Seasonal development of gonads of the hagfish, Eptatretus burgeri, correlated with their seasonal migration
Seasonal development of gonads of the hagfish, Eptatretus burgeri, correlated with their seasonal migration
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DOI：
10.2108/zsj.17.225
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发表时间：
2000-03-01
影响因子：
0.9
通讯作者：
Kobayashi, H
中科院分区：
文献类型：
--
作者：
Nozaki, M;Ichikawa, T;Kobayashi, H
在1971年10月至1973年3月和1977年11月至1978年12月期间，研究了在日本太平洋沿岸相模湾的Misaki海洋生物站附近捕获的八目鳗Eptatretus burgeri性腺的季节性发育。在靠近车站的小次郎湾6至10 m水深（浅水）或车站以西约1，600 m和4.800 m的50和100 m水深（深水）处收集盲鳗。它们每月从浅水和深水沃茨收集，但由于季节性迁移，在温暖的夏季（7月至9月）无法从浅水收集。1 - 4月在浅水和深水沃茨采集的雌鱼的平均总长度分别为40.7 ± 0.4 cm（+/-SEM; n=317）和34.5 ± 0.3 cm（+/-SEM; n=556）。发育卵的年生长曲线在浅水区和深水区没有差异，发育卵的大小在10月份最小，9月份最大。两个位置之间的睾丸发育没有明显差异，因此将这些数据合并。睾丸发育发生在总长度大于38厘米的雄性。睾丸重量以7月最重，9月最轻。在秋季和冬季，大多数睾丸卵泡只含有精原细胞。春季含精母细胞的卵泡增多。含精细胞或成熟精子的卵泡在夏季相对丰富。虽然卵子沉积应该发生在9月和/或10月初的深水中，但此时睾丸重量和精子发生都很小。为什么睾丸发育是最低的时候，女性大概存款鸡蛋讨论有关的问题产卵场的位置。
Seasonal development of gonads was studied in the hagfish, Eptatretus burgeri, caught near the Misaki Marine Biological Station facing the Sagami Bay of the Pacific coast of Japan, during periods from October 1971 to March 1973 and from November 1977 to December 1978. The hagfish were collected at water depths of 6 to 10 m (shallow water) in Koajiro Bay close to the Station or water depths of 50 and 100 m (deep water), about 1,600 and 4.800 m west to the Station. They were collected monthly from both shallow and deep waters, but they could not be collected from shallow water during warmer summer months (July-September) due to seasonal migration. The mean total lengths of the females collected in both shallow and deep waters during January to April were 40.7+/-0.4 cm (+/-SEM; n=317) and 34.5+/-0.3 cm (+/-SEM; n=556), respectively, In both locations, developing eggs longer than 5 mm were found in females larger than 39 cm in total length. There was no difference in the annual growth curves of developing eggs between shallow and deep water: the sizes of the developing eggs were the smallest in October, and was the largest in September. There was no apparent difference in testicular development between two locations, so these data were combined. Testicular development occurs in males larger than 38 cm in total length. The testis weight was the heaviest in July, and was the lightest in September. In autumn and winter, most testicular follicles contained only spermatogonia. In spring, follicles containing spermatocytes increased. Follicles with spermatids or maturing sperms were relatively abundant in summer. Although egg deposition is supposed to occur in September and/or early October somewhere in deep water, both testis weight and spermatogenesis were minimal at this time. Why testis development is lowest at the time when females presumably deposit eggs is discussed in relation to the question of the location of the spawning ground.