REPRODUCTIVE-CYCLES AND FECUNDITIES OF 2 SPECIES OF SIPHONARIA (MOLLUSCA-PULMONATA) IN SOUTHEASTERN AUSTRALIA
REPRODUCTIVE-CYCLES AND FECUNDITIES OF 2 SPECIES OF SIPHONARIA (MOLLUSCA-PULMONATA) IN SOUTHEASTERN AUSTRALIA
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DOI：
10.1071/mf9800037
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发表时间：
1980-01-01
期刊：
影响因子：
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通讯作者：
CREESE, RG
中科院分区：
文献类型：
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作者：
CREESE, RG
对S. denticulata和S. virgulata通过测量每个物种的卵的长度或重量来确定。S.具齿的卵会产下一条典型的盘绕的凝胶状卵带，粘在岩石底层上。S. virgulata产下球状卵块，直接释放到水中。后一种形式的产卵显然是肺状软体动物中唯一的。S. denticulata有一个漫长的繁殖季节，从11月延长- 12月至次年4 - 5月。大的成虫通常每2周产卵一次，但较小的成虫（即，更年轻的）帽贝产卵频率较低。产卵期与满月或新月期相对应。在此基础上，提出了中华绒螯蟹繁殖季节的确切长度。virgulata未知。从卵块内的卵计数获得生殖力的估计值。不同虫态的生殖力存在差异。denticulata，但S. denticulata和S.同一地区的virgulata对相似大小的动物具有相似的繁殖力。S.在实验中，放置在海岸高处的denticulata比放置在海岸低处的denticulata遭受更高的干燥死亡率，这可能解释了为什么S. virgulata通常生活在比同类更高的海岸上，具有远洋卵块。
The reproductive cycles of S. denticulata and S. virgulata were determined by measuring the length or weight of the spawn of each species. S. denticulata lays a typical, coiled, gelatinous egg ribbon, cemented to the rocky substratum. S. virgulata lays a globular egg mass which is released directly into the water. This latter form of spawning is apparently unique among pulmonate mollusks. S. denticulata has a long breeding season, extending from Nov.-Dec. to the following April-May. Spawning usually occurs every 2 wk for large adults, but smaller (i.e., younger) limpets spawn less frequently. Periods of spawning correspond to periods of full or new moons. The exact length of the breeding season of S. virgulata is unknown. Estimates of fecundity were obtained from counts of eggs within egg masses. There were differences in the fecundity of S. denticulata between localities, but S. denticulata and S. virgulata from the same locality had similar fecundities for similar-sized animals. Egg ribbons of S. denticulata experimentally placed high on the shore suffered higher mortality from desiccation than those lower on the shore, which may explain why S. virgulata, which generally lives higher on the shore than its congener, has pelagic egg masses.