Round Weight Research Articles

Growth, sexual maturation, and spawning season of Atlantic halibut, Hippoglossus hippoglossus, in Faroese waters

Biological data on Atlantic halibut, Hippoglossus hippoglossus, caught in an exploratory bottom trawl fishery in November–February 1983–1986 in a recently discovered deep water spawning area and in other both coastal and bank areas in Faroese waters, are presented. Studies of increases in length and weight confirmed the sex-dependent growth patterns found in earlier works, i.e. a higher growth rate in females than males especially after sexual maturity. The data show that Faroese halibut grow much more rapidly and mature at lower average ages (c. 4.5 years in males and slightly above 7 years in females) than in any other area investigated in the North Atlantic. Average length and round weight at sexual maturity were slightly above 55 cm and c. 1.7 kg in males, while the corresponding values in females were 110–115 cm and c. 18 kg. Spawning in the area appeared to commence in January and intensify in February. The peak in spawning activity was apparently not attained during the study period (November–February), and most probably occurred later in winter or early in spring.

Record Size of Freshwater Pink Salmon

A record-sized pink salmon Oncorhynchus gorbuscha was caught on October 10, 1985, in the Bridgeland River, a tributary of the Thessalon River, which empties into Lake Huron. The male exhibited a pronounced humpback, sharp canine teeth, and large black spots over the back and the caudal fin. Round weight was 5 kg, total length was 760 mm, and fork length was 720 mm. Twelve other big pink salmon were observed at the same river.

Fillet Yields of Dover Sole versus Depth of Capture and Length

The fillet yield (100% x fillet weight ÷ round weight) of Dover sole (Microstomus pacificus) caught off central and northern California was examined with respect to fish total length and depth of capture. The yield from Dover sole caught at depths greater than 458 m was not related to fish length. However, the yield from fish caught at shallower depths was correlated with fish length; the maximum yield was obtained from fish 40-42 cm long. Fillet yield was substantially lower for fish larger than 42 cm. A comparison of the yields of shallow- and deep-caught fish showed that shallow-caught fish had a 4.1% higher yield.

Return of 1-Year-Old Pink Salmon in Michipicoten River, Eastern Lake Superior

Five 1-year-old male pink salmon (Oncorhynchus gorbuscha) were found in the Michipicoten River in 1981. They were smaller than the 2-year-old pink salmon, averaging 328 mm in fork length and 352 g in round weight. This is the first record of precocious male pink salmon found in a freshwater environment.

SLAUGHTER AND CARCASS CHARACTERISTICS OF CATTALO, HEREFORD, AND 1/4 BRAHMAN–3/4 HEREFORD YEARLINGS

Slaughter and carcass data were obtained from 60 cattalo that averaged 1/7 bison–6/7 domestic (27 bulls, 33 heifers), 19 Hereford (11 bulls, 8 heifers), and 17 1/4 Brahman–3/4 Hereford (12 bulls, 5 heifers) yearlings. At a constant age, 1/4 Brahman and Hereford exceeded cattalo in growth rate, i.e. slaughter weights were: 1/4 Brahman 381 ± 10 kg, Hereford 376 ± 8 kg, and cattalo 353 ±5 kg. At a constant 24-h cold carcass weight, cattalo exceeded Hereford in carcass length (2.3%). Breed groups did not differ in mean fat thickness over, or area of, the longissimus dorsi, dressing percent, or transit shrink. At a constant carcass weight, the weight of the loin section was similar in all breed groups, but Hereford exceeded cattalo in round weight (2.6%), cattalo surpassed 1/4 Brahman in rib weight (4.3%), and 1/4 Brahman exceeded Hereford in shoulder weight (3.2%). Bison and cattalo were reported to have heavier front than rear quarters. This study suggests that the cattalo were not heavier in the shoulder but were lighter in the round than the Hereford and that the difference basically was in the weight of the hind shank.

Management of the Pacific Halibut Fishery

The International Pacific Halibut Commission (IPHC) has managed the Canadian and United States halibut fishery since 1923. During the early years of the Commission the abundance of the halibut stocks was declining and there were major changes in fishing techniques. After 1930 the Commission instituted more regulatory control, and catches gradually improved, reaching a maximum in the early 1960s. Some scientists attribute IPHC’s success to its organizational structure; others credit the simplicity of the fishery; still others contend that success was possible because the two nations have similar cultures. A more important factor has been the control of the fishery, i.e. the authority to introduce conservation measures that are supported by adequate enforcement.Since 1960 IPHC has lost control of certain elements in the fishery, and the abundance of halibut has declined markedly. The total catch by the North American longline fleet in 1962 was approximately 45,000 metric tons, while in 1972 it was 25,000 metric tons (round weight). Maximum catch per unit effort (CPUE) was reached before the expansion of domestic (Canada and United States) and foreign trawling. In the late 1950s IPHC had increased the removals to test the estimated maximum sustained yield (MSY) of the stock and expected a decline in CPUE when fishing intensity was increased; however, the rate of decrease was greater and lasted longer than anticipated. Changes in recruitment may have contributed to this decline. By 1965, the incidental catch of halibut by foreign and domestic trawl fisheries had increased substantially, and this accelerated the decrease in abundance. Reductions of the catch limits of the longline fleet failed to arrest the decline. In addition, longline fishermen had improved the effectiveness of their gear by increasing the spacing between hooks; as a result IPHC’s measure of CPUE since 1960 was overestimated. The effects of this gear change are far reaching and basic parameters of the halibut populations must be reassessed. Though the fishery has changed measurably, and IPHC has lost some control through the incidental catch by trawlers, a viable fishery has been maintained through the sacrifice of yield by the North American longline fleet. Productivity of this fishery is in jeopardy because losses to trawl fleets are not controlled, and continue to increase.

Population Dynamics of F1 Splake (Salvelinus fontinalis × S. namaycush) in Lake Huron

Ninety-eight percent of 5391 F1 splake recovered from a 1966 planting of 49,000 yearlings in Burnt Island Bay (45°50′N, 82°57′W) on the south shore of Manitoulin Island were taken within 32 km (20 miles) of the planting site. Remaining recaptures were made at distances up to 322 km (200 miles).Growth rates of the hybrids in Lake Huron exceeded those reported for native and planted lake trout. A commercial size of 0.9 kg (2 lb) round weight was attained by the fall of their 2nd year in the lake. The splake grew rapidly through the winter months. Yearlings fed mainly on invertebrates and 2- to 4-year-olds fed almost entirely on fish.Eight percent of 3054 hybrids examined had one or more lamprey marks. Fish less than 30 cm (12 inches) bore no evidence of lamprey attack; larger hybrids showed frequencies of lamprey marks increasing from 5.4% for 30- to 40-cm fish to 11.6% for those larger than 40 cm. The incidence of fresh lamprey marks was minimal in spring and early summer and reached a peak in September when more than 20% of the specimens bore fresh marks.Of the 2- and 3-year-old splake recovered, 50 and 40%, respectively, were males. The onset of sexual maturity in both sexes occurred at age II. By age III, 86% of the males and 58% of the females were mature. Ripe 3-year-old hybrids of both sexes were captured over former lake trout spawning grounds. Fecundity of 3-year-old females averaged 2512 eggs. Although survival to age IV was low, a substantial number of the hybrids attained sexual maturity.A total of 8.4% of the planting of 49,000 yearling hybrids was reported taken by sport and commercial fisheries during a 3-year period.

Islamic Bronze Weights From Egypt

Few Islamic bronze weights are known from the literature. The late John Walker published in 1935, a flat, square bronze weight of six (mithqil), engraved by hand with the protocol of Hajjdj b. Ytisuf 1). As there was no date, Walker, and later Miles, when he discussed this issue 2), thought, that it was probably produced around 75 H. The weight has been clearly inspired by the so common Byzantine square bronze weights. There is no doubt about it being a coin weight, a multiple of the gold mithqil or dinar, and at the same time the earliest known example of an original Islamic bronze weight. Two other weights which may be contemporaneous, are the well known glass coin-weight of the Caliph 'Abdul-Malik in the Cabinet des Medailles in Paris 3), and 'Abdul-Malik's other extant glass sanj in the Syrian National Museum in Damascus 4). In 1939, George C. Miles described a Byzantine round disk weight of two ounces, validated for circulation in the Muslim empire by the Umayyid Caliph Walid I. (86-96 H.) 6). In 1962, yet another Byzantine bronze weight, also adapted for the use of Muslims by the Syrian official Bishr b. Marwan (ca. between 66 and 71 H.), has been published by George Miles 6).

Bone muscle relationships in the bovine carcass.

Sixty-three half-sib Hereford steer carcasses were studied to determine the relationships between metacarpal length, weight, weight-length ratio, area, live and trimmed depth and width, specific gravity and numerous measurements of muscling and cutability. Metacarpal weight, weight-length ratio and area were related to the length of body, length of loin, rib weight, loin weight, round weight and the weight of boneless, closely trimmed steak and roast meat obtained from the chuck, loin, rib, round and rump. Metacarpal length was found to have virtually no relationship to the various muscling characteristics studied except length of body and length of loin. These data tend to indicate that steers with metacarpal bones which are larger in area and weight will also possess heavier boneless, closely trimmed retail cuts from the chuck, loin, rib, round and rump.

Methods of predicting kilograms of retail cuts in the beef carcass

Various carcass measurements were obtained from 216 Hereford steers and evaluated in an attempt to find traits or combinations of traits which accurately estimate carcass composition. Carcass weight and trimmed retail cuts from the round proved to be the best single estimators of kilograms of retail cuts. Prediction equations were developed using carcass weight, trimmed retail cuts from the round, longissimus dorsi area, measures of fat thickness at the 12th rib, untrimmed round weight and weight of kidney, heart and pelvic fat in various combinations. Eighty-four to 94 % of the total variation in actual kilograms of retail cuts could be accounted for by using these equations.

Volume of Beef Round Related to Carcass Composition

Three linear carcass measurements recorded on the chilled carcass were used to compute volume of round. Computed round volume was compared to actual weight of round. Correlations between computed volume of round and round weight at 6 months of age and market weight were 0.96 and 0.83, respectively. Correlations between round weight and carcass lean at 6 months and market weight were 0.96 and 0.93, respectively. Correlations between round volume and carcass lean at 6 months and market weight were 0.97 and 0.80, respectively. Carcass lean developed at a significantly faster rate than carcass fat up to 6 months of age. Correlations between carcass lena and fat at 6 months and market weight were −.06 and −.20, respectively.