Spatial variation in mean growth rates at size of southern rock lobster, Jasus edwardsii, in South Australian waters

1999 ◽  
Vol 50 (4) ◽  
pp. 333 ◽  
Author(s):  
R. McGarvey ◽  
G. J. Ferguson ◽  
J. H. Prescott
Keyword(s):  
Growth Rates ◽  
Carapace Length ◽  
Fishery Management ◽  
Individual Growth ◽  
Von Bertalanffy ◽  
Jasus Edwardsii ◽  
Length Increment ◽  
The Mean ◽  
Dependent Growth ◽  
Specific Growth Rates

Size-specific growth rates of Jasus edwardsii were estimated from 16 000 recaptures of tagged lobsters during a 3-year mark–recapture study. The von Bertalanffy growth model was fitted to observed increases in carapace length. A normal likelihood of predicted length increment as a function of starting length and time-at-large was maximized. Estimated standard deviation of the likelihood, taken as an allometric function of predicted length increment, quantified individual growth variation. The distributions of residuals indicated satisfactory fits. von Bertalanffy parameters of growth were estimated at three levels of spatial resolution: 18 statistical reporting blocks, 6 growth subregions, and 2 fishery management zones. Among blocks, the mean annual growth of lobsters of 100 mm carapace length was 7–20 mm for males and 5–15 mm for females. Females grew more slowly after reaching sexual maturity. Growth rates declined by approximately 1 mm year –1 per 20 m increase in depth of habitat, at depths of 20 m and deeper. Density-dependent growth was indicated by spatial anti-correlation between male growth rates at 100 mm and fishery catches by number per unit effort. Regression implied that a 10% decrease in catch rate corresponded to increased growth by weight of 2–5%.

Do abiotic mechanisms determine interannual variability in length-at-age of juvenile Arcto-Norwegian cod?

2002 ◽  
Vol 59 (1) ◽  
pp. 57-65 ◽  
Author(s):  
Geir Ottersen ◽  
Kristin Helle ◽  
Bjarte Bogstad
Keyword(s):  
Growth Rates ◽  
Gadus Morhua ◽  
Barents Sea ◽  
Water Masses ◽  
Inverse Relation ◽  
Lower Growth ◽  
Density Dependent ◽  
The Barents Sea ◽  
The Mean ◽  
Dependent Growth

For the large Arcto-Norwegian stock of cod (Gadus morhua L.) in the Barents Sea, year-to-year variability in growth is well documented. Here three hypotheses for the observed inverse relation between abundance and the mean length-at-age of juveniles (ages 1–4) are suggested and evaluated. Based on comprehensive data, we conclude that year-to-year differences in length-at-age are mainly determined by density-independent mechanisms during the pelagic first half year of the fishes' life. Enhanced inflow from the southwest leads to an abundant cohort at the 0-group stage being distributed farther east into colder water masses, causing lower postsettlement growth rates. We can not reject density-dependent growth effects related to variability in food rations, but our data do not suggest this to be the main mechanism. Another hypothesis suggests that lower growth rates during periods of high abundance are a result of density-dependent mechanisms causing the geographic range of juveniles to extend eastwards into colder water masses. This is rejected mainly because year-to-year differences in mean length are established by age 2, which is too early for movements over large distances.

Growth Patterns in Bluegill (Lepomis macrochirus) and Pumpkinseed (L. gibbosus) Sunfish: Environmental Variation and the Importance of Ontogenetic Niche Shifts

1988 ◽  
Vol 45 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Craig W. Osenberg ◽  
Earl E. Werner ◽  
Gary G. Mittelbach ◽  
Donald J. Hall
Keyword(s):  
Growth Rates ◽  
Lepomis Macrochirus ◽  
Growth Patterns ◽  
Adult Performance ◽  
Littoral Habitat ◽  
Ontogenetic Niche Shifts ◽  
Niche Shifts ◽  
Dependent Growth ◽  
Specific Growth Rates ◽  
Recent Experimental Work

Size-specific growth rates were determined for bluegill (Lepomis macrochirus) and pumpkinseed (L. gibbosus) sunfish collected between 1978 and 1985 in nine lakes in southwestern Michigan. Variation in growth rates was attributable to lake effects as well as an interaction between lake and year effects. Year effects explained none of the observed variation, suggesting that growth rates were influenced more by unique lake differences than by annual climatic differences. Analyses of the covariation in growth among different size-classes of bluegill and pumpkinseed revealed that small bluegill (< 55 mm standard length (SL)) and small pumpkinseed (< 40 mm SL) exhibited similar responses to environmental factors, while large bluegill (> 55 mm SL) and large pumpkinseed (> 50 mm SL) responded differently. These breaks in the growth patterns coincide with the sizes at which each species exhibits an ontogenetic shift in diet. Comparison of growth rates and resource densities suggests that the growth rates of the large fishes were food limited. Small fishes showed significant density-dependent growth. This correlative evidence for competition is in agreement with recent experimental work. We suggest that the competition between juvenile sunfishes is driven by the effects of adult resources on adult performance and the eventual recruitment of juveniles into the littoral habitat.

scholarly journals Growth Rate Variation and Larval Survival: Inferences from an Individual-Based Size-Dependent Predation Model

1993 ◽  
Vol 50 (1) ◽  
pp. 133-142 ◽  
Author(s):  
James A. Rice ◽  
Thomas J. Miller ◽  
Kenneth A. Rose ◽  
Larry B. Crowder ◽  
Elizabeth A. Marschall ◽  
...  
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Individual Variability ◽  
Individual Growth ◽  
Rate Variation ◽  
High Survival ◽  
Initial Growth ◽  
Size Dependent ◽  
The Mean ◽  
Selection For

We used an individual-based Monte Carlo simulation model to explore how changes in the mean and variance of growth rates of individuals in a larval fish cohort interact with size-dependent predation to affect the number and characteristics of individual survivors. Small changes in initial cohort mean growth rate can change survival over the first 60 d of life 10-to 30-fold. But when variance in growth rate among individuals is high, survival can be substantially higher than expected from the initial mean cohort growth rate. Selection for faster-growing individuals becomes stronger with increasing variance and increasing predation rate. In some cases, > 80% of the survivors may come from the upper 25% of the initial growth rate distribution, and the mean growth rate of the survivors may exceed twice the initial mean growth rate. When individual growth rates change from day to day rather than remaining constant, the contribution of atypical individuals is accentuated even further. Counterintuitively, most of the selection for faster-growing individuals happens only after the majority of mortality has already taken place. These results suggest that interactions between individual variability and selective mortality may have important cohort-level implications for survival in fishes.

Temperature-Dependent Growth and Production by a Marine Copepod

1981 ◽  
Vol 38 (1) ◽  
pp. 77-83 ◽  
Author(s):  
I. A. McLaren ◽  
C. J. Corkett
Keyword(s):  
Growth Rates ◽  
Life Cycles ◽  
Temperature Dependent ◽  
Marine Copepod ◽  
Development Times ◽  
Body Sizes ◽  
Eurytemora Herdmani ◽  
Growth Production ◽  
Dependent Growth ◽  
Specific Growth Rates

Highly synchronous cohorts of the copepod Eurytemora herdmani at a station near Halifax, Nova Scotia, were followed in samples taken during late July and early August, 1980. Individuals from the same population were reared in the laboratory from copepodite I (CI) to adult in conditions of food satiation. Development times and adult body sizes in nature were about the same as predicted for comparable temperatures in the laboratory. Weight increments between CI and adult male in samples from nature were exponential. Females became heavier, because of eggs, after CIII, but developed more slowly, so that their specific growth rates were about the same as for males. Production estimated from weights and stage increments in successive samples (cohort method) was adequately predicted from biomasses in samples and temperature-dependent development times from the laboratory. Production of egg matter by adult females was also adequately predicted by temperature-dependent growth rates of younger stages. These "rules" of development, growth, and production need wider empirical testing and theoretical justification.Key words: Copepoda, temperature, life cycles, development, growth, production

Estimation of Recent Growth of Field-Caught Postlarval American Lobsters, Homarus americanus, from RNA:DNA Ratios

1994 ◽  
Vol 51 (2) ◽  
pp. 286-294 ◽  
Author(s):  
Marie Antonette R. Juinio ◽  
J. Stanley Cobb
Keyword(s):  
Growth Rates ◽  
Food Limitation ◽  
Homarus Americanus ◽  
Zooplankton Biomass ◽  
Individual Growth ◽  
Prolonged Duration ◽  
The Mean ◽  
Temperature And Growth ◽  
Relationship Of ◽  
The Relationship

We developed a growth model for the postlarvae of the American lobster, Homarus americanus, using the relationship of RNA:DNA ratios, temperature, and growth rates during postmolt through early pre-molt of laboratory-reared postlarval lobsters. The model was used to estimate individual growth rates of 385 postlarval lobsters in molt stages C and D0, collected at two sites in Block Island Sound over three years, 1988–90. The mean growth rates of postlarvae collected in June 1989 and 1990 (0.57 ± 0.19 and 0.54 ± 0.18 mg protein∙d−1) were significantly higher than those collected in July (0.39 ± 0.17 and 0.43 ± 0.18 mg protein∙d−1). Changes in sea surface temperatures of zooplankton biomass did not account for the seasonal difference in growth rates, nor was there correlation between the biweekly mean growth rates and postlarval densities. The incidence of poorly nourished postlarval lobsters (individuals with growth rates < 0.22 mg protein∙d−1) was less than 10% of the total samples in each year. We found no evidence that food limitation, resulting in starvation or prolonged duration of the postlarval instar, was a significant factor contributing to the observed interannual variability of postlarval densities.

scholarly journals The Growth Rate Of Verruca Stroemia (O. Müller)

1958 ◽  
Vol 37 (2) ◽  
pp. 427-433 ◽  
Author(s):  
H. Barnes
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Specific Growth ◽  
Maximum Size ◽  
Rhythmic Pattern ◽  
The Mean ◽  
Rhythmic Growth ◽  
Specific Growth Rates ◽  
High Level ◽  
Balanus Balanoides

Data are presented on the growth rate of Verruca stroemia under natural conditions and when exposed continuously and cleaned repeatedly. Several series exposed at different times of the year were followed.Rapid growth takes place (under raft conditions) following settlement; the maximum size is virtually reached in one season's growth between spring and early winter. There is little growth in midwinter.Differences between the mean specific growth rates of the various series can be ascribed to differences in the availability of food.The question is discussed as to whether there is any seasonal rhythm; the evidence indicates that no marked rhythmic pattern of growth exists.Observations on deep-water populations would be of value for comparison and to unmask any relatively weak rhythmic growth.The mean specific growth rates at half their maximum size are compared for several species—Balanus balanoides, B. crenatus, B. balanus, Chthamalus stellatus and Verruca stroemia; it is similar for all species except Chthamalus stellatus. The high level barnacle may require stimulation such as is provided by wave action to elicit full metabolic activity.

Are Growth Parameters Estimated from Tagging and Age–Length Data Comparable?

1988 ◽  
Vol 45 (6) ◽  
pp. 936-942 ◽  
Author(s):  
R. I. C. C. Francis
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growth Parameters ◽  
Growth Models ◽  
Maximum Length ◽  
Fish Growth ◽  
Data Sets ◽  
Von Bertalanffy ◽  
Length Data ◽  
The Mean

The two most common ways of estimating fish growth use age–length data and tagging data. It is shown that growth parameters estimated from these two types of data have different meanings and thus are not directly comparable. In particular, the von Bertalanffy parameter l∞ means asymptotic mean length at age for age–length data, and maximum length for tagging data, when estimated by conventional methods. New parameterizations are given for the von Bertalanffy equation which avoid this ambiguity and better represent the growth information in the two types of data. The comparison between growth estimates from these data sets is shown to be equivalent to comparing the mean growth rate of fish of a given age with that of fish of length equal to the mean length at that age. How much these growth rates may differ in real populations remains unresolved: estimates for two species of fish produced markedly different results, neither of which could be reproduced using growth models. Existing growth models are shown to be inadequate to answer this question.

Growth rates of juvenile southern rock lobster (Jasus edwardsii) estimated through a diver-based tag - recapture program

2012 ◽  
Vol 63 (2) ◽  
pp. 110 ◽  
Author(s):  
Adrian Linnane ◽  
David Hobday ◽  
Stewart Frusher ◽  
Caleb Gardner
Keyword(s):  
Growth Rates ◽  
South Australia ◽  
Individual Growth ◽  
Rock Lobster ◽  
South Eastern ◽  
Growth Increments ◽  
Eastern Australia ◽  
Significant Difference ◽  
Jasus Edwardsii ◽  
South Eastern Australia

Despite being one of the most economically important fisheries in south-eastern Australia, growth rates of juvenile southern rock lobster (Jasus edwardsii) have not previously been quantified in the wild. This study utilised a diver-based tag–recapture program to estimate growth rates of individuals between 40–80 mm carapace length (CL) in temperate reef sites across south-eastern Australia. Of the 7064 lobsters tagged and released, 978 (14%) were recaptured with recapture rates of 23, 5 and 7% in the States of Tasmania, South Australia and Victoria respectively. Although individual growth increments were similar between the sexes, differences in annual growth rates were evident at 50 mm CL, with males growing ~1.4 times faster than females. Increased levels of growth in males resulted from a higher moult frequency, which was found to significantly reduce in females as they reached sexual maturity at ~70–80 mm CL. No significant difference was found in growth rates of males or females between the States when all sites within each State were combined. The growth estimates from this work contribute to the understanding of juvenile lobster population dynamics and will improve current fishery models by confirming relationships between early juvenile, pre-recruit abundance and entry to the fishable biomass.

Dynamics of individual growth in a recovering population of lake trout (Salvelinus namaycush)

2001 ◽  
Vol 58 (2) ◽  
pp. 262-272 ◽  
Author(s):  
Mary C Fabrizio ◽  
Robert M Dorazio ◽  
Stephen T Schram
Keyword(s):  
Growth Rates ◽  
Lake Trout ◽  
Growth Dynamics ◽  
Salvelinus Namaycush ◽  
Wild Fish ◽  
Individual Growth ◽  
Wisconsin Department ◽  
Growth Increments ◽  
Before And After ◽  
The Mean

In 1976, the Wisconsin Department of Natural Resources established a refuge for a nearly depleted population of lake trout (Salvelinus namaycush) at Gull Island Shoal, Lake Superior. The refuge was intended to reduce fishing mortality by protecting adult lake trout. We examined the growth dynamics of these lake trout during the period of recovery by comparing estimates of individual growth before and after the refuge was established. Our estimates are based on an annual mark-recapture survey conducted at the spawning area since 1969. We developed a model that allowed mean growth rates to differ among individuals of different sizes and that accommodated variation in growth rates of individuals of the same size. Likelihood ratio tests were used to determine if the mean growth increments of lake trout changed after the refuge was established. Our results suggest that growth of mature lake trout (particularly wild fish) decreased significantly in the postrefuge period. This decreased growth may have been associated with a reduction in food availability. We also observed reductions in growth as wild fish grew older and larger, which suggests that the growth of these fish may be adequately approximated by a von Bertalanffy growth model if it becomes possible to obtain accurate ages.

Studies of the permanent incisor eruption, and body development, of the Large East African Zebu (Boran): 2. Relations of incisor eruption with body growth, body development, and carcass composition

1977 ◽  
Vol 88 (2) ◽  
pp. 361-373 ◽  
Author(s):  
A. B. Carles ◽  
K. Meidie Lampkin
Keyword(s):  
Growth Rates ◽  
Linear Growth ◽  
Specific Growth ◽  
Carcass Composition ◽  
Head Development ◽  
Body Development ◽  
Partial Correlations ◽  
Eruption Age ◽  
The Mean ◽  
Specific Growth Rates

SUMMARYA comparison was made of the growth curves for early and late eruptors (steers whose eruption age of the first incisor pair was less than the mean, and greater than the mean respectively). From birth to 195 weeks early eruptors were consistently heavier than late eruptors (P < 0·01) by approximately 4% of the overall mean body weight. Growth was linear from birth up to 126 weeks of age, and the variability increased markedly from about 60 weeks of age.The average daily gain from birth to 195 weeks was 341 g. Linear growth-rates for consecutive stages within this period were generally faster for early eruptors, with the differences ranging between 4 and 6% of the mean for periods exceeding 60 weeks. Comparison of these differences showed that linear growth-rates were only significantly different for growth periods of approximately 120 weeks and longer. When the specific growth-rates were compared no differences were significant.The differences between the growth rates of fast and slow eruptors (steers whose eruption period was less than the mean, and greater than the mean respectively) were not significant, both for linear and specific growth rates.Early eruptors had larger heads (head length x head width) relative to body weight (P < 0·05), indicating eruption at an earlier stage of body development. Also early eruptors had longer narrower heads, suggesting slower maturation rates.Partial correlations between eruption age and head length varied from 0·37 to 0·74 (P < 0·01) showing a close relation with stage of head development. Partial correlations with other measures of skeletal development showed that they were of negligible importance relative to head development.Relations between eruption age of the first incisor pair and six measures of carcass composition were negligible, as none of the partial regression coefficients was significant.

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