Sphaeroma terebrans, a wood-boring isopoda, is distributed worldwide in tropical and subtropical mangroves. The taxonomy of S. terebrans is usually based on morphological characteristics, with its molecular identifica...Sphaeroma terebrans, a wood-boring isopoda, is distributed worldwide in tropical and subtropical mangroves. The taxonomy of S. terebrans is usually based on morphological characteristics, with its molecular identification still poorly understood. The number of teeth on the uropodal exopod and the length of the propodus of the seventh pereopod are considered as the major morphological characteristics in S. terebrans, which can cause difficulty in regards to accurate identification. In this study, we identified S. terebrans via molecular and morphological data. Furthermore, the validity of the mitochondrial cytochrome c oxidase subunit I （COl） gene as a DNA barcode for the identification of genus Sphaeroma, including species S. terebrans, S. retrolaeve, and S. serratum, was examined. The mitochondrial COl gene sequences of all specimens were sequenced and analysed. The interspecific Kimura 2-parameter distances were higher than intraspecific distances and no intraspecificinterspecific distance overlaps were observed. In addition, genetic distance and nucleotide diversity （TT） exhibited no differences within S. terebrans. Our results revealed that the mitochondrial COl gene can serve as a valid DNA barcode for the identification of S. terebrans. Furthermore, the number of teeth on the uropodal exopod and the length of the propodus of the seventh pereopod were found to be unreliable taxonomic characteristics for S. terebrans.展开更多
The tropical and subtropical mangrove biomes form the foundation of a highly productive and biologically rich ecosystem providing essential goods and services to human beings. Despite its values, the stability and sur...The tropical and subtropical mangrove biomes form the foundation of a highly productive and biologically rich ecosystem providing essential goods and services to human beings. Despite its values, the stability and survival of mangroves are consistently threatened by anthropogenic activities and their associated degradation, resulting in their disappearance. After realizing their ecological importance, in recent years, rehabilitation and restoration programs for mangrove forests have been launched globally. Unfortunately, most mangrove restoration efforts yielded negative results and failed to re-establish mangrove forests because of technical and social failures. Besides, the continued outbreak of wood borer, Sphaeroma spp., in mangrove forests has become one of the destructive causes of natural and restored mangrove forests in some nations including China. However, few studies on the biology of Sphaeroma spp. found in Chinese mangrove ecosystem have been done, and little is known concerning the factors affecting their outbreak in China. In this review, we discussed the possible factors that affect the rapid growth and recruitment of Sphaeroma spp. in the mangrove ecosystem by examining the information of the wood borer Sphaeroma spp. from the scattered pieces of literature with great regard. We discussed the relationship between the recruitment of Sphaeroma spp. and the tide and flow of water, food availability from the surrounding water and water quality including salinity, temperature, and the pollution of water. In addition to these factors, the reduced biodiversity of restored mangrove forest could be one of the main reasons for the outbreak of isopod. We also discussed the destructive impact of the isopod’s outbreak and the possible ways to control their outbreak in mangrove forest.展开更多
基金funded by the GEF China Wetlands System Project,Science and Technology Foundation of Macao(045/2010/A)Special Fund for Marine-Scientific Research in the Public Interest(201305021)
文摘Sphaeroma terebrans, a wood-boring isopoda, is distributed worldwide in tropical and subtropical mangroves. The taxonomy of S. terebrans is usually based on morphological characteristics, with its molecular identification still poorly understood. The number of teeth on the uropodal exopod and the length of the propodus of the seventh pereopod are considered as the major morphological characteristics in S. terebrans, which can cause difficulty in regards to accurate identification. In this study, we identified S. terebrans via molecular and morphological data. Furthermore, the validity of the mitochondrial cytochrome c oxidase subunit I （COl） gene as a DNA barcode for the identification of genus Sphaeroma, including species S. terebrans, S. retrolaeve, and S. serratum, was examined. The mitochondrial COl gene sequences of all specimens were sequenced and analysed. The interspecific Kimura 2-parameter distances were higher than intraspecific distances and no intraspecificinterspecific distance overlaps were observed. In addition, genetic distance and nucleotide diversity （TT） exhibited no differences within S. terebrans. Our results revealed that the mitochondrial COl gene can serve as a valid DNA barcode for the identification of S. terebrans. Furthermore, the number of teeth on the uropodal exopod and the length of the propodus of the seventh pereopod were found to be unreliable taxonomic characteristics for S. terebrans.
文摘The tropical and subtropical mangrove biomes form the foundation of a highly productive and biologically rich ecosystem providing essential goods and services to human beings. Despite its values, the stability and survival of mangroves are consistently threatened by anthropogenic activities and their associated degradation, resulting in their disappearance. After realizing their ecological importance, in recent years, rehabilitation and restoration programs for mangrove forests have been launched globally. Unfortunately, most mangrove restoration efforts yielded negative results and failed to re-establish mangrove forests because of technical and social failures. Besides, the continued outbreak of wood borer, Sphaeroma spp., in mangrove forests has become one of the destructive causes of natural and restored mangrove forests in some nations including China. However, few studies on the biology of Sphaeroma spp. found in Chinese mangrove ecosystem have been done, and little is known concerning the factors affecting their outbreak in China. In this review, we discussed the possible factors that affect the rapid growth and recruitment of Sphaeroma spp. in the mangrove ecosystem by examining the information of the wood borer Sphaeroma spp. from the scattered pieces of literature with great regard. We discussed the relationship between the recruitment of Sphaeroma spp. and the tide and flow of water, food availability from the surrounding water and water quality including salinity, temperature, and the pollution of water. In addition to these factors, the reduced biodiversity of restored mangrove forest could be one of the main reasons for the outbreak of isopod. We also discussed the destructive impact of the isopod’s outbreak and the possible ways to control their outbreak in mangrove forest.
