Growth ofA Research Articles

Field assessment of aeroponically grown and nodulated Acacia mangium

Acacia mangium seedlings were grown and nodulated with selected elite strains of Bradyrhizobium spp. under aeroponic conditions. The aeroponics system is well known for furnishing a very rich air environment around the roots and has been shown in our earlier work to induce rapid growth and enhance performance of Acacia seedlings under greenhouse conditions. This paper reports that the positive effects on growth, such as increased height and leaf area, induced by aeroponic culture with the Bradyrhizobium strains, Tel 2 from Malaysia and Aust 13c from Australia, continued to be sustained for 4 months after plants were transferred to field conditions. Random sampling and analyses of Bradyrhizobia by polymerase chain reaction–restriction fragment length polymorphism (PCR–RFLP) also showed that Aust 13c continued to persist in root nodules of inocualated plants in the field, with inoculated plants having significantly higher nitrogen and phosphorus concentrations as well as higher photosynthetic rates than non-inoculated controls. The A. mangium plants were only 8 months old from germination but had already reached mean heights of approximately 2.4 m. The results suggest that aeroponic growth and nodulation should be further investigated for their potential to promote growth of A. mangium, especially on difficult soils.

Digestion in the rumen of lactating dairy cows given mixtures of urea-treated whole-crop wheat and grass silage

Abstract To measure the effect of partially replacing grass silage with urea-treated whole-crop wheat (WCW) four multiparous Holstein/Friesian lactating cows fitted with cannulas in the rumen and proximal duodenum were offered four diets in a Latin-square experiment. Grass silage (GS) was produced from the primary growth of a perennial ryegrass sward. Spring wheat (cv. Axona) was harvested at 603 g dry matter (DM) per kg and preserved with 20 (WCW-20) or 40 (WCW-40) kg urea per t DM. The diets were 6 kg DM of a dairy concentrate daily with one of four forages offered ad libitum The forage treatments were GS alone, a 2: 1 DM ratio of GS with WCW-40 (2: 1 40), or a 1: 2 DM ratio of GS with WCW-20 (1: 2 20) or WCW-40 (1: 2 40). Each period lasted 4 weeks with rumen and duodenal samples being taken on 2 days in the last week. Concentrations of milk fat and protein were increased by WCW inclusion. The digestibility in the rumen of DM, organic matter (OM) neutral-detergent fibre (NDF), acid-detergent fibre and starch fell with increasing WCW-40 inclusion in the diet. Flow of starch and non-ammonia nitrogen to the duodenum increased with WCW inclusion. It was estimated that the amounts of OM, starch, NDF and nitrogen digested post ruminally increased with WCW. With WCW there were increases in the rumen in the ratio of acetic acid plus n-butyric acid to propionic acid and in ammonia concentrations. The level of urea inclusion had no significant effects on rumen digestion. It is concluded that the large reduction in the contribution of the rumen to total OM digestion when WCW partially replaces grass silage may have implications for calculations of metabolizable protein supplies to animals given such diets. Possible means to improve food utilization include processing of the wheat grains and inclusion of readily fermentable carbohydrates in the diet to facilitate the utilization of the rumen ammonia.

Catecholamine enhancement ofAeromonas hydrophilagrowth

Several species of bacteria have been shown to respond to the administration of norepinephrine and other catecholamines with increased growth (in culture) and virulence. In this study, we examined the effects of catecholamines on the growth of cultures ofAeromonas hydrophila, a Gram-negative bacillus found in brackish water. Bacterial cultures were maintained in tryptic soy both, then washed free of medium and transferred to a bovine serum-supplemented minimal salts medium. Treatment ofA. hydrophilacultures with 10−3to 10−5M norepinephrine resulted in dramatic increases in growth at 24 h and longer, as assessed by spot plate analysis on tryptic soy agar plates. Norepinephrine-treated cultures had 4.5 log greater bacterial numbers than control cultures. Epinephrine, dopamine and isoproterenol were shown to be similarly effective in enhancing growth ofA. hydrophila, over narrower concentration ranges. Acetylcholine supplementation of cultures did not alter the growth ofA. hydrophila.Serotonin slightly enhancedAeromonasgrowth when administered at very high concentrations (10−3M). The increased growth observed after catecholamine administration may alter the capacity to infect an animal under stressful conditions, and is another potential mechanism by which a stress response can affect susceptibility to disease.

Effect of metabolites produced by trichoderma harzianum biotypes and agaricus bisporus on their respective growth radii in culture

Trichoderma harzianum biotypes Th1, Th2, and Th3 produced volatile metabolites in vitro which had similar fungistatic effects on the growth of Agaricus bisporus. Metabolites present in agar colonized by these strains also inhibited mycelial growth of A. bisporus, although the reduction in growth was less in the presence of metabolites produced by biotype Th2 than that in the presence of metabolites produced by Th1 or Th3. A. bisporus produced metabolites in liquid culture that inhibited the growth of Th1 and Th3 but stimulated the growth of Th2. A compound(s) responsible for the inhibition and stimulation was extracted from A. bisporus culture filtrate and from compost-grown fruit bodies with n-butanol, but the identity of the compound(s) was not determined. We suggest that the stimulation of Th2 by metabolites produced by A. bisporus and the relatively low level of inhibition of A. bisporus by Th2 facilitate colonization of compost by both fungi. However, as compost colonization reaches a maximum, a change in the competitive balance in favor of Th2 results in the inhibition of fruit body production by A. bisporus and the devastating green mold epidemics affecting mushroom production.

Age and growth rates of North Atlantic eel larvae (Anguilla spp.), based on published length data

The age of glass eels arriving at the European coasts is estimated by different authors to range from 3/4 to 3+years; some of these estimates are based on counts of “daily rings”. The present study reviews published data on North Atlantic length frequency distributions. The only years for which larvae samples are available from the spawning area to the European continental slope are 1979 and, to a certain extent, also 1922. In the spring of both years, length frequency distributions exhibited two distinct maxima which are considered to belong to the AG 0 (mean lengths 12 and 18 mm for 1979 and 1922, respectively) and the AG I (47 and 44 mm). In addition, a third, less distinct maximum is visible and the existence of an AG II must be considered. Growth during the first year of life is calculated using the means of total lengths of sufficiently large samples, collected with progressing season, of the years 1920, 21, 22, 79, 81. From the resulting linear regressions forAnguilla anguilla until the beginning of winter, a daily length increase of 0.15 mm was estimated. Growth ofA. rostrata was faster (0.22 mm·day−1) Daily length increase ofA. anguilla in winter was only 0.03 mm; during a possible second summer 0.06–0.09 mm·day−1 and during a possible third summer considerably less. There is a length increase of the European eel larvae from south to north, known also from glass eels, which makes evaluation of length increase from west to east even more difficult. A higher age of glass eels in the north than in the south is therefore likely.

Effects of early season defoliation on above-ground growth ofAnthyllis cytisoides, a Mediterranean browse species

Anthyllis cytisoidesL. is a traditional forage species, well adapted to grazing pressure, and so might be expected to respond positively to moderate grazing. We performed a hierarchical design analysis of variance with three levels of plant defoliation (10, 50 and 90%) and three of stem defoliation (10, 50 and 90% of shoots removed), in three age classes based on trunk base perimeter (≤11cm, 11–20cm and >20cm). Response to herbivory was measured as total vegetative length, inflorescence length, leaf number, flower number, and the ratio of the number of floral axes to the total number of axes.We found thatA. cytisoidescompensated for herbivory. That is, above-ground growth ofA. cytisoidesincreased with the percentage of plant defoliation, with respect to elongation of the stem and increase in the total flower and leaf number. In contrast, growth following stem defoliation declined in the target stem as stem defoliation increases. Stem defoliation effect was more evident in young plants than in older ones. The increase in plant growth with plant defoliation was seen both in the average growth per floral axes and the number of floral axes per stem. However, only the number of floral axis per stem was responsible for the reduction in stem productivity with experimental defoliation.Stem overcompensation (greater elongation in defoliated stems than control) occurred only in stems suffering 10% defoliation when plants were under medium and high experimental herbivore pressure, indicating the ability ofA. cytisoidesto produce a compensatory response to herbivory. The growth consequences of early season defoliation persist after two growing periods, increasing above-ground growth differences among treatment groups.

Effect of Cattle Grazing and Seedling Size on the Establishment ofAraucaria cunninghamiiin a Silvo-pastoral System in Northeast Australia

A study was undertaken to assess the effect of tree age at which grazing commenced and seedling size on the establishment ofAraucaria cunninghamii(hoop pine) trees in a silvo-pastoral system on the Atherton Tablelands of northeast Australia. Grazing with dairy cattle commenced at three ages after tree planting: (1) 2 weeks; (2) 6 months and (3) 18 months. Seedlings of two size classes, small (15 cm tall and 18 months old) and large (45 cm tall and 27 months old), were used. Trees were measured for survival and height, and assessed for physical damage and development of multi-stems at ages 6, 12 and 24 months. Results showed that tree survival and height did not differ significantly with age at which grazing commenced and that grazing did not cause unacceptable mortality, damage or reduction in height growth ofA. cunninghamii. The lack of cattle impact was mainly becauseA. cunninghamiihas a special morphological feature, prickly needles, which discourages cattle from physical contact. Although tree height ofA. cunninghamiivaried significantly between the two seedling sizes, the difference became smaller as the trees grew. It is suggested that for the establishment ofA. cunninghamiiin silvo-pastoral systems, grazing can be allowed almost immediately after tree planting, providing an appropriate stocking rate is used. There are no apparent advantages in using larger, compared with smaller, seedlings.

Production of aflatoxin byAspergillus parasiticus and its control

The aim of the present work was to investigate the production of aflatoxin byAspergillus parasiticus and to find out the possible ways to control it. Of 40 food samples collected from Abha region, Saudi Arabia, only 25% were contaminated with aflatoxins. Oil-rich commodities had the highly contaminated commodities by fungi and aflatoxins while spices were free from aflatoxins.Bacillus megatertum andB cereus were suitable for microbiological assay of aflatoxins. Czapek's-Dox medium was found a suitable medium for isolation of fungi from food samples. The optimal pH for the growth ofA. parasiticus and its productivity of aflatoxin B1 was found at 6.0, while the best incubation conditions were found at 30°C for 10 days. D-glucose was the best carbon source for fungal growth, as well as aflatoxin production. Corn steep liquor, yeast extract and peptone were the best nitrogen sources for both fungal growth and toxin production (NH4)2HPO4 (1.55 gL(-1)) and NaNO2 (1.6 gL(-1)) reduced fungal growth and toxin production with 37.7% and 85%, respectively. Of ten amino acids tested, asparagine was the best for aflatoxin B1 production. Zn(2+) and Co(2+) supported significantly both fungal growth, as well as, aflatoxin B1 production at the different tested concentrations. Zn(2+) was effective when added toA. parasiticus growth medium at the first two days of the culture age. The other tested metal ions expressed variable effects depending on the type of ion and its concentration. Water activity (aw) was an important factor controlling the growth ofA. parasiticus and toxin production. The minimum aw for the fungal growth was 0.8 on both coffee beans and rice grains, while aw of 0.70 caused complete inhibition for the growth and aflatoxin B1 production. H2O2 is a potent inhibitor for growth ofA. parasiticus and its productivity of toxins. NaHCO3 and C6H5COONa converted aflatoxin B1 to water-soluble form which returned to aflatoxin B1 by acidity. Black pepper, ciliated heath, cuminum and curcuma were the most inhibitory spices on toxin production. Glutathione, quinine, EDTA, sodium azide, indole acetic acid, 2,4-dichlorophenoxy acetic acid, phenol and catechol were inhibitory for both growth, as well as, aflatoxin B1 production. Stearic acid supported the fungal growth and decreased the productivity of AFB1 gradually. Lauric acid is the most suppressive fatty acid for both fungal growth and aflatoxin production, but oleic acid was the most potent supporter. Vitamin A supported the growth but inhibited aflatoxin B1 production. Vitamins C and D2 were also repressive particularly for aflatoxin production The present study included studying the activities of some enzymes in relation to aflatoxin production during 20-days ofA. parasiticus age in 2-days intervals. Glycolytic enzymes and pyruvate-generating enzymes seems to be linked with aflatoxin B1 production. Also, pentose-phosphate pathway enzymes may provide NADPH for aflatoxin B1 synthesis. The decreased activities of TCA cycle enzymes particularly from 4th day of growth up to 10th day were associated with the increase of aflatoxin B1 production. All the tested enzymes as well as aflatoxin B1 production were inhibited by either catechol or phenol.

Inhibitory effect of garlic, clove and carrot on growth ofAspergillus flavus and aflatoxin production

The inhibitory effect of crude extracts of garlic, clove and carrot at concentrations of 20,000, 40,000, 60,000, 80,000 and 100,000 μg/mL on growth ofAspergillus flavus and aflatoxin production in rice was investigated. The results showed that garlic, clove and carrot could inhibit the growth ofA. flavus and aflatoxin production. Garlic and clove at 100,000 μg/mL highly reduced the level of aflatoxin from 5.94 to 0.15 and 0.06 μg/g respectively whereas carrot at 20,000 μg/mL reduced the most level of aflatoxin from 5.94 to 0.03 μg/g. Garlic, clove and carrot at 100,000μg/mL also inhibited the mould growth. The most effective herb for inhibiting the growth ofA. flavus and aflatoxin production was garlic.

Effects of various environmental conditions on growth and reproduction of the sea hareAplysia oculifera (Adams and Reeve, 1850)

We studied the influences of food type, food quantity, water currents, starvation and light on growth and reproduction of the sea hareaplysia oculifera (Adams and Reeve, 1850) under laboratory conditions. Out of five species of algae served as food,Enteromorpha intestinalis promoted the fastest growth ofA. oculifera, Ulva spp. slower growth,Cladophora sp. allowed maintenance spp. slower growth,Cladophora sp. allowed maintenance of steady body mass, and the brown algaeColpomenia sp. andPadina pavonia were rejected by the sea hares. When sea hares were exposed to four levels of water currents, growth rates decreased as water currents increased. Sea hares fed on 50% ration grew slower than those fed on 100% ration (ad libitum). During 10 days of starvation sea hares lost weight, but when subsequently fed 100% ration they recovered and grew at a rate similar to those fed continuously with 100% ration. Under shade and under natural sunlight sea hares grew at the same rates. Whenever growth rates decreased, sea hares began to spawn at a smaller body size.A. oculifera demonstrated physiological plasticity that adapted them to varied and unpredictable environmental conditions. At different conditions of food availability they applied different tactics of resource allocation between growth and reproduction.

On the growth of algebras with bialgebra action

Ifk is a field,A ak-algebra, andB ak-bialgebra which acts onA, we study the rate of growth ofA under its algebra structure together with the action ofB. We then briefly place our results in the more general context of a vector spaceA on which anoperad acts, and sketch an application to a (still open) question on finitely generated subalgebras of free associative algebras.

Biological species of Armillaria and their mycoparasitic associations with Rhodophyllus abortivus in Hokkaido

Specimens of basidiomes and/or rhizomorphs ofArmillaria mellea complex and basidiomes ofRhodophyllus abortivus, developing on the same decaying stumps or stems of forest trees, were collected in three forests in Hokkaido. Normal basidiomes ofR. abortivus were found near to, but free from, the rhizomorphs and/or basidiomes ofArmillaria, while abnormal basidiomes, as carpophoroid forms, were developed on the rhizomorphs ofArmillaria. Of three mycoparasiticArmillaria isolates found withR. abortivus, one was identified asA. gallica and two asA. jezoensis. The isolates ofR. abortivus showed excellent mycelial growth and rhizomorph formation on PDA. However, on MDA, RMDA and BMDA, they showed poor aerial mycelia growth and no rhizomorphs. In the contrapositional cultures, the growth ofA. gallica was completely inhibited byR. abortivus on PDA but only slightly inhibited on MDA and RMDA. On the other hand, mutual inhibition at a distance was observed on BMDA. The mycelial growth and rhizomorph formation inA. jezoensis were severely inhibited by the colony ofR. abortivus on PDA, but only slightly inhibited on MDA. On RMDA and BMDA, the colonies of twoArmillaria species andR. abortivus showed mutual inhibition at a distance and apparent rhizomorph formation by bothArmillaria species.

Phytotoxicity of cacalol and some derivatives obtained from the roots ofPsacalium decompositum (A. Gray) H. Rob. & Brettell (Asteraceae), matarique or maturin

The effect of cacalol and extracts (water and petroleum ether) derived from the roots ofPsacalium decompositum (Asteraceae) on the germination and radicle growth of two plants.Amaranthus hypochondriacus (Amaranthaceae) andEchinochloa crusgalli (Poaceae), and on the radial growth of four phytopathogenic fungi is described. The activity of two cacalol derivatives (methyl cacalol and cacalol acetate) was also investigated. Germination ofA. hypochondriacus was inhibited by almost all the treatments. The extracts and cacalol produced a significant inhibition of radicle growth ofA. hypochondriacus andE. crusgalli. Cacalol acetate showed a specific inhibition onE. crusgalli, and methyl cacalol significantly inhibited the growth ofA. hypochondriacus. In general, antifungal activity depended upon the target fungi and the concentration of each treatment. Cacalol had also effects on the morphology and coloration of the fungal mycelium. The bioactivity shown by the extracts ofPsacalium decompositum on the tested seeds and fungi is mainly due to their content in cacalol.

Allelopathic potential ofAnthoxanthum odoratum for invadingZoysia-grassland in Japan

The growth ofZoysia japonica surroundingAnthoxanthum odoratum onZoysia-grassland in Japan was investigated in June 1994. The stem density ofZ. japonica tended to decrease with short distances between twoA. odoratum plants. This showed that the growth ofZ. japonica surroundingA. odoratum was reduced. Basic, neutral, and acidic fractions extracted fromA. odoratum plants inhibited the seedling growth of lettuce. In particular the neutral fraction showed the strongest activity among the three fractions. The main inhibitory compound obtained atR f 0.6-0.7, on the thin-layer chromatogram of the neutral fraction, was isolated and identified as coumarin by means of GC-MS. Coumarin solution inhibited seedling growth ofZ. japonica in low concentrations but, conversely, promoted seedling growth ofA. odoratum. Coumarin was contained in all parts ofA. odoratum and its concentration varied with the season and from one individual plant to another. In particular, coumarin was highly concentrated in the leaves, accounting for more than 2.5% of dry leaf weight in June. The inhibitory effect of these aqueous extracts was correlated to the amount of coumarin inA. odoratum leaves and cournarin was considered to be the main inhibitory compound.

Transfer of genes fromPseudomonas saccharophila to construct xylose-utilizing strains ofAlcaligenes eutrophus

About 1500 hybrid broad-host-range plasmids from a genomic library ofPseudomonas saccharophila were individually transferred by conjugation fromEscherichia coli toAlcaligenes eutrophus. Direct selection for pentose-utilizing transconjugants yielded three clones capable of growth on xylose. Growth ofP. saccharophila as well as the transconjugants ofA. eutrophus on xylose was relatively slow, exhibiting doubling times of about 9.5 h. Plasmid pGN3 harbored by one transconjugant contained a 28-kb DNA insert, 16.4 kb of which comprised the minimal information required for xylose utilization byA. eutrophus. At least thexyl genes encoding xylose isomerase and xylulokinase were located within this region, as indicated by their induction during growth ofA. eutrophus (pGN3) on xylose. Southern hybridizations with a heterologous gene probe confirmed the presence of thesexyl genes. In bothP. saccharophila andA. eutrophus (pGN3), low activities of several enzymes operating in the pentose phosphate and Entner-Doudoroff pathways might limit the rate of xylose catabolism.

Characterisation of haemolytic activity fromAeromonas caviae

Aeromonas caviae, an enteropathogen associated with gastroenteritis, displays several virulence characteristics. Studies on the kinetics of growth of A. caviae and expression of beta-haemolytic toxin revealed that A. caviae produced maximum haemolytic activity extracellularly during the stationary phase. Preliminary studies on the properties of A. caviae haemolysin suggested that divalent cations (Mg2+ and Ca2+) and thiol compounds, dithiothreitol and mercaptoethanol enhanced the haemolytic activity. Addition of L-cysteine, glutathione and EDTA reduced the haemolytic activity. The iron chelator, 2-2' bipyridyl, significantly inhibited the growth of A. caviae possibly by iron limitation, with parallel enhancement of haemolysin production compared to A. caviae grown in excess of iron. These results suggest that A. caviae produces only beta-haemolysin, which resembles the haemolysins reported for several other bacteria and the activity might be regulated by environmental factors especially iron.

Estuarine gradients determining the quality of tidal marsh halophytes as host plants for endophagous insect larvae: Experimental evidence

Phytophagous insects of estuarine tidal marshes which live inside their host plants, are, in contrast to the plants, not directly exposed to the estuarine salinity gradient. Previous field studies, however, have shown that patterns of growth and development ofAgapanthia villosoviridescens larvae, stem-borers of the halophyteAster tripolium, gradually change on tidal marshes along the Westerschelde estuary (HEMMINGA and VAN SOELEN, 1988). In the present study we carried out a laboratory experiment in which we followed growth ofA. villosoviridescens larvae from two different Westerschelde tidal marshes; the larvae either were kept inA. tripolium stems from their own marsh, or they were kept in stems from the other marsh. It was found that larvae from both tidal marshes showed larger weight increases inA. tripolium stems from the least saline marsh. Apparently, differences in host plant quality between stems of the two marshes exist. The results lend support to the hypothesis that growth and development, and distribution and abundance of phytophagous insects in estuarine tidal marshes may be indirectly influenced by estuarine gradients,via the host plant quality which changes along the estuary.

A simulation model of Avena fatua L. (wild‐oat) growth and development

SummaryAn eco‐physiological simulation model of the growth and development of Avena fatua was parameterised and tested. The model simulates growth ofA. fatua, in kg dry matter ha‐1 day‐1 from sowing to maturity as a function of irradiance, temperature and various species characteristics. Parameter values were derived from the literature and from field experiments, including both autumn and spring sowings of A. fatua over three years at two sites in southern England. With two exceptions, a single set of parameter values was sufficient to accurately simulate the emergence, growth and development of both autumn and spring cohorts over all years and sites. The two exceptions were the result of differences between autumn and spring cohorts of A. fatua in the rate of early leaf area growth and in the relationship between specific leaf area and developmental stage.

Attachment, colonization and proliferation ofAzospirillum brasilense andEnterobacter spp. on root surface of grasses

Root colonization studies, employing immunofluorescence and using locally isolated strains, showed thatEnterbacter sp. QH7 andEnterobacter agglomerans AX12 attached more readily to the roots of most plants compared withAzospirillum brasilense JM82. Heat treatment of either root or inoculum significantly decreased the adsorption of bacteria to the root surface. Kallar grass and rice root exudates sustained the growth ofA. brasilense JM82,Enterobacter sp. QH7 andE. agglomerans AX12 in Hoagland and Fahraeus medium. All the strains colonized kallar grass and rice roots in an axenic culture system. However, in studies involving mixed cultures,A. brasilense JM82 was inhibited byEnterobacter sp. QH7 in kallar grass rhizosphere and the simultaneous presence ofEnterobacter sp. QH7 andE. agglomerans AX12 suppressed the growth ofA. brasilense JM82 in rice rhizosphere. The bacterial colonization pattern changed from dispersed to aggregated within 3 days of inoculation. The colonization sites corresponded mainly to the areas where root mucigel was present. The area around the point of emergence of lateral roots usually showed maximum colonization.

Relative Growth of the Speckled Swimming Crab Arenaeus Cribrarius (Lamarck, 1818) (Brachyura, Portunidae), Near Ubatuba, State of São Paulo, Brazil

AbstractArenaeus cribrarius is a mainly tropical crab that occurs in the Western Atlantic Ocean, Brazil being its type-locality. The species ranges from Vineyard Sound, Massachusetts, USA to La Paloma, Uruguay. Information about this species is scarce. The relative growth ofA. cribrarius was analyzed, based on some morphometric relations, where the carapace width, excluding lateral spines (CW), was used as an independent variable. A total of 403 specimens (189 males and 214 females), was collected in Ubatuba, State of São Paulo, Brazil, with otter-trawls. The animals were sexed and sorted to maturation phase (juvenile or adult). Some measurements were made: carapace (length and width excluding lateral spines), abdomen (greatest width of the fifth somite in females and the sixth in males) and major chela (greatest length, width and height, dactylus length). This study was made by the application of the power function (y=a.xb) which was fitted to the data and the pattern of growth established for each parameter by the "b"-value (constant of allometry), as positive allomctry (b>1), negative allometry (b<1) or isometry (b=1). The morphometric relations of the carapace showed a tendency to isometry. In females, the abdominal width grew in positive allometry, higher in juveniles (b= 1.33) than in adults (b=1.18). In this case, an overlap and discontinuity was noticed between the phases over a carapace width range of 55 to 70 mm, where the puberty molt occurs. The majority of relationships showed that the major chela of the males grew in positive allometry, however, the greatest allometric difference between the phases was observed towards the propodus length with 1.09 as juvenile and 1.26 as adult "b"values. In the males, this variable showed an inflection between the CW range of 45 to 55 mm, where the transition to the maturation phase occurs. The relative growth of this species is similar to those of previously studied species. This indicates, that the propodus length and the abdominal width are the morphometric variables most appropriate to estimate the size at the beginning of the sexual maturity for males and females of this species, respectively.