476 
Fishery Bulletin 11 5(4) 
Table 1 
Locations, numbers, and dates of sampling of female spiny dogfish (Squalus acanthias) off southern New England, between 
Massachusetts and Rhode Island, and off New Jersey from July 2013 to July 2015. 
No. of 
Month/Year 
General location 
Date 
Latitude (N°) 
Longitude (W°) 
samples 
July 2013 
Southern New England 
7/9/2013 
4104.47 
7137.01 
30 
August 2013 
Southern New England 
8/21/2013 
4108.18 
7119.16 
19 
Southern New England 
8/29/2013 
4103.44 
7129.24 
11 
September 2013 
Southern New England 
9/11/2013 
4102.58 
7123.01 
28 
October 2013 
No samples 
November 2013 
Southern New England 
11/5/2013 
4100.44 
7133.70 
30 
December 2013 
Southern New England 
12/8/2013 
4054.55 
7130.94 
30 
January 2014 
Southern New England 
1/29/2014 
4057.56 
7116.28 
30 
February 2014 
Southern New England 
2/9/2014 
4019.61 
7117.72 
23 
Southern New England 
2/26/2014 
4106.54 
7120.69 
7 
March 2014 
Southern New England 
3/25/2014 
4049.07 
7131.32 
6 
Southern New England 
3/24/2014 
4035.88 
7123.47 
8 
April 2014 
Southern New England 
4/21/2014 
4054.08 
7132.74 
30 
Southern New England 
4/22/2014 
4100.00 
7135.00 
31 
May 2014 
Southern New England 
5/27/2014 
4113.66 
7129.06 
31 
June 2014 
Southern New England 
6/17/2014 
4116.11 
7127.14 
42 
Southern New England 
4116.00 
7143.00 
July 2014 
Southern New England 
7/8/2014 
4113.48 
7128.45 
12 
Southern New England 
7/25/2014 
4100.40 
7133.97 
17 
August 2014 
Southern New England 
8/26/2014 
4100.12 
7137.83 
14 
8/25/2014 
4100.12 
7137.00 
16 
September 2014 
No samples 
October 2014 
New Jersey 
10/29/2014 
3947.43 
7358.87 
30 
November 2014 
Southern New England 
11/4/2014 
4116.68 
7124.79 
29 
December 2014 
New Jersey 
12/11/2014 
3950.00 
7401.00 
30 
January 2015 
Southern New England 
1/14/2015 
4059.24 
7113.29 
31 
February 2015 
Southern New England 
2/4/2015 
4051.59 
7132.05 
28 
March 2015 
No samples 
April 2015 
Southern New England 
4/7/2015 
4036.22 
7149.37 
32 
May 2015 
No samples 
June 2015 
Southern New England 
6/5/2015 
4113.45 
7141.31 
14 
Southern New England 
6/4/2015 
4114.30 
7139.00 
13 
traditionally caught (Fig. 1). Quantity, date, and loca¬ 
tion of sampling varied owing to fishing activity. 
Fecundity and litter characteristics 
Most spiny dogfish in- 551) contained embryos in the 
uteri. Of the samples without embryos (n=71), 64 were 
caught between January and April and all but 2 of 
these fish had mature ovarian follicles that were ready 
for ovulation. Those 2 females appeared to be matur¬ 
ing for the following mating season. Of the 7 remain¬ 
ing individuals: 4 appeared to have pupped owing to 
stress, 2 appeared to be maturing, and it could not be 
determined why the last individual did not have pups. 
A bimodal distribution of embryo sizes was observed 
in most months of sampling and indicated that some 
females were in the first year of gestation, while some 
were in the second year. In no case were candled (first 
year) and free-living (second year) embryos found in 
the same individual; therefore only 1 set of developing 
embryos was observed per female. 
A total of 2545 embryos, ranging in size from non- 
visible candled to term (30.8 cm STL), were examined. 
Of these, 1447 embryos were developed sufficiently for 
sex determination. Although individual litters were 
commonly seen to be predominantly of one sex, the 
overall sex ratio was 1:1 (733 female, and 714 male). 
Candled embryos were visible to the naked eye in June 
and had an average size of 0.21 cm STL and by Novem¬ 
ber they averaged 6 cm STL. Embryos averaged 19 cm 
STL by the following June. 
Fecundity was estimated by the number of develop¬ 
ing embryos in the uteri and the number of developing 
oocytes in the ovaries. Many of the dogfish, regardless 
of the stage of gestation, appeared to lose embryos be¬ 
fore dissection. Evidence for this consisted in observa¬ 
tions of pups being partially extruded through the clo- 
