Eggs of Atlantic silverside, Menidia menidia, were fertilized and incubated at 15, 17, 20, 25 and 30 C. The times to hatching at each temperature were 27.0, 12.4, 9.8, 4.8 and 3.0 days respectively. Thermal shocks of +8 C produced 0% mortality for larvae reared at 17 and 20 C, 19% for larvae reared at 25 C, and 11% for larvae reared at 30 C. Thermal shocks of q-•[4 C produced 3% mortality for larvae reared at 17 C, 0% for larvae reared at 20 C, and 100% for larvae reared at 25 and 30 C. Since the larvae of Menidia menidia are present in Long Island Sound when temperatures are in the 15-20 C range, it appears that the population will undergo a minimum of stress due to thermal shock as a result of nuclear power plant development on Long Island.

Hematological variables including erythrocyte numbers, hematocrit, osmotic fragility, differential leucocyte count, and cellular morphology were studied in wild (freshly caught) cunners Tautogolabrus adspersus, and compared with those of cunners held in captivity for 4 days. Statistically significant differences were found between wild and captive fish and between the sexes of wild fish. In captive fish, values for erythrocyte (RBC) numbers, hematocrit, mean erythrocyte volume, osmotic fragility, lymphocytes, eosinophils, and the incidence of degenerating RBCs were depressed, whereas values for immature RBCs, fine granulocytes, and immature fine granulocytes were increased compared with wild fish. Captive male cunners showed more pronounced changes in the incidence of immature fine granulocytes (increased) and hematocrit (depressed) than did females. The hematocrit appears to be a good variable for assessment of erythrocyte hematological status in cunner, based upon significant differences between groups of fish and on significant correlations between hematocrit and erythrocyte numbers. Survival of test fish was 95%. These results and methods should be useful in future studies of cunner, especially if recent interest in its use for pollution monitoring continues.

No abstract

During a one‐year marine ichthyofaunal study of Northport, New York, only one abnormal fish was taken, a striped bass, Morone saxatilis. This 3‐year‐old fish, lacking a lower jaw and part of the upper, was apparently injured between its second and third year of life, as evidenced by much reduced scale formation during that period. The fish, measuring 260 mm standard length and weighing 291.1 grams, was much smaller than normal fish of comparable age, being nearer the size of 2‐year‐old fish. This stunted growth was presumably due to reduced feeding ability resulting from the injury.