SUMMARY 2 93 



All sizes of sperm whales are taken in the Azores. Of 417 males at Horta, the largest measured 

 18-00 m. (59 ft. 1 in.). The largest of 202 females measured 12-30 m. (40 ft. 4 in.), which is the greatest 

 reliable measurement of a female known to the author. 



External characters are examined. Proportional measurements of five foetuses and one adult male 

 are not significantly different from measurements in a comparable range of southern whales. Colour 

 markings show no sexual differences in their variation and no obvious differences from those of other 

 stocks. Foetal pigmentation is discussed. Behind the dorsal fin of all whales there are from one to six 

 ' posterior dorsal humps ' whose variation is examined. Variation in the number and pattern of throat 

 grooves suggests these are derived from an arrangement of two grooves like that characterizing 

 ziphioid whales. 



The mandibular (functional) teeth are erupted late, when the female is between 8-4 m. (28 ft.) and 

 9-5 m. (31 ft.) long, that is, at the time of sexual maturity, and probably at about the same time in 

 males. Erupted teeth in males varied from sixteen to twenty-six on each side, and in females from 

 nineteen to twenty-six. Average numbers of teeth are similar in males and females, and in whales 

 from the North Atlantic, the North Pacific, and the Southern Seas. Maxillary (rudimentary) teeth 

 were erupted more often in Azores males than in females. 



External parasites of Azores whales are the whale-lice Cyamus physeteris and C. catodontis, the 

 • degenerate copepod Penella balaenopterae, and the stalked barnacles Conchoderma virgatum and 

 C. auritum. Diatom film was not observed, but a whale examined in the Scottish Hebrides bore a skin 

 diatom Navicula sp., apparently identical with the species infesting antarctic sperm whales. Internally 

 the nematode Anisakis physeteris occurs in the stomachs of all Azores whales, the tapeworm Priapo- 

 cephalus grandis is recorded from the gut, and another cestode forms cysts in the blubber. 



One or two pathological conditions are noticed, but whales caught in the Azores are generally free 

 from disease. A characteristic but rare deformity of the sperm whale is a crooked lower jaw, a new 

 example of which is recorded from the Azores. Some slight injuries to the body surface are dis- 

 cussed. 



Squids are the staple food, and those measured from stomachs in 1949 had an average standard 

 length of 0-94 m. (3 ft. 1 in.). Giant squids are occasionally taken; one whale captured at Fayal in 

 1955 had swallowed intact a specimen of Architeuthis sp., weighing 184 kg. (405 lb.) and measuring 

 10-49 m. (34 ft. 5 in.) in total length and 4-96 m. (16 ft. 3 in.) in standard length. Azores whales are 

 known to feed on eight species of squids. The diet at Fayal was Histiotenthis bonelliana (59% by 

 numbers), Cucioteuthis unguiculatus (39%) and Tetronychoteuthis dussumierii (2%), but of these the 

 bulky C. unguiculatus has the greatest nutritional importance. Large fish are a subsidiary item in the 

 diet, and at Fayal these included black shark, basking shark, barracuda and albacore, and two species 

 of large bathypelagic angler fish, Ceratias holbolli and Himantolophus groenlandicus . The sperm whale 

 occasionally eats demersal or benthic organisms and so must visit the sea floor at times. The amount 

 of food in stomachs shows that, at least between June and November, there is a substantial food supply 

 for whales around the Azores. 



Estimates of the mean length at sexual maturity of Azores sperm whales, concluded from the size 

 and histology of the testes and the condition of the ovaries, are 9-6 m. (31 ft.) or less for males, and 

 8-8 m. (29 ft.) for females. 



Dated records of foetal lengths show that pregnancy lasts sixteen months. The pairing season lasts 

 from January to July, with most activity between March and May. The calves are born from May to 

 November, but mostly between July and September. From the sizes of the largest foetus recorded 

 and of four new-born whales, it is established that, at least in the North Atlantic, the mean length of 

 the sperm whale at birth is 3-92 m. (12 ft. 10 in.). 



