A comparison of meristic and morphometric characters of green sturgeon Acipenser medirostris

The green sturgeon Acipenser medirostris is widely distributed along the coast of North America, with known spawning populations in the Klamath, Sacramento, and Rogue rivers. It also spawns in the Tumnin River, Russian Federation (formerly USSR) but is otherwise uncommon in Asia. Whether North American and Asian populations are conspecific has been debated; recent genetic analyses indicate these populations should likely be considered as distinct species. As part of a cooperative study aimed at determining the systematics of sturgeons of the North Pacific, meristic and morphometric data were collected from 50 green sturgeon harvested from the Columbia River, Oregon, USA in August 1999. Our meristic data expand the observed range for lateral scutes, ventral scutes, and gill rakers and confirm the published range for dorsal scutes. We found considerable overlap in meristic counts of Asian and North American populations of green sturgeon. Morphometric data showed considerable differences between populations, especially measures related to snout length; however, a lack of raw data precluded statistical comparison. Specific detailed procedures for collecting sturgeon morphometric and meristic characters should be established to facilitate comparison of data.