Age determination in fish fish. Johannes Reibisch, working for the Commission of Scientific Investigation of German Seas at Kiel, attempted to use Hoffbauer’s techniques to age plaice ("Plueronectes platessa") but found it difficult to accurately discern annuli. He decided to study a different structure and in 1899 he published the first procedures using otoliths as an aging structure. A fellow scientist also with the German Commission at Kiel, Friedriche Heincke, also frustrated with difficult scale annuli, further studied other structures to age fish. He discovered annuli in the vertebrae, opercula, and pectoral girdle and published his findings in Heicke 1905. The works of Hoffbauer,
Gaeana maculata as on the upper side. Wing-span 3¾ inches (95 mm). Gaeana maculata Gaeana maculata is a species of cicada. It was first described by Dru Drury in 1773, from China. Upper side: head black. Eyes yellow brown, round, and projecting from the head a little; between them are two small orange spots. Antennae small and short. Thorax black, with four orange spots in a row, placed across it, and behind them two others. Abdomen black, consisting of seven annuli or rings, besides the tail part, the last of which is edged with orange. Anus orange-coloured, and furnished with a bristle