摘要:

In Atlantic cod, muscle glycogen was reduced by about 50% at moderate swimming speeds and over 80% at higher speeds. Muscle glycogen for a given swimming speed was generally lower after 30 min exercise than after 15 min exercise. During the 8-hr period after strenuous exercise, muscle glycogen increased but remained well below the level for unexercised fish.At moderate swimming speeds, fish exhibited comparatively small amounts of muscle and blood lactic acid. At higher swimming speeds, fish accumulated significantly larger quantities of lactic acid in the muscle and blood. During the recovery period after strenuous exercise, muscle and blood lactic acid increased precipitously. Muscle lactic acid remained high for 1 hr after exercise and then decreased in 8 hr to levels similar to those of unexercised cod. Blood lactic acid followed a similar pattern except that it continued to increase for 1.5 hr after exercise.Serial samples of blood taken before and after 30 min strenuous exercise showed marked differences in lactic acid among individuals. Blood lactic acid usually continued to increase for 30–60 min after exercise, and decreased to the level for unexercised fish about 24 hr after exercise.No mortalities attributable to muscular fatigue occurred among cod.

ISSN:0706-652X    

DOI:10.1139/f68-079

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The degradation of uniformly labelled glucose-C14was followed in the caeca preparations of the marine wood borerBankia setacea(Tryon). This digestive organ was found to contain large quantities of soluble protein. Various accumulating intermediates were isolated, indicating the presence of enzymes typical of the Embden–Meyerhof pathway, the pentose pathway, the citric acid cycle, and the non-triose pathway. The presence of wood in the caeca may be required for the synthesis of glutamic and aspartic acids within the caeca. Approximately 10% of the added glucose was found in an unidentified, unstable, electronegative compound called glucose-X. The function of this compound is unknown.

ISSN:0706-652X    

DOI:10.1139/f68-080

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The ultrastructure of the brook, brown, and rainbow trout cornea as observed using the light and electron microscopes is described. The transition between the central and limbal areas of the cornea is included. The limbal region, unlike the central cornea, contained epithelial microvilli, unorganized Bowman's membrane with various size collagen fibrils, and a stroma containing melanocytes and capillaries. These corneas also possess prominent keratocytes and an endothelium.

ISSN:0706-652X    

DOI:10.1139/f68-081

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

An experiment was conducted to examine the roles of olfaction and vision in directing the choice of spawning site by homing adult chinook salmon (Oncorhynchus tshawytscha) on the lower Columbia River. Male fish that voluntarily entered the Spring Creek National Fish Hatchery were treated to occlude their olfactory or visual senses or both. Treated and untreated (control) fish were released upstream and downstream in the river, more than 19 km from the hatchery. Effects were assessed by analyzing returns to the hatchery and to other points.Of 866 fish released, 348 or 40% were recovered; about half of them, or 176 returned to Spring Creek. Three per cent of the olfactory occluded, 23% of the visually occluded, and 46% of the control fish returned to Spring Creek. Of the fish recovered elsewhere, 77% were recovered at hatcheries and spawn-taking sites along the lower Columbia; 23% were recovered from sources unrelated to spawn taking.Olfaction appeared to be the key sense that directed the return of these fish to Spring Creek; vision was held to be less important. Olfactory occlusion also reduced the recoveries at other spawn-taking sites, where blinded fish were recovered in appreciable numbers. Recovery of the control fish, especially the smaller ones, at other spawn-taking sites was associated with advancing sexual maturity.

ISSN:0706-652X    

DOI:10.1139/f68-082

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Three specimens ofHalargyreus johnsoniitaken on the southwestern and southeastern slopes of the Grand Bank in 1959 and 1964 are apparently the first records of this species and genus from the western Atlantic. These specimens are compared with the holotypes ofH.johnsoniiGünther and ofH.brevipesVaillant and with the syntypes ofH.affinisCollett and also with specimens identified asH.affinisfrom the north-central and northeast Atlantic and with specimens ofH.johnsoniifrom Madeira and New Zealand. These three nominal species are also compared. Is it concluded that for the present all North Atlantic specimens may be referred toH.johnsoniiand that the other two species names should be considered as junior synonyms ofH.johnsonii.The New Zealand specimens ofHalargyreus, described by Günther (1887, Challenger Rept., 22(Zoology), p. 1–268) asH.johnsonii, have higher numbers for some meristic characters than Atlantic specimens ofH.johnsoniibut these differences are not too great to be possibly due to environmental differences. Pending the study of additional specimens in better condition, these New Zealand specimens are tentatively allowed to remain asH.johnsonii.

ISSN:0706-652X    

DOI:10.1139/f68-083

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

In the northern part of its western Atlantic range, the swordfish feeds on relatively few species of fish. Volumetrically the most important species are Atlantic mackerel, barracudinas, silver hake, redfish, and Atlantic herring. Squid are also important in the diet, and accounted for nearly one-fifth of the volume in the stomachs examined. There is evidence that the swordfish frequently uses its sword to attack and disable even small individual food items before ingesting them.

ISSN:0706-652X    

DOI:10.1139/f68-084

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

Trimethylamine (TMA) was produced in frozen cod fillets and in scallop muscle under conditions where bacterial activity could not take place. The amounts formed were smaller than those which usually accompany bacterial deterioration of unfrozen fish. Decreases in storage temperature between −3 and −26 C reduced the rate of TMA formation. At −26 C no measurable increase of TMA was produced in cod fillets during storage periods up to 700 days.TMA formation appeared to be related to other chemical changes taking place in the frozen muscle. It followed shortly after the formation of free fatty acids and was almost simultaneous with changes taking place in the amounts of extractable protein.

ISSN:0706-652X    

DOI:10.1139/f68-085

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

The total amounts of free amino acids, comprising both the intracellular and plasmal pools, as well as the amino acids combined in small peptides were determined with an automatic amino acid analyser in muscular tissues of freshly killed cod and in cod suffocated in simulated gillnetting conditions. The total amount of the free amino acids in the musculature was 2.4% of the amino acids composing the proteins. More than 90% of the free amino acid pool was represented by histidine, taurine, glycine, alanine, lysine, and β-alanine. The amino acids that were not found in small peptides are taurine, alanine, threonine, lysine, tyrosine, cystine, and methionine. In the absence of flexion or handling of the suffocated fish there was no evidence of enzymatic processes up to 72 hr after death. There was a slight, continuous loss of the free amino acids from the intact body of the fish during the prerigor and rigor periods. No evidence of deaminase activity affecting the amino acids was detected. Histidine, with its methyl homologues, was the major free amino acid.

ISSN:0706-652X    

DOI:10.1139/f68-086

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

In place of the widely ranging, abundant, and variable speciesAnonyx nugax, previously recorded from Canadian Atlantic and Arctic waters, eight less variable species of this genus are here recognized, one of which (sarsi) is new to science. Detailed descriptions, figures, distribution maps and a key applying to all sizes are given. The study of the species is based on examination of available type-specimens and the use of new characters. The systematics of the genus is discussed in a chronological review of all the relevant literature, and the status of several species is revised.Since the young of large and small species are similar among themselves, and have sometimes been wrongly described as distinct species, they are also described and illustrated at two sizes. Mature males are distinguished by elongated second antennae equipped with calceoli, in most species by the armature of the second and third uropods, and sometimes by their enlarged eyes.Three species are characterized by a row of spines accompanying single setae on the hind margin of segment 6 of peraeopods 3–4, and by a rather unprominent upper lip. One may distinguish them as follows. The large (> 33 mm)A.laticoxaehas short spines on peraeopods 3–4, an anteriorly well-expanded first coxa, and an unconstricted short-spined inner ramus of uropod 2.Anonyx compactusis smaller (12–17 mm), has one elongated ventral spine on each of the first two flagellar segments of antenna 1, a posterior projection marked off by an angle from the lateral plate of metasome segment 3, a strongly parachelate peraeopod 1 with a perpendicular palm, and a fairly strongly subchelate peraeopod 2.Anonyx sarsiis of medium size (20–31 mm), has a very low and unprominent upper lip and, on the outer ramus of uropod 2, small similar-sized spines on the proximal two-thirds of the inner margin (no such spines inlaticoxaeandcompactus); the female has tufts instead of a row of setae on the dorsal margin of the fourth peduncular segment of antenna 2, but otherwise the species is morphologically similar toA.nugax.The other five species are characterized by a row of pairs of long setae on the hind margin of segment 6 of peraeopods 3–4 and, exceptnugax, have a rather prominent upper lip. Except inochoticusandlilljeborgi, uropod 2 bears spines on the inner margin of its outer ramus.Anonyx ochoticusis the smallest (9–11 mm) species, and has on urosome segment 1 a prominent dorsal keel well overlapping the next urosome segments.Anonyx debruyni, rather small (15–21 mm), has a parachelate peraeopod 1 with an oblique palm, a very strongly subchelate peraeopod 2, most prominent and pointed upper lip and interantennal angle, and, on the outer ramus of uropod 2, only two small spines on the distal half of the inner margin.Anonyx lilljeborgiis small (9–18 mm), has a very prominent but high and usually evenly rounded upper lip, a concave cephalic ventral margin (likedebruyni), and a lateral plate of metasome segment 2 with a nearly toothless postero-ventral corner.Anonyx nugaxis the largest (31–44 mm) species, with a little-projecting upper lip, a prominent tooth at the postero-ventral corner of metasome lateral plate 2, a short posterior projection, with a nearly straight ventral margin, on the lateral plate of metasome segment 3 and, on the inner margin of the outer ramus of uropod 2, a row of similar-size small spines not extending into the distal third of the ramus.Anonyx pacificusis also large (27–34 mm) and similar tonugax, but differs in the more prominent and pointed upper lip, the longer and ventrally concave posterior projection on metasome lateral plate 3, and, on the outer ramus of uropod 2, spines which increase in size distally and reach into the distal third of the inner margin.Three species,nugax,lilljeborgi, andsarsi, have a circumpolar arctic-boreal distribution, the latter chiefly in shallow water (< 50 m). Four (pacificus,laticoxae,ochoticus, andcompactus) are colder-water forms apparently of Pacific origin and all new for the North Atlantic. The distribution ofdebruyniis uncertain.

ISSN:0706-652X    

DOI:10.1139/f68-087

出版商:NRC Research Press    

年代:1968

数据来源: NRC

摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f68-088

出版商:NRC Research Press    

年代:1968

数据来源: NRC