Young ISDR

How do you define a new species of Nitzschia ? An example from an Ethiopian crater lake By Dai Grady* Around 50 km south east of the hectic Addis Ababa (Ethiopia) is a group of maars – explosion crater lakes – surrounded by hotels on the lake edges and populated by people practicing water sports. Around 65 m below the water surface at one of these lakes (Lake Babogaya ; Figure 1), however, are laminated sediments that have accumulated through the Holocene as a result of the seasonal mixing of lake waters in the dry season and stratification in the wet season. These laminated sediments were an important part of my recent Ph.D. where I used diatoms to reconstruct past environmental change in the area over the last 5,500 years. Due to their short life-cycles, rapid dispersal and colonisation diatom fossil remains accumulate in lake sediments and can be used to effectively reconstruct environmental change. But, shortly into my Ph.D., I realised I was going to ...

  CARBALLEIRA, R., TROBAJO, R., LEIRA, M.,  BENITO, X ., SATO, S. & MANN D.G. 2017.   A combined morphological and molecular approach to Nitzschia varelae sp. nov., with discussion of symmetry in Bacillariaceae.   European Journal of Phycology .  A previously unknown member of the Bacillariaceae was discovered almost simultaneously in four different brackish coastal wetlands on the Atlantic and Mediterranean coasts of the Iberian Peninsula. It appears to tolerate a wide range of salinities but was never common in samples where it occurred. The frustules were consistently hantzschioid (i.e. with the raphe systems always on the same side of the frustule) and the valve outline was asymmetrical about the apical plane, two features that have until recently been considered characteristic of Hantzschia . Molecular phylogenies based on rbc L and LSU rDNA indicated, however, that the new species does not belong in Hantz...