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In Florida, United States, the Caribbean spiny lobster, Panulirus argus, supports an important commercial fishery and also perhaps the most intensive recreational fishery of any lobster species, with sales of recreational lobster fishing permits exceeding 100 000 annually. For the past decade, we have used mail surveys of recreational lobster license holders to estimate spatially explicit landings and fishing effort when recreational fishers are most active—during the state's “Special Two‐Day Sport Season”, which takes place just before the opening of the commercial season, and during the first month of the regular recreational season, which coincides with the commercial season. From 1993 through 2002, fishing effort during the Special Two‐Day Sport Season has ranged from 60 000 to 112 000 person‐days, and landings have ranged from c. 112 to 255t. Both fishing effort and landings have varied without trend. Fishing effort during the regular season over the same period has ranged from 261 000 to 514 000 person‐days, and landings have ranged from 434 to 825 t. Fishing effort has shown a marginally statistically significant decreasing trend, the result of a progressive decrease in effort since 1999. The largest proportion of both fishing effort and landings was concentrated along the south‐east coast. Despite the recent decrease in landings, the proportion of total landings made by the recreational fishery has increased. From 1993 through 1998, the fishery was responsible for c. 30% of commercial landings; by 2001, that percentage increased to nearly 40%. Such a shift in landings away from the commercial trap fishery toward the recreational fishery was recognised as a potential but unintended effect of the ongoing management plan of restricting effort in the commercial trap fishery. Our 2001 surveys revealed that recreational lobster fishers spent more on a person‐day basis than the general visitor to the Florida Keys did, but less than those visitors using the region's coral reefs. Consequently, managers must establish management strategies that allow the coexistence of this resource's user groups and also incorporate the social and environmental concerns of nonuser groups. 相似文献
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本文以人工配合饲料为对照组，4种添加剂为实验组，对中国龙虾进行50d的生长试验，结果表明：复合脱壳素（实验组1^#)效果最佳，其次分别是脱壳素（实验组2^#)、甲壳粉（实验组3^#)、喹乙醇（实验组4^#)和对照组，其增重率分别为：17.08、8.41%、7.62%、5.45%和4.21%；蜕壳率分别为58.33%、50.33%、33.33%、33.33%和33.33%；蜕壳后增重率为29.29%、16.90%、22.85%、16.43%和12.68%；饲料系数分别为7.57、7.11、7.92、11.00和14.21；对照组和实验组4^#存活率为91.67%，其余均为100%。整个试验过程龙虾生长良好。 相似文献
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Phyllosoma larvae collected to date in Japanese and Taiwanese waters have been classified into two genera (Linuparus, Panulirus) of the Palinuridae, four genera (Ibacus, Parribacus, Scyllarides, Scyllarus) of the Scyllaridae, and one genus (Palinurellus) of the Synaxidae. However, phyllosoma larvae of three Scyllarus species (S. bicuspidatus, S. cultrifer, S. kitanoviriosus) are absolutely dominant among the larvae collected in the waters. Scyllarus larvae are abundant in coastal waters while those of Panulirus are often collected in offshore/oceanic waters. Based on previous and ongoing studies dealing with spatial distributions
of phyllosoma larvae in Japanese and Taiwanese waters, it appears that phyllosoma and nisto larvae of the Scyllarus are retained within coastal waters north of the Kuroshio Current. On the other hand, the life history of the Panulirus (particularly P. japonicus) may be completed within the Kuroshio Subgyre: their phyllosoma larvae may be flushed out from coastal waters into the Kuroshio,
then transported through the Counter Current south of the Kuroshio into the water east of Ryukyu Archipelago and Taiwan where
they attain the subfinal/final phyllosoma or puerulus stages, once again entering the Kuroshio and dispersing into coastal
waters.
This revised version was published online in July 2006 with corrections to the Cover Date.
An erratum to this article is available at . 相似文献
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锦绣龙虾消化系统的解剖学及组织学研究 总被引：1，自引：0，他引：1
锦绣龙虾的消化系统由消化管和消化腺组成,消化管包括口、食道、胃、中肠和后肠。胃分为贲门胃和幽门胃,中肠较长,占消化管总长度的74.18%。消化管的基本结构由内向外可分为4层,即黏膜层、黏膜下层、肌肉层和外膜。黏膜层主要由单层柱状上皮和基膜构成,除中肠外其余消化管管壁上皮均覆盖有几丁质膜,黏膜下层和外膜均为结缔组织层,消化道的结缔组织中分布有皮肤腺。消化腺主要是肝胰腺,由肝小管组成,根据其形态和功能的不同,可把构成肝小管的单层细胞分为四类:分泌细胞、吸收细胞、纤维细胞和胚细胞。 相似文献
16.
Philip Tortell 《新西兰海洋与淡水研究杂志》2013,47(3):539-541
Samples of particulate matter were analysed for nitrogen by the micro‐Kjeldahl technique in an attempt to obtain an indication of the food available for mussels. The small amounts of nitrogen available in the samples prevented the detection of seasonal variation by this method. The mean concentration of 11.8 μg‐at of nitrogen per litre obtained from this study compares favourably with data from mussel farming areas in Spain. 相似文献
17.
The ornate rock lobster (Panulirus ornatus) is distributed across Torres Strait between Australia and Papua New Guinea and supports the most important commercial fishery to Islanders in the region. The long-term sustainability of the fishery is of importance not only to local island communities but also to the bilateral relationship between the two countries. In this paper, we developed an age-structured fishery model to assess the current stock status and estimate the long-term sustainable catch. The model was fitted to catch statistics and survey-based population estimates through a weighted maximum likelihood approach. Natural mortality was estimated at 0.732 yr−1, and fishing mortality ranged from 0.19 to 0.65 yr−1 from 1989 to 2005. The maximum sustainable yield was estimated at about 640 tonnes whole weight with a corresponding fishing mortality of 0.5 yr−1. A stock–recruitment model was established based on outputs of the stock assessment model. To obtain the maximum sustainable yield, spawning stock should be maintained at 120×104 lobsters. The lobster spawning stock has been fished down below this level twice since 1989, in 1999 and 2002, and was higher than this level in 2004 and 2005. These results suggest that the Torres Strait lobster stock is not over-fished and that the current harvest strategy is likely to maintain the stock at or above the level that would support the maximum sustainable yield if the current cap on fishing effort remains in place. 相似文献
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波纹龙虾雄性生殖系统的解剖学与组织学研究 总被引：1，自引：0，他引：1
用解剖学和组织学方法研究了波纹龙虾雄性生殖系统,结果表明,波纹龙虾雄性生殖系统由精巢、输精管及生殖孔三部分组成。精巢横切面一般为圆形,外被一层结缔组织被膜,内部为许多圆形或椭圆形的生精小管,生精小管间充满了网状结缔组织。精子的发生经历精原细胞、初级精母细胞、次级精母细胞、精细胞和精子5个阶段。输精管管壁由外到内依次由结缔组织被膜、结缔组织、肌肉层和上皮细胞组成,管壁上的柱状上皮细胞、肌肉组织及结缔组织一起向管内延伸形成纵褶突。管壁和纵褶突上的柱状上皮细胞向管腔中分泌嗜酸性黏液。精荚呈管状,在中段输精管形成,并储存在管腔的黏液中。 相似文献
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Phase distribution of tidal constituents around New Zealand 总被引：2，自引：2，他引：0
R. A. Heath 《新西兰海洋与淡水研究杂志》2013,47(2):383-392
The phase distributions of the M2, S2, K1, and O1 tidal constituents around New Zealand are plotted from existing harmonic analyses of tidal heights. Both semidiurnal constituents exhibit a complete 360° range of phase around New Zealand, with complex areas of rapid phase change through or near the strait separating the two main islands. The K1 amphidrome and that for O1, which previously were thought to be centred on New Zealand, are shown to be located cast of New Zealand. The distributions plotted highlight areas where tidal observations are lacking. 相似文献