查看更多>>摘要：Improving the accuracy of fishing ground prediction for oceanic economic species has always been one of the most con-cerning issues in fisheries research.Recent studies have confirmed that deep learning has achieved superior results over traditional methods in the era of big data.However,the deep learning-based fishing ground prediction model with a single environment suffers from the problem that the area of the fishing ground is too large and not concentrated.In this study,we developed a deep learning-based fishing ground prediction model with multiple environmental factors using neon flying squid(Ommastrephes bartramii)in Northwest Pacific Ocean as an example.Based on the modified U-Net model,the approach involves the sea surface temperature,sea surface height,sea surface salinity,and chlorophyll a as inputs,and the center fishing ground as the output.The model is trained with data from July to November in 2002-2019,and tested with data of 2020.We considered and compared five temporal scales(3,6,10,15,and 30 days)and seven multiple environmental factor combinations.By comparing different cases,we found that the optimal temporal scale is 30 days,and the optimal multiple environmental factor combination contained SST and Chl a.The inclusion of multiple factors in the model greatly improved the concentration of the center fishing ground.The selection of a suitable combination of multiple environmental factors is beneficial to the precise spatial distribution of fishing grounds.This study deepens the understanding of the mechanism of environmental field influence on fishing grounds from the perspective of artificial intelligence and fishery science.
查看更多>>摘要：The genus Callistoctopus comprises 13 species,and has been reported mostly in the Western Pacific Ocean.Here,we described three new species from China,Ca.paucilamellus sp.nov.,Ca.sparsus sp.nov.,and Ca.gracilis sp.nov.,based on morphometric and meristic characteristics.The diagnoses,descriptions and detailed morphometric data are provided for each species.The cytochrome c oxidase I(COI)genes of the three new species are sequenced,and compared with related species and analyzed for their systematic positions.Both phylogenetic trees constructed using three mitochondrial genes(12S rRNA,16S rRNA,COI)and one nuclear gene(Rhodopsin)revealed that our new species formed into two distinct clades with strong support values.One clade included Ca.gracilis sp.nov.,Ca.sp.1,Ca.xiaohongxu,Ca.tenuipes and Ca.paucilamellus sp.nov.,which clustered together.The other clade showed that Ca.sparsus sp.nov.was closely related to Ca.sp.2 and Ca.sp.3.Ca.luteus and Ca.macropus were located at the base of the Callistoctopus group.Based on our integrative studies,both morphological and molecular evidence suggested strongly that O.minor is more likely to be classified as a species of Callistoctopus.Morphological comparisons were made between the three new species and related taxa,which could be recognized based on the 7-8 gill lamellae of each demibranch,numerous small black spots on the subdermal layer of the arms,and an elongated body.
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