(A study on word fish, Xiphias gladius Linnaeus, 1758, biology and fishery in the South and Southeast of Brazil (1971 to 1981)

Abstract

The swordfish represents about 24% of the total catch of the Brazilian longliners which operate in the area 20°-33°S and 039°-050°W, being usually the second most caught species. Commonly, the values of yield, catch per unit of effort and average weight were higher in the third quarter (winter). The great increase of yield and catch per unit of effort verified in 1980 was probably due to changes of the bait used and the schedule of fishery. The analysis of these data suggests a potential to be better studied. The obtained data included the sex ratio: 1/1.14; the dressed weight/length: Pe = 1.24 x 10^-5C^3.04; and the total weight/dressed weight: P_t = 1.17 Pe relationships. The catch comprehended specimens between 50 and 290 cm, the sizes of 85 to 185 cm being the most frequent. In this region the spawning of the species occurs from the middle of the fourth to the end of the first quarter, mainly in January-February. During this period the fleet operated in the area 20°-28°S and 039°-048°W. Three species of ectoparasites of the genus Pennella and three commensals of the genus Remora were identified, and the result of the action of the predators was observed.