Reproductive Physiology of the Clouded Leopard: I. Electroejaculates Contain High Proportions of Pleiomorphic Spermatozoa throughout the Year1

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Abstract
Ejaculates were analyzed from clouded leopards (Neofelis nebulosa) subjected to a regimented anesthesia/electroejaculation protocol. Group I males (n = 4), maintained individually in an environment with natural fluctuations in photoperiod, were electroejaculated on the same day at monthly intervals (January–December). Group II clouded leopards (n = 8), maintained in random zoo populations throughout the U.S., were evaluated on a single occasion. Phase contrast and electron microscopy indicated a high proportion of structurally abnormal spermatozoa in seminal fluid (Group I range, 14.8–78.9%; Group II range, 32.3–93.0%), the predominant deformity being a tightly coiled flagellum. Semen quality, including spermatozoal concentration and the incidence of abnormal sperm forms, varied (p < 0.05) among males. Evaluating the numbers of motile spermatozoa/ejaculate (MS/E) among individual males from Group I on a monthly basis suggested a seasonal influence; gradually increasing MS/E values with peaks in June and July were observed in three of four animals. A simultaneous analysis of international breeding records for captive female clouded leopards demonstrated that 46.2% of parturitions occurred in March and April, indicating that most estrual periods occurred from late December through February. These data suggest that a physiological asymmetry may exist in peak reproductive performance between the male and female clouded leopard, perhaps as a result of differing adaptations to the captive environment. Motile spermatozoa can be recovered throughout the year using electroejaculation and, when used over time, a standardized procedure can determine a hierarchy of seminal quality among males of unknown reproductive potential. The relatively high proportions of structurally abnormal spermatozoa in the ejaculates of the clouded leopard may be related to a low degree of genetic variation within the species and/or hyperadrenal activity in captive populations.