Dear MARMAM subscribers,
We are pleased to announce the publication of the following new paper in the Journal of Mammalogy: Emma L Betty, Karen A Stockin, Adam N H Smith, Barbara Bollard, Mark B Orams, Sinéad Murphy, Sexual maturation in male long-finned pilot whales (Globicephala melas edwardii): defining indicators of sexual maturity, Journal of Mammalogy, Volume 100, Issue 4, 27 July 2019, Pages 1387–1402, 1402, https://doi.org/10.1093/jmammal/gyz086 Abstract: Male reproductive biology is described for the Southern Hemisphere long-finned pilot whale (Globicephala melas edwardii), a subspecies that regularly mass strands along the New Zealand coastline. Ten mass stranding events sampled over a 7-year period enabled assessments of key life history parameters. Sexual maturation in immature, maturing, and mature males was assessed using morphological data and histological examination of testicular tissue. Variation was observed in the age (11–15 years) and length (450–490 cm) at which individuals attained sexual maturity. Using Bayesian cumulative logit regression models, we estimated the average age and length at the attainment of sexual maturity to be 13.5 years and 472 cm, respectively. Combined testes weight, combined testes length, an index of testicular development (combined testes weight/combined testes length), and mean seminiferous tubule diameter were all good indicators of sexual maturity status. Combined testes length was the best nonhistological indicator, and all testicular measures were found to be better indicators of sexual maturation for G. m. edwardii than age or total body length. Sexual maturity was attained before physical maturity (> 40 years and 570 cm), and at a younger age and smaller body length than previously reported for Globicephala melas melas in the North Atlantic. Given the ease of collection, minimal processing, and applicability to suboptimal material collected from stranding events, future studies should assess the value of testicular size as an indicator of sexual maturity in pilot whales and other cetacean species. Estimates of the average age and length at sexual maturity for G. m. edwardii provided in this study may be used to inform population models required for conservation management of the subspecies, which is subject to high levels of stranding-related mortality. Download here: https://academic.oup.com/jmammal/article/100/4/1387/5510509 or email [email protected] for a PDF. Sexual maturation in male long-finned pilot whales ( Globicephala melas edwardii ): defining indicators of sexual maturity<https://academic.oup.com/jmammal/article/100/4/1387/5510509> academic.oup.com Abstract. Male reproductive biology is described for the Southern Hemisphere long-finned pilot whale (Globicephala melas edwardii), a subspecies that regularly Regards, Emma. Dr Emma Betty Coastal-Marine Research Group | School of Natural & Computational Sciences | College of Sciences | Massey University Private Bag 102904 | Albany, Auckland 0745 | New Zealand Physical Address: Massey University Auckland | Gate 4| The Station Crescent | Building 5 | Albany 0632 E-mail: [email protected]<mailto:[email protected]> | Telephone: +64 9 414 0800 - Internal Ext: 43513 - DDI 09 213 6513
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