediterranean Sea feed on mesopelagic and bathypelagic squids. Teuthids were represented by 48 species from 14 families, octopods by two species from two families and the Vampyromorphida by the one species Vampyroteuthis infernalis (Table 3). The percentage numerical abundance and abundance by percentage weight of cephalopod species from each ecotype and composition group in samples were compared between stranding sites, sex, and age groups. This not only prevents the interpretation of the contribution of these species to overall mass, it also limits the interpretation of the contribution of other species to overall mass.

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