SYSTEMATIC REPORT 177 



Antarctomysis ohlini Hansen, 1908 



1908 Antarctomysis sp. Tattersall, p. 36, figs. 



1908 Antarctomysis ohlini Hansen, p. 13; 1913, p. 20, figs. 



1923 Antarctomysis ohlini, Tattersall, p. 300. 



1930 Antarctomysis ohlini, Rustad, p. 21. 



Occurrence : 

 St. 39. 25. iii. 26 (day). East Cumberland Bay, South Georgia. 179-235 m., 21 cJ<J, largest 51 mm., 8 (JcJ, juv., 



26 $$, largest 54 mm. (breeding), 10 ??, juv. 

 St. 41 E. 28. iii. 26 (night). South Georgia. 100-50 m., 1 adult $, 43 mm. (damaged). 

 St. 42. 1. iv. 26 (day). Cumberland Bay. Two hauls: (a) N7-T, 120-204 m -> 7 <$<3> largest 54 mm., 2 SS juv., 



16 $$, largest 51 mm., 1 $, juv. (parasitized), (b) Net N4-T, 120-204 m -'> man y J uv -> a few adults, largest 



40 mm. 

 St. 45. 6. iv. 26 (day). South Georgia. 238-270 m., 2 $?, largest 45 mm. 

 St. 123. 15. xii. 26 (day). Cumberland Bay. 230-250 m., 13 $$, largest 52 mm., 12 $$ breeding, largest 52 mm. 



One specimen of 33 mm. with advanced embryos in the marsupium, 3 $?, juv. 

 St. 142. 30. xii. 26 (day). Cumberland Bay. 88-273 m -> 2 9 o*6\ 45-52 mm., 5 $$, juv., 12 $$, 45-51 mm., 23 $$, 



juv., largest 11-5 mm. 

 St. 154. 18. i. 27 (day). South Georgia. Two hauls: (a) Net N4-T, 60-160 m. 6 $6*. largest 30 mm., 15 $$, 



largest 29 mm., all juv.; (b) Net NCS-T, 60-160 m. 3 <^(J, 50-52 mm., 1 $, 44 mm., 21 $$, juv. 

 St. 205. 6. iv. 27 (day). South Shetlands, no depth on label, 1 $, 14 mm. juv. 

 St. 208. 7. iv. 27 (day). South Shetlands. 8oo(-o) m., 1 <J, 15 mm., 3 $?, 14-5 mm., all juv. 

 St. 376. 11. iv. 30 (day). South Shetlands. 750-500 m., 1 juv. ?. 

 St. WS 32. 21. xii. 26 (day). South Georgia. 225 m., 1 <$, 44 mm. 

 St. MS 68. 2. iii. 26 (day). East Cumberland Bay. 220-247 m -> 2 d<$> 5° mm., 1 $, 46 mm. 



Remarks. This species can be distinguished from A. maxima by the form of the eyes and by the 

 slope of the anterior lateral margins of the carapace. In A. ohlini the corneal elements occupy only the 

 distal end of the eye, so that the eyes look essentially forward, while in A. maxima they extend over 

 a large part of the outer margin of the eye as well and so look forward, outward and downward. The 

 anterior lateral portions of the margin of the carapace are oblique and the antero-lateral angles lie 

 well behind the insertion of the eyestalks, but in A. maxima these margins are vertical in lateral view 

 and the antero-lateral angles lie just below the insertion of the eyestalks. 



A. ohlini was taken at nine stations round South Georgia and at three near the South Shetlands. 



Tattersall (1923, p. 300) has noted that this species, like A. maxima, grows to a much larger size in 

 more southerly, colder waters. Hansen recorded adult females of 50 mm. and males of 52-5 mm. from 

 lat. 54 S., but Tattersall found in his material from the Ross Sea that a female of 52 mm. was quite 

 immature, while an ovigerous female measured 71 mm. Rustad (1930, p. 21) recorded an ovigerous 

 female of 47 mm. from South Georgia. 



The Discovery material does not add greatly to our knowledge on this subject, for all the specimens 

 taken from the South Shetlands were juvenile and all the others came from around South Georgia. 

 At station 123 (in December) in Cumberland Bay, a female with advanced embryos in the brood pouch 

 measured only 33 mm., while the largest specimen in the collection was an ovigerous female of 54 mm. 

 from station 39 (in March) also in Cumberland Bay. It is evident that there is great variation in the 

 size at which this species can breed in these waters. 



The following note on the colour of these specimens is given on the label from station 208 : ' Whitish 

 and transparent. Stomach deep purplish brown. Mouth parts and endopods of all the legs a rich 

 madder-red. A row of red chromatophores on under side of abdomen. Eyes black. Largest specimen 

 tinged with red throughout.' 



23 D 



