Atlantic white-sided dolphins are distributed, primarily offshore, in the cool waters between the Gulf Stream and the Labrador Current. They have been observed from Hudson Canyon, off New York City, north to southern Greenland and perhaps Davis Straits. Their normal range shares a southern boundary with the white-beaked dolphin but does not extend as far to the north.
Stranded Specimens
In addition to the features described above for living animals at sea, stranded Atlantic white-sided dolphins can be distinguished from white-beaked dolphins by the following:
| Atlantic White-Sided Dolphin | White-Beaked Dolphin |
|---|---|
| NUMBER OF TEETH | |
| 30-40 per side per jaw,sometimes more in upper. | 22-28 per side per jaw; havelarger individual teeth—to 6mm in diameter. |
| FLIPPERS | |
| Lower portion of forwardmargin more curved. | Lower portion of forwardmargin less acutely curved. |
| VENTRAL COLOR | |
| White coloration of bellyextends high onto sides ofbody. | White coloration of bellyextends to lower jaw but notabove flippers on sides. |
| CAUDAL CRESTS | |
| Tail stock strongly compressedlaterally; taller, narrowsrapidly just in front of flukes. | Tail stock less laterallylcompressed, tapers moregently towards tail flukes. |
