DISTRIBUTION AND GENERAL NOTES ON THE SPECIES 



319 



Several series of length frequencies of Macruronus showed strong and moderately consistent in- 

 dications of year classes, but the wide dispersion of our data in time as well as in space preclude any 

 useful pooling of these results. As Petersen found long ago it was the younger fishes that tended to 

 show this feature best. A few unmanipulated frequencies from stations worked early in the season, 

 in the northern region, are shown in Fig. 30. These indicate possible year classes at 18-19 cm- (prob- 

 ably just two years old) at 27 cm. and at 35 cm. (.'' three and four years old respectively) while the 

 third confirms the probable existence of a year class 35 cm. or so in length at that season. Later 



0-700 



650- 



^ 600- 



z 



U 0-350- 



MERLUCCIUS 



0CT05ER NOVEMBER I DECEMBER JANUARY FEBRUARY MARCH 



MACRUKONUS 



0-3QO- 



250 



OCTOBER InovEMBER I DECEMBER I JANUARY [FEBRUARY | MARCH 



Fig. 31. Seasonal variation in ponderal index of Merluccius, a summer spavvner, and of 

 Macruronus, which would seem to spawn in spring. 



results suggest that growth is most rapid in summer, and that the yearly increments diminish so that 

 fish of over 70 cm. may only grow some 5 cm. in the course of a year, but the data are insufficient to be 

 conclusive. 



Norman (1937, p. 50) has already pointed out the extremely close relationship between M. magel- 

 lanicus (Lonnberg) and M. novae-zelaiidiae (Hector) from Tasmania and New Zealand, with which 

 it was at first identified. This afiinity extends beyond morphological features to coloration and 

 habits. From Waite (1911, pp. 180-1) we learn that M. novae-zelandiae attains much the same sizes 

 as the Patagonian species, that its colour may be described as a deep iridescent purple with the fins 

 smokey and the lower parts silvery, and that it has been observed to feed upon Clupea neopilchardiis. 

 During the New Zealand trawling experiments of which Waite was writing several considerable 

 catches of the species were made, all between 16 and 28 fm., and it was not observed in deeper water. 



