LOBSTER-KRILL 



ANOMURAN CRUSTACEA THAT ARE THE FOOD 



OF WHALES 



By L. Harrison Matthews, m.a. 



(Plate IV; text-fig. i) 



TWO species of the genus Munida, M. subrngosa (White) and M . gregaria (Fabricius), 

 are closely allied and very similar in general characters. They are often found 

 together in the same localities, and occur in both the South Atlantic and Pacific 

 Oceans. They are of particular interest to the Discovery investigations as M. gregaria, 

 probably with a third allied species, Pleuroncodes planipes (Stimpson) from the Pacific 

 coast of Mexico, form an important food of some species of whale. 



M . gregaria has a pelagic post-larval stage which differs in appearance from the adult, 

 while in M. subrugosa the corresponding stage is bottom-living and similar to the adult. 

 Considerable confusion as to the relation of the pelagic post-larval stage of M. gregaria 

 to the adult exists in the literature relating to the species. This post-larval stage was 

 originally named as a separate species, Grimothea gregaria, and the name Grimothea is 

 used in this paper as a convenient label for this stage of the species. The hybrid English- 

 Norwegian term, " lobster-krill 'V is adopted as more descriptive than the corresponding 

 New Zealand name, "whale-feed", which in that country refers only to the Grimothea 

 stage of M. gregaria. 



MATERIAL EXAMINED 



The Discovery collections contain a long series of both species and their post-larval 



stages. 



St. 51. 4. v. 26. Off Eddystone Rock, East Falkland Islands. Large otter trawl, 1 05-1 15 m. 



M. subrugosa. 19 specimens, 7 $, 12 $, 16-5-38-0 mm., 3 with Bopyrid parasites on the gills. 

 M. gregaria. 45 specimens, 28 3, 17 $, 13-0-38-0 mm., 1 with Bopyrid parasite on gills. 

 Fine nets on trawl, 1 05-1 15 m. 

 M. subrugosa. 12 specimens, 5 6\ 7 ?. 12-0-20-0 mm.; 81 specimens, post-larval, 3-5-8-5 mm. 

 M. gregaria. 39 specimens, post-larval {Grimothea), 8-0-12-0 mm. 



St. 67. 23. v. 26. 47 18' 00" S, 51 52' 00" W. 4066 m. i-metre horizontal tow-net, 90 (-0) m. 



M. gregaria. 27 specimens, post-larval {Grimothea), 9-0-11-0 mm. 

 St. 223. 27. iv. 27. St Francis' Bay, Cape Horn. 55° 51' 15" S, 67 29' 30" W. Rectangular bottom 

 net, 63 m. 



M. subrugosa. 35 specimens, 21 <J, 13 $, 20-0-35-0 mm. 



M. gregaria. 60 specimens, 30 $, 30 $, 20-0-34-0 mm. 



St. WS 100. 23. iv. 27. 50 53' 00" S, 6i° 26' 00" W. 132 m. i-metre horizontal tow-net, 61 m. 

 M. gregaria. 276 specimens, post-larval {Grimothea), 7-5-9-0 mm. 



1 " Krill" is a Norwegian word meaning "whale-food". 



