FISHES OF THE GULF OF MAINE 



81 



2. 



KEY TO GULF OF MAINE STURGEONS 



The successive bucklers in the dorsal row touch each other or even overlap; the space between the dorsal row of buck- 

 lers and the uppermost of the two lateral rows is thickly set with coarse prickles Sea sturgeon, p. 81. 



The successive bucklers in the dorsal row are separated one from the next by spaces up to % 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. 



Sea sturgeon Acipenser sturio Linnaeus, 1758 86 

 Jordan and Evermann, 1896-1900, p. 105 



Description. — The skin of the sturgeon is 

 armored with a row of large bony shields or 

 bucklers along the middle of its back (the succes- 

 sive bucklers touching or even overlapping) with 

 a second row of smaller bucklers high up along 

 each side of the body; and with a third row, also 

 smaller, lower down, along the line of transition 

 from side to belly. Each buckler has a longitu- 

 dinal keel with a spur, which is so sharp on small 

 fish that these are hard to handle, lower and 

 blunter on large. On the average there are 10 

 or 11 (10 — 16) bucklers in the mid-dorsal row; 

 28 or 29 (26 — 34) in each upper lateral row; and 

 9 to 14 in each of the lower lateral rows. The 

 dorsal row runs from above the gill covers back 

 to the dorsal fin, and each of the dorsal shields 

 reaches to the next shield or even overlaps it. 

 The upper lateral rows run from the gill openings 

 back to the root of the tail fin; the lower lateral 

 rows from close behind the pectoral fin to the 

 pelvic fin, also from the pelvic fin back as far as 

 the anal fin. And each shield in each of the two 

 lateral rows is separated from the next shield by 

 a space up to one-half as long as the shields. 



The body is rather slender and rendered more 

 or less pentagonal in cross section by the five rows 

 of shields, instead of rounded as it is in the majority 

 of bony fishes. The snout is narrow in young 

 sturgeons less than 2 to 2% feet long, depressed 

 below the level of the forehead, nearly flat below, 



M It still is an open question, that we cannot answer, whether the sea 

 sturgeon of eastern North America is identical with the European sea stur- 

 geon, Is a recognizable race of the latter, or is a separate species; if the 

 last, its scientific name is Acipenser oxyrinchus Mitchill, 1816. 



and longer (from the eyes forward) than the dis- 

 tance is from the eyes rearward to the upper 

 corners of the gill openings. But it changes 

 shape as the fish grows, becoming blunter, straight 

 in dorsal profile, and considerably shorter rela- 

 tively. The mouth, situated on the under side 

 of the head, is small, toothless (except in larval 

 stages), with protractile lobed lips, and there are 

 four pointed barbels in a row across the lower 

 side of the snout in front of the mouth. The 

 single rather small triangular dorsal fin stands 

 far back, with its rear edge over that of the still 

 smaller anal fin. The ventral fins are likewise far 

 back. The pectorals are set almost as low as the 

 plane of the belly. 87 



Color. — Olive greenish or bluish gray above, 

 gradually fading on the sides and changing 

 rather abruptly below the upper lateral rows of 

 shields to the white of the belly. 



Size. — The sea sturgeon is a very large fish. 

 In the Delaware River where sturgeon persisted 

 until recently in larger numbers than in New 

 England, ripe males are up to about 6 to 7 feet 

 in length, averaging 65 pounds in weight; the 

 spawning females (which are larger), up to about 

 10 feet and to about 250 pounds, 88 with a larger 

 one taken from time to time. And the general 

 run was about the same in the Kennebec, to judge 

 from an average weight of 120 pounds for males 

 and females together, during the years when a 

 fishery was carried on there. But some still grow 

 considerably larger in Gulf of Maine waters. 

 Thus 9 weighing between 350 pounds and 600 



«' Vladykov and Beaulieu (Natural. Canad., vol. 73, 1946, pp. 143-204), 

 give a detailed account of the characters that separate the sea sturgeon from 

 the lake sturgeon (Acipenter fulvescens Raflnesque, 1817). 



» According to Cobb, Rept. U. S. Fish Comm. (1899), 1900, p. 277. 



* f r~^B^3^ ^si 1 -^*!* 





Figure 36. — Sturgeon {Acipenser sturio), Potomac River specimen. From Goode. Drawing by H. L. Todd. 



