Comparisons of Growth in Weight of Temperate and Tropical Marine Fish Counterparts

1984 ◽  
Vol 41 (9) ◽  
pp. 1381-1384 ◽  
Author(s):  
R. R. C. Edwards
Keyword(s):  
Marine Fish ◽  
Growth Rates ◽  
Metabolic Costs ◽  
The Tropics

For temperate and tropical marine teleosts I compared growth in mean weight with age with similar trophic positions and ecological habits. Temperate demersal forms generally grew faster than tropical counterparts whereas mesopelagic and pelagic forms were similar. I suggest that differences in growth rates may be related to higher metabolic costs in the tropics in comparison with temperate waters.

scholarly journals Transient Growth of Thermodynamically Coupled Variations in the Tropics under an Equatorially Symmetric Mean State*

2010 ◽  
Vol 23 (21) ◽  
pp. 5771-5789 ◽  
Author(s):  
Daniel J. Vimont
Keyword(s):  
Boundary Layer ◽  
Heat Flux ◽  
Latent Heat ◽  
Latent Heat Flux ◽  
Zonal Wind ◽  
Growth Rates ◽  
Transient Growth ◽  
Propagation Characteristics ◽  
Meridional Mode ◽  
The Tropics

Abstract The dynamics of thermodynamically coupled disturbances in the tropics that bear a strong resemblance to observed meridional mode variations are investigated using two simple linear coupled models. Both models involve an ocean equation coupled to the atmosphere via the linearized effect of zonal wind variations on the surface bulk latent heat flux. The two models differ in their atmospheric components, which consist of (i) a Gill–Matsuno style model of the free troposphere in which atmospheric heating is parameterized to be linearly proportional to sea surface temperature and (ii) a reduced-gravity model of the tropical boundary layer in which SST anomalies are associated with hydrostatic pressure perturbations throughout the boundary layer. Both atmospheric models follow the standard shallow-water equations on an equatorial beta plane. Growth rates and propagation of coupled disturbances are calculated and diagnosed via eigenanalysis of the linear models and singular value decomposition of the Green’s function for each model. It is found that the eigenvectors of either model are all damped, not orthogonal, and not particularly meaningful in understanding observed tropical coupled variability. The nonnormality of the system, however, leads to transient growth over a time period of about 100 days (based on the choice of parameters in this study). The idealized initial and final conditions that experience this transient growth resemble observed tropical meridional mode variations and tend to propagate equatorward and westward in accord with findings from previous theoretical and modeling studies. Instantaneous growth rates and propagation characteristics of idealized transient disturbances are diagnosed via the linearized atmospheric potential vorticity equation and via propagation characteristics of atmospheric equatorial Rossby waves. Constraints on the poleward extent of initial conditions or imposed steady forcing that can lead to tropical meridional mode variations are identified through analysis of the steady coupled equations. Three constraints limit the poleward extent of forcing that can generate tropical meridional mode variations: (i) a dynamical constraint imposed by the damping rate of the temperature equation as well as the propagation speed of the mode along its wave characteristic; (ii) a constraint imposed by the effectiveness of zonal wind variations in generating surface latent heat flux anomalies; and (iii) the surface moisture convergence, which limits the poleward extent and strength of ocean to atmosphere coupling.

Performance of Anthocephaluschinensis in Puerto Rico

1985 ◽  
Vol 15 (3) ◽  
pp. 577-585 ◽  
Author(s):  
Ariel E. Lugo ◽  
Julio Figueroa
Keyword(s):  
Puerto Rico ◽  
Growth Rates ◽  
Calcareous Soils ◽  
Basal Area ◽  
Annual Rainfall ◽  
Fast Growing ◽  
Single Tree ◽  
Basal Area Growth ◽  
Area Growth ◽  
The Tropics

The growth of kadam (Anthocephaluschinensis (Lam.) A. Rich. ex Walp.), a fast-growing Asiatic species, was studied under different soil and climatic conditions in Puerto Rico. Plantings included a 10-year-old line planting, a 12.5-year-old plantation, 12 localities with 20-year-old single tree plots, and 1 locality with four 52-year-old trees. Over 600 trees were measured in all. Growth rates were comparable to those of fast-growing species elsewhere in the tropics; e.g., the 12.5-year-old plantation had a volume growth of 27.8 m3•ha−1•year−1 (77% was merchantable wood), a basal area growth of 1.82 m2•ha−1•year−1, and a total aboveground biomass production of 11.5 t•ha−1•year−1. Trees grew well both in plantations and in lines under natural forest. The 20-year-old single tree plots averaged up to 1 m•year−1 in height growth and 53 cm2•year−1 in basal area growth. Highest rates were observed in localities with high annual rainfall (>2500 mm) and with phosphorus- and silt-rich soils of high bulk density and low pH. After 10 years, basal area growth of trees was fastest in volcanic deep clay locations, followed, in order, by trees on volcanic shallow loams, calcareous soils, and plutonic sandy loams. However, basal area growth during the first 5 years was fastest in the plutonic sandy loams and slowest in the calcareous soils. After 20 years, volcanic deep clay soils still supported the fastest basal area growth rate (about 100 cm2•year−1), while the other locations converged at about 30 cm2•year−1. Trees reached maximum height after 20 years (average, 19 m; maximum, 26.5 m). Kadam growth was limited by close spacings (below 2.5 × 2.5 m). Trees exhibited excellent form (ratio of diameter at 1.3 m to diameter at 4.9 m > 0.8). We found no evidence of pest or disease attacks on trees, but noted severe tapering and stem twist in localities having poor growth rates. Results underline the need for caution when making species adaptability assessments in the tropics with short-term (<10 years) data.

Indigofera species with agronomic potential in the tropics. Rat toxicity studies

1987 ◽  
Vol 38 (1) ◽  
pp. 177 ◽  
Author(s):  
JH Aylward ◽  
RD Court ◽  
KP Haydock ◽  
RW Strickland ◽  
MP Hegarty
Keyword(s):  
Growth Rates ◽  
Dry Matter ◽  
Histological Changes ◽  
Synthetic Diet ◽  
Lack Of Information ◽  
Feeding Value ◽  
Agronomic Potential ◽  
The Tropics ◽  
Potential Use ◽  
Deleterious Substance

Lack of information on the feeding value and on the presence of deleterious substances in many species belonging to the genus Indigofera has limited the potential use of these species as feed and fodder legumes. To obtain such information, leaves and seeds of 46 accessions representing 19 species of Indigofera that had shown some agronomic value were incorporated into a semi-synthetic diet at 5% w/w (seed) or 20% w/w (forage). The diets were fed to groups of young rats for 4 weeks, and dry matter intakes and growth rates relative to control diets were measured. Selected organs were examined for any histological changes. Seed and forage samples were analysed for indospicine, a hepatotoxin, and for the presence of another potentially deleterious substance, 3-nitropropanoic acid. Thirteen of the accessions representing 8 species were readily eaten and did not depress growth rates relative to control feeds, and another 13 representing 10 species gave acceptable growth rates. Liveweight gains were less affected by forage diets than by those containing seeds. With the exception of those in rats fed on diets containing I. spicata and I. nigritana, the organs of all other rats were histologically normal. It is unlikely that the concentration of 3-nitropropanoic acid (0.5-3.4 mg g-1 dry matter) in any feed was high enough to cause any of the observed toxic signs. Indospicine was present in only 4 of the 23 species tested, including all accessions of I. spicata, and the concentration of indospicine was a good indicator of the toxicity of these feeds. It is concluded that accessions that had produced growth rates comparable to those of controls may be recommended as non-toxic feeds suitable for further testing.

scholarly journals Global tree-ring analysis reveals rapid decrease in tropical tree longevity with temperature

2020 ◽  
Vol 117 (52) ◽  
pp. 33358-33364 ◽  
Author(s):  
Giuliano Maselli Locosselli ◽  
Roel J. W. Brienen ◽  
Melina de Souza Leite ◽  
Manuel Gloor ◽  
Stefan Krottenthaler ◽  
...  
Keyword(s):  
Tree Ring ◽  
Growth Rates ◽  
Tree Mortality ◽  
Forest Biomass ◽  
Global Scale ◽  
Forest Composition ◽  
Future Evolution ◽  
Tree Ring Data ◽  
The Tropics ◽  
Tropical Lowlands

Forests are the largest terrestrial biomass pool, with over half of this biomass stored in the highly productive tropical lowland forests. The future evolution of forest biomass depends critically on the response of tree longevity and growth rates to future climate. We present an analysis of the variation in tree longevity and growth rate using tree-ring data of 3,343 populations and 438 tree species and assess how climate controls growth and tree longevity across world biomes. Tropical trees grow, on average, two times faster compared to trees from temperate and boreal biomes and live significantly shorter, on average (186 ± 138 y compared to 322 ± 201 y outside the tropics). At the global scale, growth rates and longevity covary strongly with temperature. Within the warm tropical lowlands, where broadleaf species dominate the vegetation, we find consistent decreases in tree longevity with increasing aridity, as well as a pronounced reduction in longevity above mean annual temperatures of 25.4 °C. These independent effects of temperature and water availability on tree longevity in the tropics are consistent with theoretical predictions of increases in evaporative demands at the leaf level under a warmer and drier climate and could explain observed increases in tree mortality in tropical forests, including the Amazon, and shifts in forest composition in western Africa. Our results suggest that conditions supporting only lower tree longevity in the tropical lowlands are likely to expand under future drier and especially warmer climates.

scholarly journals Determination of the Minimum Crude Protein Requirements of Broiler Starters and Finishers in the Tropics

2021 ◽  
Vol 3 (1) ◽  
pp. 126-138
Author(s):  
G. M. Babatunde ◽  
B. L. Fetuga
Keyword(s):  
Growth Rates ◽  
Crude Protein ◽  
Live Weight ◽  
Broiler Chicks ◽  
Protein Requirements ◽  
Protein Levels ◽  
The Third ◽  
Percent Nitrogen ◽  
The Tropics ◽  
Protein Diets

THREE experiments were conducted with broiler chicks to determine the minimum crude protein levels in the diets of broiler starters and finishers reared in a tropical environment. The first two trials covered both the starter and finisher periods of 12 weeks while the third experiment covered only the finishing period. The calculated dietary crude protein levels used in the first trial were 14,16 18, 20, 22 and 24%; in the second trial, 20, 22, 24 and 26% and in the third trial, 14, 16, 18 and 20% on air dry basis. Results showed the 24% crude protein (trial 1) and 26% crude protein (trial 2) diets promoted highly significantly better live weight gains than all the other rations during the starter period while during the finishing period, there were no significant differences in the liveweight gains on the diets containing 18, 20, 22, 24 and 24% although growth was always better on the higher protein diets. Diets containing 14, 16 and 18% crude protein were grossly inadequate for the broiler starters while during the finishing period, if all the birds were on adequate broiler starter diets before being put on finisher diets, all those diets promoted growth almost equally well, there being no significant differences among growth rates. The feed/gain ratios followed the same trends as obtained for growth rates, the ratios becoming significantly better for higher protein diets. Mortality was highest for the lowest protein diets and lowest for the highest protein diets, while the percent nitrogen retained tended to be better, though not significantly so, for the higher protein diets. On the basis of these studies, it is recommended that the diets of broiler starter chicks in the tropics should not contain less than 24% crude protein, while those of the finishers should not contain less than 18% crude protein on air dry basis for optimal results.  

Plasma protein-bound iodine and growth rates of beef cattle

1963 ◽  
Vol 14 (4) ◽  
pp. 572 ◽  
Author(s):  
TB Post
Keyword(s):  
Beef Cattle ◽  
Plasma Protein ◽  
Growth Rates ◽  
Seasonal Difference ◽  
Thyroid Activity ◽  
Summer Heat ◽  
Breed Differences ◽  
The Tropics ◽  
Poor Nutrition ◽  
The Relationship

Plasma protein-bound iodine (P.B.I.) levels determined in February and August at Rockhampton, Qld., in 177 grazing heifers and steers were compared with post-weaning gains during summer (October to March) and winter (March to October). In contrast to a large difference in average gain between summer (96 lb) and winter (41 lb), reflecting changes in nutrition, there was no seasonal difference in P.B.I. Significantly lower mean gains in British (Hereford x Shorthorn) breed groups (40 lb) than in F1 (96 lb) or F2 (71 lb) Zebu (Brahman and Africander) x British crossbreds, and in F2 than in F1 crossbreds, were accompanied by similar breed differences in P.B.I. (British 2.91 µg %, F1 crossbreds 3.94 µg %, F2 crossbreds 3.55 µg %). P.B.I.'s were repeatable between seasons (r = 0.4) but gains were not (r = –0.07). Coefficients of correlation between summer gain and both summer and winter P.B.I. were significant in the British and F2 Zebu x British crosses, averaging about 0.5, but were near zero in the F1 crosses. Poor nutrition may have been responsible for the failure to observe significant correlations between winter gains and P.B.I. In summer, differences in P.B.I. accounted for about 25% of differences in gain between British and F2 Zebu x British crossbreds, and among animals within these breeds. The relationship between P.B.I. and gain was linear over the whole range of P.B.I. observed, which indicated that optimal levels of P.B.I. had not been exceeded. These data suggest that summer heat in the tropics may depress thyroid activity to an extent which imposes limitations on growth rates. Differences in performance among animals and breeds of beef cattle may be due in part to differences in ability to maintain adequate thyroid function under heat stress.

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