Length–length and length–weight relationships of oilfish (Ruvettus pretiosus), escolar (Lepidocybium flavobrunneum), snake mackerel (Gempylus serpens), and longnose lancetfish (Alepisaurus ferox) from the Gulf of Mexico and the western North Atlantic Ocean

Oilfish, escolar, snake mackerel (order Aulopiformes, family Gempylidae), and longnose lancetfish (order Perciformes, family Alepisauridae) sampled from the western North Atlantic and the Gulf of Mexico were analyzed for length–weight and length–length relationships. These species are encountered as occasional bycatch of pelagic longline fisheries. The fish (161 specimens, 19.0–149.1 cm TL) were collected over a 3‐year period (January 2007–January 2010) from pelagic longline gear targeting swordfish and tuna. For each species, 95% confidence limits (CI) of parameters b and log a and regression coefficients (r²) were calculated for log‐transformed length–weight relationships. The length–weight parameter b for all species ranged from 2.881 to 3.358, with regression coefficients (r²) ranging from 0.75 to 0.98. Linear relationships between fork lengths, standard lengths, and total lengths were also calculated.     

Temporal change in the morphometry–body mass relationship of polar bears

Accurate information on animal body mass is often an essential component of wildlife research and management. However, for many large-bodied species, obtaining direct scale weights from individuals may be difficult. In these cases, morphometric equations (e.g., based on girth or length) may provide accurate and precise estimates of body mass. We developed predictive equations to estimate the body mass of free-ranging polar bears (Ursus maritimus) in western Hudson Bay, Canada. Using multiple linear and non-linear regression, we identified a strong relationship between polar bear body weight and linear measures of straight line length and axillary girth. The mass–morphometry relationship appeared to change over time and we developed separate equations for polar bears measured during 2 time periods, 1980–1996 and 2007–2009. Non-linear models were more accurate and provided body mass estimates within 5.8% (R² = 0.98) and 6.1% (R² = 0.98) of scale weight in the earlier and later time periods, respectively. Earlier equations developed for polar bears in this subpopulation performed poorly when applied to recently sampled individuals. In contrast, some contemporary equations from other regions performed reasonably well, suggesting that temporal changes within a subpopulation may be more pronounced than regional differences and can render earlier predictive equations obsolete. Our results have important implications for current and future studies of polar bear body condition and the effects of ongoing climate warming. © 2011 The Wildlife Society.     

Size at sexual maturity,egg number and reproductive output of the snapping shrimp Alpheus euphrosyne euphrosyne De Man, 1897

Abstract

Aspects of the reproductive biology of snapping shrimp Alpheus euphrosyne euphrosyne inhabiting a tropical estuary were studied between August 2007 and July 2008 by examining 1309 females of 8.5–21.5 mm carapace length. Although the occurrence of ovigerous females was noted from October, the main breeding season extended from January to March. Size at 50% sexual maturity was estimated as 10.6±1.40 mm CL. Number of eggs per brood ranged from 141 to 1553 in females of 11.2 to 19.2 mm CL and mean absolute fecundity was estimated as 480±272 eggs. Regressions of log egg number on log total length, log carapace length and log weight revealed isometric relationships (p <0.01). Results of ANOVA revealed significant variation between mean short and long axes of eggs among five embryo developmental stages (P <0.05). The estimated egg batch 33 volume ranged from 4.99 to 32.09 mm³ with a mean of 12.44 mm³. Estimates of reproductive output from 41 females ranged between 8.21 to 31.25% with a mean value of 18.55±5.81.     

北京市幼儿园2—6岁儿童生长情况

1985年5月—8月,作者对北京市幼儿园833名2—6岁儿童进行了人体测量调查,并对所获得的数据进行了统计分析。结果表明2—6岁儿童身高增长较快,平均每年增加70毫米,身体各部分的长度变化基本与身高的增长相协调;围度的变异范围大于长度的变异范围。同1975年调查结果相比,儿童的体重、身高、胸围等项目数值都有所增加,但身高的增加速度已减慢。     

Length–weight and length–length relationships of 11 fish species from the Sea of Okhotsk

Estimated length–weight relationships are presented for 11 marine fish species representing six families, found above the continental shelf and in the pelagial of the Okhotsk Sea. A total of 13,841 specimens were caught by trawls that were equipped with a 1.0 by 1.2 cm mesh webbing inset. The period between 1974 and 2015 comprised mostly spring and autumn months. All length–weight relationships were highly significant (r² ≥ .95) on a log scale. None of the species had previous length–weight estimates, and two species had no previous length–length estimates in the FishBase.     

ARTIFICIAL SELECTION ON HORN LENGTH-BODY SIZE ALLOMETRY IN THE HORNED BEETLE ONTHOPHAGUS ACUMINATUS (COLEOPTERA: SCARABAEIDAE)

Males of the horned beetle Onthophagus acuminatus Har. (Coleoptera: Scarabaeidae) exhibit horn length dimorphism due to a sigmoidal allometric relationship between horn length and body size: the steep slope of the allometry around the inflection of the sigmoid curve separates males into two groups; those larger than this inflection possess long horns, and those smaller than this inflection have short horns or lack horns. I examined the genetic basis of the allometric relationship between horn length and body size by selecting males that produced unusually long horns, and males that produced unusually short horns, for their respective body sizes. After seven generations of selection, lines selected for relatively long horns had significantly longer horn lengths for a given body size than lines selected for relatively short horns, indicating a heritable component to variation in the allometry. The sigmoidal shape of the allometry was not affected by this selection regime. Rather, selected lines differed in the position of the allometry along the body size axis. One consequence of lateral shifts in this allometric relationship was that the body size separating horned from hornless males (the point of inflection of the sigmoid curve) differed between selection lines: lines in which males were selected for relatively long horns began horn production at smaller body sizes than lines selected for relatively short horns. These results suggest that populations can evolve in response to selection on male horn length through modification of the growth relationship between horn length and body size.     

WEIGHTS AND ANATOMICAL MEASUREMENTS OF NORTHEASTERN ATLANTIC FIN (BALAENOPTERA PHYSALUS, LINNAEUS) AND SEI (B. BOREALIS, LESSON) WHALES

Piecemeal body weights of eleven fin and four sei whales and intact weights of three foetuses, obtained from Iceland, are compared with published weight data. The Icelandic fin are similar to other northern hemisphere animals but are significantly leaner than their Antarctic counterparts. The Icelandic sei appear heavier than the North Pacific sei whales. Their weights cannot be predicted from a North Pacific sei whale weight/length formula. Length, girth and blubber thickness measurements indicate changes in relative body dimensions in the early fin whale foetus compared with juveniles and adults; however, the midterm sei whale foetus is similar to the adult and juvenile sei whales. The blubber appears to form a major component even in the foetal body. The integration of a standard series of lengths, girths and blubber thicknesses in juveniles and adults can provide an estimate of the blubber component. Both girth and length are significant parameters in estimating body weight, a simple weight/length formula being found to be inadequate to allow for variability in body fatness. Evaluation of such a multiple parameter formula for calculating weight appears satisfactory for both fin and sei whales. Apparent weight/length differences between species and stocks may thus be partly due to variations in body fatness.     

Age-variability in body shape associated with excess weight: the UK National Sizing Survey

Background: The health risks of obesity are disproportionately due to central abdominal adiposity; however, the extent to which age is associated with the body shape of obese adults is not known. Objective: Three‐dimensional (3D) data on body shape from the UK National Sizing Survey were analyzed to investigate age‐associated changes in body shape within the BMI bands <20, 20–24.99, 25–29.99 and ≥30 kg/m². Methods: Measurements of anthropometry (weight and height) and a 3D body scan were obtained in 4,344 men and 5,266 women recruited from eight British cities. Results: The body shape of men showed high consistency within BMI bands between early adulthood and old age. In contrast, the body shape of women altered within each BMI band with increasing age. In obese, overweight, and normal weight women, age was associated with decreased thigh girth, increased waist, and bust girth. Whereas young obese women maintained an hourglass shape, in old age the body shape of obese women converged on that of obese men. Discussion: The association of age with body shape is markedly different between the sexes, with the impact of obesity on shape strongly age‐dependent in women but not in men. The age delay in the association between obesity and high waist girth in women may contribute to the sex‐difference in life expectancy. The relationship between body shape change and cardiovascular risk merits longitudinal investigation within individuals.     

Sexually dimorphic male horns and their use in agonistic behaviors in the horn-headed cricket <Emphasis Type="Italic">Loxoblemmus doenitzi</Emphasis> (Orthoptera: Gryllidae)

Sexual dimorphism, the difference between the sexes in secondary sexual characters, is in general driven by processes of sexual selection. The horn-headed cricket, Loxoblemmus doenitzi, exhibits sexual dimorphism in head shape. Males have flat heads and triangular horns on both sides of their heads, whereas females have rounded heads and no horns. We hypothesized that male horns have evolved due to intra-sexual selection, in which males use these horns as weapons in aggressive interactions. We tested two predictions of this hypothesis by conducting agonistic trials with field-caught males of L. doenitzi: (1) the horns should be used in agonistic interactions between males, and (2) the asymmetry in horn size or horn use may determine contest outcome. Horn length was significantly correlated with thorax length and hind femur length. During agonistic interactions, males aggressively used their horns by beating the opponent’s horns with their own or by poking the opponent’s body. However, logistic regression analysis revealed that neither horn length nor horn use were significant factors for contest outcome. Instead, body size was significant for determining contest outcome. We discuss possible scenarios for evolution of male horns in L. doenitzi.     

Investigation of individual heterozygosity correlated to growth traits in Tongshan Black-boned goat

Ten single nucleotide polymorphisms were used for genotyping of 176 Tongshan Black-boned goats, which are Chinese indigenous goat colony for meat production. The average individual heterozygosity was 0.292. To assess the correlations between individual heterozygosity and growth in Tongshan Black-boned goat individuals, and the potential of using individual heterozygosity as an indicator of growth, the data of growth traits, including body weight, height at withers, body length, chest girth and cannon circumference, were collected. Significant correlations were observed between individual heterozygosity and body weight, height at withers, body length, heart girth, cannon circumference (P < 0.05). All the significant regression showed positive slope with R square values ranged from 0.0251 to 0.0368. These data suggests that individual heterozygosity is positively correlated with growth traits in Tongshan Black-boned goat individuals and associative overdominance may affect Tongshan Black-boned goat growth significantly. Therefore it is possible to use individual heterozygosity as an indicator of growth. Our results also provide a strong support to the overdominance hypothesis.     

How Big Is It Really? Assessing the Efficacy of Indirect Estimates of Body Size in Asian Elephants

Information on an organism’s body size is pivotal in understanding its life history and fitness, as well as helping inform conservation measures. However, for many species, particularly large-bodied wild animals, taking accurate body size measurements can be a challenge. Various means to estimate body size have been employed, from more direct methods such as using photogrammetry to obtain height or length measurements, to indirect prediction of weight using other body morphometrics or even the size of dung boli. It is often unclear how accurate these measures are because they cannot be compared to objective measures. Here, we investigate how well existing estimation equations predict the actual body weight of Asian elephants Elephas maximus, using body measurements (height, chest girth, length, foot circumference and neck circumference) taken directly from a large population of semi-captive animals in Myanmar (n = 404). We then define new and better fitting formulas to predict body weight in Myanmar elephants from these readily available measures. We also investigate whether the important parameters height and chest girth can be estimated from photographs (n = 151). Our results show considerable variation in the ability of existing estimation equations to predict weight, and that the equations proposed in this paper predict weight better in almost all circumstances. We also find that measurements from standardised photographs reflect body height and chest girth after applying minor adjustments. Our results have implications for size estimation of large wild animals in the field, as well as for management in captive settings.     

Length–weight and length–length relationships for six commercial fishes from southern Korean waters

Presented are the relationships between total length and weight, and between total length and standard length for six commercial fishes collected twice a month from local fish markets in southern Korea between 2005–2006 for Acanthopagrus schlegelii (Bleeker, 1854), Hexagrammos agrammus (Temminck & Schlegel, 1843) and Hexagrammos otakii (Jordan & Starks, 1895), and monthly in 2004 for Dentex tumifrons (Temminck & Schlegel, 1843), Doederleinia berycoides (Hilgendorf, 1879) and Scomberomorus niphonius (Cuvier, 1832). The LWR for D. tumifrons is estimated for the first time, and a new maximum length was recorded for S. niphonius. All total length and weight relationships were significant (all r² > .953). The values of exponent b, estimated using simple linear least squares of log‐transformed weight and length data, ranged from 2.945 to 3.317.     

Trawl codend design (44 mm diamond PE mesh) and the effect on selectivity for Pagellus erythrinus and Pagellus acarne, two species with different morphometrics

The effects of different body shapes on size selectivity were analysed. Relationships between total length and fork length, height, width and girth were estimated and the selectivity parameters of a 44 mm PE diamond mesh codend determined for common pandora (Pagellus erythrinus) and axillary sea bream (Pagellus acarne). Two data sets were collected during demersal trawl trials carried out in Izmir Bay (Aegean Sea) between May 1996 and February 1997. Regression analyses were used to determine the relationships between total length and other measured dimensions of the species. However, selectivity parameters were estimated from pooled data by using the logistic equation with the maximum likelihood method. Fork length, height, width and girth were found to increase linearly with total length for both species (R² > 0.90, except TL–W for axillary sea bream, 0.76). Ratios of average body thickness (W/H) were 0.45 (±0.002) for common pandora and 0.52 (±0.002) for axillary sea bream. L₅₀ and SR values were found as 12.4 (±0.44) and 2.2 (±0.51) from the eight valid hauls for common pandora and as 13.6 (±0.13) and 1.9 (±0.26) from the three valid hauls for axillary sea bream, respectively. The difference between the size selectivity of the two species in the same family can be explained by the body shape and fish behaviour distinctions.     

Microsatellite polymorphism and its association with body weight and selected morphometrics of farm red fox (Vulpes vulpes L.)

Polymorphism of 30 canine-derived microsatellites was studied in a group of 200 red foxes kept on 2 Polish farms. 22 out of 30 microsatellites were selected to study association between marker genotypes and body weight (BW), body length (BL), body circumference (BC), tail length (TL), ear height (EH), length of the right front limb (FRLL), length of the right rear limb (RRLL), length of the right front foot (FRFL) and length of the right rear foot (RRFL). A total of 112 alleles and 243 genotypes were found at 22 autosomal microsatellite loci. Three monomorphic loci deemed as uninformative were excluded from the study. The association between marker genotypes and the studied traits was analysed using general linear model (GLM) procedure and least squares means (LSM). Linkage disequilibrium (LD) was estimated to assess non-random association between microsatellite loci. Out of 19 microsatellites studied four markers showed no association with the studied traits, three markers had a significant effect on one trait, and another three markers had significant effect on two traits. Among ten microsatellites with significant effect on four economically important traits (BW, BL, BC, TL) four were associated with two characters: marker FH2613 with BW and BC, marker FH2097withBL and BC, marker ZUBECA6 with BW and BC, whereas marker REN75M10 was associated with BL and TL. The strongest LD (r² ranged from 0.15 to 0.33) was estimated between nine loci with significant effect on economically important traits (BW, BL, BC, TL).     

Length‐weight relationships of 6 fish species from the lower reaches of the YarlungZangbo River,Southwest China

The relations between total length and weight were evaluated for six fish species from the lower reaches of the YarlungZangbo River, southwest China, including Schizothorax molesworthi (Chaudhuri, 1913); Psilorhynchus homaloptera Hora & Mukerji, 1935; Creteuchiloglanis kamengensis (Jayaram, 1966); Parachiloglanis hodgarti (Hora, 1923); Glaridoglanis andersonii (Day, 1870); Pseudecheneis sulcate (McClelland, 1842). All fish were collected from March to May, October and November 2017 using electro fishing and gill net. The relationships between total length and weight were significant (all r² > .955, p < .01). And the values of exponent b, estimated using simple linear least squares of log‐transformed weight and length data, ranged from 2.687 to 3.147.     

Gestation length, metabolic rate, and body and brain weights in primates: epigenetic effects

The relationship of brain and body weights can be expressed in log-log regression: log (brain weight) = log (A) + B log (body weight). To investigate further the weights' similarity, gestation length and brain and body weights were determined from the literature for 46 primate genera. The results of allometric and path regression analyses suggest that the relationship between brain and body weights may not be mainly pleiotropic in the order Primates. The correlation between brain and body weights appears to be due to epigenetic factors in hyperplastic growth related to time constraint by gestation length and to energy utilization limitations imposed by metabolic rate.     

Length–weight relationships of five fish species from the Beijiang River,China

The length–weight relationships (LWRs) were determined for five fish species from the Beijiang River in China. Fishes were caught by gill nets (mesh sizes: 5, 7, 9 cm), and cage nets (mesh sizes: 0.5 cm) from April to September 2018. Length–weight relationships of four species were unknown to FishBase, and new records of maximum lengths are given for two species, one of which, Ancherythroculter lini, is endemic species of the Pearl River. All length–weight relationships were highly significant on a log scale with the coefficient of determination (r²) values ranged from 0.939 to 0.991. Values of b were within the expected range, varied from 2.935 for A. lini to 3.414 for Parasinilabeo assimilis.     

Estimates of general combining ability in Hevea breeding at the Rubber Research Institute of Malaysia

Summary Estimates of general combining ability of parents for yield and girth obtained separately from seedlings and their corresponding clonal families in Phases II and IIIA of the RRIM breeding programme are compared. A highly significant positive correlation (r = 0.71***) is found between GCA estimates from seedling and clonal families for yield in Phase IIIA, but not in Phase II (r = –0.03^NS) nor for girth (r= –0.27^NS) in Phase IIIA. The correlations for Phase II yield and Phase IIIA girth, however, improve when the GCA estimates based on small sample size or reversed rankings are excluded.When the best selections (based on present clonal and seedling information) are compared, all five of the parents top-ranking for yield are common in Phase IIIA but only two parents are common for yield and girth in Phases II and IIIA respectively. However, only one parent for yield in Phase II and two parents for girth in Phase IIIA would, if selected on clonal performance, have been omitted from the top ranking selections made by previous workers using seedling information.These findings, therefore, justify the choice of parents based on GCA estimates for yield obtained from seedling performance. Similar justification cannot be offered for girth, for which analysis is confounded by uninterpretable site and seasonal effects.     

Mechanical limits to maximum weapon size in a giant rhinoceros beetle

The horns of giant rhinoceros beetles are a classic example of the elaborate morphologies that can result from sexual selection. Theory predicts that sexual traits will evolve to be increasingly exaggerated until survival costs balance the reproductive benefits of further trait elaboration. In Trypoxylus dichotomus, long horns confer a competitive advantage to males, yet previous studies have found that they do not incur survival costs. It is therefore unlikely that horn size is limited by the theoretical cost–benefit equilibrium. However, males sometimes fight vigorously enough to break their horns, so mechanical limits may set an upper bound on horn size. Here, I tested this mechanical limit hypothesis by measuring safety factors across the full range of horn sizes. Safety factors were calculated as the ratio between the force required to break a horn and the maximum force exerted on a horn during a typical fight. I found that safety factors decrease with increasing horn length, indicating that the risk of breakage is indeed highest for the longest horns. Structural failure of oversized horns may therefore oppose the continued exaggeration of horn length driven by male–male competition and set a mechanical limit on the maximum size of rhinoceros beetle horns.     

Cube law, condition factor and weight–length relationships: history, meta-analysis and recommendations

This study presents a historical review, a meta‐analysis, and recommendations for users about weight–length relationships, condition factors and relative weight equations. The historical review traces the developments of the respective concepts. The meta‐analysis explores 3929 weight–length relationships of the type W = aL^b for 1773 species of fishes. It shows that 82% of the variance in a plot of log a over b can be explained by allometric versus isometric growth patterns and by different body shapes of the respective species. Across species median b = 3.03 is significantly larger than 3.0, thus indicating a tendency towards slightly positive‐allometric growth (increase in relative body thickness or plumpness) in most fishes. The expected range of 2.5 < b < 3.5 is confirmed. Mean estimates of b outside this range are often based on only one or two weight–length relationships per species. However, true cases of strong allometric growth do exist and three examples are given. Within species, a plot of log a vs b can be used to detect outliers in weight–length relationships. An equation to calculate mean condition factors from weight–length relationships is given as K_mean = 100aL^b?3. Relative weight W_rm = 100W/(a_mL^bm) can be used for comparing the condition of individuals across populations, where a_m is the geometric mean of a and b_m is the mean of b across all available weight–length relationships for a given species. Twelve recommendations for proper use and presentation of weight–length relationships, condition factors and relative weight are given.