Research

Leopard conservation project research in conjunction with University of Johannesburg.

Physiological and Morphological study of the reproductive aspects of the leopard (panthera pardus).


The leopard, Panthera pardus, is a member of the felidae family. This secretive and elusive large cat was once distributed across eastern and southern Asia and Africa. Now at the centre of a severe man-animal conflict because of expanding agricultural practices and development projects, its habitat has depleted to mostly sub-Saharan Africa and fragmented populations in Asia (Stuart, 2007). As one of South Africa’s “Big Five”, the leopard forms a lucritive part of South Africa’s economy being a favourite in both the tourist and hunting industries. The ecological importance of this animal lies in its position at the top of the food chain in most ecosystems (LEAP, 2010).

The depletion of the leopard’s habitat has forced these mammals out of its once isolated habitat and into the open. The unique adaptability of this species has helped its success by straying into villages and farms, preying on dogs and live stock. Thereby creating a man-animal conflict, leaving little support in the conservation of this animal.

Little is known about the conservation status of leopards in South Africa and although it is thought that the leopard can survive in a human-dominated world (Leopard Conservation Science Project, 2009), it is listed as “near threatened” by the IUCN (International Union for Conservation of Nature) (Henschel, et al., 2008). Leopard numbers in South Africa remain questionable, with no true value. In 2005, concerns were raised by the Population Habitat Viability Assessment workshop that found that leopard populations were smaller than previously thought, that is most definitely a result of growing human population, and therefore loss of habitat, persecution and hunting. Based on the insufficient knowledge of leopard numbers and status, decisions such as CITES doubling the amount of hunting permits given per annum in 2004 continue to happen (LEAP, 2010). The key to all species survival is the success of reproduction. In studying the physiological, morphological, development and viability of the spermatozoa from the males of these untraditionally researched animals, this could lead to later success in assisted reproduction (Wildt, et al,. 1995). This information could also provide knowledge on possible problem factors such as pollution that may be interfering in the viability of the sperm for reproduction. Understanding these intricate physiological processes of the leopards that ultimately affects its existence could ensure its future existence in South Africa (LEAP, 2010).

The Leopard Conservation Project in conjunction with the University of Johannesburg will carrying out this study at the start of January 2011 by the cryopreservation of sperm for the use of ART (assisted reproductive technology) and conducting a semen analysis that will evaluate certain physical and chemical parameters of the semen and the sperm contained in the semen. Spermatozoa will be flushed from the epididymis of recently hunted leopard. The motility, plasma membrane integrity, acrosome integrity and morphology of pre-freeze and post-thaw spermatozoa will be compared. This will include the analysis of the spermatozoa and testis morphology using Scanning electomicroscopy (SEM) and motility of the sperm (using Computer Assisted Semen Analysis, CASA).

Cryopreservation of the sperm could aid in the management and conservation of the leopards in ART (Wildt, et al., 2007). The cryopreservation of sperm is a process whereby the sperm is preserved by cooling to sub-zero temperatures (John Hopkins University, 2008). The drastic increase in both tourist and local hunting activities of the leopard will result in a decrease of the “good” gene pool within this species. The cryopreservation of sperm as well as spermatology research could lead to the successful application of ART and ensure the re-introduction of this gene pool into the environment (Wildt, et al., 1995).

There is a definite gap in the knowledge regarding the physiological aspects of reproduction in leopards. Thus the aim of this study is to fill these gaps and help in the conservation of the wild leopard population in South Africa through possible methods such as assisted reproductive techniques. The specific aims and objectives are as follows:

    A study of the histomorphology of the spermatozoon as well as the testis and epididymis. This will include a closer look at the integrity of the acrosome. Any abnormalities found in these structures could result in the inability of fertilization.
    Analysis of the development of the spermatozoon – spermatogenesis.
    Semen analysis, all physical and chemical properties of the seminal plasma will be analyzed. Changes in the properties could adversely affect the sperm and fertilization process. The chemical components of the semen will be described as the handling and treatment during the ART processes, can change the metabolic activity of the semen.
    A comparison of the motility of both pre-freeze and post-thaw spermatozoa using CASA to determine the efficiency of the motility of the spermatozoa.

The increase in knowledge of the reproductive physiology of these animals can facilitate in the conservation of leopards with the aid of breeding and management.

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