The Comparison of Semen Collection in Electroejaculation, Rectal Massage and Combination of Both Methods in the Critically Endangered Malayan Pangolin, Manis javanica

Abstract

This article describes the semen characteristics from different collection methods between captive and confiscated Malayan pangolins, Manis javanica. Semen was collected from 15 pangolins; two captive and 13 confiscated individuals at the mean weight of 9.36 ± 1.94 kg. The three semen collection methods employed were electroejaculation, rectal massage and a combination of both techniques. The semen characteristics (mean ± standard deviation) of the Malayan pangolin are volume (73.75 ± 144.57 µL), pH (7.63 ± 0.53), spermatozoa concentration (997.19 ± 728.98 × 106 /mL), total motility (59.60% ± 30.00%), progressive motility (48.95% ± 30.93%), mass motility (3.50 ± 1.50) and live spermatozoa (80.25% ± 13.45%). There was no significant difference in semen characteristics between the three collection methods. The percentages of live spermatozoa were significantly different, suggesting better samples from captive compared to confiscated animals. However, there was no significant difference in spermatozoa kinetics between the captive and confiscated samples, suggesting the potential of utilizing confiscated individuals for gamete recovery to conserve the genetic pool of pangolins. All three methods of semen collection were successfully performed in pangolins and should be considered; however, electroejaculation remains the most consistent method of obtaining semen from the species.

Short Communication: Characteristics of the endangered Javan banteng (Bos javanicus) spermatozoa

“…The collection of banteng semen by the transrectal massage method has not been previously reported. This method has been used in swamp buffalo (Bubalus bubalis), rhinos (Dicerorhinus sumatrensis), elephants (Elephas maximus), and pangolins (Manis javanica) (Arifiantini and Ferdian 2006;Agil et al 2008;Kiso et al 2013;Tarmizi et al 2020). The volume of banteng semen in this study was less than the semen volume successfully collected by electroejaculation reported in previous studies (Yoelinda et al 2018).…”

“…Research by Abril-Sánchez et al (2017) shows that this method is less stressful. Furthermore, several studies have shown that the quality of semen, especially microscopically, obtained by an electro-ejaculator is not significantly different from that of transrectal massage (Sarsaifi et al 2013;Tarmizi et al 2020).…”

Increasing the Yield and Cryosurvival of Spermatozoa from Rhinoceros Ejaculates Using the Enzyme Papain

“…This phenomenon is shared by other species, including camelids [ 23 , 28 ], elephants [ 18 , 34 ], hippopotamus’ [ 19 ] and primates [ 21 , 22 ]. Spermatozoa trapped within the viscous (low sperm) fractions of the ejaculate equate to almost half of the total spermatozoa collected [ 11 , 17 , 20 ], but are often discarded. In the current study, treatment of viscous, low sperm rhinoceros spermatozoa, with papain prior to cryopreservation, not only enabled the utilisation of spermatozoa within these fractions, but resulted in improved motility and viability post-thaw.…”

“…It would also be interesting to see if this protein is conserved across other species of rhinoceros, such as the critically endangered black [ 48 ], Sumatran [ 49 ] and Javan [ 50 ] rhinoceroses and vulnerable greater one-horned rhinoceros [ 51 ], particularly the Sumatran rhinoceros, given less than 30 individuals remain, and all published reports of semen collection report severely low sperm counts and volume [ 39 , 52 ]. Similarly, comparison against the seminal plasma proteome of the hippopotamus [ 19 ], elephants [ 20 , 35 ] and primates [ 22 ] would show whether this protein is responsible for causing the production of viscous fractions across a wide variety of species. More so, it would confirm whether papain could be used as a tool to improve the quantity and quality of spermatozoa collected and cryopreserved from wildlife species following electro-ejaculation.…”

“…This is followed by subsequent fractions containing large amounts of seminal plasma but lower sperm concentration [ 12 ]. In fact, the increasing degree of viscosity in fractions collected after the first, low volume sperm-rich fraction, is a characteristic not only of rhinoceros ejaculates [ 15 , 16 , 17 ] but also of other wildlife species, including the elephant [ 18 ], hippopotamus [ 19 ], pangolin [ 20 ], primates [ 21 , 22 ] and camelids [ 23 , 24 ]. Even marsupial semen has been reported to coagulate following EJ collection [ 25 , 26 ].…”