Some Biological Observations of Billfishes Taken in the Eastern Pacific Ocean , 1967 - 1 970 MAXWELL

  • PAUL G. WARES
  • Published 2004

Abstract

From 1967 through 1970 sport-eaught billflsbes were sampled at Mazath, Sinplop; and BWM V W , Baja California, and at San Dkgo, California. Lengths, weights, morphometries, merisl.ics, and gonad data were gathered on a total of 2,056 striped marlin, 821 SPimPh, 61 blue marlin, and 1 black marlin. This paper presents information on reproduction, average length and condition factor, food habits for 1970, and notes on parasites. Developing g o a d s were found only in the Mexican flsh. Our data on reproduction Indicated that both striped marh and SPIlILsh spawn once per year with peak spawning rrtivity probably in June and July. There b also the possibility that SaillLSh spawn in other months. First maturity in striped marlin and s;rllilsh occoRpd in the 155-165 em eye-fork length class. Fecundity estimates ranged from 2 to 5 million eggs for four spllilsh and from 11 to 29 millbn eggs for three striped marlin. It appears tnat striped marh move o f f h from the Mexican coastllw to spawn while srrililsb remain closer to shore. Much of the interest in billfishes in the eastern Pacific Ocean stems from their popularity among sport fishermen. Commercial fishermen have also been interested in the biUish resources as indicated by their extensive and continuous operation in this area since 1956 (Suda and Schaefer, 1%5). Since 1963 this fishery has concentrated off Mexico where it is directed primarily at striped marlin (Tetrapturus audax) and sailfish (Istiophorus platypterus) (Kume and Schaefer, 1966; Kume and Joseph, 1969a). Throughout the history of the billfish fishery in the eastern Pacific no attempt has been made to manage these resources; this is partly due to the lack of information on the life history and population dynamics of these fishes. This report provides data gathered from billfishes landed at sportfishing sites in southern California and Mexico from 1967 to 1970. Specimens were examined at San Diego, California; Buena Vista, Baja California; and Mazatlan, Sinaloa, Mexico (Fig. 1). A total of 2,056 striped marlin, 821 sailfish, 61 blue marlin (Makaira nigricans) and 1 black marlin (M. indica) were sampled. This paper is one of a series of publications describing the results of these studies. Evans 'NOAA, National Marine Fisheries Service, Tiburon Fisheries Laboratory, Tiburon CA 94920. 89 and Wares (1972) published information of the food habits of fish collected in 1%7-1%9, and another paper (Wares and Sakagawa, 1973) has been prepared to present meristic and morphometric analyses. The purpose of this paper is primarily to present

Cite this paper

@inproceedings{WARES2004SomeBO, title={Some Biological Observations of Billfishes Taken in the Eastern Pacific Ocean , 1967 - 1 970 MAXWELL}, author={PAUL G. WARES}, year={2004} }