Size: To 38 mm. 



Least depth of capture: To 350 m at night. 



Distribution: Known only from ofTChile near Valparaiso northward to about Iquique and 

 westward to about 79° W. Apparently does not occur northward of about 21° S for it was not 

 recorded from north of that latitude by Bussing ( 1965); not taken on Cruise 12 of the R/V 

 Anton Bruun off Peru in 1965, nor during the Scripps expedition Piquero in 1969, on the R/V 

 Thomas Washington. Most captures lie well within the confines of the Peru-Chile Current. 

 Discussion 



The preceding three species Protomyctophum (Hierops) chilense, P. (H.) beckeri, and P. 

 (H. ) crockeri are closely related and superficially very similar. They are separable by only a 

 few of the characters listed in Tables 2 (counts) and 3 (body proportions). In each table, data for 

 P. (H.) crockeri are only from specimens from the type locality, Cortes Bank, about 100 mi (160 

 km) west of San Diego, California. This restriction was imposed because of the existence of 

 subpopulations throughout the range of the species, as demonstrated above. 



Table 3. Body Proportions for Protomyctophum (Hierops) chilense, P. (H.) beckeri, 



AND P.(H.) crockeri 



*0ne specimen only. 

 "'Data for P. (H.) crockeri are taken from specimens from near type locality, off San Diego, California. 



The similarity of these three species is attested by the complete overlap in numbers of fin 

 rays and AO photophores and in most body proportions. Only the numbers of lower and total 

 gill rakers (Table 2) serve to separate P. iH.) beckeri from the other two species. Of the body 

 proportions (Table 3) the head and prepectoral lengths are most useful in distinguishing the 

 three species. The head of P. (H.) chilense averages 4% longer than that of P. (H.) beckeri and 

 6.1'7f longer than that of P. (H.) crockeri, with no overlap in values. The prepectoral length of 

 P. (H.) chilense averages 2.2% greater than that of P. (H.) beckeri and 3.7% greater than that 



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