Facultative parthenogenesis discovered for the first time in Jamaican boa (Chilabothrus subflavus) using novel microsatellite markers.

The mode of reproduction most often seen in snakes is sexual, but studies have noted facultative parthenogenesis in at least six families. Here, we provide evidence for the first observed case of facultative parthenogenesis in a captive Jamaican boa (Chilabothrus subflavus). A 7-year-old female Jamaican boa, isolated since birth, was found to have produced a litter of 15 offspring. To provide molecular DNA evidence of parthenogenesis, 13 new microsatellite loci were isolated in the species. All offspring were found to be homozygous at each locus and only possess alleles found in the dam, implicating that they were born from asexual reproduction. Several developmental abnormalities, including stillbirths and spinal deformities, were noted in the litter which may be explained by their increased level of homozygosity. To preserve genetic diversity in the captive population, research should be conducted to understand the prevalence of this mode of reproduction and to guide future management decisions of this IUCN listed Vulnerable species.

Characterisation of sperm production and morphology in the male Philippine crocodile Crocodylus mindorensis via voluntary behavioural training.

Philippine crocodiles Crocodylus mindorensis are critically endangered due to agricultural and fishing threats that have severely fragmented their habitat and population in the Philippines. Captive management plans are important to safeguard against their extinction, but the current population in US zoos is small, and breeding is hampered by the slow growth of this species and the danger of introducing differently sized animals for breeding. There is little information regarding the sperm characteristics of crocodilians, and none for Philippine crocodiles. In this study, we sought to characterise sperm production in the male Philippine crocodile (n =1) by performing voluntary (without sedation or restraint) collections (n =181) over a 3.5-year period. Peak sperm production in this individual occurs from January to July, when the mean (±s.e.m.) total number of spermatozoa recovered was 10.2×106 ±3.8×106 (n =104), compared with 0.3×106 ±0.2×106 (n =71) for all other months of the year. Analysis of sperm morphology indicated that 15.9% of spermatozoa exhibited normal morphology. A bent tail was the most common abnormality (48.2%) observed. Understanding the basic reproductive biology of the male Philippine crocodile will facilitate the development of artificial reproductive technologies to improve captive propagation and genetic management of this species.