Indicator Of Physiological State Research Articles

Effects of mercury on the biosynthesis of porphyrins in bivalve molluscs ( Cerastoderma edule (L.) and C. lamarcki (Reeve))

Growth of Cerastoderma (= Cardium) edule (L.) and C. lamarcki (Reeve) exposed to mercury in situ in the western part of ther Limfjord, Denmark, was compared with that of non-exposed populations. Physiological condition index values of cockles sampled during growth periods in 1990 and 1991 were not significantly different for exposed and non-exposed populations when species, lenght, and sampling date were taken into account (stepwise multiple regression analysis, and ANOVA). Mercury exposure in the laboratory confirmed these findings. Biosynthesis of porphyrin precursors, δ-amino levuleic acid (ALA) and porphobilinogen (PBG), detected by ion-exchange chromatography, was clearly perturbed by mercury exposure in the environment as well as in laboratory experiments; thus, the two biochemical components can be considered biomarkers of mercury exposure. For the porphyrins (uro-, proto- and copro-porphyrins) detected by HLPC, no general effect could be established. The mechanistic basis of disturbance of the essential porphyrin biosynthesis (the prerequisite of cytochrome formation) and a possible alternative porphyrin source are discussed.

Seasonal changes in adenylate energy metabolism in the muscle and liver of the redear sunfish,Lepomis microlophus

Levels of muscle and liver adenylates, phosphocreatine (PCr), total adenylates (TA) and the adenylate energy charge (AEC) exhibited significant seasonal changes. Fish size and condition factors were significantly different throughout this study; however there were no correlations between fish size or condition factor and metabolite levels. Muscle adenosine triphosphate (ATP), TA and AEC were lowest in winter and positively correlated with temperature; while adenosine diphosphate (ADP) and adenosine monophosphate (AMP) levels were high in winter and negatively correlated with temperature. Muscle AEC's dropped into the stressed range (0.5–0.75) during winter months. ATP/ADP ratios were lowest while PCr/ATP ratios were highest in winter months; indicating that a capacity for phosphate buffering existed and could not account for these low muscle AEC's. Liver ATP, TA, PCr, AEC, and adenylate ratios were lowest in the spring and were not correlated with temperature, but rather coincided with reproduction. Liver AEC's dropped into the lethal range ( 0.5) in April; although no fish mortalities were observed. Liver AEC's were lower than muscle AEC's throughout the study. The AEC appears to have some validity as a long-term indicator of physiological status and may have application in monitoring/predictive programs due to its predictable response to seasonal change. However, cautious use is suggested until temperature effects on adenylate metabolism and seasonal effects on metabolic recovery following capture stress can be established.

Biochemical composition of the blue crab Callinectes sapidus exposed to the water-soluble fraction of crude oil

The biochemical composition of juvenile blue crabs, Callinectes sapidus, exposed to sublethal concentrations of the water-soluble fraction of South Louisiana crude oil (0 to 2 504 ppb) for 21 d were examined. Although growth took place in all crabs, tissue content varied inversely with exposure concentration while percentage tissue water varied directly with exposure concentration. Total protein, lipid and RNA content of crabs exposed to crude oil were significantly less than that of control crabs by Day 21. DNA content was not significantly different from that of control crabs, suggesting that the difference in tissue content was due to differences in cell volume and not cell number. There were no consistent differences in the concentration of the major biochemical components, indicating that the relative contribution of each of the components remained stable during the period of sublethal stress. Ratios of RNA:DNA and protein:DNA decreased in exposed crabs and were positively correlated with scope for growth and observed growth. The ratios may be useful as indirect indicators of physiological condition. Analysis of lipid classes indicated that structural lipids in stressed crabs were less affected than were lipids used for energy storage. The changes in biochemical composition suggest that the pattern of energy utilization was altered in crabs exposed to crude oil. Growth in size without comparable growth in tissue resulted in decreased tissue content. Available energy was used for growth, with little being stored in lipid reserves.

Incidence of hematopoietic neoplasia in Mya arenaria: Monthly monitoring of prevalence and indices of physiological condition

Incidence of hematopoietic neoplasia in Mya arenaria: Monthly monitoring of prevalence and indices of physiological condition

Variability in Mandible Marrow Fat in 3 Moose Populations in Sweden

The usefulness of mandible marrow fat as an indicator of marrow fat deposition was analyzed to compare 3 moose (Alces alces) populations (Furudal, Hagfors, and Grimsi) in southcentral Sweden. Marrow fat levels were related to autumn and winter season, age, and carcass weight in 978 moose collected during 1981-84. Within each population no between year difference for specific sex and age classes was found. Average fat levels in autumn were low among calves (53-62%) but increased rapidly to yearlings (68-73%). Adult females had high fat levels throughout life (76-78%), whereas males had substantially less fat with increasing age (38% at -10 years). The males at Grims6 had consistently less marrow fat (P < 0.05) than those at Furudal and Hagfors. The overall relationship between mandible marrow fat and carcass weight differed between the sexes and resembled the typical fat-age relationship. Marrow fat was positively correlated with carcass weight of calves but not of adults. During October-December male calves and adult females had stable fat levels, whereas female calves tended to mobilize and adult males to build up the fat. J. WILDL. MANAGE. 50(4):719-726 Bone marrow fat has been used widely as an indicator of physiological status of ungulates (Cheatum 1949, Riney 1955, Ransom 1965, Greer 1968, Neiland 1970, Verme and Holland 1973, Ratcliffe 1980). Development of Neiland's (1970) dry-weight method for estimating percentage of marrow fat allowed quantification with relatively little effort and at low cost. Its simplicity and objectivity led Hunt (1979) to recommend this method for fat determination in wildlife studies. Using Neiland's (1970) method, Snider (1980) and Ballard et al. (1981) found positive correlations between marrow fat in femur, metatarsus, and mandibles of moose from 2 North American populations. Mandibles can be collected routinely from a large number of moose during the hunting season, and Ballard et al. (1981) suggested that mandibular marrow fat could be used as an indicator of individual moose condition. They also recommended that paired samples of mandibles and different longbones from other populations should be collected to test the general usefulness of mandibular marrow fat technique. To date marrow fat primarily has been used in broad judgments of whether an animal is in good or poor condition. However, due to the relative simplicity of the method it also may be a useful tool in studies at the population level. Comparisons must then take into account sex and age of the animals (Franzmann and Arneson 1976, Snider 1980, Ballard et al. 1981) as well as seasonal changes in fat deposition and mobilization (Franzmann and Arneson 1976, Bjarghov et al. 1977, Fong 1981, Huot 1982). No data comparing fat levels in different cervid populations, with simultaneous consideration to the above-mentioned factors, appear to have been published. The objectives of our study were to determine the relationships between seasonal and ageand weight-related fat levels in the mandible, metatarsus, and femur marrow in 3 moose populations. We thank A. N. Pehrson for valuable criticism of the manuscript, all hunters for collection of the material, and P. G. Ahlqvist and L. B. Pettersson for field and laboratory assistance. The advice and practical help of L. Norling on the statistical analyses also is appreciated. This study was financially supported by the Natl. Swedish Environ. Prot. Board and the Swedish

Lipid as an index of growth and viability in three species of bivalve larvae

The larvae of three species of bivalve molluscs, Crassostrea virginica (Gmelin), Ostrea edulis (L.) and Mercenaria mercenaria (L.) were cultured under a variety of temperature and food species regimes in the laboratory. Data were collected on growth, survival, total lipid content and lipid class composition of both healthy and starved larvae. Subsamples were stained specifically for lipid content with the lipid-specific stain Oil Red O. Newly formed straight hinge larvae of all three species exhibited small lipid droplets dispersed throughout the tissues. These were resorbed within 4 days of the initiation of feeding while the digestive gland filled with exogenously supplied lipid. Embryogenesis took place at the expense of 69 and 71% of parentally derived total lipid, 92.8 and 68.3% of which was composed of triacylglycerols ( M. mercenaria and C. virginica, respectively). After 8 days of feeding on Isochrysis aff. galbana (clone T-ISO), total lipid had increased 2.7-fold in larvae of C. virginica grown at 25°C, 37.6-fold in larvae of M. mercenaria grown at 22°C, and 1.7-fold in larvae of O. edulis grown at 25°C. Shell growth in larvae of C. virginica grown at 30°C was initially higher than that at 25°C, but lipid was accumulated 2.5 times slower and survival of pediveliger larvae through metamorphosis was considerably reduced at this elevated temperature. The lipid class composition of healthy larvae of C. virginica and M. mercenaria was dominated by triacylglycerols and phospholipids in approximately equal proportions; however, triacylglycerols were preferentially catabolized during starvation and were responsible for greater than 80% of the total lipid loss. Color photographs of larvae stained with Oil Red O are presented that illustrate lipid levels in developing larvae in both healthy and poor condition. From these, a visual index of lipid content was developed to allow comparisons between larval survival and lipid levels. In general, high survival was always accompanied by a high lipid index but a high lipid index did not guarantee good survival. We suggest that the lipid index may be used to document visually the lipid content in individual bivalve larvae as an indicator of physiological condition and potential for successful metamorphosis.

Buffering capacity as an indicator of physiological state in a continuous culture ofCandida utilis

Alkalimetric titration of the supernatant and the whole steady-state cell suspension was used to determine the buffering capacity of aCandida utilis culture during continuous cultivation at different dilution rates. Differences in the two types of titration curves were used to calculate, by means of the theory of dissociation of polyelectrolytes, the change in Gibbs free energy necessary to remove one proton from a live cell. The energy, 4.5 × 10-20 J (0.28 eV), corresponded to the energy of hydrogen bonds. With increasing growth rate the quantity of these bonds per unit dry mass increased, in direct proportion to the sum of the content of proteins and RNA per unit biomass. They reflect the weak buffering forces exerted by cell macromolecules, which are measurable under our experimental conditions and may serve as a marker of the physiological state of the cells.

Seasonal change in body fat of the Hyrax&lt;i&gt; Procavia capensis&lt;/i&gt; (Pallas, 1766) using a body fat ranking index

Changes in the body fat content of the hyrax Procavia capensis were used as an indicator of physiological condition. Body fat rankings for the different sexes showed seasonal variations related to physiologically stressful periods (rutting, gestation and lactation). The subjective body fat rankings were correlated significantly with total body fat.

A Physiological Condition Index for Wintering Mallards

Mallards (Anas platyrhynchos) were collected during winter 1982-83 in eastern Colorado and subjected to whole-carcass analysis to determine carcass composition and develop a physiological index. Condition index was defined as body fat/fat-free body weight. Multiple regression equations using body weight and wing length were highly correlated with total body fat in male (R2 = 0.643) and female (R2 = 0.679) mallards. When tested on an independent data set, fat predictor equations accurately estimated measured body fat (R2 = 0.796). Weight and wing measurements were easily obtained on live mallards under field conditions with high repeatability among observers (CV < 1%). By accounting for variability in structural size among birds, models were able to detect differences in body that were not detectable using body weight alone. J. WILDL. MANAGE. 49(3):564-568 Early studies of the endogenous reserves of live waterfowl used body weight as an indicator of nutritional status (Hanson 1962, Folk et al. 1966, Street 1975, Owen and Cook 1977). Implicit in this approach were the assumptions that: (1) lean body weight was constant within a species (Connell et al. 1960); (2) fat was most important in determining condition; and (3) structural size differences among individuals of a species did not affect conclusions about nutritional status. Later, researchers recognized that structural size biased based only on body weight, and condition indices were developed to eliminate such biases. Most have used the simple quotient of body weight divided by a measure of structural size such as wing, keel, tarsus, bill, or total body length, or a combination thereof. Whereas some researchers have used body measurements that correlate with lean body weight (Bailey 1979, Chappell and Titman 1983), skeletal weight (Wishart 1979), or total body fat (Woodall 1978), others have adopted arbitrary structural measurements (Harris 1970, Bennett and Bolen 1978) or ocular estimates (Owen 1981). We define as a measure of the chances of survival of an individual at a particular time of the year and/or of its potential for breeding successfully (Evans and Smith 1975). During winter, fat is the component of that is the most labile and potentially limiting to the mallard. In addition to serving as a supplemental energy source necessary for survival during winter periods of high energy demand and food scarcity (Jordan 1953), winter fat reserves may also provide a source of energy and nutrients used during reproduction (Krapu 1981). Waterfowl researchers are striving to understand the interrelationships among the breeding, post-breeding, and wintering periods. Energetics, with emphasis on the dynamics of nutrient reserves, is the common denominator linking these periods. A physiological index for the mallard, a species that serves as he focus for much duck research and management, would aid winter energetics studies by providing managers with a method to evaluate the biological effects of hunting regimes and habitat manipulations. The objectives of our study were to: derive an equation to predict total carcass fat of live birds; develop a index using estimated fat and a structural size measure; and test the index on a sample data set to evaluate its performance. The index had to be suitable for use in field situations on live birds, offer a major improvement over body weight alone in predicting condition, and be applicable throughout the winter period (late Nov-Feb) on birds of all sexes and age-classes. We acknowledge the help of G. M. Lorentzson in duck trapping and carcass preparation and especially thank J. F. Corey for his dedicated work on all phases of the study. D. C. Bowden offered guidance on statistical analyses. Many Div. of Wildl. employees assisted in trapping operations, particularly M. C. Creamer and G. Berlin. C. A. Weinland and M. L. Stevens conducted laboratory analyses and offer d valuable advice, and M. P. Schoenfeld coded and entered carcass and data. Thanks are extended to J. E. Black for manu-

The use of physiological condition indices in marine bivalve aquaculture

The physiological condition indices most commonly used in bivalve aquaculture are reviewed and evaluated. Two general categories of indices may be distinguished: static and dynamic. Of the static indices reviewed, only one is recommended for use in the culture of early developmental stages — the dry ash weight: total dry weight ratio. In the case of juveniles and adults, the easily-measured dry tissue weight: dry shell weight is recommended for most routine work. The dynamic indices reviewed are based on production estimates, and hence reflect physiological changes over specified time intervals. Of these indices, only net growth efficiency is recommended for use in bivalve aquaculture, and it is applicable to all life stages. While this index gives the most information about the physiological state of the animals comprising a population, it is very difficult to evaluate and is thus most appropriate as a research tool.

Effects of prey concentration, prey size, predator life stage, predator starvation, and season on predation rates of the carnivorous copepod Euchaeta elongata

Adult females of the large carnivorous copepod Euchaeta elongata Esterly were collected from 1977 to 1980 in Port Susan, Washington, USA. Predation rates of the adult females increased with increasing prey abundance when fed the following 4 sizes of copepods: adult females of Calanus pacificus (average prosome length [PL] of 2 650 μm), adults of Aetideus divergens (PL of 1 560 μm), adult females of Pseudocalanus spp. (PL of 1 060 μm), and nauplii of C. pacificus (PL of 410 μm). Saturation feeding levels were reached when adult females of the predator were fed the small adult copepod, Pseudocalanus spp. Maximum biomass ingested of this small copepod was more than the maximum amount ingested of the larger copepods. Predation rates of the predatory copepodids at Stages IV and V also increased with increasing concentration of the 1 060 μm (PL) prey. High feeding rates exhibited by both adults and copepodids at Stage V of the predator indicate their importance as sources of mortality on populations of small copepods. Ingestion efficiency E i (prey wholly consumed [prey attacked]-1) varied as follows: adults of E. elongata were more efficient than copepodids of E. elongata; adults were more efficient than copepodids when ingesting smaller prey; starved adults were more efficient than fed ones; and both adults and copepodids were more efficient at low food concentrations. For adults of E. elongata, there were no marked seasonal variations in predation or respiratory rates that would represent acclimatory responses; however, small adults obtained during winter were more efficient at ingesting prey than were the larger adults gathered in summer. This seasonal variation in the efficiency of ingestion may be a useful indicator of physiological state: high E i values could indicate that predators are starving in winter, and low E i values could indicate that predators are satiated in summer.

Estimating Lipid Content of Sandhill Cranes from Anatomical Measurements

mate total lipid reserves in sandhill cranes (Grus canadensis) from mid-continental North America. Lipid content alone (Evans and Smith 1975, Woodall 1978, Bailey 1979) and lipid content with protein reserves (Wishart 1979) have been used as indicators of physiological condition. Positive relationships have been found between the physiological condition of common eiders (Somateria mollissima) during winter (Milne 1976) and geese in spring (Maclnnes et al. 1974, Ankney and Maclnnes 1978) and subsequent clutch size. Also, a positive relationship was detected between condition of mallards (Anas platyrhynchos) and wintering food supplies (Owen and Cook 1977). Lower body weights of Canada geese (Branta canadensis) during winter may be caused by decreased winter food supplies (Hanson 1962, Raveling 1968). Knowledge of the physiology and condition of a species is essential to the understanding of habitat requirements (Fredrickson and Drobney 1977). The ability to assess the condition of sandhill cranes provides a management technique to evaluate the physiological response of a species to dynamic environmental conditions and to quantify management activities related to refuging species. Approximately 10,000 cranes are harvested annually in mid-continental North America (Lewis 1977). Methods are needed to allow periodic evaluation of the condition of sandhill cranes, particularly because lipid levels of cranes have been shown to vary annually during comparable periods in the annual cycle (Iverson 1981).

The adenylate energy charge in marine phytoplantkon: The effect of temperature on the physiological state of Skeletonema costatum (Grev.) Cleve

The adenylate energy charge ([ATP] + 1 2 [ADP]) [0ATP+ADP+AMP] was measured in axenic batch cultures of Skeletonema costatum (Grev.) Cleve at 2°, 10°, 15°, 20°, 24° and 30°C. The results suggest that this eurythermal diatom is physiologically capable of adapting to the 28 °C range of temperature with little apparent difference in the potential energy available to the cell. In N-limited continuous cultures at 15 °C, the energy charge values were lower than those observed in batch culture by 0.2, implying nutrient stress may result in decreased intracellular chemical energy. The utilization of the adenylate energy charge as an indicator of physiological state is suggested.

Some observations upon the relationship of microhaematocrit values to haemoglobin concentrations and erythrocyte numbers in the carp Cyprinus carpio L. and brook trout Salvelinus fontinalis (Mitchill)*

Simultaneous determinations of microhaematocrit, erythrocyte numbers and haemoglobin concentrations have been obtained for samples of carp and trout of both sexes acclimated to various temperature regimes, and varying seasonal and nutritional states. Because haematological parameters have been used as indices of physiological condition in fishes correlational and multivariant regression analyses were carried out in an effort to determine whether valid correlations existed between the readily‐determined parameter, microhaematocrit, and the other 2 variables. Results obtained indicate that microhaematocrit can be used as a general index of haematological status in the carp but not the brook trout.

Some physiological consequences of keepingMytilus edulis in the laboratory

1. Nutritive and temperature stresses in experiments cause a decline in general body condition and dry weight ofMytilus edulis L. Carbohydrate and protein are lost from the body; these losses are greater from the germinal (mantle) than from the somatic (non-mantle) tissues. There is a more rapid loss of carbohydrate than of protein.M. edulis is able to maintain and continue maturation of the gametes in spite of this considerable utilisation of general body reserves. 2. The greater the degree of stress imposed on the test animals the greater is the utilisation of carbohydrate and protein. However, the mussels maintain a balance between these two components so that, at any one time, the carbohydrate to protein ratio does not differ between individuals subjected to different degrees of stress. 3. During the cultures there was a decline in oxygen consumption. Nitrogen excretion either increases or slightly decreases. The ratio oxygen consumed to nitrogen excreted declines in all experiments, indicating an increased use of protein as an energy substrate. The greater the degree of stress imposed upon the test animal, the greater the rate of decline of the O:N ratio. The values for this ratio suggest thatM. edulis normally utilises carbohydrate or fat substrates, though proteins may also be utilised in response to stress. 4. Indices of physiological condition should prove useful in determining the degrees of stress that are experienced by lamellibranchs under cultivation. In order to measure the effects of stress, knowledge of the normal seasonal variations in physiological indices is needed, to serve as a “base-line” with which induced changes in condition may be compared.

Studies of the Eastern Brook Trout Population and Fishery in Sunkhaze Stream, Maine

As a further indication of physiological state at various intervals it is pertinent to comment on the precocial antler development of the experimental males. Almost all fawns have naked antler buttons up to inch long when 4-5 months old. At 15 months, when the wild stock usually have spike antlers, or at the most forked antlers, our animals have had 3 or even 4 point antlers with a spread of up to 12 inches.