FISHES OF THE GULF OF MAINE 



469 



caudal fin is uniform grayish or brownish; the 

 anal plain brown; the ventrals plain yellow to 

 brown. The pectorals are yellow or orange, 

 strikingly marked with two broad dusky bars, one 

 of them crossing the middle of the fin, and the 

 other crossing its outer third. The pectoral 

 filaments are orange. 



Size. — The maximum length is 15 to 16 inches, 

 but few of them grow to be more than a foot long. 



Habits. — Sea robins, like the sculpins, tend to 

 keep to the bottom. But they swim actively, 

 usually with the pectorals closed against the body. 

 They are often hooked close to the surface; we 

 have caught them when trolling for mackerel, and 

 many anglers have told us of similar experiences. 

 When on the bottom they often lie with the fanlike 

 pectorals spread. If disturbed they bury them- 

 selves in the sand, all but the top of the head and 

 eyes, and they are said to employ the feeler-like 

 rays of the pectorals in stirring up the weeds 

 and sand to rout out the small animals upon 

 which they feed. They are usually found on 

 smooth hard grounds, less often on mud or about 

 rocks. 



Along southern New England, where robins 

 are far more plentiful than they are farther north, 

 a large part of the population appear inshore in 

 May or June, to pass the summer there; some 

 close to tide line, but others remaining in depths of 

 5 to 30 or 40 fathoms, or deeper. Like many 

 warm-water fishes, they disappear from the coast 

 in October, to pass the cold season well out on the 

 shelf, as recently proved by catches made at 50 to 

 55 fathoms off southern Massachusetts by the 

 dragger Eugene H in late January, 61 in 1950, also 

 at 21 to 93 fathoms off North Carolina, in that 

 same month and the next, by the Albatross III. 62 



The fact that the Albatross III trawled up to 

 83 sea robins per haul off New York and off south- 

 ern New England at 22-61 fathoms as late in the 

 season as mid-May of that same year suggests 

 that some of them may remain well offshore until 

 into the summer, if not all summer. 



Notwithstanding this inshore and offshore mi- 

 gration, some at least of the sea robins experience 

 a temperature range of nearly 30° F. with the 

 change of the seasons, for those that come closest 

 inshore are in water as warm as 68°-70° at the end 



of the summer, while some that were trawled 

 along the 30- to 40-fathom zone in May were in 

 water as cold as 40.2° to 41.4°. 



The sea robin is a voracious fish, feeding indif- 

 ferently on shrimps, crabs of various kinds, 

 amphipods (crustaceans are its chief diet), squids, 

 bivalve mollusks, annelid worms, and on small 

 fish, such as herring, menhaden, and small winter 

 flounders. Seaweed has also been found in sea 

 robin stomachs. They bite greedily on any bait, 

 and are often taken with a spinner, or other 

 artificial lure. 



About Woods Hole the common sea robin 

 spawns from June to September with July and 

 August as the peak of the season. 63 But some may 

 spawn earlier, for we have examined females 

 taken at 50-55 fathoms off southern New Ens- 

 land at the end of January with eggs so large as 

 to suggest that they would be spawned by April 

 or May. Unlike the sculpin tribe, the robin 

 produces buoyant eggs, which are 0.94 to 1.15 

 mm. in diameter, slightly yellowish, with a vari- 

 able number (10 to 25) of oil globules of various 

 sizes, usually arranged in a more or less definite 

 ring. Incubation occupies about 60 hours at a 

 temperature of 72°, but any eggs that might be 

 spawned in the cooler water of our Gulf would be 

 slower in hatching. The newly hatched larvae 

 are 2.5 to 2.8 mm. long, with two transverse 

 yellow cross bands, one of these close behind the 

 pectoral fins, the other midway between vent and 

 tail. The yolk is absorbed, the mouth formed, 

 and the yellow markings no longer prominent in 

 5 days, at a length of 3 to 3.4 mm. The dorsal 

 and anal fin rays are visible and the lower pectoral 

 rays have separated from the remainder of the 

 fin at about 9 mm., and young fish of 25 to 30 

 mm. are darker, with transverse bands, and 

 already show most of the distinctive characters 

 of the adult. 



General range. — Coastal waters of eastern North 

 America from the Bay of Fundy to South Carolina; 

 chiefly west and south from Cape Cod. 



Occurrence in the Gulf of Maine. — Plentiful 

 though the sea robin is off southern New Eng- 

 land, 64 only a few are taken north of Cape Cod. 



«i We saw these catches which ranged from up to 5,000 fish per haul, in 

 54 trawl hauls. 

 •i One to one hundred and thirty sea robins per haul. 



— Kuntz and Radcliffe (Bull. U. S. Bur. Fish., vol. 35, 1918, p. 105-109) 

 give an account of its embryology and larval stages, subsequently confirmed 

 and supplemented by Welsh. 



" A catch of 1,000, in a day, in one trap, is recorded for Vineyard Sound, 

 and of as many as 3,000 to 5,000, per trawl haul, at 50 to 55 fathoms off southern 

 Massachusetts in winter. See footnote 61, p. 469. 



