NOTES ON HABITS AND DEVELOPMENT OF EGGS AND 

 LARWE OF THE SILVERSIDES MENIDIA MENIDIA AND 

 MENIDIA BERYLLINA. 



By SAMUEL F. HILDEBRAND, 

 Assistant, U. S. Bureau of Fisheries. 



& 

 Contribution from the U. S. Fisheries Biological Station. Beaufort, N. C. 



INTRODUCTION. 



The present paper embodies the results of observations made on eggs, larvae, and 

 adults of the silversides Menidia menidia and Menidia beryllina. All observations 

 were made on living or fresh material, in the immediate vicinity of the Fisheries Biologi- 

 cal Station, Beaufort, N. C, and they extend over a period beginning in April, 1914, 

 and ending in August, 1916. 



The eggs used in this work were artificially spawned and hatched in the laboratory. 

 The descriptions and drawings are offered with the view of affording means of identi- 

 fving the eggs and larva? with the adult. The two closely related species under consid- 

 eration are compared and contrasted in order to show likenesses and differences in their 

 habits and development. 



Menidia menidia, SILVERSIDE. 

 ADULTS. 



This fish belongs to the family Atherinidae, the silversides, which arc elongate 

 shapely fishes with a silvery lateral stripe. Most of them are of small size, inhabiting 

 fresh or salt water of temperate or tropical latitudes, and they usually run in I 

 schools. The genus Menidia may lie distinguished from related genera by the strongly 

 curved premaxillary, the narrow bands of teeth on the jaws, the short lower jaw, which 

 is included in the upper when the mouth is closed, the rounded abdomen, and the smooth, 

 firm scales. There are only two species of the genus known from North Carolina waters. 

 The present species may be distinguished from Menidia beryllina, the other species, by 

 the larger size, by the longer anal fin, which consists of one spine and 21 to 26 soft rays, 

 by the more posterior position of the dorsal fins, and by the black peritoneum. 



This species is exceedingly abundant in the vicinity of Beaufort, X. C, inhabiting 

 both salt and brackish water, and it is the only fish which occurs in large numbers in the 

 shallow waters throughout the winter. Large schools may be seen along the shores of 

 Pivers Island during the coldest days, when practically all other fishes have migrated to 

 deeper water or to a warmer latitude. 



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