Table 5. — List of parasites found on sailfish (adapted from 

 Silas, 1967, and Silas and Ummerkutty, 1967). 



Locality 



Parasite 



Location on 

 host 



guilty of aggressive behavior of this type as are 

 marlins and swordfish. 



Evans and Wares (1972) examined stomachs from 

 151 sailfish captured in the eastern Pacific and found 

 22% with stomach ulcers. They suggested that injuries 

 from the spines of prey fishes were factors in the ul- 

 cerations. 



3.4 Nutrition and Growth 



3.41 Feeding 



One of the most detailed accounts of sailfish feeding 

 is found in Voss (1953): 



Apparently no feeding was done at night for in the early 

 morning the fish were scattered. Around 9:00 the first schools 

 began to appear as the sailfish, numbering from 6 or 8 to 25 or 30 

 began to mill about small groups of "pilchards," forcing them 

 into compact schools by slowly circling about them at the sur- 

 face, their sails half raised. While feeding the sailfish were 

 oblivious to their own danger and a boat could be eased down 



into the mass of circling fish until often the sailfish would ac- 

 tually bump against the sides of the vessel. . . . 



At short intervals, while the "pilchards" were kept bunched 

 up by the circling sailfish, a single sailfish would break out of the 

 circle and swim rather slowly directly through the small school 

 of "pilchards," thrashing vigorously sideways with its bill, hit- 

 ting fairly large numbers of the small fish stunning or killing 

 them. After thrashing through the school, the sailfish would 

 then turn, swim slowly downward beneath the school where it 

 would then swim about picking up the dead "pilchards" as they 

 sank downwards. 



Voss added that in normal feeding, sailfish were 

 relatively slow in their actions and bursts of speed 

 were exceptions. He concluded that accounts of 

 sailfish being fast swimmers were exaggerated and 

 that speeds of over 13 knots were probably unusual. 



3.42 Food 



It has been fairly well established that the food of 

 very young sailfish consists primarily of copepods 

 (Beebe, 1941; Voss, 1953; Gehringer, 1956) (see 3.23). 

 Voss noted that with only a few millimeters increase 

 in size, the diet of young sailfish changed to 

 predominately fishes. Gehringer (1956) stated that in 

 the 32 larvae he examined from the South Atlantic 

 coast of the United States, fish were a major portion of 

 the diet in all larvae above 6.0 mm. He also noted that 

 no copepods were found in sailfish above 13.0 mm long 

 (15 specimens). The food of sailfish from the eastern 

 and western Atlantic, off the West African shelf and 

 off northeast Brazil, was examined by Ovchinnikov 

 (1970), who gave a list of food items taken from the 

 stomachs of sailfish from both areas. He stated that 

 the composition of food from eastern Atlantic fish 

 altered according to the season. He reported that in 

 February the food was mainly cephalopods, 

 anchovies, and Otoperca, whereas in April sailfish fed 

 on Sardinella and in May jack mackerel. He indicated 

 that forage resources were more scant in the open 

 ocean with about half of the stomachs examined being 

 found empty. The qualitative composition of the food 

 was also different, squid and gempylids being the 

 main items. 



The above confirms what appears to be a general 

 consensus that although fish and squid form the ma- 

 jor portion of their diet, adult sailfish are fairly oppor- 

 tunistic feeders and eat whatever happens to be pres- 

 ent. Nakamura (1949) stated that billfishes in general 

 probably do not have any particular tastes in food and 

 probably feed on whatever was abundant in the area 

 or what could be most easily seen or caught. He added 

 that billfish definitely did not feed on demersal 

 organisms although they did feed occasionally on 

 deep-sea fishes. He also stated that it is more 

 reasonable to believe that deep-sea fishes are eaten at 

 night when they approach the surface rather than 

 billfishes diving deep to feed during the day. Ovchin- 

 nikov (1970) presented data on the degree of stomach 

 fullness of sailfish off the West African shelf, which in- 



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