834 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



(believe the egg not to be agglutinated). My observations have been 

 wholly confined to Crosswick's Creek, seven miles south of Trenton, N. 

 J. This stream is a tidal one, with an uninterrupted flow of about eight 

 miles, to the dam at Groveville. The rock-fish are taken in it, by both 

 nets and line-fishing, in considerable numbers. At the wharf at Abbott- 

 ville I have taken a dozen with a line in the course of a morning's fish- 

 ing. As is usual in such cases, they were associated with the white 

 perch, (Morone americana). My belief is, that the (comparatively speak- 

 ing) few adult fish that pass up the creek in March and April, accom- 

 panying the shad, breed in the upper cool waters of the stream ; for on 

 reference to my field-notes, I find records made of young rock-fish 

 taken in specimen nets as small as one and a quarter (1^) inches in 

 length; the capture bearing date of June 8, 12, 9, 11, and 13, of five 

 successive summers. These very young fish in every case were quite 

 abundant, and associated in large loose schools, as though a single 

 '•batch" had remained together, just as young cat-fish do, but without 

 the parent fish. They are easily recognized by the broad transverse 

 bands of bluish-gray, which remain more or less distinct until late in 

 autumn. I have seen these young rock-fish as late as October 13, 

 4| inches long, with these transverse bands still quite perceptible, 

 although not as clearly defined as in individuals of but half that size. 

 These young rock-fish do not content themselves with feeding exclu- 

 sively on young minnows, such as young Hyhopsis hifrenatus or R. 

 procne; but when they reach a size of 2 inches or but little more, will 

 readily seize a minnow as large as themselves, and, with a large pro- 

 portion of the captured fish protruding from its jaws, swim about for 

 several hours before rid of the annoyance, as it seems to be. Size for 

 size, young rock-fish are more voracious than young pike. 



It is a question whether the objections that have been so generally 

 raised against the pike are not equally applicable to the rock-fish, and 

 if it is not really undesirable to increase their numbers. That this can 

 be done there is no doubt whatever, as gravid females are easily obtained. 

 For stocking inland still-water ponds it is not suitable, and, all things 

 considered, where it would thrive it is not as desirable as the popular 

 black bass. 



To return to the river : If it is desirable to have an abundant supply 

 of shad and herring in the Delaware, then the rock-fish should be kept 

 down rather than protected with a view to its increase, for the ravages 

 they commit in August and September upon young shad, I am convinced, 

 is equal to the destruction caused by dams, fish-baskets, and illegal 

 fishing together. Perhaps I may err in this, but there can be no doubt 

 but that the chief natural enemy of the shad is the rock-fish. 



The rock-fish is easily captured with a hook and line, especially if 

 some care is exercised in selecting the bait. A minnow is the best bait 

 that can be used. In "trolling" for them in the Delaware, a silver 

 spoon-shaped disc, such as is used in blue-fish fishing, answers very 



