The northern sea area of the South China Sea is situated between 107.5°～122.5°East longitude and 17°～25° North latitude with high temperature and a large quantity of rainfall which belongs to the...The northern sea area of the South China Sea is situated between 107.5°～122.5°East longitude and 17°～25° North latitude with high temperature and a large quantity of rainfall which belongs to the oceanic climate of the torrid zone and subtropical zone. From September, 1994 to June, 1998,during the research on the species of Horseshoe crab within the scope between the south from North gulf and the north to Xiamen, choosing Xiamen, Shantou, Wuchuan, Donghaidao and Qishui as fixed positions and irregularly going to Xuwen and Suixi in Guangdong province and Fangcheng in Guangxi province, we found that there was only Tachypleus tridentatus in the northern sea area of the South China Sea and the sea area from Wuchuan to Xiamen, and found that there were two species of horseshoe crab which were Tachypleus tridentatus and Carcinoscorpius rotundicauda in the southern area to East Sea Island, referring to East Sea Island, Qishui, Xuwen, Suixi and Fangcheng, most of which were Tachypleus tridentatus, and found a great number of larvae of Tachypleus tridentatus including zooids with different sizes from 7cm bodily length to mature. In Minan we found not only big colonies of adult Carcinoscorpius rotundicauda , but also a great number of larvae of Carcinoscorpius rotundicauda with different body size from 7cm body length to maturity. All these show that the northern sea area of the South China Sea is the area where both Tachypleus tridentatus and Carcinoscorpius rotundicauda distribute and reproduce. On January 1st, 1998 at the town of Qishui in Leizhou, we found an adult male Horseshoe crab and majority of its eggs was immature, while the eggs with above 4mm diameters were only 0.87 percent but the eggs with below 1.0mm diameter was 58 percent(1 160 pills). It shows that Qishui is a place where Tachyplers tridentatus survive in the winter.展开更多
American horseshoe crabs Limulus polyphemus were tracked using acoustic telemetry and traditional tagging in a semi-enclosed bay on Cape Cod （Pleasant Bay）, Massachusetts, USA, to determine seasonal movement pattern...American horseshoe crabs Limulus polyphemus were tracked using acoustic telemetry and traditional tagging in a semi-enclosed bay on Cape Cod （Pleasant Bay）, Massachusetts, USA, to determine seasonal movement patterns. Fifty-five actively spawning females were fitted with transmitters in 2008 and 2009 and were tracked using acoustic telemetry from May 2008 through July 2010. Fil^een crabs with transmitters also had archive depth-temperature tags attached. In addition, over 2000 spawning crabs （males and females） were tagged with US Fish and Wildlife CIdSFWS） button tags over the same period. Ninety-one percent of the crabs with transmitters were detected during this study. In the spring, crabs were primarily located in the northern section of the bay near spawning beaches, whereas in the fall crabs moved towards the deeper portions of the bay, and some may have overwIntered in the bay. There was evidence that a majority （58%-71%） of the females with transmitters spawned in two sequential seasons. One archive tag was recovered resulting in a year-long continuous record of depth and tem- perature data that, when integrated with telemetry data, indicated that the crab overwintered in the bay. The live recapture rate of crabs with USFWS button tags was 11%, with all re-sighted crabs except one observed inside Pleasant Bay. Eighty-three percent of recaptures were found within 2.5kin of the tagging location, and 51% were observed at the same beach where they were tagged. This study provides further evidence that horseshoe crabs in Pleasant Bay may be philopatric to this embayment展开更多
The goal of this study was to determine the year round movement patterns of American horseshoe crabs, Limulus polyphemus, in the Great Bay Estuary, New Hampshire （USA） by using acoustic telemetry to track the moveme...The goal of this study was to determine the year round movement patterns of American horseshoe crabs, Limulus polyphemus, in the Great Bay Estuary, New Hampshire （USA） by using acoustic telemetry to track the movements of 37 adult Limulus, for periods ranging from 2 to 31 months. During the winter （December-March） horseshoe crabs moved very little. In the spring, when water temperatures exceeded II^C, horseshoe crabs moved at least 1 km further up into the estuary to shallower subtidal areas about a month prior to spawning. The mean distance traveled during spring migrations was 2.6 ＋ 0.5 （n=20） km up the estuary. Mating occurred in May and June and during these months animals spent most of their time in shallow subtidal areas adjacent to mating beaches. In the summer （July-Augnst）, animals moved 1.5 ± 0.5 （n=26） km down the estuary, towards the ocean, and ranged widely, using extensive portions of the estuary. In the fall （September-November） movement was more limited （0.5 ± 0.5 km; n = 24） while animals settled into wintering locations, where they remained until spring. The mean annual linear range for all animals was 4.5 ± 0.3 km （n =35） and the maximum distance traveled by an individual horseshoe crab within one year was 9.2 km. There was no evidence that any of the horseshoe crabs tracked during this study left the estuary展开更多
基金国家自然科学基金!资助项目 (No . 38970 42 0 )广东省高教厅 1997年重点课题!资助项目 (No . 975 7)厦门市海洋科技计划资助!项目
文摘The northern sea area of the South China Sea is situated between 107.5°～122.5°East longitude and 17°～25° North latitude with high temperature and a large quantity of rainfall which belongs to the oceanic climate of the torrid zone and subtropical zone. From September, 1994 to June, 1998,during the research on the species of Horseshoe crab within the scope between the south from North gulf and the north to Xiamen, choosing Xiamen, Shantou, Wuchuan, Donghaidao and Qishui as fixed positions and irregularly going to Xuwen and Suixi in Guangdong province and Fangcheng in Guangxi province, we found that there was only Tachypleus tridentatus in the northern sea area of the South China Sea and the sea area from Wuchuan to Xiamen, and found that there were two species of horseshoe crab which were Tachypleus tridentatus and Carcinoscorpius rotundicauda in the southern area to East Sea Island, referring to East Sea Island, Qishui, Xuwen, Suixi and Fangcheng, most of which were Tachypleus tridentatus, and found a great number of larvae of Tachypleus tridentatus including zooids with different sizes from 7cm bodily length to mature. In Minan we found not only big colonies of adult Carcinoscorpius rotundicauda , but also a great number of larvae of Carcinoscorpius rotundicauda with different body size from 7cm body length to maturity. All these show that the northern sea area of the South China Sea is the area where both Tachypleus tridentatus and Carcinoscorpius rotundicauda distribute and reproduce. On January 1st, 1998 at the town of Qishui in Leizhou, we found an adult male Horseshoe crab and majority of its eggs was immature, while the eggs with above 4mm diameters were only 0.87 percent but the eggs with below 1.0mm diameter was 58 percent(1 160 pills). It shows that Qishui is a place where Tachyplers tridentatus survive in the winter.
基金supported by the National Park Service under Cooperative Agreement Number CA452099007 with the University of Rhode Island
文摘American horseshoe crabs Limulus polyphemus were tracked using acoustic telemetry and traditional tagging in a semi-enclosed bay on Cape Cod （Pleasant Bay）, Massachusetts, USA, to determine seasonal movement patterns. Fifty-five actively spawning females were fitted with transmitters in 2008 and 2009 and were tracked using acoustic telemetry from May 2008 through July 2010. Fil^een crabs with transmitters also had archive depth-temperature tags attached. In addition, over 2000 spawning crabs （males and females） were tagged with US Fish and Wildlife CIdSFWS） button tags over the same period. Ninety-one percent of the crabs with transmitters were detected during this study. In the spring, crabs were primarily located in the northern section of the bay near spawning beaches, whereas in the fall crabs moved towards the deeper portions of the bay, and some may have overwIntered in the bay. There was evidence that a majority （58%-71%） of the females with transmitters spawned in two sequential seasons. One archive tag was recovered resulting in a year-long continuous record of depth and tem- perature data that, when integrated with telemetry data, indicated that the crab overwintered in the bay. The live recapture rate of crabs with USFWS button tags was 11%, with all re-sighted crabs except one observed inside Pleasant Bay. Eighty-three percent of recaptures were found within 2.5kin of the tagging location, and 51% were observed at the same beach where they were tagged. This study provides further evidence that horseshoe crabs in Pleasant Bay may be philopatric to this embayment
基金supported by National Science Foundation grants NSF lOB 0517229 and NSF IOS 0920342 to WHW Ⅲ and CCC
文摘The goal of this study was to determine the year round movement patterns of American horseshoe crabs, Limulus polyphemus, in the Great Bay Estuary, New Hampshire （USA） by using acoustic telemetry to track the movements of 37 adult Limulus, for periods ranging from 2 to 31 months. During the winter （December-March） horseshoe crabs moved very little. In the spring, when water temperatures exceeded II^C, horseshoe crabs moved at least 1 km further up into the estuary to shallower subtidal areas about a month prior to spawning. The mean distance traveled during spring migrations was 2.6 ＋ 0.5 （n=20） km up the estuary. Mating occurred in May and June and during these months animals spent most of their time in shallow subtidal areas adjacent to mating beaches. In the summer （July-Augnst）, animals moved 1.5 ± 0.5 （n=26） km down the estuary, towards the ocean, and ranged widely, using extensive portions of the estuary. In the fall （September-November） movement was more limited （0.5 ± 0.5 km; n = 24） while animals settled into wintering locations, where they remained until spring. The mean annual linear range for all animals was 4.5 ± 0.3 km （n =35） and the maximum distance traveled by an individual horseshoe crab within one year was 9.2 km. There was no evidence that any of the horseshoe crabs tracked during this study left the estuary
