Elemental analysis of vertebrae discerns diadromous movements of threatened non-marine elasmobranchs.

River sharks (Glyphis spp.) and some sawfishes (Pristidae) inhabit riverine environments, although their long-term habitat use patterns are poorly known. We investigated the diadromous movements of the northern river shark (Glyphis garricki), speartooth shark (Glyphis glyphis), narrow sawfish (Anoxypristis cuspidata), and largetooth sawfish (Pristis pristis) using in situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) on vertebrae to recover elemental ratios over each individual's lifetime. We also measured elemental ratios for the bull shark (Carcharhinus leucas) and a range of inshore and offshore stenohaline marine species to assist in interpretation of results. Barium (Ba) was found to be an effective indicator of freshwater use, whereas lithium (Li) and strontium (Sr) were effective indicators of marine water use. The relationships between Ba and Li and Ba and Sr were negatively correlated, whereas the relationship between Li and Sr was positively correlated. Both river shark species had elemental signatures indicative of prolonged use of upper-estuarine environments, whereas adults appear to mainly use lower-estuarine environments rather than marine environments. Decreases in Li:Ba and Sr:Ba at the end of the prenatal growth zone of P. pristis samples indicated that parturition likely occurs in fresh water. There was limited evidence of prolonged riverine habitat use for A. cuspidata. The results of this study support elemental-environment relationships observed in teleost otoliths and indicate that in situ LA-ICP-MS elemental characterization is applicable to a wide range of elasmobranch species as a discriminator for use and movement across salinity gradients. A greater understanding of processes that lead to element incorporation in vertebrae, and relative concentrations in vertebrae with respect to the ambient environment, will improve the applicability of elemental analysis to understand movements across the life history of elasmobranchs into the future.

A new species and subgenus of Elseya (Testudines: Pleurodira: Chelidae) from New Guinea.

The New Guinea freshwater turtle, Elseya novaeguineae (senu lato) is a long-term, widespread resident of New Guinea and has been subject to substantial vicariance in one of the most geologically dynamic regions on earth. Thus, it should come as no surprise that the taxonomy of this turtle is poorly resolved. Elseya novaeguineae has long been recognized as a species complex, though which elements of this taxon warrant recognition as separate species has been debated. In this paper, we restrict Elseya novaeguineae to the Birds Head region of New Guinea, west of the Langguru Thrust and Fold Belt; we resurrect from synonymy Elseya schultzei for the populations north of the Central Ranges; and we describe a new species for the populations to the south of the Central Ranges. We revisit the classification of the genus Elseya throughout its range in the light of our work and recently published reports, and erect three subgenera that recognize the three major clades within this genus. Subgenus Elseya is the nominate subgenus, to which we assign Elseya dentata, E. branderhorsti and undescribed E. sp. aff. dentata [Sth Alligator]. Elseya novaeguineae, E. schultzei and our new species are assigned to a new subgenus, Hanwarachelys. Species of northern and eastern Queensland, E. albagula, E. irwini, E. lavarackorum and the fossil taxa E. uberrima and E. nadibajagu, are assigned to subgenus Pelocomastes, resurrected from synonymy.