90 



WHALES 



washed up on the beach or attached to the bottom of ships. The Nor- 

 wegians call them 'KnoUus' since they occur in great number on Hump- 

 back Whales (Knolhval), especially on the head and the pectoral fins 

 (Fig. 47) . In Sperm Whales they can be found between the teeth as well. 

 A common type looks like a six-pointed star, and against the black back- 

 ground of its host strongly reminds us of a decoration worn on a dress 

 suit. It was probably for this reason that Darwin named it Coronula reginae 

 (Qiieen's Coronet). In other, generally larger, members oï Coronula, the 

 resemblance to a coronet is more striking still (see Fig. 48). 



Another sessile crustacean often fovmd on Cetaceans is called Penella. 

 It looks like a long wire, and its anterior appendages burrow deep into 

 the skin. Its abdomen is feather-shaped and trails a number of filiform 

 egg strings (Fig. 48). Penella, and also the Acorn Barnacles, occur less 

 frequently on Rorquals in the Antarctic than in the tropics, and old 

 animals are generally more strongly infested than young ones. In addition 

 to the parasites listed, whales also harbour the cirripeds known as Stalked 

 Barnacles (Figs. 47 and 48). These barnacles seem to prefer a firmer 

 support than skin provides, and hence they generally cling to Acorn 

 Barnacles, to Penella, to the baleen, and to the teeth of Sperm Whales. 

 The only non-sessile parasites are small crustaceans (maximum length 

 ^ inch) known as whale lice. Like Penella, these are true parasites, which 

 feed on the whale's skin, to which they cling with sharp little claws. They 

 generally keep to grooves and slits - the lips, the corners of the mouth, the 

 ear slit or the genital folds - where they are more protected against water 



Figure ^8. Some common parasites found on 

 whales. 



A = Penella balaenopterae; B = 

 whale louse, Cyamus spec. ; C = Stalked 

 Barnacle, Conchoderma auritum attached 

 to D ^^ Acorn Barnacle, Coronula 

 diadema; E = Acorn Barnacle, Coronula 

 reginae. 



Approx. y their natural sizes. {Peters, 



1938.) 



