In order to improve the inter-specific selectivity of a new bottom trawl design for demersal crustaceans, an experimental attempt was carried out to compare the shrinkage effect in length of net structure accessories, particularly shorter bridles and sweeps, based on previous studies on escape behavior of gadiform fishes. For this purposes, an experimental fishing for nylon shrimp (Heterocarpus reedi) was carried out on board of two trawler vessels. The results showed no significant differences in catch per unit of fishing effort (CPUE) for the target species between gears and significant reductions (p < 0.05) for the most important by-catch species (Merluccius gayi) with the modified gear. In fact, the average CPUE for M. gayi decreased 5.6 kg h-1 (19.2%) and 35.7 kg h-1 (47.5%) for each vessel.