13 .-THE EMBRYOLOGY OF THE SEzV BASS (SERRANUS ATRARIUS). 
BY HENRY V. WILSON, PH. D., 
Assistant, U S. Fish Commission. 
(Plates Lxxxvni to cvii and 12 figures in text.) 
INTRODUCTION. 
The following paper, dealing with the embryology, forms part of a monograpli on 
the Sea Bass in course of preparation under the direction of the United States Com- 
missioner of Fisheries, Hon. Marshall McDonald. The monograph will contain, be- 
sides the embryology, a description of the larval development and of the adult fish, 
an account of the habits and distribution of the fry and the adult, and an account of 
the Bass viewed as a food-hsh from an economic standpoint. 
As might be inferred from its wide distribution along the Atlantic coast, all the 
way from Cape Cod to Florida, the Sea Bass is known under a variety of popular 
names. South of Cape Hatteras it is called Blacktish, in the Middle States “ Black 
Will,” “ Black Uarry,” and Hannahills.” Sea Bass is the common name along the 
New England coast.* 
My work on the bass was carried on at the Wood’s Holl Station of the Fish Com- 
mission. It was begun in May, 1889, and has been continued without interruption to 
the iiresent time. The bass makes its appearance in the neighborhood of Wood’s 
Holl (Buzzard’s Bay and Vineyard Sound) about the middle of May, and the spawning 
season lasts from that time until near the first of July. The fish is one of several 
(mackerel, scup, tautog, etc.), which at this season are reared in the hatchery of the 
Wood’s Holl Station, and I was therefore able to obtain, with the least amount of 
trouble, as complete a set of material as could be desired. The collector, Mr. Viual 
Edwards, visits the fish “iiouuds” in the neighborhood every morning at the time 
when the fish are taken out. Any fish that are found to be ripe are at once “ spawned,” 
i. e., the eggs are pressed out into jars of sea water, with which milt is then mixed. 
The eggs thus fertilized are brought as quickly as possible to the hatcheiy and are 
placed in “tidal” jars or boxes, in which the water alternately rises and falls. The 
eggs during most of the period of incubation float at the surface of the water, but, as 
in the case of some other species of fish, there is a short period of time, not long 
before hatching, when they sink as though they were dead. The specific gravity, 
* The Fisheries aud Fishery Industries of the United States, Section I, 1884, p. 407. 
Bull. U. S. F. C. 89 14 
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