MIDDLETON and MUSICK: ABUNDANCE AND DISTRIBUTION OF MACROURIDAE 



length interval, combined the head lengths in subsets 

 whose mean depths did not differ significantly from 

 each other, and defined the constituents of each 

 subset. 



Due to the large size and thickness of the macrou- 

 rid otoliths, standard age determination techniques 

 proved unsuccessful (Christensen 1964; McEachran 

 and Davis 1970). Therefore, a thin section was re- 

 moved from each otolith and, using a dissecting 

 microscope, the number of bands presumed to be an- 

 nual were counted and recorded. 



Gonads of the specimens were classified into repro- 

 ductive stages for analysis. The criteria for these 

 stages were as follows: 



Stage 1— Undeveloped. The gonads were immature 

 and no development was evident. The reproduc- 

 tive organs were difficult to distinguish within the 

 body cavity. 



Stage 2— Early Immature The reproductive organs 

 had enlarged slightly. The sex could be determined, 

 but no vascularization of the ovaries was apparent. 

 The organs of both sexes had a highly translucent 

 appearance. 



Stage 3— Immature The ovaries were enlarged and 

 vascularization had begun. The testes had become 

 discernibly "sausage shaped". The organs of both 

 sexes were opaque. 



Stage 4— Late Immature The reproductive organs 

 of both sexes were full size The ovaries were about 

 90% vascularized. The testes had become milky 

 white in color. 



Stage 5— Mature The reproductive organs were 

 developed completely. Ovaries were fully vascular- 

 ized and had a granular appearance. 



Stage 6— Ripe. Advanced spermatogenesis or 



oogenesis was evident. The oocytes were fully 

 developed in the females and the male testes con- 

 tained milky-white seminal fluid. 

 Stage 7— Spent. The testes and ovaries were spent. 

 The reproductive organs were flaccid and had 

 recently released sperm or eggs. 



RESULTS AND DISCUSSION 



Species Accounts 

 Coelorinchus c. carminatus (Goode 1880) 



Coelorinchus c. carminatus is a relatively shallow 

 water macrourid reported from depths of 89-849 m 

 (Marshall and Iwamoto 1973). In the study area this 

 species was captured in depths of 210-884 m (Fig. 

 3). Marshall and Iwamoto (1973) reported C. c. car- 

 minatus from northern Brazil to the Grand Banks, 

 but absent in the Bahama Island chain. The largest 

 specimen captured in our study had a head length 

 of 70 mm, while Marshall and Iwamoto (1973) 

 reported specimens with 73 mm HL. 



During our study, a maximum of 188 individuals 

 and 4 kg of C. c. carminatus were captured in a 0.5-h 

 trawl. This species also contributed as much as 34.2% 

 of the number and 27.8% of the biomass of benthic 

 fishes captured in individual samples. 



Figure 4 shows the depth distribution of C. c. car- 

 minatus incremented by 2 mm size groups. A slight 

 increase in head length with increase of depth was 

 apparent. The slopes of the regression lines were 

 shown to be significantly different from zero. The 

 coefficient of determination (Table 1) also showed a 

 correlation between head length and depth. There 

 was variability among cruises, but this may be at- 



_ 2 



S 



o 



o"n = 305 

 ? n = 422 



Coryphaenoides armatus 



-i 1 1 r 



-i r 



~r 



d*n = 156 

 $ n = 279 



Coryphaenoides rupestns 



10 20 30 40 SO 60 O 10 20 30 40 SO 60 70 80 90 100 



HEADLENGTH (mm) 



-i — i — i — i — i — 

 30 50 



100 



-I 



ISO 



200 



Figure 2.— The log (wt) versus head length regressions for Nezumia bairdii, Coryphaenoides armatus, and Coryphaenoides rupestris. 



37 



