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,
Tawny fish owl They tend to be an orangey-rufous color on the crown and upperparts, which are overlaid with broad, blackish markings on the central part of the feathers and spots of the same color as the reddish-brown feather edges. The scapulars are a dingy yellow color, forming a contrasting band which runs across the owl's shoulders. The flight and tail feathers are strongly barred dark brown and buffish. The facial disc is poorly defined but a sizeable off-white area on the eyebrows and forehead stands out. While buffy and brown fish owls are featherless on their legs and the Blakiston's fish owl