Peemoeller and Stevens: Age, size, and sexual maturity of Busycotypus canaliculatus in Buzzards Bay, Massachusetts 
267 
(1998). Whelk from different sites were mixed; 
sites sampled in 2010 were mostly in eastern 
Buzzards Bay, and those sites sampled in 2011 
were mostly in western Buzzards Bay. Because 
we mixed whelk from a large number of sites, we 
did not measure water temperature at individual 
sites; instead, seawater temperatures were exam- 
ined from the NOAA Data Buoy Station BZBM3, 
at the Northeast Fisheries Science Center dock 
in Woods Hole, Massachusetts (NOAA station 
8447930, http://www.ndbc.noaa.gov/station_his- 
tory.php?station=bzbm3). 
We measured whole wet weight (Wt) of shell 
and tissue to the nearest 0.1 g, SL to the nearest 
0.1 mm, and lip width (LW, maximum distance 
across the upper edge of the largest whorl) to 
the nearest 0.1 mm. Length of the male copula- 
tory organ (penis length), measured to the near- 
est 0.1 mm, was recorded for 93 males only in 
2011. We also measured the SW for the first 166 
whelk. Although SW is very similar to the mea- 
surement used by fishermen and managers for 
the minimum size limit, channeled whelk have 
an asymmetrical shell structure, and there is no 
standard procedure for measuring SW. We used 
LW instead of SW as our primary width mea- 
surement because it was more easily replicated 
and more precise than SW; the mean coefficient 
of variation for whelk in 5 -mm intervals of LW 
was 2.14 times greater for SW than for LW, with 
a range from 1.21 to 4.13 for SW. 
For this study, 292 channeled whelk (155 fe- 
males and 137 males) were sampled through the 
random selection of at least 20 whelk of various 
sizes in each 10-mm-SL interval. In 2010, we 
filled most of our SL intervals except for the in- 
tervals for very small (<100 mm SL) and very 
large (>190 mm SL) whelk. In 2011, we focused 
on the collection of whelk from these unfilled SL 
intervals to extend the sampling range for this 
study. After whelk were weighed and measured, 
we cracked their shells with a hammer to deter- 
mine sex. Males were defined as those whelk with a 
penis, and females were defined as those whelk with 
a nidamental gland. Scissors were used to separate 
the gonad from the digestive gland (gonads were not 
weighed). We removed the entire gonad from smaller 
whelk (<120 mm SL), and larger whelk had an ap- 
proximately 2-cm section removed from the terminal 
end of the gonad (closest to the tip of the shell spire) 
to the start of the gonad (closest to the operculum). 
Gonads were stored in 10% formalin for 1 week before 
they were transferred to 80% ethanol (EtOH) (Stoner 
et al., 2012). 
Age analysis 
Opercula from our dissected channeled whelk were re- 
moved with a scalpel, labeled, and stored in 10% for- 
Figure 1 
Map of approximate capture sites (gray circles) of channeled whelk 
(Busycotypus canaliculatus ) collected in August 2010 and July 2011 
in Buzzards Bay, Massachusetts. Specimens came from numerous 
sites within Buzzards Bay; however, capture site was not recorded 
for each whelk, 
malin for 1 week, and then transferred to 70% EtOH. 
Whelk opercula were taken out of EtOH, bleached for 
30 min with 5% sodium hypochlorite, and then blotted 
dry with paper towels. Annuli were defined as growth 
striae that form on the interior margin and extend 
across the operculum to the exterior margin (Fig. 2; 
Bruce et al. 3 ). The first annulus of each operculum gen- 
erally had a 6-mm linear distance that ranged from 
the interior to the exterior margin. To count annuli, 
opercula were placed under a light source and pho- 
tographed with an Olympus Stylus 400 4 4-megapixel 
digital camera (Olympus Optical Co., Ltd., Center Val- 
ley, PA). Opercula did not dry and curl during this pro- 
4 Mention of trade names or commercial companies is for iden- 
tification purposes only and does not imply endorsement by 
the National Marine Fisheries Service, NOAA. 
