Like his brother Friedrich Specht, he also produced illustrations of animals and landscapes for a number of publications, such as Brehms Tierleben and Die Gartenlaube.
Perhaps the greatest change in the second edition was the addition of new illustrations by Gustav Mützel, the brothers August and Friedrich Specht and others, which Charles Darwin said were the best he had ever seen.
He provided illustrations of animals and landscapes for a large number of zoology and veterinary science publications, notably for the first edition of Brehms Tierleben (1864–69) conceived by Alfred Edmund Brehm, Brockhaus and Efron Encyclopedic Dictionary (1890—1907), Karl Christoph Vogt's Die Säugetiere in Wort und Bild (1883–89) and Richard Lydekker's Royal Natural History (1894–96).