FISHERY BULLETIN: VOL. 75, NO. 1 



TABLE 1. — Trawling gear used by the RV Oregon II during slope 

 fishery surveys in the Gulf of Mexico and Caribbean Sea from 

 June 1969 through September 1973. 



TABLE 2. — Gonad classification code — modified from Nikolsky 



(1963). 



Trawl size 



(headrope length) 



(m) (feet) 



Door size 

 (length x width) 

 (m) (feet) 



Type of door 



12 

 22 

 38 



40 



46 



58 



62 



68 



40 



71 



125 



130 



150 



191 



204 



224 



2.4 x 1.03 

 3 x 1.12 

 3 x 1.22 



3 x 1.22 



3 x 1 .22 



3 x 1 .22 



3 x 1 .22 



3 x 1.22 



8 x 3.33 

 10 x 3.67 

 10 x 4 



10x4 



10 x 4 



10x4 



10 x 4 



10 x 4 



Wooden chain 

 Wooden chain 

 Iron bound wooden 



bracket 

 Iron bound wooden 



bracket 

 Iron bound wooden 



bracket 

 Iron bound wooden 



bracket 

 Iron bound wooden 



bracket 

 Iron bound wooden 



bracket 



Specimens were measured at sea to the nearest 

 millimeter standard length (SL). Additional 

 specimens were frozen for processing ashore, and 

 were measured in standard, fork, and total lengths 

 (SL, FL, and TL) for computation of a conversion 

 curve and were also processed for length-weight 

 relationship, gonad maturation, and stomach 

 content data. Gonad maturation stages were 

 classified by a scheme modified from that by 

 Nikolsky (1963) and are listed in Table 2. Ovaries 

 were weighed to the nearest 0.1 g. Otoliths re- 

 moved from selected specimens (one specimen per 

 centimeter SL) were prepared and evaluated 

 following Jensen (1965). Morphometric and 

 meristic measurements were taken as defined by 

 Ginsburg (1954). 



Age-class lines were computed using techniques 

 described by Harding (1949) and Cassie ( 1954) and 

 compared with ages determined from length- 

 frequency data. 



Weights were recorded to the nearest ounce on 

 specimens larger than 200 mm SL and to the 

 nearest 0.1 g on smaller fish. The method of least 

 squares using the log transformation of the gen- 

 eral equation W = aL b was used to compute the 

 length-weight equations for males, females, and 

 sexes combined. 



The sample design for RV Oregon II cruise 27 

 allowed for equal effort per stratum regardless of 

 stratum size, because distributional patterns and 

 abundance levels of M. albidus were undefined. 

 The sample area (Figure 1) on the De Soto Canyon 

 slope north of Tampa, Fla., was divided into four 

 90-m depth strata ranging from 370 to 730 m. 

 Each stratum was then further subdivided into 2.5 

 x 15 nautical mile sample sites (12,874 hectares 

 per site). The entire sampling area of 84 sites 



U-1 



Female: 

 F-2 



F-3 



F-4 



F-5 



F-6 



Male: 

 M-2 



M-3 



M-4 



M-5 

 M-6 



Gonads undeveloped, vestigial tubes, sex determination impossible 

 by gross examination 



Immature gonads, sex determinable by gross examination, gonads 

 very small, uninflated 



Developing gonads, small yellow or white with no eggs visible to the 

 naked eye 



Maturing gonads, filled with opaque yellow to yellowish-orange eggs 

 detectable by the naked eye 



Ripe gonads, ovaries with translucent yellowish-white to whitish- 

 green eggs easily expelled from the genital opening by lateral pres- 

 sure on the gonads 



Spent gonads, ovaries collapsed and bloodshot with some eggs being 

 reabsorbed 



Immature gonads, sex determinable by gross examination, testes 



very small, uninflated 



Developing gonads, inflated to the same degree as those of F-3 



females and white or whitish-pink in color 



Maturing gonads, inflated to same degree as those of F-4 females and 



milky white without free running milt 



Ripe gonads, fully developed with free running white milt 



Spent gonads, collapsed and bloodshot 



totaled 1,081,416 hectares. Five sample sites were 

 randomly selected within each 90-m depth 

 stratum from a number table; however, only four 

 sites were sampled in stratum 4 due to a mal- 

 function of the trawl. No special consideration in 

 site selection was given to latitude. 



Each sample site was fished with a 40-m trawl 

 (Table 1) for 5 h at 3 knots with a 2.5:1 scope ratio 

 (i.e., 2.5 m of wire out for each meter of depth). 

 Drag distance was variable because of changes in 

 the surface and bottom currents. Area swept in 

 hectares per drag was computed by measuring the 

 distance between the starting and ending point of 

 each tow and multiplying by a conversion factor. 

 An XBT (expendable bathythermograph) probe 

 was dropped at the start and finish of each station. 



Standing stock estimates were computed using 

 an "area-swept" method. This method is computed 

 as follows: 



SS, = (P wi )(Ai) 



(1) 



where SS, = standing stock estimate in the ith 



area 



P wi — average population expressed as 



kilograms per hectare in the ith area 



A, = total bottom area within the ith 



area. 



SStot = S ss, 



; = 1 



where SS t , = total standing stock estimate 



'tot 



expressed as kilograms 



148 



