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,
Ticto barb Ticto barb The ticto barb or twospot barb ("Pethia ticto") is a species of subtropical freshwater fish belonging to the family Cyprinidae. It is a native of the upper Mekong, Salwen, Irrawaddy, Meklong and upper Charo Phraya basins in the countries of Nepal, India, Pakistan, Myanmar, Bangladesh, Thailand, and Sri Lanka. It has frequently been confused with the Odessa barb in the aquarium trade, but in that species the male is reddish-orange (lacking in "P. ticto"). The ticto barb is silver and gold with two black spots; one just before the pectoral fin and one near the back tail. It