摘要:

The nutrient circulation and microbial abundance of oyster-producing waters in the Malpeque Bay area, Prince Edward Island, were followed at two stations through an open season, and the efficiency of carbon assimilation and dissimilation was estimated. Part of the organic fall-out evidently entered the water again in the spring as nutrient salts, but a certain portion was not returned and this represented a net loss from the ecosystem. The nutrient circulation at a station located in a saltwater pond was more efficient than at a station located in a river estuary. In the pond, mineralization was 31% of primary production, largely by mud bacteria; in the estuary it was 17%, about equally by mud and water organisms.

ISSN:0706-652X    

DOI:10.1139/f66-155

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The chemical composition of male and female meat of the American crayfish (Orconectes limosusRaf.) was determined and the relationship between the weight, and total length and the yield of edible meat of the crayfish was established.The American crayfish meat was found to contain on the average for both sexes 80.9% water and 2.75% total nitrogen of which 83% accounts for protein nitrogen.In the protein composition myosin constitutes 32.9%, myogen 30.1%, residual intracellular protein 26.4%, and protein of stroma 10.5% of the true protein. The amine nitrogen content of both sexes averages 202.1 mg/100 g, which accounts for 42.6% of nonprotein nitrogen.The American crayfish contains more phosphorus than do fishes. Its meat averages 296.4 mg/100 g P of which the acid insoluble fraction constitutes 36.1%, inorganic phosphorus 35.5%, and ester phosphorus 28.4%. Males contained more total, acid-insoluble, and ester phosphorus and less inorganic phosphorus than did females.The amino acid composition of free amino acid fraction, protein, and acid hydrolyzate prepared from the equal quantities of the male and female water–alcohol meat extracts were also determined. The crayfish amino acid composition resembles that, of fishes with certain distinctive features.

ISSN:0706-652X    

DOI:10.1139/f66-156

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

The starch gel electropherogram of muscle myogens and blood hemoglobins of representatives from the families Petromyzontidae, Esocidae, Centrarchidae, and Percidae were found to be within the limits of species specificity with some exceptions. Evidence of polymorphism was found in the muscle myogen ofStizostedion vitreumof the family Percidae. Only one type of homozygous pattern, designated A, was found in specimens from Great Slave lake, while both the homozygotes A and B as well as the heterozygote AB were found in samples from Lake St. Clair. Further genetically interpretable polymorphisms were also found in the minor protein zones. These natural chemical markers are discussed from the standpoint of their usefulness in subpopulation analyses. The presence of protein zones of common electrophoretic mobilities in three species of the family Petromyzontidae indicated marked resemblances of the muscle myogens at the family level. Total plasma proteins ofP.marinusshowed vast changes during their parasitic and nonparasitic stages of development. The muscle myogens of some members of the family Centrarchidae also showed strong familial relationships. In hybrids of this group biosynthetic systems for muscle myogens and plasma proteins of both parents were present.

ISSN:0706-652X    

DOI:10.1139/f66-157

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

During U.S. Bureau of Commercial Fisheries' Atomic Energy Commission trawling investigations in waters adjacent to the mouth of the Columbia River, a total of 54 species and one subspecies of sea stars was collected from bottom depths of 50–1050 fath. The sea stars in the area of study can be divided into four faunal assemblages by benthic zones: (1) an outer sublittoral fauna (50–108 fath) consisting of several shallow-water species, some of which have their apparent maximum depth of occurrence in this zone. The number of species and the availability of sea stars per hour of trawling is much lower in this zone compared to the other benthic zones in the study area; (2) an upper bathyal fauna (122–258 fath) consisting of several species having either a continuous or discontinuous circumboreal distribution; (3) a lower bathyal fauna (275–500 fath) characterized by a large number of species and a high availability of sea stars in terms of numbers and weight per hour of trawling. Several of the more frequently occurring and abundant species in this zone belong to genera endemic to the northeastern Pacific; and (4) an abyssal fauna (900–1050 fath) consisting almost entirely of species belonging to cosmopolitan genera.The bathyal-abyssal zone (585–850 fath) is considered a zone of transition because of the intrusion into this zone of elements of the sea star fauna from both the lower bathyal and the abyssal.

ISSN:0706-652X    

DOI:10.1139/f66-158

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Stephanodiscus tenuisHust.,Melosira islandicaO. Müll., andDiatoma elongatum(Lyngb.) Ag., on a cell volume basis, were the three most important species from January 1964 to July 1965 in the surface water of Lake Ontario near Gibraltar Point.Stephanodiscus tenuiswas by far the most abundant species. It was present during most of the year and accounted for about 87% of the total number of algae present during the spring outbursts.In more central areas of the lakeMelosira islandicaandAsterionella formosaHass. replacedStephanodiscus tenuisas the most important species.On the basis of the major phytoplankton species present the central area of Lake Ontario appears to be oligotrophic. High numbers ofStephanodiscus tenuisin inshore waters may be indicative of a more eutrophic environment.

ISSN:0706-652X    

DOI:10.1139/f66-159

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

[The concept of biological production is best approached from the point of view of aproduct, defined as a group of organisms (not necessarily all belonging to the same species) which have similar food habits, and which are useful to man or are of special interest for some other reason.Productionis defined as the sum of all organic matter added to the stock of a product (or other defined organic unit) in a unit of time, regardless of whether or not it remains alive (i.e. part of the stock) at the end of that time. Production may be expressed in various units, particularly biomass (wet or dry weight), nitrogen content, or calorific content, but the last of these is to be preferred.In order to trace the flow of energy in a body of water from solar radiation up to a given product, four types of study are needed. The first is a quantitative determination of the formation of primary organic matter — the fixation of solar energy by plankton and macrophytes. For plankton this is estimated from the oxygen produced (usually in light-and-dark-bottle experiments); for macrophytes, direct measurements of the growth of the plant body have been used.Secondly, the paths of energy transformation that lead to the chosen product must be identified. Although a complete analysis for even one product would usually be extremely complex and tedious, the complexity can be greatly reduced by concentrating on the predominant foods of each organism and ignoring second-grade components.Thirdly, theecotrophic coefficientmust be determined for each step in the food pyramid that leads from primary organic matter up to the product. The term ecotrophic coefficient is defined by Ivlev in two different ways. In discussing the flow of energy through an ecosystem, what is involved is the "dynamic" ecotrophic coefficient, the ratio of a consumer's intake of a particular food organism to the latter's production during some rather long time interval — usually a year. The energy content of the production of each food present, multiplied by the corresponding dynamic ecotrophic coefficient, gives the energy of that type ingested by the consuming organism during the time unit chosen; and the sum of these quantities for all foods eaten by this consumer gives the total energy that ascends that step in the food pyramid per unit time. Bacteria must of course be considered, both as consumers and as foods, and must be included in the picture whenever they comprise one of the steps leading to the chosen product. Unfortunately, measurements of the dynamic ecotrophic coefficient have scarcely begun; to be useful they must be carried out in real bodies of water, not in the laboratory.What may be called the "static" ecotrophic coefficient is the ratio of the quantity of a particular food consumed to the total supply of it available at a given time; it is useful, for example, in studying daily rations. Laboratory experiments in this field have demonstrated a numerical relation between the quantity of food present and the quantity consumed, and also the fact that consumption increases if the food is distributed in aggregates.Finally, there must be determinations of theenergy coefficient of growth— the fraction of consumed food that is converted into body substance, for each step. This coefficient has very similar values (about 0.35) for the very young (but post-embryonic) stages of practically all animals, but it decreases with age and approaches zero as growth ceases; the course of this decline can be represented by a parabola. External factors, temperature in particular, have little effect on the magnitude of the growth coefficient. The production of any organism is equal to the quantity of food it ingests multiplied by the growth coefficient.]

ISSN:0706-652X    

DOI:10.1139/f66-160

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

Inlet spawning migrations of longnose suckers (Catostomus catostomus) and white suckers (Catostomus commersonnii) in Sixteemile Lake commenced in the spring when daily maximum temperatures in the inlet reached S and 10 C, respectively. Migrating fish were trapped in the stream near the lake, marked by subcuticular injection of liquid latex, and recovered during their lakeward migration following spawning. Upstream migrants from later parts of the run spent less time in the stream than fish from early parts of the run. Longnose suckers returned to the lake before white suckers. The females of each species returned before the males. Spawning mortality was 10–40%. Suckers marked as mature spawners in 1956 made up an appreciable proportion of the spawning run for several years thereafter. Some fish spawned in several successive years. Scales did not provide a reliable measure of age of spawners, but recoveries of marked fish suggested maximum ages of 12–16 years. Growth of adult fish was 10–20 mm/year. Estimates of the adult population size were 2000 longnose and 800 white suckers of which 25–50% spawned each year. Low annual recruitment was indicated in these slow-growing populations. The downstream movement of sucker fry was nocturnal and largest when stream levels were high and the water turbid or the nights particularly dark. Peak fry migration was approximately 1 month after spawning. Several investigations have indicated the general similarity of inlet spawning migrations of rainbow trout, redside shiner, squawfish, and the two species of suckers.

ISSN:0706-652X    

DOI:10.1139/f66-161

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f66-162

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f66-163

出版商:NRC Research Press    

年代:1966

数据来源: NRC

摘要:

not available

ISSN:0706-652X    

DOI:10.1139/f66-164

出版商:NRC Research Press    

年代:1966

数据来源: NRC