Reproductive Strategy of the Squid, Todarodes pacificus, Produce Large Gelatinous Egg Masses

太平洋鱿鱼的繁殖策略，产生大的凝胶状卵块

基本信息

批准号：
09460080
负责人：
SAKURAI Yasunori
金额：
$ 6.53万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09460080/
关键词：
Todarodes pacificus Spawning Behavior Gelatinous Egg Mass Recruitment ROV Marine GIS Stock Fluctuation Climate Change 卵塊の性状卵塊の密度躍層滞留 GIS 共食い卵塊の中層浮遊再生産海域

项目摘要

Reproductive strategy related to stock fluctuation on the ommastrephid squid Todarodes pacificus are examined by field survey and captive experiments. Immature squid were collected and maintained in a raceway tank where they matured, mated, and spawned. Gelatinous egg masses were spherical and nearly buoyant. The largest egg mass measured 80 cm in diameter and contained approximately 200,000 eggs. The egg-mass surface layer effectively prevented crustaceans, protozoans, and bacteria from infesting the masses. Paralarvae hatched after 4-6 days at 18-19℃ and actively swam at once, with many individuals swimming at the surface. Egg masses disintegrated soon after hatching. Survival of eggs and paralarvae were examined at temperatures ranged from 3.5-29℃ to determine the optimum temperature range for development and survival. Highest embryonic survival rates occurred between 15 and 23℃. It is sugggested that T. pacificus spawns in waters warmer than 15℃, and egg masses maintain their struc … More ture for about 4-9.5 days before disintegrating at temperatures between 15 and 23℃.The inferred spawning sites of T. pacificus around Japan are assumed that egg masses and hatchlings occur at temperatures between 15 and 23℃, and above the continental shelf and slope, because captive females regularly sit on the tank bottom just before spawning. Annual catches of Todarodes pacificus in Japan have gradually increased since the late 1980s. Paralarval abundances have also been higher since the late 1980s than during the late 1970s and mid-1980s. We propose a possible scenario for the recent stock increase based on changing environmental conditions. First, we examined trends in the annual variations of stock and larval catches, and infer potential spawninig areas, assuming that egg masses and hatchlings occur at temperatures between 15 and 23℃, and over the continental shelf. We then infer changes in the spawning areas during 1984-95 based on GIS data. We conclude that since the late 1980s the fall and winter spawning areas have overlapped in the Tsushima Strait and near the Goto Islands, and that winter spawning sites have expanded over the continental shelf and slope in the East China Sea. Less

通过现场调查和圈养实验，检查了与omastrephid鱿鱼Todarodes Pacificus上库存波动有关的生殖策略。收集未成熟的鱿鱼并将其维护在一个赛道储罐中，并在那里成熟，交配和产卵。凝胶状卵块是球形的，几乎浮力。最大的卵子的直径为80厘米，含有约200,000个卵。卵质表面层有效地阻止了甲壳类动物，原生动物和细菌侵扰质量。 Paralarvae在4-6天后以18-19℃孵化，并立即积极游泳，许多人在地面游泳。孵化后不久，鸡蛋块分解了。在温度为3.5-29℃中，检查了卵和副群的存活，以确定开发和存活的最佳温度范围。最高的胚胎存活率发生在15至23℃之间。有人建议，太平洋的t. t. pacificus在水中的温度高于15℃的水中，卵质量保持其结构……在15至23°之间的温度下瓦解之前，大约4-9.5天的结构更为4-9.5天。假定日本周围的T. Pacificus的推断产卵位置是在15至23°之间的温度下发生的卵块和孵化场，并且在连续的架子和斜坡上方发生，因为圈养的女性在产卵前经常坐在坦克底部。自1980年代后期以来，日本的Todarodes Pacificus的年度捕获逐渐增加。自1980年代后期以来，派层的丰度也比1970年代后期和1980年代中期高。我们建议根据不断变化的环境条件来增加库存增加的情况。首先，我们检查了库存和幼虫捕获量的年变化的趋势，并推断潜在的产卵区域，假设卵子质量和孵化场在15至23°之间的温度以及连续的架子上发生。然后，我们根据GIS数据来推断1984 - 95期间产卵区域的变化。我们包括，自1980年代后期以来，秋季和冬季产卵区已在Tsushima海峡和Goto群岛附近重叠，并且冬季产卵场在东中国海的连续架子和坡度上扩展。较少的