Il8 BULLETIN OF THE BUREAU OF FISHERIES. 



LARWE. 



The newly hatched larva is approximately 5 millimeters in length. Considerable 

 coiling, obviously, is necessary in order that a fish of this length may be contained 

 within an egg only 1.25 millimeters in diameter. The larvae are very slender, having an 

 extremely long tail. They are very active, but for want of proper food or other causes 

 they lived only a short time (usually about three days) in the aquarium after hatching. 

 The yolk is completely absorbed by this time, but no important structural changes are 

 evident. The newly hatched fry are highly transparent, only a few yellowish-green 

 pigment spots being present. A few large spots occur on the upper surface of the head 

 and a row of smaller ones along the base of the ventral fin fold. Circulation, due to the 

 transparency of the newly hatched fish, can be nicely observed with a low power of the 

 microscope. The blood may be seen flowing through the aorta to the tail, then curving 

 sharply and returning through the caudal vein. One large blood vessel is still evident 

 on the small yolk yet remaining. The vertical fins appear as continuous folds, sur- 

 rounding the entire caudal portion of the body (fig. 93). Swimming appears to be accom- 

 plished by the very rapid vibration of the tail. The young fish has assumed practically 

 all of the characters of the adult when it reaches a length of 13 millimeters, and it is then 

 easily recognized (fig. 94). 



Menidia beryllina, SILVERSIDE. 

 ADULTS. 



This fish differs from M. menidia in the smaller size, in the shorter anal fin, which 

 consists of 16 to 19 soft rays, in the more anterior position of the dorsal fins, and in the 

 pale silvery peritoneum. It is much less abundant than M. menidia, and it inhabits 

 only fresh and brackish water in the vicinity of Beaufort, N. C, although it is reported 

 from salt water from other localities. It is fairly common in the mullet pond ?nd in 

 the fresh or brackish water creeks along the inland waterway and above the "narrows" 

 in Newport River. 



The females, as in the foregoing species, are somewhat larger than the males, reach- 

 ing an average length of about 61 millimeters and a maximum length of 72 millimeters, 

 while the males reach an average of only about 55 millimeters and a maximum length 

 of 65 millimeters. The ratio of the males to the females appears to be about equal. 

 The food of this species consists of small fish, small crustaceans, diatoms, and algae. 



SPAWNING. 



This fish, as does M. menidia, spawns throughout the summer, or from March to 

 September. The author has taken ripe or nearly ripe fish during March, April, May, 

 June, and July, but the small size of the young taken during October and November 

 indicates that it spawns as late as September. This species also selects shallow 

 water with an abundance of vegetation for its spawning ground. It is quite evident 

 that this fish, as does M. menidia, spawns several times during one season, for it has ova 

 of several sizes in the ovaries at one time, and when one lot of eggs is ripe those of the next 

 largest size are big enough to be plainly visible with the unaided eye. 



