scholarly journals Comparative growth, age at maturity and sex change, and longevity of Hawaiian parrotfishes, with bomb radiocarbon validation

2018 ◽  
Vol 75 (4) ◽  
pp. 580-589 ◽  
Author(s):  
Edward E. DeMartini ◽  
Allen H. Andrews ◽  
Kathrine G. Howard ◽  
Brett M. Taylor ◽  
Dong-Chun Lou ◽  
...  
Keyword(s):  
Fork Length ◽  
Logistic Models ◽  
Growth Curves ◽  
Sex Change ◽  
Terminal Phase ◽  
Large Species ◽  
Small Species ◽  
Bomb Radiocarbon ◽  
Current Minimum ◽  
Fishery Species

Growth rates and longevities were estimated for five major fishery species of parrotfishes (“uhu”) at Oahu, Hawai’i. All species grew rapidly with von Bertalanffy growth formula k values ≥0.4·year−1. Longevities were found to range broadly among the three small species, 4 years in Calotomus carolinus and 6 and 11 years in Scarus psittacus and Chlorurus spilurus, and to 15–20 years in Scarus rubroviolaceus and Chlorurus perspicillatus for the two large species. Age reading and growth curves for the latter two large species were validated using bomb radiocarbon dating. Median ages at sexual maturity as females (AM50) and at sex change (from female to terminal phase male, AΔ50) were estimated using logistic models. Sexual maturation occurred at 1–2 years for the small species and at 3–3.5 years in the large species. AΔ50 estimates ranged from 2 to 4 years in the small species and were about 5 and 7 years in S. rubroviolaceus and C. perspicillatus, respectively. Estimated milestones poorly corresponded to the current minimum legal size for uhu in Hawai’i (12 in. or 30.5 cm fork length). Pooling these parrotfishes for management seems generally inappropriate, especially for the two large species. Age-based metrics are more informative than size-based metrics for these fishes.

scholarly journals The Cumulative Risk of Chemical and Nonchemical Exposures on Birth Outcomes in Healthy Women: The Fetal Growth Study

2019 ◽  
Vol 16 (19) ◽  
pp. 3700 ◽  
Author(s):  
Leah Zilversmit Pao ◽  
Emily W. Harville ◽  
Jeffrey K. Wickliffe ◽  
Arti Shankar ◽  
Pierre Buekens
Keyword(s):  
Birth Outcomes ◽  
Fetal Growth ◽  
Cumulative Risk ◽  
Logistic Models ◽  
Growth Curves ◽  
Adverse Outcomes ◽  
Risk Scores ◽  
Growth Study ◽  
Race Ethnicity ◽  
Pregnancy Weight

Metals, stress, and sociodemographics are commonly studied separately for their effects on birth outcomes, yet often jointly contribute to adverse outcomes. This study analyzes two methods for measuring cumulative risk to understand how maternal chemical and nonchemical stressors may contribute to small for gestational age (SGA). SGA was calculated using sex-specific fetal growth curves for infants of pregnant mothers (n = 2562) enrolled in the National Institute of Child Health and Human Development (NICHD) Fetal Growth Study. The exposures (maternal lead, mercury, cadmium, Cohen’s perceived stress, Edinburgh depression scores, race/ethnicity, income, and education) were grouped into three domains: metals, psychosocial stress, and sociodemographics. In Method 1 we created cumulative risk scores using tertiles. Method 2 employed weighted quantile sum (WQS) regression. For each method, logistic models were built with three exposure domains individually and race/ethnicity, adjusting for age, parity, pregnancy weight gain, and marital status. The adjusted effect of overall cumulative risk with three domains, was also modeled using each method. Sociodemographics was the only exposure associated with SGA in unadjusted models ((odds ratio) OR: 1.35, 95% (confidence interval) CI: 1.08, 1.68). The three cumulative variables in adjusted models were not significant individually, but the overall index was associated with SGA (OR: 1.17, 95% CI: 1.02, 1.35). In the WQS model, only the sociodemographics domain was significantly associated with SGA. Sociodemographics tended to be the strongest risk factor for SGA in both risk score and WQS models.

scholarly journals Biology, not environment, drives major patterns in maximum tetrapod body size through time

2012 ◽  
Vol 8 (4) ◽  
pp. 674-677 ◽  
Author(s):  
Roland B. Sookias ◽  
Roger B. J. Benson ◽  
Richard J. Butler
Keyword(s):  
Body Size ◽  
Environmental Factors ◽  
Abiotic Factors ◽  
Logistic Models ◽  
Growth Curves ◽  
Maximum Size ◽  
Generalized Least Squares ◽  
Least Squares Regression ◽  
Geological Time ◽  
Cenozoic Mammals

Abiotic and biological factors have been hypothesized as controlling maximum body size of tetrapods and other animals through geological time. We analyse the effects of three abiotic factors—oxygen, temperature and land area—on maximum size of Permian–Jurassic archosauromorphs and therapsids, and Cenozoic mammals, using time series generalized least-squares regression models. We also examine maximum size growth curves for the Permian–Jurassic data by comparing fits of Gompertz and logistic models. When serial correlation is removed, we find no robust correlations, indicating that these environmental factors did not consistently control tetrapod maximum size. Gompertz models—i.e. exponentially decreasing rate of size increase at larger sizes—fit maximum size curves far better than logistic models. This suggests that biological limits such as reduced fecundity and niche space availability become increasingly limiting as larger sizes are reached. Environmental factors analysed may still have imposed an upper limit on tetrapod body size, but any environmentally imposed limit did not vary substantially during the intervals examined despite variation in these environmental factors.

scholarly journals Mathematical models to describe the growth curves of white-egg layers

2018 ◽  
Vol 39 (3) ◽  
pp. 1327
Author(s):  
Cleber Franklin Santos de Oliveira ◽  
João Marcos Novais Tavares ◽  
Gerusa Da Silva Salles Corrêa ◽  
Bruno Serpa Vieira ◽  
Silvana Alves Pedrozo Vitalino Barbosa ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Mean Squared Error ◽  
Computer Software ◽  
Logistic Models ◽  
Growth Curves ◽  
Gompertz Model ◽  
Information Criterion ◽  
Coefficient Of Determination ◽  
Population Densities

The aim of this study was to compare mathematical models describing growth curves of white-egg layers at different population densities. To fit the models, 4,000 growing white-egg layers were utilized. The experimental design was completely randomized, with population densities of 71, 68, 65, 62, and 59 birds per cage in the starter phase and 19, 17, 15, 13, and 11 birds per cage in the grower phase, with 10 replicates each. Birds were weighed weekly to determine the average body weight and the weight gain. Gompertz and Logistic models were utilized to estimate their growth. The data analysis was carried out using the PROC NLMIXED procedure of the SAS® statistical computer software to estimate the parameters of the equation because mixed models were employed. The mean squared error, the coefficient of determination, and Akaike’s information criterion were used to evaluate the quality of fit of the models. The studied models converged for the description of the growth of the birds at the different densities studied, showing that they were appropriate for estimating the growth of white-egg layers housed at different population densities. The Gompertz model showed a better fit than the Logistic model.

The first specimen of Deinotherium indicum (Mammalia, Proboscidea, Deinotheriidae) from the late Miocene of Kutch, India

2020 ◽  
Vol 94 (4) ◽  
pp. 788-795 ◽  
Author(s):  
Ningthoujam Premjit Singh ◽  
Advait M. Jukar ◽  
Rajeev Patnaik ◽  
K. Milankumar Sharma ◽  
Nongmaithem Amardas Singh ◽  
...  
Keyword(s):  
South Asian ◽  
Late Miocene ◽  
Indian Subcontinent ◽  
Morphological Diversity ◽  
Western India ◽  
Large Species ◽  
Small Species ◽  
Old World ◽  
First Occurrence

AbstractDeinotheriidae Bonaparte, 1845 is a family of browsing proboscideans that were widespread in the Old World during the Neogene. From Miocene deposits in the Indian subcontinent, deinotheres are known largely from dental remains. Both large and small species have been described from the region. Previously, only small deinothere species have been identified from Kutch in western India. In the fossiliferous Tapar beds in Kutch, dental remains have been referred to the small species Deinotherium sindiense Lydekker, 1880, but the specimens are too fragmentary to be systematically diagnostic. Here, we describe a large p4 of a deinothere from the Tapar beds and demonstrate that it is morphologically most similar to Deinotherium indicum Falconer, 1845, a large species of deinothere, thereby confirming the identity of deinotheres at Tapar. Deinotherium indicum from Tapar is larger than other deinotheres identified from Kutch and is the first occurrence of the species in the region. This new specimen helps constrain the age of the Tapar beds to the Tortonian and increases the biogeographic range of this species—hitherto only known from two localities on the subcontinent. This specimen also highlights the morphological diversity of South Asian deinothere p4s and allows us to reassess dental apomorphies used to delimit Indian deinothere species. Lastly, we argue that by the late Miocene, small deinotheres in Kutch were replaced by the large Deinotherium indicum.

Velloziaceae in honorem appellatae

Phytotaxa ◽  
2014 ◽  
Vol 175 (2) ◽  
pp. 85 ◽  
Author(s):  
Renato Mello-Silva ◽  
NANUZA LUIZA DE MENEZES
Keyword(s):  
New Species ◽  
Minas Gerais ◽  
Large Species ◽  
Small Species ◽  
Fourth Species

Four new species of Vellozia are described and named after people linked to Velloziaceae and Brazilian botany. Vellozia everaldoi, V. giuliettiae, V. semirii and V. strangii are endemic to the Diamantina Plateau in Minas Gerais, Brazil. Vellozia giuliettiae and V. semirii are small species that share characteristics that would assign them to Vellozia sect. Xerophytoides, which include an ericoid habit with no leaf furrows and six stamens. Vellozia everaldoi, although a small, ericoid species, could not be placed in that section because it has conspicuous furrows, although it is considered closely related to species of that section. The fourth species, V. strangii, is a relative large species closely related to V. hatschbachii. Descriptions and illustrations of the species are followed by a discussion of their characteristics and putative relationships.

The flight of petrels and albatrosses (procellariiformes), observed in South Georgia and its vicinity

1982 ◽  
Vol 300 (1098) ◽  
pp. 75-106 ◽  
Keyword(s):  
Body Mass ◽  
The Body ◽  
Large Species ◽  
Small Species ◽  
Classical Dynamic ◽  
South Georgia ◽  
Mass Comparison ◽  
Gliding Flight ◽  
Field Season ◽  
Simple Power Function

Nine procellariiform species, covering a range of body mass exceeding 200: 1, were studied during a visit to Bird Island, South Georgia, with the British Antarctic Survey, in the 1979-1980 field season. Speed measurements were made by ornithodolite of birds slope-soaring over land, birds flying over the sea but observed from land, and birds observed from a ship. In the second group, which showed the least anomalies, lift coefficients corresponding to mean airspeeds were about 1 for albatrosses, decreasing to about 0.3 for the smallest petrels. All species increased speed when flying against the wind. The small species proceeded by flap-gliding, while the large ones flapped infrequently, and only in light winds. The small species flew lower than the larger ones, but this may be related to the fact that most of the observations were of birds flying into wind. The albatrosses ( Diomedea, Phoebetria ) and giant petrels ( Macronectes ) were found to have a ‘shoulder lock’, consisting of a tendon sheet associated with the pectoralis muscle, which restrained the wing from elevation above the horizontal. This arrangement was not seen in the smaller species, and was interpreted as an adaptation reducing the energy cost of gliding flight. The main soaring method in the large species appeared to be slope-soaring along waves. Windward ‘pullups’ suggestive of the classical ‘dynamic soaring’ technique were seen in large and medium-sized species. However, the calculated strength of the wind gradient would have been insufficient to maintain airspeed to the heights observed, and it was concluded that most of the energy for the pullups must come from kinetic energy, acquired by gliding along a wave in slope lift. Gliding downwind through the wind gradient should significantly increase the glide ratio, but this was not observed. Slope-soaring along moving waves in zero wind was recorded. The data were used to derive estimates of the average speeds that the different species should be able to maintain on foraging expeditions. Estimates of the rate of energy consumption were also made, taking into account the greater dependence on flapping in the smaller species, and on soaring in the larger ones. The distance travelled in consuming fuel equivalent to a given fraction of the body mass would seem to be very strongly dependent on mass. Comparison of the largest species ( Diomedea exulans ) with the smallest ( Oceanites oceanicus ) suggests that ‘range’, defined in this way, varies as the 0.60 power of the mass, although the relation is more complex than a simple power function.

Colonization dynamics in trophic-functional patterns of biofilm-dwelling ciliates using two methods in coastal waters

2015 ◽  
Vol 95 (4) ◽  
pp. 681-689 ◽  
Author(s):  
Qi Wang ◽  
Henglong Xu
Keyword(s):  
Species Richness ◽  
Coastal Waters ◽  
Logistic Models ◽  
Growth Curves ◽  
The Yellow Sea ◽  
Artificial Substratum ◽  
Initial Stage ◽  
Functional Patterns ◽  
Colonization Dynamics ◽  
Stage 1

The colonization dynamics in trophic-functional structure of biofilm-dwelling ciliate fauna were studied using two methods based on an artificial substratum in Korean coastal waters of the Yellow Sea during April 2007. Polyurethane foam enveloped slide (PFES) and conventional slide (CS) systems were used to collect ciliate samples at a depth of 1 m. The ciliate fauna represented similar colonization dynamics in trophic-functional patterns that were driven mainly by the algivores, bacterivores and non-selectives in both systems. Simple trophic-functional patterns (e.g. algivores and non-selectives) occurred within the ciliate fauna at the initial stage (1–3 days), while complex patterns (e.g. algivores, non-selectives and bacterivores) were established at the transitional (5–7 days) and equilibrium (9–19 days) stages. However, the time in which ciliate fauna reached a stable trophic-functional pattern was shorter in the PFES than in the CS system. Among four trophic-functional types, the algivores and bacterivores significantly fitted the MacArthur-Wilson and logistic models in colonization and growth curves in both systems, respectively. Furthermore, the species richness and diversity of algivores and bacterivores were significantly higher in the PFES system than in the CS. These results suggest that the PFES system was more effective than the conventional slide method for a colonization survey on trophic-functional patterns of biofilm-dwelling ciliate fauna in marine ecosystems.

Instar Increments in Copepod Growth

1986 ◽  
Vol 43 (8) ◽  
pp. 1671-1674 ◽  
Author(s):  
Alan R. Longhurst
Keyword(s):  
Growth Patterns ◽  
Large Species ◽  
Adult Size ◽  
Small Species

There is a difference in the growth patterns of large and small copepods as indicated by lengths at each instar for 55 species of copepods from all latitudes. Large species put on a greater proportion of their adult size relatively late in life compared with small species. This confirms an earlier suggestion based on a comparison of only two species.

Sizes and ages in commercial landings with estimates of growth, mortality and yield per recruit of yellowtail kingfish (Seriola lalandi) from New South Wales, Australia

2004 ◽  
Vol 55 (5) ◽  
pp. 489 ◽  
Author(s):  
John Stewart ◽  
Douglas J. Ferrell ◽  
Bryan van der Walt
Keyword(s):  
Growth Rates ◽  
New South ◽  
New South Wales ◽  
Fork Length ◽  
South Wales ◽  
Current Minimum ◽  
Yellowtail Kingfish ◽  
Seriola Lalandi ◽  
Size At Age ◽  
Yield Per Recruit

The size and age compositions of yellowtail kingfish (Seriola lalandi) were studied in commercial landings in New South Wales, Australia between 1998 and 2000. The fishery was dominated by fish smaller than 65 cm fork length and these fish were estimated to be 2 and 3 year olds. Estimates of growth rates were made using size-at-age data from sectioned otoliths. The oldest yellowtail kingfish found was 21 years and measured 136 cm fork length. There were no differences in the growth rates between regions or between sexes. Yellowtail kingfish grow rapidly and reach their minimum legal length of 60 cm total length at around 2 years of age. These estimates showed that previous studies, which estimated ages using whole otoliths, may have underestimated the ages of older yellowtail kingfish. Total instantaneous mortality rates generated from catch curves ranged between 0.43 and 0.79. Yield per recruit models suggest that the population is currently growth overfished. The information provided is used to discuss the suitability of the current minimum legal length for yellowtail kingfish in New South Wales.

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