78 



DEPARTMENT OF THE NAVAL SERVICE 



Whether Zoarcvs angvillaris resemlbles Zoarces vivipauvs in being ovoviviparovis 

 has not been determined. Goods (loc. cit.) states that the fish spawns in July and 

 August in the deep waters of Massachusetts bay, bvit gives no evidence in supjwrt 

 of his statement. 



Mcintosh (loc. cit.) states that Zoarces viviparus in Scottish waters may liberate 

 young up to the lengh of 4-5 cm. Va:n Bambeke (loc. cit.) states that females of this 

 epecies from 30-39 cm. in length contain from 200-400 young. Fryd (loc. cit.) gives 

 about 100 young for specimens 30 cm. in length, and 206 for a specimen 37-7 cm. in 

 length. Bridges (1904) gives the number of young produced as 20 — 300 or more 

 (according to the size of the female and adds that the eggs hatch in about 20 days, aiid 

 the young are not born until about four months after fertilization when they are 

 .about IJ inches long. It is apparent that a much smaller number of eggs mature in 

 Zoarces viviparus than in Zoarces anguUlaris. If the muttonfish is ovoviviparous it 

 is not probable that it would retain 1,800 you-ng until they attain a length of 4-5 cm. 

 They would probably only be about 1 or 1-5 cm. in length when liberated since the 

 young reach a length of only 2-5 to 3-7 cm. by April. It is unlikely that this short 

 period would have any relation to the first light area surrounding the " nucleus " of 

 the otolith. 



7. EELATION OF TEMPERATUEE TO THE PERIODS OF MIGRATION 



AND REPRODUCTION. 



The extremes of temperature for the bottom waters of the St. Croix river, Passa- 

 maquoddy bay and the Bay of Fundy in 1916 and 1917 are shown in the following 

 table. The writers are indebted to Professor A. Vachon, Laval University, for these 

 records. 



Locality. 



St. Croix river 



Passamaquoddy bay 

 Bay of Fundy 



Date. 



Mar. 15, 1917 



" 28, 1918 



Feb. 23, 1917 



Mar. 21, 1918 



Feb. 28, 1917 



Mar. 20, 1918 



Lowest 

 Temper- 

 ature. 



— 03 

 -•27 

 — 10 

 -•74 

 -^•49 

 + •70 



Date. 



Sept. 6, 1917 



" 19, 1918 



" 6, 1917 



Sept. 22, 1917 



" 9, 1918 



Highest 

 Temper- 

 ature. 



10-48 

 10-94 

 10-02 



923 

 9-78 



Depth. 



30 m. 

 30 m. 

 30 m. 



The sexually mature muttonfish leave the St. Croix river and Passamaquoddy bay 

 about the end of July, and the remainder probably have left by the end of October. 

 The height of the outward migration therefore occurs at the period of highest 

 temperature. The inward migration probably begins early in April, which is the 

 time when the temperature of the water in the St. Croix river and Passamaquoddy 

 bay goes above 0° C. Fertilization of the eggs probably occurs in September 

 which is the period of highest bottom temperature. There is thus a coincidence 

 between the temperature extremes and the migration periods, but whether or not 

 there is a causal relation it is impossible to decide at the present time. 



8. RELATION OF WEIGHT TO AGE, LENGTH AND SEX. 



The following table shows the relation of the weight to the age and length and 

 gives the probable average increase in weight for each year. 



