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How large can the smallest and largest gasterosteiform fishes grow?

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Lined seahorse (Hippocampus erectus) — gasterosteiform Lined seahorse (*Hippocampus erectus*).

Within the order Gasterosteiformes, there is a significant range in the physical size of the various species. The smallest adult gasterosteiform fishes grow to approximately 2 cm (about 0.8 inches) in length, while the largest members of the order can reach lengths of about 200 cm (about 79 inches).1