WENNER: BIOLOGY OF DEEP-SEA LOBSTERS 



Figure l. — Abundance oi Stereomastis nana and S. scuplta by depth, expressed as tog U + 1) 

 per 0.5 h tow, where x is number of individuals. Ratios over bars indicate number of stations 

 where Stereomastis spp. were captured to total number of stations within depth intervals. 



Table 2. — Summaries for three depth strata of morphological and reproductive data on Stereomastis nana and S. sculpta from the 

 continental slope, .v = arithmetic mean; SCL = short carapace length in millimeters; 95'7f confidence limits (CL* follow the means. 

 Percent ovigerous females is based on total female samples only. 



'ND = no data 



Table 3. — Chi-square test for goodness of fit. using Yates correc- 

 tion for continuity of male: female ratios of Stereomastis nana 

 and S. sculpta by depth interval. 



Depth 

 interval (m) 



Frequency 



Sex 



S nana S sculpta S nana S sculpta 



phores from these individuals were dislodged 

 during capture. Thirty-seven male S. nana >19 

 mm were also found with a hardened secretion of 

 spermatophores projecting out of the gonopore at 

 the base of the fifth pereopod (Figure 2). Ovigerous 

 females, nonovigerous females, and males with 

 external spermatophores occurred at all depths, 

 with maximum numbers at 1,400-2,199 m. No 

 males or females with external spermatophores. 

 and only one ovigerous female occurred deeper 

 than 2,400 m. 



By examination of ovaries, I defined six stages of 

 ovarian development in Stereomastis spp. (Figure 



437 



