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Abstract In order to improve the fishing and management technology of offshore fishery resources conser‐vation ,and to promote the implement of National Marine Fishing Gear Catalog ,we performed a selective comparative experiment of Monolithic gillnet with mesh sizes of 40 mm ,50 mm ,and 60 mm ,Dual gillnet , Triple gillnet and Production control network for mantis shrimp Oratosquilla oratoria in Liaodong Bay in October and November ,2014 to provide the basis for determing the adscription of managing Bohai T riple gillnet .Results showed that the main fishing species by various types of experimental nets were basically the same ,with the dominant species of mantis shrimp and perch Lateolabrax japonicus .The larger each types of gillnets had the decreasing IRI value of mantis shrimp with increase in mesh size ,while the IRI value of L .japonicus showed an increasing trend .The Monolithic gillnet ,Dual gillnet and Triple gillnet had significant difference in mantis shrimp catch (P<0 .05) .The proportion of mantis shrimp catch in the total showed growth trend in order of Monolithic gillnet ,Dual gillnet ,and Triple gillnet .In the same mesh size ,the mantis shrimp catches which come up to the standard showed growth trend in order of Mon‐olithic gillnet ,Dual gillnet ,and Triple gillnet ,without significant differences in the proportion in the to‐tal .For the same type of gillnets ,with the increase in mesh size ,the proportion of mantis shrimp catches did not rearch the standard declined gradually .Gamma selectivity curve displayed ,when the mesh size was more than 50 mm ,the mantis shrimp catches advantage length of the three types of gillnets was no less than that standard .However ,the economic benefits of the triple gillnet was more than Monolithic gillnet obviously ,and had no difference in terms of damage to fishery resources .Therefore ,Monolithic gillnet is difficult to replace T riple gillnet w hich operates in current Bohai Fisheries of mantis shrimp .
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Received: 25 April 2016
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