Table of Contents
The sturgeons, like the sharks, have an uneven ("heterocercal") tail with the vertebral column extending out along the upper lobe. But there is no danger of mistaking a sturgeon for a shark for it has only one gill opening on each side, while the gills are enclosed by bony gill covers. And the combination of gills of this kind with sharklike tail and with the fact that the head is covered by bony plates united by sutures, sets the sturgeons off from all other Gulf of Maine members of their own class. Two species of sturgeons are known from the Gulf, one of which once was rather common there; the other is extremely scarce everywhere.
| KEY TO GULF OF MAINE STURGEONS | |||
|---|---|---|---|
| 1. | The successive bucklers in the dorsal row touch each other or even overlap; the space between the dorsal row of bucklers and the uppermost of the two lateral rows is thickly set with coarse prickles | — | Sea sturgeon, p. 81 |
| 2. | The successive bucklers in the dorsal row are separated one from the next by spaces up to 1/2 as long as the bucklers; the space between the dorsal row of bucklers and the uppermost of the two lateral rows is only sparsely strewn with fine prickles | — | Short-nosed sturgeon, p. 84 |