Punctularia

Abstract: Organosolv pulping of fungally pretreated samples of Pinus radiata was evaluated. A screening study using five white-rot fungi indicated that Ceriporiopsis subvermisopora and Punctularia artropurpurascens were the most selective ones for lignin degradation. These fungi were further cultured in bioreactors containing 2.5 kg of wood chips. Fungally-pretreated samples were delignified by formic acid/acetone (7:3) at 150°C. Pulping kinetics and strength properties of the resulting unbleached pulps were evaluated. Delignification rates and xylan solubilization rates were higher for the decayed samples than for the undecayed control, except for the sample biotreated with P. artropurpurascens for 30 days. C. subvermispora proved appropriate for treating the wood samples before organosolv pulping, since pretreatment with this fungus resulted in faster wood delignification and pulps with lower residual lignin. Increases in tensile index ranging from 3% to 22% were observed for most pulps prepared from biotreated samples, independently both of the fungal species used in the pretreatment and of the extent of the wood biodegradation expressed as wood weight loss. However, tear and burst indexes and brightness were lower than or similar to those of pulps prepared from the undecayed control.

Abstract: We examined differentiation within the Colombian wood turtle Rhinoclemmys melanosterna, and among R. melanosterna and the closely allied species R. diademata, R. funerea and R. punctularia, based on 1060 base pairs of the mitochondrial cyt b gene. We also assessed the phylogenetic relationships among these species using 2050 bp of mtDNA (partial cyt b, 12S and 16S genes) and 3620 bp of nuclear DNA (partial Rag 1, Rag 2, C-mos, R35 and ODC genes). There is considerable phylogeographic structuring within R. melanosterna, with seven distinct clades distributed across the species’ range. These clades correlate to some extent with previously described differences in the dorsal pattern of head coloration. Individual and combined analyses of mitochondrial and nuclear DNA indicated contradictory relationships among R. melanosterna, R. diademata, R. funerea and R. punctularia. Mitochondrial DNA sequences revealed R. melanosterna to be non-monophyletic with respect to R. diademata, R. funerea and R. punctularia. In contrast, R. melanosterna constituted a well-supported monophyletic clade using nuclear DNA. This conflict between mitochondrial and nuclear data suggests past gene flow among the allopatrically and parapatrically distributed species R. melanosterna, R. diademata, R. funerea and R. punctularia. Compared to the other Rhinoclemmys species, the taxa under study are weakly differentiated. To assess their taxonomic status, further research is warranted using additional nuclear markers and additional samples of R. diademata, R. funerea and R. punctularia. For the time being, a continued classification of R. melanosterna, R. diademata, R. funerea and R. punctularia as distinct species is justified owing to their allopatric and parapatric distributions, and to conserve the established usage of names that is based on morphological and karyotypic differentiation.

Abstract: Rhinoclemmys punctularia flammigera subsp. nov. is described from the region of confluence of the Ventuari and Orinoco rivers in southern Venezuela. The controversy on the systematic position of Rhinoclemmys punctularia diademata (Mertens) is discussed, and conservatively it is considered that Rhinoclemmys punctularia (Daudin) has three subspecies: the nominal form from eastern Venezuela, Trinidad, the three Guianas and northern Brasil; R. p. diademata (Mertens) from the Maracaibo Basin in Venezuela and Colombia ; and the new subspecies here described. Rhinoclemmys punctularia flammigera subsp. nov. seems to be more closely related to R. p. punctularia (Daudin), the other Guianan representative of the genus. Available biological information on the new subspecies is presented.

Abstract: Rhinoclemmys punctularia punctularia is a semi-aquatic chelonian found in Northern South America. We analyzed the habitat use, size structure and sex ratio of the species on Algodoal-Maiandeua Island, a pro- tected area on the Northeastern coast of the Brazilian state of Para. Four distinct habitats (coastal plain lake, flooded forest "igapo", interdunal lakes, and tidal channels) were surveyed during the rainy (March and April) and dry (August and September) seasons of 2009, using hoop traps. For the analysis of population structure, additional data were taken in March and August, 2008. A total of 169 individuals were captured in flooded forest (igapo), lakes of the coastal plain and, occasionally, in temporary pools. Capture rates were highest in the coastal plain lake, possibly due to the greater availability of the fruits that form part of the diet of R. p. punctularia. Of the physical-chemical variables measured, salinity appeared to be the only factor to have a significant negative effect on capture rates. The sex ratio was only slightly biased to females, and did not vary between habitats or seasons. Straight carapace length was significantly larger in females, but did not vary between habitats. Overall, the evidence indicates that both biotic and abiotic factors like food availability, low current and salinity, influ- ence the habitats selection and use by R. p. punctularia on Algodoal-Maiandeua Island. Rev. Biol. Trop. 60 (1): 413-424. Epub 2012 March 01.