The by-catch of Sciaenidae fishes in experimental fishing with an otter trawlnet used in the seabob shrimp, Xiphopenaeus kroyeri, fishery in Paraná State, Brazil

Abstract

Experimental bottom trawls were made to gauge the by-catch of Sciaenidae fishes in the seabob shrimp fisheriy area of Paraná’s inshore, Brazil. Otter trawlnets were used in monthly hauls during the period from August, 2004 to July, 2005 at the 6, 9, 12 and 15 meters in five coastline perpendicular radials, between Barra da Ararapira and Matinhos. A total of 41,674 fishes, representing 21 taxa of Sciaenidae family, were caught. The dominant species were Stellifer rastrifer (37.8%), Ctenosciaena gracilicirrhus (11.8%), Paralonchurus brasiliensis (11.1%), Larimus breviceps (10.0%), Stellifer brasiliensis (9.5%), Cynoscion jamaicensis (5.1%), Isopisthus parvipinnis (5.1%), Menticirrhus americanus (3.3%), Nebris microps (1.9%) and Stellifer stellifer (1.6%), accounting for 97.3% of the Sciaenidae overall catch. The highest abundance had been at 6 meters (39%), followed by the 9-meter (28%), 12-meter (18%) and 15-meter (15%) depth ranges. Most of the fish were either immature or of indeterminate sex. Sciaenidae family contributed with more than 50% of the total ichthyofauna biomass, accounting for, at least 19.8 kg (34.2%) in November, 2004 and, at most, 99,3 kg (74.0%) in March, 2005.