Stevens and Guida: Biological paranneters of Chaceon quinquedens in the Mid-Atlantic Bight 
351 
depth of 288 m. There was no relationship between tem- 
perature and size (CL) of male crab (F=0.833, coefficient 
of determination [r2]= -0.0001, P=0.362, df=1189), but 
size of female crab increased with temperature (F=31.3, 
r2=0.018, P<0.001, df=1622). 
Sex ratios (M:F) varied greatly both among sizes 
and between sampling sites. For pairs in the smallest 
size group for their sex (females: 55-60 mm CL; males: 
75-80 mm CL) and in which females carried eggs, sex 
ratios ranged from 2.1 to 3.6; however, for the interval 
in which female sexual maturity occurs (60-65 mm CL), 
ratios exceeded 1.0 only at sites BIC and Nor (Fig. 7). 
For females between 70 and 80 mm CL, only site BIC 
had a sex ratio >0.5, and ratios at all other sites were 
<0.4. For females >80 mm CL, there were no sites or size 
categories where sex ratios exceeded 0.1. At female sizes 
above 60 mm CL, crab at sites BIC and Nor generally 
had higher sex ratios than crab at sites Hud or BWC. 
Female maturity and ovigerity 
The smallest female with external eggs was 58.5 mm 
CL. Logistic regression of maturity, based on gono- 
pore condition, showed that the SM 50 was 61.6 mm 
CL (SE 0.1), equivalent to 78.2 mm SW (Fig. 8 ). In 
January 2012, 33.3% of mature female crab 
were ovigerous, and the maximum propor- 
tion exceeded 50% only in the size group 
of 95-100 mm CL (Fig. 9). In contrast, in 
July 2013, only 5.9% of mature female crab 
were ovigerous, and the maximum propor- 
tion was 17.9% in the size group of 80-85 
mm CL. Analysis of egg samples taken in 
July 2013 indicated that 80% of eggs were 
at stage 6 (prehatching or hatching stage), 
whereas 20 % of eggs were at stage 1 (early 
cell division). 
Discussion 
Our results add significantly to previous 
studies of red deepsea crab. Wigley et al. 
(1975) sampled extensively off the southern 
New England shelf but included only 2 sta- 
tions off the Maryland coast, and all sites 
sampled by Wahle et al. (2008) were north 
of Delaware Bay (at approximately 38°40'N). 
We sampled 2 sites (BWC and Nor) that were 
farther south and that represent locations 
that are targeted heavily by the current 
commercial fishery. In addition, we captured 
about 10 times more crabs than Wigley et 
al. (1975) and twice as many as Wahle et 
al. (2008), and we sampled twice as many 
females as Haefner (1977). Our report is the 
first to conduct detailed analysis of morpho- 
metries of the red deepsea crab and the first 
to provide detailed information on distribu- 
tion by temperature and shell condition. 
Catch and density 
Tows made during our cruises were not optimized for 
estimating abundance of red deepsea crab because the 
net was not outfitted with mensuration gear to mea- 
sure the net width or bottom contact. As a result, area 
towed was estimated on the basis of the operator’s 
(subjective) estimate of contact time, distance towed, 
and average net width. Furthermore, differences in 
vessel characteristics, operational protocols, and net 
efficiency make any direct comparisons with previous 
surveys questionable. The trawl nets we used had a 
belly mesh of 6 cm and smaller mesh codend liners 
than those in nets with 3.8-cm mesh used by Wigley 
et al (1975) and Wahle et al (2008), but all trawl nets 
caught a similar size range of crab and few crab <50 
mm SW. Nonetheless, because there are no other esti- 
mates of density of red deepsea crab, our data can be 
compared with previous estimates in a relative context. 
Two of our sites (Hud and BWC) overlap with the 
area defined as “geographic zone A” by Wigley et al. 
(1975) (referred to as “sectors” by Wahle et al [2008]). 
Therefore, we estimated biomass density of red deepsea 
crab separately within each depth stratum over those 2 
