56 FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



to become partially embedded in the mesenteries, but the infection never appears to 

 be serious. Goezia annulata, although comparatively rare, is probably a much more 

 serious pest. MacCallum (1921: 261) says: 



Its mode of living is calculated to interfere very materially with the function of the stomach, 

 inasmuch as it burrows under the mucous membrane, in fact excavating in some cases quite a space 

 where several worms cohabit. . . . There are often several of these nests in the stomach, each 

 nest may be 30 mm. to 40 mm. across, and as they cause a good deal of swelling and irritation, 

 they may and do in some cases so restrict the cavity of the host's stomach that its food cannot be 

 taken in any quantity sufficient to keep it alive. Thus the worms are a very serious menace to 

 the fish. 



This species is not common in striped bass, however, and according to reports is quite 

 cosmopolitan in its choice of host, having been recorded from many other species of 

 fish. Trematode infections are probably sufficiently rare in striped bass in their 

 natural habitat to be of small importance. Nigrelli and Breder (1934) have shown 

 that many of the Serranid fishes have developed a. resistance to Epibdella melleni, 

 while Jahn and Kuhn (1932) noted that "... the possibility of the development of 

 immunity seems to be more strongly suggested in this family" (Serranidae) . Copepod 

 parasites are also apparently of small consequence to the striped bass. 



It is worth mention that a surprising number of striped bass were encountered 

 in the Thames and Niantic Rivers, Conn., that had cataracts of the eye. These were 

 found commonly only in the Thames River, where they sometimes reached above 10 

 percent of the catch by seine. This opacity of the lens was encountered in all degrees 

 from a slightly cloudy to a dead-white condition. It was almost universally bilateral, 

 was rare in 2-year-old bass, and more common in the larger sizes. It was equally 

 common in all months from April to October. A number of dissections under low- 

 power magnification failed to reveal any parasites, such as larval digenetic trematodes, 

 which might reasonably be expected to cause such blindness. Hess (1937) has recently 

 shown that bilateral cataracts are common in trout in New York State, both in hatch- 

 ery and wild stock, and he has proved with rainbow trout (Salmo irideus) ". . . that 

 cataract in these fish is due to an unbalanced diet." He has been able to demonstrate 

 that contagious infection, light, and hereditary factors, are not in any way connected 

 with the production of such cataracts, and that the feeding of trout exclusively on pig 

 spleen caused a high incidence of cataract; while trout fed with beef liver and heart 

 never showed any trace of cataract. It seems likely, therefore, that a dietary deficiency 

 may perhaps account for the high percentage of blind striped bass in the Thames 

 River. It is interesting in this connection that the extraction of carotene by acetone from 

 the liver and fatty tissue of blind and normal bass has tended to show less carotene 

 per gram of tissue in the blind than in the normal individuals, and it is thus possible 

 that a lack of vitamin A is associated with the dietary deficiency causing cataracts. 



It is also of interest that Schultz (1931) has recorded a case of what gave every 

 appearance of being completely functional hermaphroditism in the striped bass. 

 This fish was taken in Oregon in May, and the eggs in one half of the gonads measured 

 about 1 mm. in diameter, close to the size at the time of spawning (see p. 19), while 

 the male half of the gonads was apparently developing normally. 



DISCUSSION 



It has been pointed out that there has been a striking decline in the numbers of 

 striped bass along the Atlantic coast over long-term periods. (See under section on 

 fluctuations in abundance of the striped bass, p. 8, and figs. 3 and 4.) The records 

 show that this decline has been fairly steady from at least as far back as the middle of 

 the nineteenth century, and perhaps before. They also indicate that it has been 

 interrupted only by the occasional appearance of dominant year-classes — groups of 

 striped bass that were produced in such huge amounts in certain years that they caused 

 a marked increase in the numbers caught for short periods (see p. 8, et seq.). It is 

 apparent from the available catch records (see fig. 4), however, that these dominant 

 year-classes did not bolster the stock for more than a few years, and that their effects 

 invariably have been short lived. In other words, the surplus created by them was 

 soon removed, no permanent increase in abundance — and a consequent permanent 

 increase in catch — resulted, and the decline in numbers of striped bass, although tem- 

 porarily interrupted, soon resumed its normal trend. 



