FISHERY BULLETIN: VOL. 73. NO. 1 



Tablk 9. — Variation in total length of calyptopis stages between the different areas from which samples 



were studied. 



juveniles; it is well developed in larger indi- 

 viduals but never more than one-half the length 

 of the eyestalk in specimens examined. 



DISCUSSION 



The larvae of many species of the genus 

 Euphausia have not been studied but, although 

 preliminary, it may be useful to note ways in 

 which E. gibboides larvae differ from related 

 identified forms. The described larvae of Eu- 

 phausia which have features such as armature 

 of carapace or telson similar to those of E. 

 gibboides during some phase of development 

 belong to the following species: 



Group A E. brevis — (Gurney 1942) 



E. krohnii — (Sars 1885; Lebour 



1926; Frost 1934) 

 E. diomediae — (Ponomareva 1969) 

 E. eximia — (author unpubl.) 



Group B E.pacifica — (Boden 1950; Banse 



and Komaki 19663; 

 author unpubl.) 

 Group D E. longirostris — (Tattersall 1924; 



John 1936) 

 E. spinifera — (Tattersall 1924; John 

 1936; Sheard 1953) 

 Euphausia sp. (Ruud 1932; Lebour 1949; 

 Boden 1955) 



A metanauplius with marginal fringe of spines 

 on the rostral hood of the carapace is found in 

 E. brevis, E. krohnii, E. eximia, E. diomediae, 

 E. pacifica, and Ruud's E. sp. as well as in E. 

 gibboides. The metanauplius figured by Ruud 

 differs from the others, however, in that the 



^Banse, K., and Y. Komaki. 1966. Studies of Euphausiidae 

 (Crustacea) off the Washington and Oregon coasts. Annual Re- 

 port to NSF(Natl. Sci. Found.), Grant No. GB-3360, 6 p. Unpubl. 



Table 10. — Carapace width expressed as percent of carapace length in calyptopis 

 stages of £. gibboides (the number measured is given in Table 9). 



166 



