Mycelial compatibility reactions of Australian Fusarium graminearum and F. pseudograminearum isolates compared with AFLP groupings

Using the mycelial reactions of 435 combinations of 14 Fusarium pseudograminearum and 15 F. graminearum isolates, it was demonstrated for the first time that mycelial reactions/barrage formation cannot be clearly used to distinguish F. graminearum and F. pseudograminearum. Mutually compatible isolates produced very different patterns of compatibility with other isolates. However, about 60% of pairings between F. graminearum and F. pseudograminearum isolates were compatible, indicating common ancestry. The Mantel tests used to determine any possible associations between mycelial compatibility reactions and AFLP genotypic diversity data revealed no association between the two systems in either species. In addition, no association was found between mycelial compatibility reactions and sexual reproduction in the two species. Implications of the higher frequency of mycelial compatibility reactions observed in F. pseudograminearum than in F. graminearum are discussed.

Do elasmobranch reactions to magnetic fields in water show promise for bycatch mitigation?

Elasmobranchs are under increasing pressure from targeted fisheries worldwide, but unregulated bycatch is perhaps their greatest threat. This study tested five elasmobranch bycatch species (Sphyrna lewini, Carcharhinus tilstoni, Carcharhinus amblyrhynchos, Rhizoprionodon acutus, Glyphis glyphis) and one targeted teleost species (Lates calcarifer) to determine whether magnetic fields caused a reaction response and/or change in spatial use of an experimental arena. All elasmobranch species reacted to magnets at distances between 0.26 and 0.58 m at magnetic strengths between 25 and 234 gauss and avoided the area around the magnets. Contrastingly, the teleosts showed no reaction response and congregated around the magnets. The different reactions of the teleosts and elasmobranchs are presumably driven by the presence of ampullae of Lorenzini in the elasmobranchs; different reaction distances between elasmobranch species appeared to correlate with their feeding ecology. Elasmobranchs with a higher reliance on the electroreceptive sense to locate prey reacted to the magnets at the greatest distance, except G. glyphis. Notably, this is the only elasmobranch species tested with a fresh- and saltwater phase in their ecology, which may account for the decreased magnetic sensitivity. The application of magnets worldwide to mitigate the bycatch of elasmobranchs appears promising based on these results.