Reproductive Characteristics of Male Florida Panthers: Comparative Studies from Florida, Texas, Colorado, Latin America, and North American Zoos

Abstract

Testicular volume, semen traits, and pituitary-gonadal hormones were measured in populations of Felis concolor from Florida, Texas, Colorado, Latin America, and North American zoos. More Florida panthers (F. concolor coryi) were unilaterally cryptorchid (one testicle not descended into the scrotum) than other populations (43.8 versus 3.9%, respectively). Florida panthers also had lower testicular and semen volumes, poorer sperm progressive motility, and more morphologically abnormal sperm, including a higher incidence of acrosomal defects and abnormal mitochondrial sheaths. Transmission electron microscopy revealed discontinuities in the acrosome, extraneous acrosomal material under the plasma membrane, and remnants of the golgi complex under the acrosome. No differences were detected in mean-circulating follicle-stimulating hormone, luteinizing hormone, or testosterone between Florida panthers and other populations of mountain lions. Seminal traits and concentrations of follicle-stimulating hormone, luteinizing hormone, and testosterone were similar between cryptorchid and noncryptorchid Florida panthers. Animals with F. concolor coryi ancestry were categorized on the basis of amount of genetic variation (low ~ type A; medium ~ type B; high ~ captive Piper stock). Compared to counterparts, type A Florida panthers had the lowest testicular volume and sperm-motility ratings and were the only animals exhibiting unilateral cryptorchidism. These results demonstrate the existence of major morphological and physiological differences among populations of F. concolor, a finding potentially related to differences in genetic diversity.

Reproductive Impairment in the Florida Panther: Nature or Nurture?

“…A more recent study (26) reported no significant difference between testosterone levels of five populations of cougars (including 16 Florida panthers, 7 of which were unilaterally cryptorchid). The mean testosterone concentration observed, which involved a total of 65 animals, was 720 pg/mi, which the authors thought to be low (but which was greater than mean concentrations measured in our study).…”

“…Roelke et al (9) believed that the condition in the panther resulted from a sex-linked recessive gene. A comparative study of Felis concolor populations from Florida, Texas, Colorado, Latin America, and North American zoos (26) indicated that cryptorchidism was only observed in 2 of more than 50 captive male cougars. The condition has never been reported in any other species of nondomestic cat (9), regardless of the degree of inbreeding.…”

Structure and amount of genetic variation at minisatellite loci within the subspecies complex of Phoca vitulina (the harbour seal)

“…457 low level of genetic variation (O'Brien et a!., 1985) and very poor environmental conditions (Caro & Laurenson, 1994) were indicated as the main cause. Recently, studies on the Florida panther (Barone et a!., 1994;Fergus, 1995;Hedrick, 1995) and the song sparrow (Keller et aL, 1994) have described the combined effects of inbreeding depression and environmental challenges in natural populations. Merola (1994) and Caughly (1994) have questioned the relative importance of genetic variation in species conservation, especially in the case of the cheetah.…”

Approaches and efficacy of artificial insemination in felids and mustelids

“…For example, felid species or populations lacking genetic variability tend to produce more malformed spermatozoa than more genetically diverse counterparts [37,38]. The genetically homozygous Florida panther produces extraordinarily high proportions (>90%) of pleiomorphic sperm [39,40]. The cheetah and clouded leopard (two other species well documented to have low levels of gene diversity) also routinely ejaculate >70% malformed spermatozoa [36,37,41].…”