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Fishery Bulletin 111(3) 
sachusetts and to sustain the fishery for this species. 
The minimum size limit was established by the State 
of Massachusetts on the basis of the size of market ac- 
ceptability (Glenn and Wilcox 1 ). With increased fishing 
pressure and limited biological information, channeled 
whelk can easily become overfished, especially if they 
are not able to reproduce before they enter the fishery. 
The channeled whelk ranges from Cape Cod, Mas- 
sachusetts, to Cape Canaveral, Florida (Edwards and 
Harasewych, 1988). Growth rate and size at maturity 
for channeled whelk are virtually unknown, but whelks 
of the family Melongenidae typically are slow growing, 
late maturing animals. In the seaside lagoons of Vir- 
ginia, knobbed whelk reach a mean size of 176.1 mm 
SL in 9-11 years (Kraeuter et ah, 1989). In South Caro- 
lina, knobbed whelk <90 mm SL grow faster than larger 
whelk (up to 7 times faster), although some knobbed 
whelk have minimal or negative growth (Eversole et 
ah, 2008). It has been suggested that channeled whelk 
have low fecundity because they lay egg strings only 
once a year (Edwards and Harasewych, 1988). Betzer 
and Pilson (1974) reported an annual change in gonad 
index (fresh weight of the gonad/fresh weight of whole 
soft tissues) of channeled whelk in Narragansett Bay, 
Rhode Island, with spawning most likely occurring in 
late summer and fall. No studies have been published 
that provide the spawning season of channeled whelk 
or the environmental factors, such as temperature and 
salinity, at which they spawn. In a study of this species 
in aquaria, channeled whelk began hatching from an 
egg string on 18-30 April 2010 at water temperatures of 
15-18°C; the egg string was collected on 1 March 2010 
near Cedar Island, Virginia (Harding, 2011). 
Channeled whelk may have a similar reproductive 
cycle to that of knobbed whelk. On intertidal flats in 
Virginia, knobbed whelk copulated in June and July and 
laid egg strings from mid-August to November; hatch- 
ing occurred from mid-March to early May (Castagna 
and Kraeuter, 1994). Knobbed whelk egg cases found in 
Cedar Island, Virginia, in 1977 yielded an average of 
3770 whelk per string (Castagna and Kraeuter, 1994). 
However, information on the fecundity of channeled 
whelk is needed. The mode of reproduction for whelks 
also needs investigation because Castagna and Kraeu- 
ter (1994) suggested that knobbed whelk may be pro- 
tandrous hermaphrodites. Knobbed whelk raised in a 
laboratory were all males at 9 years, but, after 13 years, 
some males changed sex, and at the age of 14 years, pro- 
duced viable offspring (Castagna and Kraeuter, 1994). 
This outcome is contrary to the findings of Avise et al. 
(2004), who determined that knobbed whelk are geneti- 
cally dioecious and sex is determined at birth. 
Aging opercula gives insight on the growth and lon- 
gevity of channeled whelk. llano et al. (2004) reported 
that striae form annually on the operculum of Bucci- 
num isaotakii and can be used to estimate age. Heude- 
Bertherlin et al. (2011) counted the number of striae 
on the operculum of waved whelk ( Buccinum undatum ) 
to determine age. Kraeuter et al. (1989) aged knobbed 
whelk by embedding opercula in plastic resin and then 
sectioning them. For validation of aging, they used labo- 
ratory-reared knobbed whelk and embedded the opercu- 
la of 3 knobbed whelk of 6+ years and 3 knobbed whelk 
of 7+ years. Kraeuter et al. (1989) reported the average 
ages of these knobbed whelk at 6.0 and 7.2 years, re- 
spectively. Another aging technique involves bleaching 
knobbed whelk opercula and counting annuli (Bruce et 
al. 3 ). In the opercula of older knobbed whelk, Power et 
al. 2 found a “bubbling effect,” from growth ring overlap, 
due to decreased growth rates. 
There are no published reports on the histological 
staging of channeled or knobbed whelk gonads. We be- 
gan this study to provide useful biological information, 
such as size and age at sexual maturity, for managers of 
the channeled whelk fishery in Massachusetts. Data on 
the size at sexual maturity will provide managers with 
information needed to set minimum size limits that al- 
low females to spawn at least once and, therefore, to 
help prevent overfishing (Gordon, 1994). We sampled 
channeled whelk in Buzzards Bay, Massachusetts, and 
expected that they would be protandrous hermaphro- 
dites as reported for laboratory-reared knobbed whelk 
by Castagna and Kraeuter (1994). We hypothesized that 
SL would increase with age and that slower growth 
would occur at older ages. We provide the first informa- 
tion on the relationship between size, age, and stages 
of gonad development for channeled whelk and on the 
size and age at 50% maturity (SM50) of male and female 
channeled whelk. 
Materials and methods 
Sampling 
Sampling was conducted off Massachusetts in Buzzards 
Bay, a large, semi-enclosed estuary in the northeastern 
United States (Fig. 1). Buzzards Bay is uniformly shal- 
low, with depths mostly at 10-15 m, and is open to 
the sea at multiple locations. As a result, the water 
column in this bay is extremely well mixed, and differ- 
ences between surface and bottom temperatures rare- 
ly exceed 1°C, and salinities are almost uniformly 30 
ppt (Turner et al., 2009). Commercial wooden or wire 
mesh conch traps, baited with the Atlantic horseshoe 
crab ( Limulus polyphemus), were used to collect chan- 
neled whelk from Buzzards Bay in August 2010 and 
in July 2011. Traps varied in size but were generally 
50x50x30 cm, and they were set at depths of 10-15 m 
at 10-12 different sites in each year to maximize catch- 
es. Traps were allowed to soak for 1 week, and they 
were retrieved weekly over a 4-week period each year. 
Channeled whelk were identified according to Pollock 
3 Bruce, D. G., R. Wong, and M. Greco. 2006. Delaware Bay 
whelk (conch) fishery assessment 2005, 36 p. Delaware Di- 
vision of Fish and Wildlife, 89 Kings Highway, Dover, DE 
19901. 
