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,
Hydnellum aurantiacum Hydnellum aurantiacum Hydnellum aurantiacum is an inedible fungus, commonly known as the orange spine or orange Hydnellum for its reddish orange or rusty red colored fruit bodies. Like other tooth fungi, it bears a layer of spines rather than gills on the underside of the cap. Due to substantial declines in sightings, this species is listed as critically endangered in the United Kingdom. "Hydnellum aurantiacum" was first described by the German naturalist August Batsch in 1789, with the name "Hydnum suberosum" var. "aurantiacum". It was given its current scientific name by Petter Karsten, who transferred it to "Hydnellum" in 1879.