Population Dynamic of the Mudskipper <Emphasis Type="Italic">Periophthalmus waltoni</Emphasis> Koumans, 1941 from the Bay of Hormozgan Province,Persian Gulf

We studied the population structure and reproductive biology of the mudskipper Periophthalmus waltoni Koumans, 1941, living on the mudflats of bay of Hormozgan province, Persian Gulf. The specimens were haphazardly and monthly collected from August 2008 to July 2009. A total of 2060 fishes was sampled, sexed 690 of which 221 (32%) were males, and 469 (68%) females. The total length (TL) and weight relationship demonstrated growth in both sexes was isometric with the function W = 0.0078TL^3.06. The asymptotic length (L∞) and growth coefficient (K) were estimated as 16.5 cm and 0.75 yr^–1, respectively. Age of the fish at zero length (to) was calculated–0.35 and the longevity was attained 3.65 year. The estimated Von Bertalanffy function was TL_(t) = 16.5[1–exp(–0.75(t + 0.35))]. Natural mortality (M) was estimated 1.74 yr^–1. Four cohorts were distinguished annuallywith mean of TL = 7.35, 10.17, 12.74 and 13.92 cm. The maximum recruitment rate was in January at 17.5%. The overall sex ratio (F: M) (1: 0.49) was significantly different than 1: 1. The peak of the gonadosomatic index (GSI) occurred in February. The size at onset of sexual maturity (LM₅₀)wasestimated at TL = 12 cm. The mean of absolute and relative fecundity were estimated as 3558 ± 2203 and 257 ± 101 eggs, respectively.     

Regulation of population numbers in the <Emphasis Type="Italic">Rana arvalis</Emphasis> frog according to the results of long-term observations on the same population

An analysis of the results of long-term stationary studies (1987–1996) on a Rana arvalis population showed that the mean body length and reproductive parameters of females increased with age. Significant interannual changes in body length and egg size (but not in fecundity and reproductive effort) were also accounted for by conditions of the warm season preceding the breeding season. The dependence of egg diameter and reproductive effort on the female body length weakened with age, and only the relationship between body length and fecundity was characterized by positive allometry. The survival rate of mature females depended on the premetamorphic survival rate and, therefore, was higher in earlier generations, in which the aquatic phase proceeded under more favorable conditions. The rate of reproduction (R ₀) decreased and, therefore, further population growth slowed down only after the initial abundance of the generation had reached a relatively high level. An increase in the initial abundance of the generation exerts a strong influence on R ₀ via a decrease in the survival of premetamorphic animals and, to a lesser extent, via a decrease in the body length and fecundity of tree-and four-year-old females. Changes in the annual abundance of breeding females in R. arvalis were more abrupt and less prolonged than those in the sympatric R. temporaria population. The holding capacity of the environment for the aquatic phase of the R. arvalis life cycle was higher than that for R. temporaria. Therefore, the population abundance of R. arvalis, compared to R. temporaria, was not subject to stringent negative feedback regulation dependent on the initial number of animals.     

Assessment of Maturity,Reproduction and Reproductive Potentials of Torpedo Scad, <Emphasis Type="Italic">Megalaspis cordyla</Emphasis> (Linnaeus, 1758) from Northern Arabian Sea Coast of Pakistan

Port landing specimens of torpedo scad, Megalaspis cordyla were collected at monthly intervals from August 2013 to June 2014 from the northern Arabian Sea coast of Pakistan. The life history characteristics revealed that torpedo scad has a prolonged breeding season which occurred with two peaks: from May to June and from November to February. The spawning seasonality was also validated with microscopic gonad examination.The highest GSI value was noted in May and January whereas the lowest in November was recorded for both sexes. The age at which individuals of both sexes become 50% mature (t₅₀) was estimated as 2.44 year. Life span (t_max) calculated as 3.96 years for male and females. The size of 270 and 265 mm at which 50% individuals attained sexual maturity (L₅₀) was determined for males and females respectively. The reproductive potential (fecundity)was made from ten ripe females ranged from 29–43.8 cm TL and weighing 220–540 g of IV–V developmental stage was enumerated as 32306–236677 eggs (CV = 2.135) with an average number of eggs 86544 counted per ripe female/season. This study contains fundamental data of an important fish species in the northern Arabian Sea coast of Pakistan. It provides vital information to the fisheries managers for implementation on sustainable use of the resource during spawning season.     

Repressible Transgenic Sterilization in Channel Catfish, <Emphasis Type="Italic">Ictalurus punctatus</Emphasis>, by Knockdown of Primordial Germ Cell Genes with Copper-Sensitive Constructs

Repressible knockdown approaches were investigated to manipulate for transgenic sterilization in channel catfish, Ictalurus punctatus. Two primordial germ cell (PGC) marker genes, nanos and dead end, were targeted for knockdown and an off-target gene, vasa, was monitored. Two potentially copper-sensitive repressible promoters, yeast ctr3 (M) and ctr3-reduced (Mctr), were coupled with four knockdown strategies separately including: ds-sh RNA targeting the 5′ end (N1) or 3′ end (N2) of channel catfish nanos, full-length cDNA sequence of channel catfish nanos for overexpression (cDNA), and ds-sh RNA-targeting channel catfish dead end (DND). Each construct had an untreated group and treated group with copper sulfate as the repressor compound. Spawning rates of full-sibling P₁ fish exposed or not exposed to the constructs as treated and untreated embryos were 85 and 54%, respectively, indicating potential sterilization of fish and repression of the constructs. In F₁ fish, mRNA expressions of PGC marker genes for most constructs were downregulated in the untreated group and the knockdown was repressed in the treated group. Gonad development in transgenic, untreated F₁ channel catfish was reduced compared to non-transgenic fish for MctrN2, MN1, MN2, and MDND. For 3-year-old adults, gonad size in the transgenic untreated group was 93.4% smaller than the non-transgenic group for females and 92.3% for males. However, mean body weight of transgenic females (781.8 g) and males (883.8 g) was smaller than of non-transgenic counterparts (984.2 and 1254.3 g) at 3 years of age, a 25.8 and 41.9% difference for females and males, respectively. The results indicate that repressible transgenic sterilization is feasible for reproductive control of fish, but negative pleiotropic effects can result.     

Population structure and growth of the Japanese littleneck clam <Emphasis Type="Italic">Ruditapes philippinarum</Emphasis> in Amursky Bay,Sea of Japan

This paper deals with the size, age, and sex structure of population and growth of the Japanese littleneck clam Ruditapes philippinarum in Amursky Bay (Peter the Great Bay, Sea of Japan). One-year-olds and individuals with a shell length less than 19.8 mm were not found in the population under study. The population consisted mostly of 3-4-year-old clams (72.4%) with a shell length of 35–45 mm (67.8%). The maximum recorded age of R. philippinarum was 7 years, and maximum shell length was 52.7 mm. The male to female ratio was approximately 2: 1. Hermaphroditism (2.1%) and parasitic castration (1.4%) were observed. Linear growth rates of clams were found to increase until the age of three years old (11.6 ± 0.6 mm/year). Mollusks reach a commercial size of over 35 mm in shell length in the fourth year of life. The parameters of the von Bertalanffy equation describing group linear growth were L _∞ = 56.6 mm, k = 0.302 year^?1, and t ₀ = 0.468 year. The relationship between the shell length and the wet body weight is described by the equation W = 0.000253L^2.954.     

Reproductive biology of <Emphasis Type="Italic">Astyanax lacustris</Emphasis> (Characiformes: Characidae) in the southern Pantanal floodplain,upper Paraguay River basin,Brazil

We studied the reproductive biology of Astyanax lacustris in the southern Pantanal, Brazil. A total of 382 fish were analyzed from February 2009 to January 2011. The sex ratio differed significantly from 1:1, with a larger proportion of females (χ² = 27.24; p < 0.001). Females achieve higher standard length than males (mean 72.30 mm and 56.51 mm, respectively), and possess negative allometric growth while males have positive allometric growth. Size at first maturation did not differ between sexes. The greatest reproductive activity occurred during the rainy season, when temperatures were highest (November to February). Total fecundity was significantly correlated with standard length (r_s = 0.74; p = 0.01), and spawn type was total. Then, the life history traits of A. lacustris are adjusted to seasonal variation in the Southern Pantanal.     

First data on the biology of <Emphasis Type="Italic">Hadropareia middendorffii</Emphasis> (Perciformes,Zoarcidae) in the Tauysk Bay,the Sea of Okhotsk

Data of long-term studies (1997–2013) on biology of Hadropareia middendorffii from different areas of Tauysk Bay, the Sea of Okhotsk are generalized. This species is widespread over the entire northern coast of the Sea of Okhotsk, and it prefers sandy-pebbly grounds. Maximum sizes and age comprise 267 mm, 73 g, and 7+; in catches, individuals with a length of 9.1–12.0 cm, weight 0.1–10.0 g, at an age of 1+ to 3+ dominate. In general size–age characteristics of females and males as a whole are rather similar, and sex ratio is nearly equal. Hadropareia middendorffii spawns from the second half of June to the first 10-day period of August; its fecundity varies within 67–219 eggs.     

Reproductive biology and management of two commercially important groupers in the SW Atlantic

The reproductive biology of Epinephelus morio (red grouper) and Mycteroperca bonaci (black grouper) were evaluated based on 533 specimens collected from artisanal fisheries landings in the Abrolhos Bank, Brazil, between May 2005 and September 2012. Sex ratio for the black grouper was 1:14 (n = 155 females and 11 males; 26.1–147 cm TL) and 1:10 for the red grouper (n = 334 females and 33 males; 15.0–96.0 cm TL). For both species, highest values of the gonadosomatic index (GSI) for females were recorded between July and October, indicating spawning during the austral winter. The length at first maturity (L₅₀) for females was estimated at 62.0 and 47.0 cm TL for the black and red grouper, respectively. Batch fecundity based on TL and TW ranged from 2 to 15.4^?10⁶ and 1.5 to 13.7^?10⁶ for the black and red grouper, respectively. Interviews with experienced fishers revealed that spawning seasons of both groupers are largely unrecognized. Results demonstrate a positive relationship between GSI peaks, lower temperatures and stronger winds. The information provided herein may help decision-making regarding fisheries management and conservation for E. morio and M. bonaci at various levels of governance in the Abrolhos Bank, the region with the largest and richest coralline reefs in the South Atlantic.     

Life history strategies of the Scotia Sea icefish, <Emphasis Type="Italic">Chaenocephalus aceratus</Emphasis>, along the Southern Scotia Ridge

Reproductive capacity can influence distribution and abundance over large spatial scales through larval dispersal, even when adult stages remain isolated following settlement. We examined size distribution, reproductive traits and age structure in Scotia Sea icefish, Chaenocephalus aceratus, an abundant benthic species with a long larval pelagic phase found on continental shelves along the Southern Scotia Ridge. In particular, we compared life history strategies between fish caught during surveys undertaken off the South Orkney Islands (SOI) and South Shetland Islands (SSI). Results corroborated regional separation after settlement and suggested distinct life history strategies, in which fish from SOI invested much less in reproduction, and somewhat more in somatic growth earlier in their life history. Compared to SSI, body weight increased faster with length and absolute fecundity was 46 % lower and increased more slowly with size for SOI population. In addition, the proportion of spawning cohorts and L _∞ was lower and k higher for SOI. The differences appeared to be a phenotypic response to environmental conditions related to regional hydrography. Lower reproductive capacity around the SOI, and strong eastward flow in the large-scale circulation, suggests that the SSI may be more important in influencing distributions and abundance of icefish along the Southern Scotia Ridge.     

Life history traits of two dwarf cichlids species in the white waters of the Amazonian floodplain

The reproductive parameters are among the most important life history aspects of fishes influenced by environmental variation. During recent years, the main life history strategies of Amazonian fish species were defined mostly by a set of reproductive parameters. In the present work, we sought to describe important life history parameters, in particular on reproductive characteristics of Apistogramma agassizii and Apistogramma bitaeniata, found in floodplain lakes of the Brazilian Amazonia. The species presented a positive sexual dimorphism, and males were significantly bigger than females. For both sexes, four developmental phase of gonad maturation were detected, and based on those it was possible to identify mature, reproductive specimens throughout the entire period of the study. From the ovaries of mature females, fecundity and spawning type were determined. Low fecundity, short spawning periods, possibly separated only by few months, and total spawning are all good indications that A. agassizii and A. bitaeniata evolved an opportunistic strategy in their life history.     

Catalytic properties of aminoacylase of strain <Emphasis Type="Italic">Rhodococcus armeniensis</Emphasis> AM6.1

Studies of substrate specificity revealed that the D-aminoacylase of Rhodococcus armeniensis AM6.1 strain exhibits absolute stereospecificity to the D-stereoisomers of N-acetyl-amino acids. The enzyme is the most active reacted with N-acetyl-D-methionine, as well as with aromatic and hydrophobic N-acetylamino acids and interacts weakly with the basic substrates. It is practically not reacted with acidic and hydrophilic N-acetyl-amino acids. Michaelis constants (K_m) and maximum reaction velocities (V_max) were calculated, using linear regression analysis, for the following substrates: N-acetyl-D-methionine, N-acetyl-D-alanine, N-acetyl-D-phenylalanine, N-acetyl-D-tyrosine, N-acetyl-D-valine, N-acetyl-D-oxyvaline, N-acetyl- D-leucine. Substrate inhibition of D-aminoacylase was displayed with N-acetyl-D-leucine (K_s = 35.5 ± 28.3 mM) and N-acetyl-DL-tyrosine (K_s = 15.8 ± 4.5 mM). Competitive inhibition of the enzyme with product–acetic acid (K_i = 104.7 ± 21.7 mM, K_m = 2.5 ± 0.5 mM, V_max = 25.1 ± 1.5 U/mg) was observed.     

Comparing the methods for quantifying the culm surface area of bamboo, <Emphasis Type="Italic">Phyllostachys pubescens</Emphasis>

We compared several methods for quantifying the culm surface area (S) of one of the most common bamboos in Japan, Phyllostachys pubescens Mazel ex Houz. Nine sample culms of P. pubescens were felled, and the true S was determined by the fine resolution analysis of the culm form (S _FRA). The S was then calculated independently with the sectional measurement method from the successive diameters measured at equal intervals of one-twentieth (S ₂₀), one-tenth (S ₁₀), one-fifth (S ₅) and one-half (S ₂) of the total culm length. The S was also quantified geometrically from the total culm length and the diameter at breast height or at base by assuming that the culm form could be approximated by a cone (S _DBH and S _DAB). The S _FRA was compared with each of the computed S values. For S ₁₀, S ₅ and S ₂, both the mean relative bias (%BIAS) and relative root mean square error (%RMSE) decreased with an increase in the number of measured diameters. The %BIAS and %RMSE of the S ₁₀ were, respectively, comparable and smaller compared to those of S ₂₀. The bias of the S _DBH and S _DAB suggested that the cone assumption of the culm form was violated. In conclusion, we recommend that the S should be quantified from the successive diameters measured at equal intervals of one-tenth of the total culm length using the sectional measurement method.     

Karyological features of the genus <Emphasis Type="Italic">Planorbarius</Emphasis> (Gastropoda,Pulmonata, Bulinidae) of the Ukrainian fauna

The absence of significant distinctions between the species of the genus Planorbarius in the narrow sense (P. corneus, P. banaticus, P. purpura, and P. grandis) has been established. All investigated species had identical chromosomal formulas (2n = 30m + 6sm = 36) and fundamental numbers (FN = 72). Reproducible distinctions between them were not found by total complement length (TCL), relative length of chromosomes (RL), and centromeric indexes. The species selected on the basis of genetic marking differed clearly by centromeric index of chromosome 12, which confirms the allospecies frame of P.corneus s. lato.     

Complex effects of Ayurvedic formulation: <Emphasis Type="Italic">Guduchi</Emphasis> and <Emphasis Type="Italic">Madhuyashti</Emphasis> on different components of life history may elude the elixir effect

Formulations from the traditional Indian medicine, Ayurveda, have long been considered to have potent life-style-enhancing effects, possibly by their effect(s) on key life-history attributes. Although several studies have reported beneficial effects of these formulations on different components of life history, few have investigated their concurrent influence on various life-history traits. Here, we report the results of an investigation showing the effect of two well-known Ayurvedic formulations, Guduchi and Madhuyashti, on fecundity and longevity of Drosophila melanogaster. Flies were either grown (i.e., larval exposure) and/or maintained (i.e., adult exposure) on standard food supplemented with 0.5% Guduchi or 0.5% Madhuyashti. It was observed that the longevity of adult flies of both sexes was not affected on feeding Guduchi food, but fecundity of the females was greatly enhanced. Fecundity was also found to be affected by the adult food and whether their mates were grown on Guduchi or normal food. Madhuyashti, on the other hand, significantly reduced mean longevity and had a stimulatory effect on female fecundity. This fecundity enhancing effect however seemed to be mediated through its effect on the males. Interestingly, much of these effects interacted with age in a complex way, making it difficult to generalize the overall effect of these formulations on the reproductive output of the flies. Our study underlines the importance of evaluating the interacting effects of these (and similar) formulations on a range of life-history traits in a holistic way to understand their utility better.     

Modeling population dynamics of yeast-like symbionts (Ascomycota: Pyrenomycetes: Clavicipitaceae) of the planthopper <Emphasis Type="Italic">Delphacodes kuscheli</Emphasis> (Hemiptera: Delphacidae)

Delphacodes kuscheli establish mutualistic relationship with yeast-like symbionts (YLS) that live in the fat body and are necessary for host survival and reproduction. We estimated for a host of age t, its body weight, W_(t), and the number of YLS per host, YLS_(t). The host body weight was calculated as: W_(t)?=?Lm/[1+ e ^(d–kt)], (Lm?=?the maximum observed weight, and d and k are constants), and the fat body was considered a fixed proportion of W_(t). We calculated the number of YLS per unit host body mass: α_(t)?=?YLS_(t)/W_(t). We also calculated the number of YLS per host, cYLS_(t), and analyzed the pattern of variation in both sexes adapting the expression of the logistic model: cYLS_(t)?=?KN_oe^rt/K+(e^rt -1)N_o, (N_o?=?initial number of YLS, r?=?intrinsic per capita rate of natural increase, and K?=?variable carrying capacity). In females the carrying capacity varied according to a constant proportion of the host’s weight: K_(t)?=?αW_(t). In males α_(t) was considered a decreasing function of the host age: K_(t)?=?α_(t)W_(t). The coefficients No, α, and r were subjected to parameterization. We found that the patterns of W_(t) and YLS_(t) of D. kuscheli were similar to other planthoppers. In females YLS increased up to the adult stage and then remained almost constant, varying similarly to individual weight. In males YLS increased up to the 5th instar nymph as the individual weight did, but the number of YLS decreased in the adult stage and the correlation was not so good. The calculated number of YLS per host matches reasonably well with the number estimated experimentally both in females and males. This is the first study that quantified and modeled the dynamics of YLS endosymbionts in a Neotropical planthopper pest. The models will be used in future studies for better understand the experimental reduction of YLS in young nymphal stages.     

Effect of gut bacteria on fitness of the Chinese citrus fly, <Emphasis Type="Italic">Bactrocera minax</Emphasis> (Diptera: Tephritidae)

A likely symbiotic association between tephritid fruit flies and gut bacteria has been recognized since the beginning of the last century. However, direct evidence for a link between gut bacteria and fruit fly fitness is still limited or absent for many species. Similar to other tephritids, the gut of Bactrocera minax (Enderlein) (Diptera: Tephritidae) is known to contain bacteria throughout the life stage, but what, if any, impact these bacteria have on B. minax fitness is entirely unknown. In order to elucidate the effects of bacteria on the fitness of B. minax, resident bacteria were isolated from the adult gut using culture-dependent techniques. Adult fly diets were subsequently supplemented with three bacterial isolates (Klebsiella pneumonia, Citrobacter braakii and Pantoea dispersa), or bacteria were removed from flies by antibiotics treatment: untreated adults provided a control. Adult fitness parameters (male and female longevity, female fecundity, male copulation number) were measured for the two treatments and one control group. Results were complex depending on the fitness parameter measured and the bacterial species. Compared to the controls, antibiotic treated B. minax had significantly decreased fecundity, but male and female longevity was increased. When flies were fed diets supplemented with any of the three bacterial isolates, female fecundity was significantly enhanced. However, only Citrobacter braakii significantly increased male mating frequency than control males. The results show that gut bacteria directly influence fitness of B. minax, but impacts are dependent on the bacterial species and the fitness parameters measured.     

Testing the cost of reproduction with the rotifer <Emphasis Type="Italic">Brachionus</Emphasis><Emphasis Type="Italic">patulus</Emphasis> at different pH levels

In the present work, we tested the hypothesis that the cost of reproduction was evident under stressful conditions with the rotifer Brachionus patulus at different pH levels (5–10 at 1 unit intervals). We used sublethal pH levels (pH 5, 9, and 10) to simulate stressful conditions. We analyzed the correlations between age-specific fecundity (m ₁, m ₂, m ₃, …) versus future survival (l _x + 1, l _x + 2, l _x + 3, … for the entire lifespan) (survival costs) and future expectation of reproduction (\( V_{ 1}^{*} , \, V_{ 2}^{*} , \, V_{ 3}^{*} , \ldots \) for the entire lifespan) (reproductive costs), using the data obtained from life table demographic studies of B. patulus under stressful and favorable (pH 6, 7, and 8) pH levels. The results showed that significant negative correlations were observed between age-specific fecundity and future survival and future expectation of reproduction at all tested pH levels, indicating that costs of reproduction exist in the rotifer B. patulus under stressful and favorable pH conditions. However, the percentage of statistically significant negative correlations from total correlations of survival and reproductive costs differed greatly, depending on the tested pH conditions. The percentage of significant negative correlation of reproductive costs is significantly higher under stressful pH conditions (pH 5, 9, and 10) than favorable pH conditions (pH 6, 7, and 8). For survival costs, the same trends are also observed, suggesting that the costs of reproduction were more obvious under stressful pH than favorable pH.     

Life History of <Emphasis Type="Italic">Cochliomyia macellaria</Emphasis> (Fabricius, 1775) (Diptera,Calliphoridae), a Blowfly of Medical and Forensic Importance

The life history traits of blow fly Cochliomyia macellaria (Fabricius, 1775) was studied under semi-controlled laboratory conditions at 29.14°C temperature, 72.53% relative humidity, and 12-h photoperiod. The raw data were analyzed based on the age-stage, two-sex life table, considering the development rates among individuals of both sexes. Cochliomyia macellaria survival rate was 0.43 (♂) and 0.40 (♀), while life expectancy was 17.9 (♂) and 20.9 (♀) days, for adult males and females, respectively. The total fecundity was 681.15 eggs/female, with an average of 3.65 batches/female and 199 eggs/batch. The intrinsic rate of increase (r) was 0.327 days^?1, the finite rate of population increase (λ) was 3.35 days^?1, the mean generation time (T) was 17.15 days, and the net reproduction rate (R ₀ ) was 272.46 offspring/individual. The population parameters found here corroborates that C. macellaria population act as a r selected species under laboratory conditions. Additionally, development data and accumulated degree days (ADD) for each stage of C. macellaria are provided and its implications for the forensic use are discussed.     

Suitability of Different Prey Aphids on the Growth,Development and Reproduction of <Emphasis Type="Italic">Chrysoperla zastrowi sillemi</Emphasis> (Esben-Petersen) (Chrysopidae: Neuroptera)

The prey preference of polyphagous predator, green lacewing (Chrysoperla zastrowi sillemi (Esben-Petersen)) was evaluated against five prey aphids viz., mustard aphid (Lipaphis erysimi), green peach aphid (Myzus persicae), cabbage aphid (Brevicorynebrassicae), black bean aphid (Aphis craccivora), spirea aphid (Aphis spiraecola) of agriculture importance and compared with eggs of Corcyracephalonica (Stainton). Lacewing larvae preferred Myzus persicae most followed by Brevicorynebrassicae. The highest growth index (8.31), larval survival (94.50 %), larval weight (10.45 mg), pupal weight (8.78 mg), faster multiplication rate (0.051) and fecundity (183.4 per gravid female) of the predator were recorded on M. persicae. However, the chrysopid reared on Corcyra eggs performed best in all biological parameters and fitness, than on aphid preys. This study explores the possibilities of selecting the most suitable prey aphid species for its exploitation as supplement for mass multiplication of chrysopid during off-season or unavailability of Corcyra eggs.     

Effects of male apparent length on female preference for absolute body size in <Emphasis Type="Italic">Xiphophorus helleri</Emphasis>

Female green swordtails (Xiphophorus helleri) prefer males of longer body and sword lengths, which may reflect perceptual constraints. Larger males project a larger image onto the female’s retina at a given viewing distance, which may elicit greater stimulation of the visual system and a stronger behavioral response. This study investigates the effects of male apparent size, as affected by proximity and sword length, on female preference for absolute body size in X. helleri. Females were presented pairs of dummy males in ten treatments organized into six categories: (1) the Actual Length Control where identically sized males were held at different viewing distances from the female; (2) the Sword Compensation Treatment in which viewing distance and apparent length (body + sword) were held constant, pairing sworded with swordless dummies of equal total length; (3) the Body Length Preference Treatment where male distance from the female was held constant, while varying body size; (4) the Apparent (Sword) Length Preference Treatments where male distance from the female was held constant, while varying sword length; (5) the Apparent Length Controls where body length, sword length, and viewing distances varied while holding apparent length constant; and (6) the Experimental Treatment in which the smaller-sworded male of the pair appeared larger. In each of the Actual Length Control, Body, and Sword Length Treatments, females preferred the closer, larger-bodied, and longer-sworded males, respectively. However, females exhibited preferences in neither any of the Apparent Size Control treatments nor any of the Sword Compensation Treatment. Additionally, females in the Experimental Treatment preferred the apparently longer-sworded dummy to the male whose sword was actually longer. These results suggest that female preference for male body and sword length is based on the male’s apparent rather than actual size.