FISHES OF THE GULF OF MAINE 345 



KEY TO GULF OF MAINE SEA ROBINS AND GURNARDS 



1. The pectoral fin reaches back only to the fifth or sixth ray of the second dorsal. The 



margin of the caudal fin is concave Common sea robin, p. 345 



The pectoral fin is larger, reaching back to the ninth or tenth ray of the soft dorsal. 

 The caudal fin is square Red-winged sea robin, p. 34S 



131. Common sea robin (Prionotus cafolinus Linnaeus) 

 Sea robin; Robin; Gkeen-ete 

 Jordan and Evermann, 1896-1900, p. 2156. 



Description. — The large head, tapering body, and fanlike pectoral fins of the 

 sea robin somewhat suggest a sculpin, but the robin is distinguished from all sculpins 

 by the incasement of its entire head in bony plates, by its smaller mouth, the flat 

 depressed dorsal profile of its snout, its large ventrals, and by the fact that the three 

 lower rays of each pectoral are separate from the rest of the fin and modified into 

 three independent feelers slightly dilate at the tips, a very noticeable and diagnostic 

 feature. Furthermore the anterior margin of the upper jaw is concave in outline 

 when viewed from above, not convex as with most fishes, giving the nose a very 

 characteristic aspect. The head plates are rough and there is one sharp spine on 

 each cheek, one at the angle of the gill cover, two short spines over each eye pointing 

 backward, a spine on either side of the nape of the neck, and one on each shoulder 

 above the base of the pectoral fin. The spiny and soft-rayed portions of the dorsal 

 are separate but in contact at their bases. The former (10 spines) is rounded in out- 

 line, decidedly higher than the soft dorsal (13 rays), but the latter is considerably the 

 longer. The caudal is of moderate size, its margin slightly concave. The anal 

 (12 rays) is similar in outline to the soft dorsal, under which it stands. The pectorals 

 (their 3 lower rays as just noted) are rounded in outline and so large that they 

 overlap the anal and the second (soft) dorsal when laid back. The ventrals (each 

 of 1 stiff spine and 5 rays) stand close behind the pectorals. 



Color. — Sea robins are usually reddish brown (some more red and some more 

 brown) above with the upper surface of the head redder than the trunk and the 

 body irregularly banded or blotched with pale and dark, while the belly is dirty 

 white to pale yellow. The presence of a dusky spot on the first doi-sal fin between 

 its fourth and fifth spines is characteristic. The second dorsal is more or less striped 

 or marbled with pale and dark and the pectorals are usually reddish brown but 

 sometimes blackish above, slaty below, their lower feelerlike rays browTi at the base 

 with white or orange tips. The ventrals are white. 



Size. — The maximum length is 15 to 16 inches but few are more than a foot long. 



General range. — Shoal water along the North American coast from the Bay of 

 Fimdy to South Carolina, cliiefly south of Cape Cod. 



Occurrence in the Gtdf of Maine. — Plentiful though the sea robin is in Vineyard 

 Sound few are taken north of Cape Cod. It has been reported from various localities 

 about Massachusetts Bay — Truro, off Lynn, and Salem; most recently at Man- 

 chester, where Welsh saw several in the trap on June 29, 1913; and Prof. A. E. 

 Gross informs us that he has often seen as many as a dozen "robins" taken in the 

 trap at the entrance to Barnstable Harbor in a single tide in the early summer of 

 1920;* but I have never seen it about Cohasset or Duxbury. North of Cape Ann 



» This is briefly mentioned in The Auk, Vol. XL, No. 1, January, 1923, p. 24. 



