The color of water appears to be an indicator of 

 probable abundance of white marlin. Nakamura 

 (1971) and Nakamura and Rivas (1972) found that 

 angling success for white marlin in the northern Gulf 

 of Mexico was greater in proportion to the blueness of 

 the water, and poorer in proportion to its greenness. 

 During the 1972 season, there was an unusual oc- 

 currence of green water at the normally productive 

 white marlin fishing areas at the edge of the continen- 

 tal shelf off Maryland and southern New Jersey, and 

 catches in this water were very poor (M. Maiorana, 

 pers. commun.). In similar areas off Virginia and 

 North Carolina, the water was the normal blue color, 

 and the fishing for white marlin was excellent, in- 

 dicating that the poor fishing further north was not 

 due to a scarcity of fish. 



In some areas, white marlin are concentrated near 

 rips (usually occurring at interfaces between different 

 masses of water), or weed lines. 



Differential distribution of white marlin is also in- 

 fluenced by bottom topography. Steep drop-offs, sub- 

 marine canyons, and shoals, when located in areas 

 with suitable water conditions, are often the scene of 

 important feeding concentrations of white marlin and 

 exceptionally productive fishing. Shoals of this nature 

 include the Placer de la Guaira, off the Venezuelan 

 port of that name (Jaen, 1964), the "Cigar" off the 

 Virginia Capes, the "Jack Spot" off Maryland 

 (Farrington, 1937, 1949a, 1949b; de Sylva and Davis, 

 1963), and the Five Fathom Shoal of southern New 

 Jersey (de Sylva and Davis, 1963). Drop-offs produc- 

 ing good white marlin fishing are found in many areas, 

 including the Bahamas, Cuba, Puerto Rico, and the 

 Virgin Islands. In recent years, excellent fishing for 

 white marlin and other oceanic game fishes has 

 developed at many of the canyons along the edges of 

 the continental shelf. Among the more important are 

 the De Soto Canyon in the northeastern Gulf of Mex- 

 ico; Norfolk Canyon off the Virginia Capes; 

 Washington, Baltimore, and Wilmington canyons off 

 the Delmarva Peninsula; and Hudson Canyon off 

 New York City. 



2.4 Hybridization 

 No information was found in the literature. 



3 BIONOMICS AND LIFE HISTORY 



3.1 Reproduction 



3.11 Sexuality 



The white marlin is heterosexual. No apparent ex- 

 ternal sexual diamorphism exists, except that the 

 females attain larger sizes than the males (de Sylva 

 and Davis, 1963; Ueyanagi et al., 1970; Nakamura 

 and Rivas, 1972), and may be somewhat heavier than 

 males of the same length (de Sylva and Davis, 1963). 



3.12 Maturity 



Ueyanagi et al. (1970) state that the species attains 

 sexual maturity at a length from orbit to fork of tail of 

 about 130 cm. The relationship of age to size of white 

 marlin is not known. 



3.13 Mating 



The only reference we have found to mating of 

 white, marlin is by Hemingway (1935, not seen by us, 

 but quoted by LaMonte and Marcy, 1941). He reports 

 paired breeding in the current off Cuba in May. 



3.14 Fertilization 



Fertilization is external. Eggs and sperm are 

 probably discharged separately by adjacent fish and 

 come together in the ambient water. 



3.15 Gonads 



White marlin gonads consist of two sausage-shaped 

 organs tapering at both ends which lie ventral to each 

 side of the stomach. The ovary is yellowish to orange 

 red, circular in cross section and often covered with 

 thick layers of connective tissue whereas the testis is 

 white to pinkish, triangular in cross section, and is 

 lobular in appearance, without connective tissue 

 covering (LaMonte, 1958b). 



LaMonte (1958b) found that in one male the gonads 

 were about 280 mm in length and 80 mm in cir- 

 cumference and very flabby; but in two others they 

 were the same length but about 170 mm in cir- 

 cumference and very firm. In a male specimen 

 weighing 17.7 kg the gonads measured 178 mm in 

 length and about 38 mm in circumference. 



Krumholz (1958) recorded the ratio of gonad weight 

 to body weight for 20 male and 22 female white marlin 

 taken in the Florida Current in late April 1956. The 

 gonads contributed from 0.097 to 1.266% of male body 

 weight with an average of 0.422 and from 0.882 to 

 9.762% of female body weight with an average of 

 4.556. The male for which the testes was 1.266% of the 

 body weight was a 36.4-kg fish, the largest examined. 

 The relative weight of gonads was also much greater 

 in large females than in small ones. Since these 

 gonads were not yet ripe, these figures do not indicate 

 the maximum relative weight of the gonads. The 

 average gonad weights, in percent of weight of fish by 

 10-pound (4.5-kg) groups (Krumholz, 1958), were as 

 follows: 



Male: 



