Reproductive biology and ecology of the boreoatlantic armhook squid Gonatus fabricii (Cephalopoda: Gonatidae)
Reproductive biology and ecology of the boreoatlantic armhook squid Gonatus fabricii (Cephalopoda: Gonatidae)
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DOI：
10.1093/mollus/eyz023
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发表时间：
2019-08-01
影响因子：
1.2
通讯作者：
Sabirov, Rushan M.
中科院分区：
文献类型：
--
作者：
Golikov, Alexey V.;Blicher, Martin E.;Sabirov, Rushan M.
乌贼Gonatus fabricii （Lichtenstein, 1818）是北极最丰富的远洋头足类动物，也是唯一在该地区度过整个生命周期的鱿鱼。尽管数量非常丰富，但其生殖生物学仍然鲜为人知，关于大型成熟和成熟标本的数据尤其罕见。本研究基于广泛的资料（51个大标本，共计约35000个标本），填补了关于布氏蝽生殖生物学和生态学知识的主要空白。雌性的繁殖力在8,862至16,200个卵母细胞之间，成熟和晚期标本分别在8,862至c. 10,000和11,402个卵母细胞之间。卵发生同步，观察卵母细胞吸收；被吸收的卵母细胞占生殖力的23.5%。成熟卵母细胞2 ~ 5个，直径4.0 ~ 5.5 mm（最大尺寸）。雄性拥有77至257个精子囊（长度为5.8-10.8毫米）。精子囊的特点是：有一个水泥体，在口端有发育良好的环和盘，射精器比水泥体长，水泥体没有锥形的尖。精子包囊大小随雄体大小的增加而均匀增加。在较新的精子囊中，精子储存库的长度、宽度和体积也增加了。雌性有62 ~ 84个精囊（长度为1.8 ~ 2.6 mm）；精囊位于颊膜上，缺乏特殊的附着结构。雌性颊膜上未见精囊。我们的研究结果与黄颡鱼产卵受地理限制的假设是一致的。该研究在格陵兰岛东南部发现了一个新的繁殖区的证据。在不同的繁殖区之间，成熟时的大小没有差异。这种地理上的局部繁殖在非深水鱿鱼中相对常见，但在深水鱿鱼中却不常见。对于G. fabricii来说，局部繁殖可能特别重要，因为在上层海洋中增加的食物供应可能会增加上层海洋幼鱼的存活率，而表面水流可能有助于它们的扩散。
The squid Gonatus fabricii (Lichtenstein, 1818) is the most abundant pelagic cephalopod in the Arctic and the only squid to spend all of its life cycle in this region. Despite being highly abundant, its reproductive biology remains poorly known, and data on large maturing and mature specimens are especially rare. This study, based on extensive material (51 large specimens and >35,000 specimens in all), fills major gaps in the knowledge of the reproductive biology and ecology of G. fabricii. The fecundity of females ranged from 8,862 to 16,200 oocytes, with mature and late maturing specimens having between 8,862 to c. 10,000 and 11,402 oocytes, respectively. Oogenesis was synchronous, and oocyte resorption was observed; resorbed oocytes constituted up to 23.5% of fecundity. Between two to five ripe oocytes were observed, and these were 4.0-5.5 mm in diameter (maximum dimension). Males possessed between 77 and 257 spermatophores (length = 5.8-10.8 mm). Spermatophores were characterized by a cement body with well-developed collar and discs at the oral end, an ejaculatory apparatus longer than the cement body and the lack of a tapered, sharp tip to the cement body. Spermatophore size showed a uniform increase in relation to increasing male size. In newer spermatophores, the length, width and volume of the seminal reservoir also increased. Females possessed between 62 and 84 spermatangia (length = 1.8-2.6 mm); the spermatangia were present on the buccal membranes and lacked special attachment structures. Seminal receptacles were not found on the buccal membranes of females. Our findings are consistent with the hypothesis of geographically restricted spawning in G. fabricii. The study found evidence for one new breeding area in south-eastern Greenland. No differences in sizes at maturity were found between the breeding areas. Such geographically localized reproduction is relatively common in non-deep-water squids, but is much less common in deep-water squids. Localized reproduction may be especially important for G. fabricii because increased food availability in the epipelagic layers would likely increase the survival of epipelagic juveniles, with surface currents potentially aiding in their dispersal.