Spawning cycle of onychoteuthid squids in the southern Indian Ocean: new information from seabird predators
Spawning cycle of onychoteuthid squids in the southern Indian Ocean: new information from seabird predators
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DOI：
10.3354/meps188093
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发表时间：
1999-01-01
影响因子：
2.5
通讯作者：
Weimerskirch, H
中科院分区：
文献类型：
--
作者：
Cherel, Y;Weimerskirch, H
头足类在南大洋的食物网中起着重要作用，但关于它们生物学的信息却很少。两种最大的亚南极海鸟，王企鹅（Aptenodytes patagonicus）和漂泊信天翁（Diomedea exulans），在克罗泽群岛的南半球冬季主要以鱿鱼为食。我们检查了这些鸟类胃中大量积累的头足类喙以及一些未消化的物质；首先，为了了解这两种捕食者在冬季（假定食物匮乏的时期）如何共享鱿鱼资源，其次，利用一种潜水海鸟和一种飞行海鸟作为南大洋头足类的生物取样器。钩腕乌贼科的个体构成了鱿鱼食物的主要部分，在王企鹅和漂泊信天翁样本中分别占下喙数量的72.6%和57.0%。鉴定出了7个不同的物种，3种主要的鱿鱼分别是长额手乌贼（Kondakovia longimana，在企鹅和信天翁样本中按数量分别占38.8%和28.0%）、巨大茎柔鱼（Moroteuthis ingens，占13.5%和26.2%）和克氏茎柔鱼（M. knipovitchi，占20.1%和2.3%）。两种海鸟都捕食相同的头足类物种，但企鹅主要捕食中小型幼体（钩腕乌贼的99.0%），信天翁则捕食较大的成年个体（96.0%）。新鲜的残骸表明成年长额手乌贼和巨大茎柔鱼是成熟个体，正如信天翁的卫星追踪所显示的，它们是在群岛周围的大陆坡以及附近的海洋水域被捕食的。本研究表明长额手乌贼和巨大茎柔鱼在冬季的几个月里在克罗泽水域交配/产卵。它还将长额手乌贼的生物地理学范围扩展到了南极极锋以北的极锋区，此前在该区域没有相关记录。
Cephalopods play an important role in the trophic web of the Southern Ocean, but little information is available on their biology. The 2 largest sub-Antarctic seabirds, the king penguin Aptenodytes patagonicus and the wandering albatross Diomedea exulans, feed primarily on squids during the austral winter at the Crozet Islands. We examined a large number of accumulated cephalopod beaks in the stomach of these birds together with some undigested items; first, to understand how these 2 predators share the squid resource during winter, a period of supposed low food availability, and, second, to use a diving and a flying seabird as biological samplers of Southern Ocean cephalopods. Individuals of the family Onychoteuthidae formed the bulk of the squid diet, accounting for 72.6 and 57.0% of the number of lower beaks in samples from king penguins and wandering albatrosses, respectively. Seven different species were identified, the 3 main squids being Kondakovia longimana (38.8 and 28.0% by number for penguins and albatrosses, respectively), Moroteuthis ingens (13.5 and 26.2 %) and M. knipovitchi (20.1 and 2.3 %). Both seabirds preyed upon the same cephalopod species, but penguins primarily took small- to medium-sized juveniles (99.0% of the onychoteuthids) and albatrosses preyed on larger adult specimens (96.0 %). Fresh remains indicated that adult K. longimana and M. ingens were mature individuals which, as shown by satellite tracking of albatrosses, were taken over the slope and nearby oceanic waters surrounding the archipelago. The present study indicates that mating/spawning of K. longimana and M. ingens occurs in Crozet waters during the winter months. It also extends the biogeography of K. longimana to north of the Antarctic Polar Front, in the Polar Frontal Zone, where it has not previously been recorded.