Reproductive Biology Of The Sumatran Rhinoceros (Dicerorhinus Sumatrensis) In Captivity

At Zoo Melaka, and the Sumatran Rhinoceros Breeding Centre in Sungai Dusun, seven wild-caught females, three wild-caught males and one captive born female Sumatran rhinoceros (Dicerorhinus sumatrensis) were studied from 1990 and 1994 to obtain information which could assist in the captive breeding of this endangered animal. The anatomy of the reproductive system was based on two post mortem specimens and transrectal real-time ultrasonography in six adult females. The cervix consisted of several folds, the uterus was bicornuate with a short body and prominent horns, and the ovaries were completely covered by the fimbriated end of the fallopian tube. The internal genitalia could be imaged by ultrasonography. The testes were located within a pendulous scrotum. Two lateral projections were located at the base or the penis A well-defined processes glandis was present at the tip of the penis. The accessory glands and the testes could be imaged by ultrasonography. The average length of the oestrous cycle as measured by plasma progesterone levels using the radioimmunoassay technique was 21 days. Oestrus determined by receptivity towards the male was about 24 hours. Common signs of oestrus were: increase frequency of urine spraying, tail raising or tail swinging, anogenital and other contacts. Mounting was recorded but the inability of the male to achieve intromission was probably the reason for failure of females to conceive. Six ejaculates were collected from a male, 4 to 6 years of age, by a combination of penile massage and an artificial vagina. The volume of semen was about 25 ml and the concentration was about one million spermatozoa/ml. It is concluded that ultrasonography, semen analysis and hormonal assays could provide valuable information for successful breeding of the S umatran rhinoceros in captivity. Because of the aggressive behaviour of the male, testing females for sexual receptivity with a male should be replaced by ultrasonography and progesterone measurements for the prediction of oestrus. The recruitment of additional males for breeding is urgently needed. Improvements in semen collection and cryopreservation are needed for future use of artificial insemination if natural mating is not possible or fails

Evaluation of semen collected by electroejaculation from captive lesser Malay chevrotain (tragulus javanicus).

Thirteen sexually mature captive male lesser Malay chevrotains (Tragulus javanicus) were each anesthetized twice with tiletamine-zolazepam for electroejaculation. Viable spermatozoa were collected from all animals. The semen was creamy, milky, pale yellowish, or watery. The mean values for ejaculate volume, sperm concentration, and percentages of sperm motility, normality and viability were 23.7 ± 2.5 μ l, 366.9 ± 127.8 × 10 spermatozoa/ml, 40.0% ± 3.1%, 71.4% ± 1.6%, and 59.6% ± 2.1%, respectively. Semen pH was 7–8. No adverse effects of electroejaculation were noted. These are the first reported values for semen of lesser Malay chevrotain. Electroejaculation should be usable for routine semen collection in this species

Molecular and morphological detection of Plasmodium species in wild macaques in Selangor, Malaysia

Malaria is a serious global health problem, and rapid, accurate diagnosis is required to control the disease. A number of methods have been developed in recent years for diagnosing this disease, including polymerase chain reaction (PCR)-based technique that detect specific nucleic acid sequences, and microscopic examination of thin blood films that remains the most widely and commonly used method. In this study, blood samples were collected from 125 wild macaques consisting of 18 Macaca nemestrina and 107 M. fasicularis from various areas of Selangor. Giemsa-stained thin blood films (TBF) were prepared, and PCR using Plasmodium genus-specific primers for initial amplification and nested species-specific primers for Plasmodium knowlesi was conducted on all the blood samples. The prevalence of Plasmodium by TBF was 1.9% in M. fasicularis and 27.8% in M. nemestrina. The molecular prevalence of Plasmodium was 64.5% in M. fasicularis and 100% in M. nemestrina. When P. knowlesi-specific PCR was carried out, the prevalence in M. nemestrina was 5.6%, whereas in M. fasicularis it was 23.3%. These results indicate that the local wild macaques harbor a high rate of infection of Plasmodium. In addition, the prevalence of P. knowlesi, the zoonotic malaria parasite is higher than previously assumed. This warrants further investigation as these macaques may be potential reservoirs of human malaria in Malaysia

Reproductive behaviour of captive Sumatran rhinoceros Dicerorhinus sumatrensis)

The Sumatran rhinoceros (Dicerorhinus sumatrensis) is on the verge of extinction in Malaysia. At the Sumatran rhinoceros Conservation Centre in Sungai Dusun, the reproductive behaviour of two female and two male rhinoceroses were studied for 8–10 months during attempts to breed them in captivity. Due to the paucity of scientific information on the reproductive biology of the Sumatran rhinoceros, this study was conducted to obtain information on the reproductive behaviour of this species. The male rhino was introduced to a female rhino in the morning for 1–2 h daily in order to observe for behavioural oestrus. Observations were made on the signs of oestrus and mating behaviour. Oestrus was determined by receptivity towards the male and lasted about 24 h. Common signs of oestrus were an increase in frequency of urine spraying, tail raising or swinging, anogenital and other contacts. Although the males exhibited mounting, the inability of the male to achieve intromission was poor. The study demonstrated that the pattern of courtship and copulation of the captive Sumatran rhinos were comparable with those of other rhino species, reported previously by other scientists and flehmen reflex was also exhibited by the male Sumatran rhinos. In a captive breeding programme, it is recommended that only an oestral female is introduced into a male enclosure due to the male solitary behaviour and to avoid serious injuries inflicted onto the females

Identification of hybrids of painted and milky storks using FTA card-collected blood, molecular markers, and morphologies

Suspicious hybrids of painted storks and milky storks were found in a Malaysian zoo. Blood of these birds was sampled on FTA cards for DNA fingerprinting. Of 44 optimized primers, 6 produced diagnostic markers that could identify hybrids. The markers were based on simple, direct PCR-generated multilocus banding patterns that provided two sets of genetic data, one for each of the two stork species and another for the hybrids. It also revealed that large DNA fragments (3,000 bp) could be amplified from blood collected on FTA cards. When the results of each individual bird’s DNA fingerprint were compared with plumage characters, the hybrids were found to express a range of intermediate phenotypic traits of the pure breeds with no dominant plumage characteristic from either parental species

Dentinogenic ghost cell tumor in a Sumatran Rhinoceros

An adult female Sumatran rhinoceros was observed with a swelling in the left infraorbital region in March 2017. The swelling rapidly grew into a mass. A radiograph revealed a cystic radiolucent area in the left maxilla. In June 2017, the rhinoceros was euthanized. At necropsy, the infraorbital mass measured 21 cm × 30 cm. Samples of the infraorbital mass, left parotid gland, and left masseter muscle were collected for histopathology (Hematoxylin & Eosin, Von Kossa, Masson’s trichrome, cytokeratin AE1/AE3, EMA, p53, and S-100). Numerous neoplastic epithelial cells showing pleomorphism and infiltration were observed. Islands of dentinoid material containing ghost cells and keratin pearls were observed with the aid of the two special histochemistry stains. Mitotic figures were rarely observed. All the neoplastic odontogenic cells and keratin pearls showed an intense positive stain for cytokeratin AE1/AE3, while some keratin pearls showed mild positive stains for S-100. All samples were negative for p53 and S-100 immunodetection. The mass was diagnosed as a dentinogenic ghost cell tumor

Establishment and cryopreservation of fibroblast cell line from a Sumatran rhinoceros (Dicerorhinus Sumatrensis)

Cell lines have been established to preserve the genetic material of endangered animals. This study aims to establish, characterize and authenticate fibroblast cells derived from the kidney tissue of a Sumatran rhinoceros’ carcass. The primary cultures were obtained using the mixed enzymatic-explant method, supplemented with complete media and maintained at 37ºC with 5% CO2 in an incubator. Following routine trypsinization, viability and growth curves were generated through the Trypan Blue counting method. Cellular senescence was quantified by Sa-β-gal staining assay and G-banding for karyotyping. As a result, the cell derivation had generated 81 frozen stocks. The viability of cells at P5 and P10 showed reasonable recovery after six months. Cell population doubling time at P5 was 20.45 hours, while it was 22.35 hours at P10 and P15. The senescence level significantly increased from P5 to P10, and was especially significant at P15. Genetic stabilities were considered stable at P5 and P10, with frequency of over 70 %. In conclusion, this study was able to derive a primary fibroblast culture from the preserved tissue of a Sumatran rhinoceros, with certain changes in morphology, senescence level, growth curves and cell viability as the number of passages increased

Semen characteristics of Bornean sun bear (Helarctos malayanus euryspilus)

The Bornean sun bear (Helarctos malayanus euryspilus), endemic to Borneo Island, is the subspecies of the Malayan sun bear. The species is at risk, not just because of anthropogenic threats, but also slow reproduction in the wild. In captivity, due to poor reproductive performance, assisted reproductive technology is deemed a fundamental tool to propagate the depleting numbers of the Bornean sun bear. This is a pioneer study that presents the semen characteristics of the Bornean sun bear via conventional semen evaluation methods. Forty-two semen samples from ten sun bears were collected via electroejaculation and evaluated. The electro ejaculator probe (2.5 cm in diameter and 7.0 cm in length) was inserted rectally and positioned dorsal to the prostate gland. The optimum voltage used to obtain semen differed with each individual, but all showed hindlegs contraction and penile erection before ejaculation. The average combined testes volume in the Bornean sun bear was 23.37 ± 5.09 cm³. The mean semen volume was 617.30 µL, with sperm concentration of 1034.40 × 10⁶ sperm/mL and pH 7.79. Sperm viability was 80.19% with a general motility of 79.13% and progressive movement of 70.20%. There were high sperm abnormalities at 70.67%. Sun bear sperm length was 61.28 ± 2.46 µm and consisted of an oval head, midpiece, and tail. From this study, good semen donors were identified from the captive Bornean sun bear population in Sabah, Malaysia. The fresh semen baseline data established in this study will provide crucial reference for assisted reproduction programs in the Bornean sun bear