Analysis Of Relative Growth Research Articles

Relative growth and sexual maturity of the spider crab Libinia spinosa Guérin, 1832 (Brachyura: Majoidea: Epialtidae), from the Southeast Brazilian coast

ABSTRACT We investigated the relative growth and sexual maturity (gonadal and morphometric) of Libinia spinosa. Crabs were sampled at Ubatuba from January to December 2000, using trawls. Based on allometric growth, males were grouped into juveniles (MJ), adolescents (MAd) and adults (MA) based on the relationship CPL (major cheliped propod length) vs. CW (cephalothorax width), all with positive allometric growth. For females, the relationship AW (abdomen width) vs. CW allowed segregating juveniles (FJ) from adults (FA), with positive allometric growth for FJ but isometric growth for FA. The morphometric maturity evidenced for MAd varied from 33.7 mm to 34.5 mm and for MA and FA. The size at which 50% of individuals reach the morphometric sexual maturity was L50 = 50.1 mm for males and L50 = 37.3 mm for females. Gonad maturity was L50 = 33.7 mm for males and L50 = 36.9 mm for females. Through relative growth analyses, we identified an adolescent male group (prepuberal phase). These individuals presented mature gonads, enabling them to copulate with females. These adolescent males may reproduce while avoiding competition with adult males, as it happens in other species of Majoidea that present more than two morphotypes in the population.

Spatiotemporal evolution and suitability of apple production in China from climate change and land use transfer perspectives

AbstractApple production in China, the world's largest apple producer and consumer, is challenged by a huge and growing population coupled with rapid industrialisation and urbanisation. China's apple output has increased continuously over the past 42 years with distinctive spatial differences. Herein, changes in the spatial patterns of apple production increases, and their potential impact factors in China are described at the provincial level. Between 1978 and 2019, the centre‐of‐gravity of apple production shifted southwest towards the upper reaches of the Yellow River, the main water source for agricultural irrigation in North China. Analysis of absolute and relative growth of apple output reveals that the Loess Plateau, characterised by fragile habitat and low land productivity, has gradually become a major contributor to apple production. Despite annual increases in apple output, apple production system has become more fragile and unstable overtime, especially in the Shaanxi‐Gansu region where apple cultivation is prevalent. With continuous changes in policy, the amount of forest transfer (i.e. the area of other land use types converted to forest) has significantly affected the impact of standardised precipitation evapotranspiration index on apple production increases in China. Thus, to prevent the degradation of new forests, a differentiated management and protection system should be implemented for apple planting sub‐regions. This should include altering subsidy policies on apple production, enhancing soil erosion control in the Loess Plateau and strengthening ecological management of forests and grassland.

Relative growth and reproductive biology of females of Macrobrachium amazonicum (Heller, 1862) (Decapoda: Caridea: Palaemonidae) in the semiarid Northeast Region, Brazil

Abstract We analyzed aspects related to the relative growth and reproduction of females of Macrobrachium amazonicum (Heller, 1862) in a population of the semiarid Northeast Region of Brazil. Carapace (CL) and total length (TL) ranged 5.57–17.61 mm (mean 10.96 ± 2.07 mm) and 28.96–80.63 mm (mean 52.14 ± 9.13 mm), respectively. Relative growth analysis showed that total length increased in a higher proportion than carapace region (positive allometry). This region also increased in a higher proportion regarding weight (negative allometry) due to energy cost in reproduction. Of the three criteria used to determine size at the onset of maturity (SOM), the smallest size observed was obtained by physiological SOM I (based on advanced vitellogenesis): 8.22 mm CL, followed by functional SOM II (8.83 mm CL, based on ovigerous females) and physiological SOM III (9.48 mm, based on CL50). SOM was influenced by the population’s phenotype, and SOM I and SOM II showed synchronicity. The estimated maximum fecundity was 2,805 eggs per female, with a mean value of 690 eggs. There was continuous reproduction and the dry season favored the percentage occurrence of ovigerous females (September-December 2016 and July-August 2017). The smaller lengths of the individuals, compared to other female populations, were due to the characteristics of the environment and the intrinsic traits of the studied population. The negative allometry for the length-weight relation and the continuous reproductive period with seasonal variation was similar as that recorded for other Brazilian localities. This suggests that these last characteristics are a pattern for this species, which shows a latitudinal variation only in the sizes reached. The fast maturation and continuous reproduction of M. amazonicum females make them a potential species for commercial exploitation.

Life History Traits of the Snapping Shrimp Alpheus carlae (Decapoda: Alpheidae) from the South-eastern Coast of Brazil.

The life history traits of the snapping shrimp Alpheus carlae were investigated. We evaluated the relative growth, morphological sexual maturity, sexual dimorphism, handedness, fecundity, and egg volume. Sampling was performed monthly in an estuarine region of Cananéia, in the south-eastern coast of Brazil. The following structures were measured to perform the relative growth analysis: length of carapace and second pleonal pleuron, length, width and height of major cheliped propodus, and length of appendix interna and appendix masculina. Juveniles and adults males and females have different growth patterns, indicating distinct strategies of energy allocation. The estimated carapace length at the onset of morphological sexual maturity of females and males was 5.6 mm and 6.2 mm, respectively. The sexual dimorphism of specific body structures was evident, mainly in the appendix interna of females and major cheliped of males. There was no evidence of handedness in females or males. The mean fecundity of females was 364 ± 204 eggs (mean ± SD) eggs and was positively correlated with the carapace length. The egg volume differed between developmental stages I and II, and I and III, with an overall volume increase of 73.23% and 95.45%, respectively. The results contribute to the knowledge about A. carlae and its life history in natural environment.

Male morphotypes of the freshwater prawn Macrobrachium brasiliense (Decapoda: Caridea: Palaemonidae)

AbstractSome decapod species have intraspecific morphological variations that result in distinct adult morphotypes that influence the population structure, social dominance, and reproduction of the population. Here we investigated whether this differentiation into morphotypes occurs in adult males of Macrobrachium brasiliense, through the analysis of relative growth and morphology. Specimens were collected in the region of Uberlândia, Minas Gerais state, southeastern Brazil. Seven dimensions of each male were measured: carapace length (CL), ischium length, merus length, carpus length, propodus length, dactylus length, and major cheliped length. Principal component analysis, clustering, and discriminant analyses were used to identify possible morphotypes. The analysis of relative growth was employed to estimate the growth patterns of body structures (dependent variables) in relation to the CL (independent variable). Two morphotypes were identified: Mirim, which has less developed chelipeds (23.31 ± 3.08 mm) with fewer spines, and Açu, which has larger chelipeds (41.39 ± 8.14 mm) with many well‐developed spines, especially in the merus. Most morphometric relationships differed significantly (p < .01) between the two morphotypes. The chelipeds were useful characters for the identification of the morphotypes of M. brasiliense, corroborating previous descriptions of the genus. We provide a detailed description of the main macroscopic characteristics that differed between morphotypes, which will enable their identification in future studies. Our results contribute to the knowledge of the population biology of M. brasiliense and should be considered in future investigations, since the presence of these male morphotypes probably influences the reproductive biology and population ecology of the species.

Sexual size dimorphism of the freshwater shrimp Macrobrachium jelskii (Miers, 1877) (Decapoda: Palaemonidae) and its relationship to Rensch’s rule

ABSTRACT Rensch’s rule attempts to explain the evolutionary processes that have resulted in the current patterns of sexual size dimorphism of several taxa. This rule predicts that sexual size dimorphism increases according to the average body size, when males are larger, decreasing when females are the largest sex. In decapod crustaceans, the general pattern of sexual size dimorphism is males with hypertrophied structures used in agonistic disputes, and females with a greater expansion of the abdominal chamber. We analyzed sexual size dimorphism of the freshwater shrimp Macrobrachium jelskii and its relationship to Rensch’s rule, as well as the relative growth between the sexes, for subpopulations from the Rosário reservoir in Ceará state, Brazil. The results of sexual size dimorphism show that females are morphometrically larger than males. Such a pattern of sexual dimorphism probably results from the selection of female fecundity, giving them greatest fecundity. This pattern indicates a female-biased SSD for this species, supported by what is proposed in Rensch’s rule. In the relative growth analysis, the males and females showed negative allometry of the cheliped. The absence of cheliped hypertrophy in males may indicate the presence of ‘pure-search’ reproductive behaviour, thus, no agonistic disputes for females.

A simple method for classifying data in relative growth analysis of crustaceans

Abstract Relative growth in crustaceans is a topic of quite high importance that allows, among other things, to estimate their size at the onset of morphometric sexual maturity. In this process, it is usual to start from a transition point and then generate regressions that reflect phases of the sexual development of the individuals (i.e., mature and immature). There are several statistical methods that allow data to be classified into subsets, but according to the specific growth pattern at issue, those methods may or may not be usable. This paper proposes a simple method to classify data into two subsets, viz., when they are overlapping over a wide range of sizes. The actual procedure consists of a linear regression that divides the data. Subsequently, a linear regression is applied to the groups generated by adjusting the parameters through maximum log-likelihood. The observed values will be classified according to the smallest residual difference generated with each regression line. The proposed method was tested by separating the sexes of Goyazana castelnaui, using real data. The efficiency of the method was analysed based on the percentage value between the number of total data and the number of correctly classified data. Additionally, the k-mean cluster was used as a conventional method, the results of which were reclassified by a linear discriminant analysis. The efficiency of the proposed method was >80% while that of the conventional method was >60%. The values misclassified by the proposed method were mixed with those of the opposite sex, so it was expected to fail in those cases. The proposed method is a simple alternative that can serve as a basis for subsequent morphometric analysis, especially for acquiring an initial insight in the structure of a dataset collected for a study of relative growth.

Morphological sexual maturity of the freshwater anomuran crab Aegla parana (Crustacea, Decapoda, Aeglidae) from Negro River Sub-basin, Upper Iguaçu Basin, southern Brazil

ABSTRACT The carapace length (CL) at the onset of morphological sexual maturity (MSM) in Aegla paranaSchmitt, 1942was estimated in a population located at Negro River Sub-basin, Upper Iguaçu Basin, southern Brazil. The animals were captured with Surber net and with baited traps in Negro River and in its tributary Totó River, in December/2017, June and July/2018. Carapace length of each individual was measured from the tip of the rostrum to the posterior margin of the carapace, with a digital caliper or under a digital microscope. Length of the major cheliped propodus (LMAP) of males and width of the abdomen (LA) of females were measured for relative growth analysis. The CL at the onset of MSM was estimated as the inflection points on the scatter plots with the REGRANS program. In Negro River, 107 males (CL range 6.90- 50.25 mm) and 95 females (10.37-39.36 mm) were obtained, while in Toto River, 225 males (4.92-25.65 mm) and 160 females (5.18- 26.45 mm). MSM is attained by males at 23.15 mm CL and females at 17.85 mm CL. The smallest ovigerous female measured 19.00 mm CL. Aegla parana reaches the highest maximum size and males attain MSM with the highest CL value among the known species of the genus.

Non-linear curve adjustments widen biological interpretation of relative growth analyses of the clam Tivela mactroides (Bivalvia, Veneridae).

Evaluation of relative (allometric) growth provides useful information to understand the development of organisms, as well as to aid in the management of fishery-exploited species. Usually, relative growth analyses use classical models such as the linear equation or the power function (allometric equation). However, these methods do not consider discontinuities in growth and may mask important biological information. As an alternative to overcome poor results and misleading interpretations, recent studies have suggested the use of more complex models, such as non-linear regressions, in conjunction with a model selection approach. Here, we tested differences in the performance of diverse models (simple linear regression, power function, and polynomial models) to assess the relative growth of the trigonal clam Tivela mactroides, an important fishing resource along the South American coast. Regressions were employed to relate parameters of the shell (length (L), width (W), height (H) and weight (SW)) among each other and with soft parts of the organism (dry weight (DW) and ash-free dry weight (ASDW)). Then, model selection was performed using the information theory and multi-model inference approach. The power function was more suitable to describe the relationships involving shell parameters and soft parts weight parameters (i.e., L vs. SW, DW, and AFDW, and SW vs. DW). However, it failed in unveiling changes in the morphometric relationships between shell parameters (i.e., L vs. W and H; W vs. H) over time, which were better described by polynomial functions. Linear models, in turn, were not selected for any relationship. Overall, our results show that more complex models (in this study polynomial functions) can unveil changes in growth related to modifications in environmental features or physiology. Therefore, we suggest that classical and more complex models should be combined in future studies of allometric growth of molluscs.

Population structure, relative growth and morphological sexual maturity of the snapping shrimp Alpheus brasileiro Anker, 2012 (Caridea: Alpheidae) from the south-eastern coast of Brazil

ABSTRACTThe present study investigated the population structure of the snapping shrimp Alpheus brasileiro. We tested the hypotheses that the sex ratio of the population differs from the expected 1:1 and that the growth pattern differs between adults and juveniles and between sexes. Reproductive period, juvenile recruitment and morphological sexual maturity were estimated. Samples were collected in two periods. The first sampling occurred bimonthly from March 2013 to January 2014. The second sampling occurred monthly from April 2015 to March 2016. The population structure was determined based on the size-frequency distribution of different demographic categories. To analyse the relative growth, we measured the second pleuron length, major cheliped propodus length, major cheliped propodus width, major cheliped propodus height, appendix interna length, appendix masculina length. The results showed that the sex ratio did not differ from 1:1 (male:female). Reproduction and juvenile recruitment were continuous throughout the study period. The analysis of relative growth confirmed the hypothesis that males and females, and juveniles and adults, have different growth patterns, indicating distinct strategies of energy allocation. The estimated carapace length at the onset of morphological sexual maturity was 4.9 mm in males and 4.7 mm in females. The results obtained in this study are probably related to the monogamous social behaviour of A. brasileiro. Monogamy can influence demographic parameters such as sex ratio and the size at which males and females reach morphological sexual maturity.

Morphological variability in populations of the fiddler crab Leptuca uruguayensis (Nobili, 1901) (Crustacea, Decapoda, Ocypodidae) from South America

Abstract A comparative study on size and shape of Leptuca uruguayensis was carried out between populations from Garças River, Brazil (BP), and Solís Grande River, Uruguay (UP). The size of the onset of sexual maturity was also estimated for UP. A total of 36 crabs BP and 387 crabs UP were analyzed. In the relative growth analysis, carapace width (CW) for both sexes, major cheliped length (LMC) for males and abdomen width (AW) for females were measured. The centroid size of carapace (1.40±0.19 cm BP and 1.88±0.30 cm UP) and cheliped (1.16±0.22 cm BP and 1.58±0.45 cm UP) differed significantly (p<0.001). The shape also differed significantly (p<0.001), having UP wider carapace than BP, rostrum projected forward and posterior margin positioned more anteriorly; the cheliped of UP was also wider than BP. In UP, males' CW ranged 4.28-19.5 mm and females' 2.53-16.3 mm CW; males' LMC ranged 1.79-31.60 mm and females' AW, 0.80-8.53 mm. The onset of sexual maturity of UP was estimated in 12.20 mm CW for males and 7.81 mm for females. These differences are likely related to abiotic variables acting distinctly in the two localities.

Population dynamics, relative growth and sex change of the protandric simultaneous hermaphroditeExhippolysmata oplophoroides(Caridea: Lysmatidae) close to an upwelling area

The present study investigated the population dynamics ofExhippolysmata oplophoroidesin an area influenced by upwelling, focusing on reproductive period, sex ratio, growth rate, longevity, mortality, relative growth and size of sex change. We also tested the hypothesis that the appendices internae increased in size with sex change from the male to the simultaneous hermaphrodite phase as possible replacements for the male appendices masculinae, which are reduced or lost at sex change. Population structure was assessed by the distribution of size frequency in three demographic groups: male phase, hermaphrodite phase with, and without embryos. For relative growth analysis, the length of the following structures was measured: carapace, second pleuron, first pereopod, second pereopod, appendices internae of the second to fifth pleopods, and appendix masculina. Smaller size classes were composed only by male-phase individuals. The sex ratio was significantly biased towards the simultaneous hermaphrodite phase. Reproduction was continuous in the population throughout the year. Slower growth rates but higher maximum body sizes than those estimated at other locations in south-eastern Brazil were observed in the population studied. Cooler temperatures and higher nutrient levels associated with upwelling may have produced this pattern of reproduction and growth, similar to that found in more southerly austral latitudes. We also found that sex change influences the relative growth of body structures such as the second pereopods, appendices internae, and appendix masculina, and hypotheses on the adaptive value of such allometric growth are proposed.

Analysis of relative productivity growth of selected public and private sector banks in India: A comparative study

This study attempts to measure the total factor productivity and the changes in its components of the selected public and private sector banks in India using Data Envelopment Analysis (DEA) during the period covering 2004–05 to 2015–16. In this study the input vector includes interest cost and operating cost and output vector includes interest income and non-interest income. We have measured the productivity growth and its components from a time series dataset obtained from RBI database. DEA method is used to measure Malmquist index of total factor productivity for a sample of top 20 commercial banks considering them within the two specified groups and among all the selected commercial banks’ performances comparisons have been carried out. A decomposition of Total Factor Productivity (TFP) measure is done to establish the source of changes in factor productivity. In performance measurement change in technical efficiency, technological change, change in pure technical efficiency, change in scale efficiency and change in total factor productivity indices are calculated based on Malmquist total factor productivity index method. Indices provide us the opportunity to compare the performance of selected public and private sector banks individually and group wise. While we consider all the selected banks taken together, the results found that there is no significant TFP growth during the sample period except in the year 2009–10. In terms of mean TFP growth private sector banks perform better than public sector banks, although in both cases negative growth is found. In terms of mean technical efficiency a negative growth is found in case of selected public sector banks. To enhance the productivity growth, inefficient banks should improve their technical efficiency, accept modern technological innovation, optimum utilisation of resources as well as government should minimise restrictions on banking activities.

Population biology of the ‘uçá'-crab, Ucides cordatus(Linnaeus, 1763) (Brachyura: Ucididae), in mangroves of the Joanes River, Bahia State, Brazil

This study evaluated the population structure, relative growth and morphological maturity size in Ucides cordatus in the Joanes River, Bahia State (Brazil). Crabs were sampled in a fragmented and human-altered mangrove ecosystem in a Brazilian Environmental Protected Area (EPA). A total of 431 crabs were sampled (265 males and 166 females) between September 2011 and August 2012. The following measurements were taken using precision callipers: carapace width (CW) and length (CL), the length of the propodus of the major cheliped (PL, males only), and the width of the 5th somite of the abdomen (AW, females only). Specimens were also weighed to a precision of 0.5 g on a scale to obtain the total wet weight (WW). The relative growth of this species was studied by using biometric relationships to estimate the morphological maturity size in both sexes (PLxCW in males and AWxCW in females). The overall sex ratio was 1.6:1, with a predominance of males (p & 0.05). The population structure of ‘uca'-crabs was composed of two normal curves (juveniles and adults) in both sexes. A relative growth analysis using the CLxCW relationship revealed a negative allometric growth in adult males whereas adult females exhibited an isometric growth, with an inverse pattern occurring in juveniles. In males, the PLxCW relationship indicated a change in allometric growth at 39.4 mm CW (isometric growth in juveniles changing to positive allometry growth in adults). In females, the AWxCW relationship indicates that morphological maturity occurs at a delay (44.5 mm CW) and that growth changes between phases (positive allometry to isometry). Isometric growth was found using the WWxCW relationship, also regardless of sex. A literature review combined with results previously published about this species in northeast Brazilian region suggests that U. cordatus had a seasonal reproduction during six months (from December to May), with a fattening season in the following six months (June to November). Joanes River is an environmental protected area, but had a high anthropic pressure by closed condos and marinas. Despite the high anthropic pressure on this EPA, the population structure and reproduction of U. cordatus did not appear to be affected.

Relative growth and morphological sexual maturity of the mangrove crab Aratus pisonii (H. Milne Edwards, 1837) (Decapoda, Brachyura, Sesarmidae) on the southern coast of the state of São Paulo, Brazil

Growth in crustaceans is characterized by ontogenetic differentiation during the development of their body structures, so studies on relative growth are widely applied in this group. In this study, the growth pattern of the body structures was verified through the analysis of relative growth, and then, morphological sexual maturity of the mangrove crab Aratus pisonii (H. Milne Edwards, 1837) was estimated. The carapace width (CW), cheliped propodus length (PL), cheliped propodus height (PH), propodus width (PW), abdomen width (AW), and first pleopod length (FPL) of the crabs were measured. The relationships that best showed changes in the allometric coefficient among demographic categories were FPL vs. CW for males and AW vs. CW for females. This study verified the increased size of the cheliped in terms of length, width, and height, which occurred mainly in adult males. This increase reflects the importance of this structure in the reproductive processes of A. pisonii. For females, the increase in abdomen growth reflects their reproductive potential, since it is a structure that provides protection for eggs.

Proximate Analysis of Protein and Relative Growth of Tilapia Fish Exposed to Heat Stress and Fed with the Combination of Willow Leaf and Chromium

This study was aimed to determine the effect of relative growth rate and proximate levels of protein in tilapia fish exposed to heat stress and supplemented with the combination of willow leaf powder and chromium. A total of 30 tilapia fish with 1.3-1.5 cm long were divided into 6 treatment groups with 5 repetitions: fed with commercial feed at temperature 29±1° C (P1S1), fed with commercial feed combined with willow leaf at temperature 29±1° C (P2S1), fed with commercial feed combined with willow leaf and chromium at temperature 29±1° C (P3S1), fed with commercial feed at temperature 35±1° C (P1S2), fed with commercial feed combined with willow leaf at temperature 35±1° C (P2S2), fed with commercial feed combined with willow leaf and chromium at temperature 35±1° C (P3S2). The treatments were carried out for 15 days. Then, relative growth rate and proximate levels of proteins were calculated using Kjedahl methods. The results showed that there was an increase of the mean of relative growth rate and proximate levels of protein. Based on statistical test using factorial completely randomized design it was showed that there was a significant effect (P0.01) on the interaction of feeding and temperature with the relative growth rate, but did not affect the relative growth rate of tilapia fish. The proximate level of tilapia fish protein was affected very significantly (P0.01) by the food and the interaction between food and temperature as well, while the temperature treatment gave no significant effect on the proximate level of tilapia fish protein. In conclusion, the commercial feed combined with willow leaf and chromium can increase the relative growth rate and the proximate level of protein of tilapia fish exposed to heat stress.Key words: relative growth rate, proximate protein, willow leaf, chromium, tilapia fish

Relative growth and morphological sexual maturity of the freshwater crab Trichodactylus fluviatilis Latreille 1828 (Decapoda, Trichodactylidae) from west central São Paulo State, Brazil

An analysis of relative growth was performed to determine the size at morphological sexual maturity of Trichodactylus fluviatilis Latreille 1828. Samples were collected by trapping at night from January 2010 through June 2011 from the Barreiro River (22°34′42″S; 49°11′92″W), west central São Paulo State, Brazil. The following measurements were obtained (mm): carapace width (CW) (independent variable), cheliped propodus length (PL), cheliped propodus height (PH), cheliped propodus width (PW), first pleopod length, and abdomen width (AW). The males showed positive allometry in the juvenile and adult stages for the following relationships: PL vs. CW, PH vs. CW, and PW vs. CW. In the females, a positive allometry was observed for AW vs. CW in the juvenile stage, and a negative allometry was observed for this relationship in the adult stage. The differential growth of the chelipeds in males could be related to territorial conflict and courtship, whereas the changes in the growth of the female abdomen most likely favor higher reproductive success.

The relative growth and sexual maturity of the freshwater crab Dilocarcinus pagei (Brachyura, Trichodactylidae) in the northwestern region of the state of São Paulo

The aim of the present study was to determine the size at sexual maturity in the freshwater crab Dilocarcinus pagei Stimpson, 1861, from a population located in Mendonça, state of São Paulo, Brazil. The crabs were sampled monthly (July 2005 to June 2007), at Barra Mansa reservoir. The specimens were captured manually or in sieves passed through the aquatic vegetation. The crabs were captured and separated by sex based on morphology of the pleon and on the number of pleopods. The following dimensions were measured: carapace width (CW); carapace length (CL); propodus length (PL); and abdomen width (AW). The morphological analysis of the gonads was used to identify and categorize individuals according to their stage of development. The morphological maturity was estimated based on the analysis of relative growth based on the allometric equation y = ax b. The gonadal maturity was based on the morphology of the gonads by the method CW50 which indicates the size at which 50% of the individuals in the population showed gonads morphologically mature to reproduction. The biometric relationships that best demonstrated the different patterns of growth for the juvenile and adult stages were CW vs. PL for males and CW vs. AW for females (p<0.001). Based on these relationships, the estimated value to morphological sexual maturity was 21.5 mm (CW) in males and 19.7 mm (CW) in females. The determination of the size at sexual maturity and the adjustment of the data based on the logistic curve (CW50) resulted in a size of 38.2 mm for males and 39.4 mm for females (CW). Based on the data obtained for sexual maturity for D. pagei, we can estimate a minimum size for capture of 40 mm (CW). This minimum size allows at least half of the population to reproduce and retains the juveniles and a portion of the adults in the population.

Comparative growth analysis of Callistephus chinensis l. Using vermicompost and chemical fertilizer

The chemical fertilizers have lost the faith on agriculture throughout the globe today; oppositely the organic amendments are gradually becoming more reliable components in the field of agriculture. The objective of the present work was to investigate the relative growth analysis of China aster ( Callistephus chinensis L.) applying the vermi compost and chemical fertilizer (10:26:26) and to observe the growth efficiency of both the amendments. The present investigation also aimed to increase the faith and awareness in the mindset of common people for the use of organic manure in the field of agriculture. Five experimental sets (T 1 , T 2 , T 3 , T 4 and T 5 ) with replicas were prepared and nine parameters were selected to study the growth efficiency. The results obtained from the experiments have proved the superiority of the vermicompost over the chemical fertilizer in each and every respect of the parameters that were used and it may be conclude that the vermicompost as an organic manure could be used as an alternative of the chemical fertilizer. These results indicate that the demands of organic agriculture for the yield performance would be more in near future.

Biology of the crab Leurocyclus tuberculosus (H. Milne Edwards & Lucas, 1843) bycatch from pink shrimp trawl fishery in the coast of Rio de Janeiro, Brazil

Trawling is known as one of less selective fishing gears and presents high index of accidental captures. The objective of this paper is to characterize the population structure, fecundity and relative growth of Leurocyclus tuberculosus often caught as bycatch in pink shrimp trawl. Sampling occurred between October 2008 and September 2009 in the coast of Rio de Janeiro State, using commercial shrimp trawl. The sample totalized 269 crabs, 168 males and 101 females (42 ovigerous). The sex ratio was 1:1.66 (M:F) and differed statistically from the expected (X2=16.68; p > 0.05). The carapace width (CW) ranged from 12.81 to 71.67 mm (mean ± SD: 48.77 ± 13.75 mm) and from 15.33 to 55.44 mm (36.19 ± 8.66 mm) in males and females, respectively. The size at onset of sexual maturity was estimated at 30 mm (females) and 55 mm (males). The individual fecundity ranged from 3,450 to 23,680 eggs/brood (10,327.3 ± 4,827.7). The analysis of relative growth did not differ from the Brachyura predictions. The histogram analysis showed that shrimp trawl affects the L. tuberculosus population equally, capturing from very young individuals to adults.