Sexual maturity in male Indo-Pacific bottlenose dolphins (Tursiops aduncus): evidence for regressed/pathological adults
Sexual maturity in male Indo-Pacific bottlenose dolphins (Tursiops aduncus): evidence for regressed/pathological adults
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雄性印度太平洋宽吻海豚（Tursiops aduncus）的性成熟：成体退化/病态的证据
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
I. Tomo
中科院分区：
文献类型：
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作者：
C. Kemper;E. Trentin;I. Tomo
摘要澳大利亚宽吻海豚的年龄和性成熟之前没有被研究过。对1989年至2011年在南澳大利亚随机收集的57只雄性印度-太平洋宽吻海豚(Tursiopsaduncus)进行了调查。通过计数牙本质组织中的生长层群来估计年龄。对福尔马林固定的睾丸和附属器进行称重、测量和亚采样以进行组织学分析。记录生精阶段、精子的存在、睾丸小管大小、曲细精管管壁和曲细精管厚度以及间质的相对数量。未成熟海豚的精巢只含有支持细胞和精原细胞，平均重量为83g，长度190 mm，管径98μm。活动海豚的精子、睾丸和附睾重量在250-1,025g之间，睾丸长度在164-292 mm之间，平均管径-gt；84μm。退化/病理海豚的睾丸重量(199-280g)，睾丸长度(195-230 mm)，管径(59-130μm)比未成熟雄性大，平均比雄性少。曲细精管壁厚将退行性/病理性男性(X̄=14.9μm)与未成熟男性(X̄=2.3μm)分开。雄性印度洋-太平洋宽吻海豚的性成熟发生在体长208-220厘米、体重90-115公斤之间。一些男性(20%)在性方面是成熟的，但在生理上并不成熟，这是由椎体骨骺融合所确定的。所有生理上成熟的男性都是性成熟的。最年轻的性成熟海豚12岁，最大的未成熟雄性海豚15岁，但样本限制在8到12岁的范围内。睾丸退行性变在Tursiopsspp中以前没有报道过。来自南澳大利亚州的3只退化雄性大体和组织学证据表明，包括睾丸在内的器官病理表明，它们的生殖状况与健康状况不佳有关，而不是季节性或个人的功能循环或衰老。讨论了重金属毒性对雄性印度洋-太平洋宽吻海豚繁殖的影响。
Abstract Age and sexual maturity have not previously been studied in Australian bottlenose dolphins. These were investigated in 57 male Indo-Pacific bottlenose dolphins (Tursiops aduncus) collected opportunistically in South Australia between 1989 and 2011. Age was estimated by counting growth layer groups in dentine tissue. Formalin-fixed testes plus epididymides were weighed, measured, and subsampled for histological analysis. Stage of spermatogenesis, presence of spermatozoa, testis tubule size, seminiferous tubule wall and tunica thickness, and relative amount of interstitial tissue were noted. Immature testis tubules contained only Sertoli cells and spermatogonia and had mean testis weights < 83 g, lengths < 190 mm, and tubule diameters < 98 μm. Testes of Active dolphins had spermatozoa, testis plus epididymis weights between 250 and 1,025 g, testis lengths between 164 and 292 mm, and mean tubule diameters > 84 μm. Regressed/pathological dolphins had testis weights (199–280 g), testis lengths (195–230 mm), and tubule diameters (59–130 μm) larger than Immature males and on average less than Active males. Seminiferous tubule wall thickness also separated Regressed/pathological male (X̄ = 14.9 μm) from Immature male (X̄ = 2.3 μm) testes. Sexual maturity in male Indo-Pacific bottlenose dolphins was attained between body lengths of 208 and 220 cm and body weights of 90 and 115 kg. Some males (20%) were sexually but not physically mature as determined by fusion of vertebral epiphyses. All physically mature males were sexually mature. The youngest sexually mature dolphin was 12 years old and the oldest immature male was 15 years, but samples were limited in the 8- to 12-year range. Testicular regression has not previously been reported in Tursiops spp. The 3 regressed males from South Australia had gross and histological evidence of organ pathology, including in the testes, suggesting that their reproductive status was related to ill health, rather than seasonal or individual cycling of function or senescence. The implications of heavy-metal toxicity on male Indo-Pacific bottlenose dolphin reproduction is discussed.