Some of the sacrificed tuna were canned immediately 

 to serve as controls. Others were held in 32°, 60°, and 78° F 

 seawater (SW)for6hr, and some were held in 78 : FSWfor 

 9 hr before canning. An equal number of fish from all 

 treatments were brine frozen (for 20 hr). then thawed and 

 canned. Sample wedges were taken before canning for 

 measurements of glycolytic and purine degradation 

 products. These measurements together with organolep- 

 tic evaluation were also determined on the canned prod- 

 uct. 



There were no commercially discernible differences 

 between rested and stressed skipjack subjected to vari- 

 ous time-temperature treatments. The relation of the 

 measured biochemical parameters to the treatment of the 

 fish and the subsequent relation to the quality of the 

 canned product were studied. There were not sufficiently 

 defined relations on which to base quality predictions. 



652. Indexed bibliography of the eggs and young of 

 tunas and other scombrids (Pisces, Scombridae), 

 1880-1970, by William J. Richards and Witold L. 

 Klawe. September 1972, iv + 107 pp., 1 table. 

 Price $1.00. 



ABSTRACT 

 This bibliography enumerates reports on the early life 

 history of tunas and other scombrid fishes published be- 

 fore 1971. All the entries are indexed, usually by species, 

 but on occasion by a larger taxonomic unit, and within 

 each taxonomic unit the entries are indexed by one or 

 more subjects. 



653. The use of electricity in conjunction with a 

 12.5-meter (headrope) Gulf-of-Mexico shrimp 

 trawl in Lake Michigan, by James E. Ellis. March 

 1972, iv + 10 pp., 1 1 figs. 4 tables. Price 25 cents. 



ABSTRACT 



The catching efficiency of a 12.5-meter standard 

 shrimp trawl and the same trawl fitted with three different 

 electrode array systems with power on and power off was 

 investigated. 



The standard trawl caught 1.54 times or 54.2% more 

 kilograms of fish than the electrode-equipped trawl with 

 power off. The electrode array hanging across the mouth 

 area of the trawl acted as a visual stimulant and thus 

 reduced the trawl's catch rate. 



Overall the electrical trawl with power on caught 1.19 

 times or 19.0% more kilograms of fish than the electrical 

 trawl with power off. Array 2 with power on had the best 

 catch rate— 1.86 times or 86.9% more kilograms of fish 

 than the power off catch rate. The avoidance of fish to an 

 electrode array was more than offset with the catch rate of 

 array 2 with power on. The dominance patterns of the 

 catches with each system tested did not change signifi- 

 cantly with the exception of chub catches with array 2 

 with power on. 



Length selectivity was highly significant for chubs 

 caught with arrays 2 and 3 with power on. No significant 

 length select ivitv occurred with the other species landed. 



654. An electronic detector system for recovering 

 internally tagged menhaden. Genus brevoortia, 

 by R.O. Parker, Jr. February 1972, iii + 7 pp., 3 

 figs.. 1 app. Price 25 cents. 



ABSTRACT 

 Operation and results are described of an electronic 

 detector-recovery system for fish with internal fer- 

 romagnetic tags. The system does not interfere with the 

 operation of fish reduction plants. Date and location of 

 recapture can be obtained since tagged fish are detected 

 and recovered as they are landed. Growth rates of 3.1 and 

 7.2 mm per month were obtained for two menhaden out 

 130 and 483 days. Scale analyses supported annulus for- 

 mation assumption. The best location for tag injection in 

 adult menhaden appears to be about 13 mm above and 

 just forward of the origin of the pelvic fin. Tag incisions 

 were healed in 85% of the fish recaptured after 10 days. 



655. Immobilization of fingerling salmon and trout 

 by decompression, by Doyle F. Sutherland. 

 March 1972, iii + 7 pp., 3 figs., 2 tables. Price 25 

 cents. 



ABSTRACT 



Laboratory experiments revealed that some chinook 

 salmon (Oncorhynchus tshawytscha) and coho salmon 

 (O. kisutch) fingerlings are immobilized when decom- 

 pressed from atmospheric pressure to high negative 

 pressures. About 69% of the chinook salmon were par- 

 tially or completely immobilized at 71 cm of mercury vac- 

 uum, 48% at 61 cm, 17% at 51 cm, and none at 41 cm. The 

 effects developed rapidly, peaking 5 min after exposure. 

 The coho salmon, in comparison, were less severely af- 

 fected. Only 9% were immobilized at 71 and 61 cm of 

 mercury vacuum (reached 10 min after exposure). 2% at 

 51 cm (5 min after exposure), and none at 41 cm. 



Studies (with coho salmon and rainbow trout [Salmo 

 gairdneri] to determine the effects of decompression 

 within a turbine of a dam did not provide conclusive 

 results. However, some fingerlings caught in the tailrace 

 immediately after their release in the turbine intake were 

 immobilized. Exposure to negative pressure below tur- 

 bine runner blades is one possible cause of immobiliza- 

 tion. 



656. The calico scallop, Argopecten gibbus, by 

 Donald M. Allen and T.J. Costello. May 1972, iii 

 + 19 pp., 9 figs., 1 table. Price 35 cents. 



ABSTRACT 

 The calico scallop, Argopecten gibbus, supports a de- 

 veloping fishery off the southeastern coast of the United 

 States and in the Gulf of Mexico. Information is given on 

 classification, description, distribution, environment, rel- 

 ative abundance, reproduction, age and growth, mortal- 

 ity, associated organisms, behavior, and the fishery. 



657. Making fish protein concentrates by enzymatic 

 hydrolysis. A status report on research and some 



