Litoria spenceri (Spencer, 1901)

Mollard, Richard, Mahony, Michael, Marantelli, Gerry & West, Matt, 2018, The critically endangered species Litoria spenceri demonstrates subpopulation karyotype diversity, Amphibian & Reptile Conservation (e 166) 12 (2), pp. 28-36 : 31

Litoria spenceri , Southern Site: field study adult specimens

One female and one male frog were studied from the Southern Site. Minimal numbers of animals were used in this study due to the critically endangered nature of this species, the lack of readily available tissue samples, and the unwillingness to harm such critically endangered animals explicitly for use in experimentation. Twenty of 23 spreads counted were 2n = 26 for the female and nine of 11 spreads in the male. Eight prepared karyotypes (chromosomes lined up in order) from the female and seven prepared karyotypes from the male confirmed the 2n = 26 karyotype, and arranged in descending order of size, revealed four larger, three medium, and six smaller chromosome pairs ( Figs. 2 , 3 , and data not shown). DAPI negative regions were evident on the long arms of chromosome 9 for each sex in all karyotypes ( Figs. 2 , 3 , 4 , and data not shown). Chromosomes 1, 4, 10, 11, 12, and 13 appear metacentric, chromosomes 2, 6, 7, 8, and 9 appear submetacentric, and chromosomes 3 and 5 appear subtelocentric ( Table 1) .

Figures

Fig. 2. Karyotype from a Southern Site L. spenceri adult female. A representative karyotype demonstrates the L. spenceri 2n = 26 karyotype and a DAPI negative area in the long arm of chromosome 9.

Fig. 3. Karyotype from a Southern Site L. spenceri adult male. A representative karyotype demonstrates the L. spenceri 2n = 26 karyotype and a DAPI negative area in the long arm of chromosome 9.

Fig. 4. Chromosomes 9 and 11 from different L. spenceri populations. Three representative chromosomes from each animal demonstrate a highly conserved DAPI negative region in the long arms of chromosome 9. A DAPI negative region is observed in the long arm of chromosome 11, but only in the Central Site juveniles and in only one matched chromosome of the Northern Site x Central Site tadpole hybrid.Arrows indicate the chromosome 11 DAPI negative region.Asterisks indicate the paired submetacentric chromosome 11 matched pair of the Northern Site x Central Site tadpole hybrid.