FISHERY BULLETIN: VOL. 71, NO 4 



5.0 



E 

 E 



4.0 



3.0 



2.0 



I mucronatus 



I longiceps 



D monachus 



S crassus 



\subtenui5, Indian Ocean sample 



Wsubtenuis, Pacific Ocean sample 



i subtenuis, Atlantic Ocean sample 







D . ill 



□ D iDD 



Li 



m 



tei 





D 



i 



80 



90 



100 



110 



20 



30 



40 



150 



PERFORATION NUMBER 



Figure 10. — The subtenuis group of Eucalanus. Perforation number plotted against total length (TL) in adult females 



comprising the pooled samples. 



second maxilla, three tergal sites regularly on 

 the genital segment, two or more tergal sites on 

 Abd.III, and, laterally, a pair of posterodorsal 

 pleural sites on each side of segments ThI, Thll, 

 and ThIII. E. deiitatus (Figure lib) shows, in 

 addition, three tergal sites across Abd.IV-V 

 while subcmf>su.s (Figure lie) has a single mid- 

 dorsal site on Abd.IV-V. 



As in the subtenuis group the species with 



the most extensive geographical range, the 

 circumglobal pileatns, shows the most distinctive 

 number of perforations within the species group 

 (Figure 12). Differences between subcrassus, 

 a broadly neritic species of the Indian and Paci- 

 fic Oceans, and dentatus, a coastal species of 

 Austral-Asian seas, are limited to arrangement, 

 the number of perforations shown by the pooled 

 samples of the two species being equal. 



986 



