FISHES OF THE GULF OF MAINE 



303 



deeper in winter, probably to avoid low tempera- 

 ture, for Hildebrand and Schroeder 49 found them 

 at depths of 5 to 27 fathoms at that season in 

 Chesapeake Bay. But this is not their universal 

 habit, for they are taken in winter through the ice, 

 as well as in summer, in the southern side of the 

 Gulf of St. Lawrence. And they are resident 

 throughout the year wherever found, generally 

 speaking. Such, at least, is the case along south- 

 ern New England. 



They are omnivorous, feeding chiefly on cope- 

 pods, mysids, shrimps, small decapod shrimps, 

 amphipods, Cladocera, fish eggs (including their 

 own), young squid, annelid worms, and molluscan 

 larvae. Insects, too, that fall into the water have 

 been found in their stomachs, as have algae and 

 diatoms mixed with sand and mud. On the other 

 hand, they are harried by every predaceous fish 

 that comes close inshore, especially by bluefish and 

 by striped bass. It was interesting in this connec- 

 tion to find that a dolphin (rare in the Gulf) , taken 

 at Sandwich, in Cape Cod Bay, in July 1951 (p. 

 361) was packed full of silversides. 



They spawn in May, June, and early July 4? on 

 the southern New England coast. Spawning may 

 begin a little later in the Gulf of Maine, corre- 

 sponding to more tardy vernal warming, while 

 Leim writes 48 that they do so in June at Prince 

 Edward Island. 



The gap in the presence of silversides in abun- 

 dance that seems to exist along the cool-water 

 stretch from the western side of the Gulf of Maine 

 to the southern side of the Gulf of St. Lawrence 

 (p. 304) suggests that they need summer tempera- 

 tures as high as 68° or so for successful reproduc- 

 tion. But young fry and adults alike are indiffer- 

 ent to temperatures down to a degree or two above 

 the freezing point of salt water, witness their 

 presence in winter in Cape Cod Bay (p. 304) and 

 below the ice in the bays on the northern side 

 of Prince Edward Island (p. 304). 



When the silversides are spawning they gather 

 in schools to deposit their eggs on sandy bottom, 

 often among the sedge grass at high tide, or 

 above low-water mark. Capt. John B. Smith has 

 described them spawning in the sedge at the head 



<• Bull. U. S. Bur. Fish., vol. 43, Pt. 1, 1928, p. 189. 



"Kuntzand Radcltffe (Bull. V. S. Bur. Fish., vol. 35, 1918, p. 127) de- 

 scribe Its development, and Hildebrand (Bull. U. 8. Bur. Fish., vol. 38[ 1921- 

 22] 1923 that of the southern race. For a recent account of Its life history see 

 Bayliffe, Pub. 90, Chesapeake Biol. Lab., Maryland Dept. Nat. Res. 1950. 



«• Proc. Nova Scotlan Inst. Scl., vol. 20, Pt. 2, 1940, p. 38. 



of Buzzards Bay, June 13, 1872, rolling from side 

 to side, some jumping clear of the water, and in 

 such multitudes that the water was "whitened 

 with the milt, and the grass was so full of eggs 

 that they could be taken up by the handfull," 

 while small fishes of various kinds were "helping 

 themselves to the dainty repast." 49 



Figure 160.— Egg. 



Figure 161. — Larva, 8 mm. 



Figure 162.— Fry, 13 mm. 

 Silverside (Menidia menidia). After Kuntz and Radcliffe. 



The eggs, 1.1 to 1.2 mm. in diameter and each 

 bearing a bunch of sticky filaments, sink and stick 

 fast in ropy clusters or sheets. Incubation occu- 

 pied 8 or 9 days in the laboratory at Woods 

 Hole. The yolk is absorbed before hatching, at 

 which time the larvae are about 3.85 to 5 mm. 

 long, and the dorsal, anal, and caudal fins are 

 formed in larvae of 12 to 15 mm. in length. The 

 young grew to a length of 9.3 to 11.7 mm. during 

 the first 20 days in the aquaria. Probably they 

 grow more rapidly at liberty, for all sizes from 

 fry of an inch or less to adults are to be found 

 throughout the summer. Probably the silverside 

 attains maturity at 1 year of age. 



General range. — The northern variety of this 

 silverside is common locally from the southern 

 side of the Gulf of St. Lawrence and the outer 



«Qoode. Fish. Ind. U. S. Sect. 1, 1881, p. 467. 



