JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 



Figure 15. — Distribution of sailfish ma.ximum ova diameters and 95th centiles by month from 



Buena Vista and Mazatlan. 



B 



» 



Figure 16. — X-ray photos of preopercular bones of striped 

 mariin from Buena Vista showing (A) cavities caused by 

 Pliilichthys xiphiae (B) a non-parasitized bone. 



Caligoid copepods (some identified as Pandarus 

 sp.) were common on the body surface and often 

 very numerous, particularly in the ventral region just 

 anterior to the anal fin. Large concentrations of 

 these parasites appeared to irritate the skin, causing 

 redness. White capsalid trematodes were commonly 

 seen on the body surface. A different species of 

 capsalid was found commonly in the nasal cavities. 

 Isopods (some identified as Nercila sp.) were quite 

 common on the body surface (usually on the fins) of 

 sailfish at Mazatlan. Up to 57 isopods were recov- 

 ered from a single sailfish. Nematodes were present, 

 often numerous, in most of the billfish stomachs 

 examined. 



FOOD HABITS 



Evans and Wares (1972) presented the data for 

 1967-1969. The contents of additional stomachs ex- 

 amined in 1970 (Table 4) are analyzed below. Table 5 

 presents the new data as percent occurrence and 

 percent of total food volume. Table 6 compares the 

 top ranked food items based on volume from the two 

 studies. Except at San Diego, where the sampling 

 dates were similar (August-October) in both studies, 

 the comparison is between seasons as well as be- 

 tween years. The 1970 sampling in Mexico was from 

 October through December whereas most of the 

 earlier data was gathered from April through July. 



98 



