252 DISCOVERY REPORTS 



PARASITES 



In describing the parasites infesting whales in the Azores, I am chiefly concerned with any evidence 

 they may provide regarding the racial identity or otherwise of sperm whales from different seas. 



External parasites 



At Horta in 1949 the practice of stripping blackskin (p. 245) sometimes hampered the search for such 

 external parasites as skin diatoms and cyamids. 



No diatom film was found on the nine males and seven females which could be examined for this 

 infection at Horta. However, there was a yellow film of skin diatoms around the margins of the jaws 

 of the male sperm whale no. WLTi, 14-3 m. long, examined at Harris in the Outer Hebrides of 

 Scotland on 16 June 1951. My colleague, Dr T. J. Hart, has kindly examined scrapings from this 

 film, and he comments as follows: 



The diatoms from Sperm whale No. WLTi are particularly interesting as they seem to be the same as (or perhaps very 

 closely allied to) those found upon Sperm whales and other whales during the [Antarctic] Season 1 930-1. I mentioned 

 them as 'Navicula sp.' without attempting detailed identification, though drawings and a photomicrograph by 

 A. Saunders were published.* Recently Hustedt has shown that they should probably be referred to the genus 

 Stouroneis, and has based a species S. olympica n.sp., upon specimens from the epiphytes on barnacles from a hump- 

 back whale captured in the Ross Sea area during the 1 950-1 season, collected by Kapt. Sven Theinemann.f Dr Hustedt's 

 paper raises several more controversial points concerning the taxonomy of these and other diatoms from the same 

 habitat. Revision of our abundant earlier material must proceed much farther before I can convince myself of the 

 propriety of these. However, the identity of Mr Clarke's Hebridean specimens with Kapt. Theinemann's and those 

 in earlier 'Discovery' material seems almost certain, and this is the first evidence known to me of skin-film diatoms 

 common to whales of both the northern and southern hemispheres. It may be significant that the cosmopolitan 

 sperm whale, rather than the more regularly migrating rorquals, was the species upon which they were first noted 

 in the North. 



Diatom film has never been recorded from whales examined in the tropics. If then the same species 

 of Navicula is indeed concerned both in the North Atlantic and in the Antarctic, this argues against 

 racial segregation of the Sperm whales parasitized (p. 288). 



Oval scars, caused by an unknown agency, were present around the gape and the margin of the 

 upper jaw, and more sparsely along the flanks, of ten males and eleven females examined in 1949. 

 Open pits, which later heal to oval scars, are found on the body surface of sperm whales and whale- 

 bone whales examined in low latitudes of the southern hemisphere. In the Antarctic the scars are 

 always healed, so the presence of healed oval scars is evidence that a southern whale has spent some 

 time in the tropics (Mackintosh & Wheeler, 1929, p. 373; Matthews, 1938, p. 126). The oval scars 

 on whales examined at Horta were all healed, yet it is interesting to note that the sperm whale ex- 

 amined at Harris (in a much higher latitude) bore on the head, beside healed scars, eleven partially 

 healed pits with scabs sloughing from them. Pike (1951) claims that, for the species of whales taken 

 off British Columbia, the open pits and the scars are caused by a parasitic lamprey, but Nemoto (1955) 

 maintains that not all such scars on North Pacific whales can be attributed to lampreys. Mr John 

 Owen, who was whaling from Harris in 1951, informs me that a Fin whale, shot between the Flannan 

 Islands and Iceland, had a fish attached to its body: when an attempt was made to collect the fish, it 

 fell off and escaped, but left an oval mark which at once reminded Mr Owen of the scars he had seen 



* Hart, T. J. (1935), The Diatoms af the Skin Film of Whales. Discovery Rept. x, pp. 247-82, pi. XI. 

 f Hustedt, Friedrich (1952). Diatomeen aus der Lebensgemeinschaft des Buckelwals (Megaptera nodosa Bonn.), Arch. 

 Hydrobiol. Bd. xlvi, S. 286-98, figs. 1-14. 



