Changes in catch rates and length and age at maturity, but not growth, of an estuarine plotosid (Cnidoglanis macrocephalus) after heavy fishing

The hypothesis that heavy fishing pressure has led to changes in the biological characteristics of the estuary cobbler (Cnidoglanis macrocephalus) was tested in a large seasonally open estuary in southwestern Australia, where this species completes its life cycle and is the most valuable commercial fish species. Comparisons were made between seasonal data collected for this plotosid (eeltail catfish) in Wilson Inlet during 2005–08 and those recorded with the same fishery-independent sampling regime during 1987–89. These comparisons show that the proportions of larger and older individuals and the catch rates in the more recent period were far lower, i.e., they constituted reductions of 40% for fish ≥430 mm total length, 62% for fish ≥4 years of age, and 80% for catch rate. In addition, total mortality and fishing-induced mortality estimates increased by factors of ~2 and 2.5, respectively. The indications that the abundance and proportion of older C. macrocephalus declined between the two periods are consistent with the perception of long-term commercial fishermen and their shift toward using a smaller maximum gill net mesh to target this species. The sustained heavy fishing pressure on C. macrocephalus between 1987–89 and 2005–08 was accompanied by a marked reduction in length and age at maturity of this species. The shift in probabilistic maturation reaction norms toward smaller fish in 2005–08 and the lack of a conspicuous change in growth between the two periods indicate that the maturity changes were related to fishery-induced evolution rather than to compensatory responses to reduced fish densities.

Changes in catch rates and length and age at maturity, but not growth, of an estuarine plotosid (cnidoglanis macrocephalus) after heavy fishing

The hypothesis that heavy fishing pressure has led to changes in the biological characteristics of the estuary cobbler (Cnidoglanis macrocephalus) was tested in a large seasonally open estuary in southwestern Australia, where this species completes its life cycle and is the most valuable commercial fish species. Comparisons were made between seasonal data collected for this plotosid (eeltail catfish) in Wilson Inlet during 2005-08 and those recorded with the same fishery-independent sampling regime during 1987-89. These comparisons show that the proportions of larger and older individuals and the catch rates in the more recent period were far lower, i.e., they constituted reductions of 40% for fish ≥430 mm total length, 62% for fish ≥4 years of age, and 80% for catch rate. In addition, total mortality and fishing-induced mortality estimates increased by factors of ~2 and 2.5, respectively. The indications that the abundance and proportion of older C. macrocephalus declined between the two periods are consistent with the perception of long-term commercial fishermen and their shift toward using a smaller maximum gill net mesh to target this species. The sustained heavy fishing pressure on C. macrocephalus between 1987-89 and 2005-08 was accompanied by a marked reduction in length and age at maturity of this species. The shift in probabilistic maturation reaction norms toward smaller fish in 2005-08 and the lack of a conspicuous change in growth between the two periods indicate that the maturity changes were related to fishery-induced evolution rather than to compensatory responses to reduced fish densities.

Young people and the justice system : consideration of maturity in criminal responsibility

The age of majority determines when a young person is considered adult in the eyes of the law, and in many countries this is set at 18 years. This does not take into account the differing ways and time-frames in which young people mature and develop. In justice systems in which individuals can be awarded leniency due to mental impairment, it becomes apparent that a similar justification can be made for issues surrounding maturity. This is of particular importance due to a growing trend in the Western world for young people to be tried as adults based on their crime, rather than their individual culpability. The aim of this review was to consider the interaction between maturity and criminal culpability.

Effects of bone-specific physical activity, gender and maturity on tibial cross-sectional bone material distribution; a cross-sectional pQCT comparison of children and young adults aged 5-29 years

Growth is the opportune time to modify bone accrual. While bone adaptation is known to be dependent on local loading and consequent deformations (strain) of bone, little is known about the effects of sex, and bone-specific physical activity on location-specific cross-sectional bone geometry during growth. To provide more insight we examined bone traits at different locations around tibial cross sections, and along the tibia between individuals who vary in terms of physical activity exposure, sex, and pubertal status. Data from 304 individuals aged 5-29 years (172 male, 132 female) were examined. Peripheral quantitative computed tomography (pQCT) was applied at 4%, 14%, 38%, and 66% of tibial length. Maturity was established by estimating age at peak height velocity (APHV). Loading history was quantified with the bone-specific physical activity questionnaire (BPAQ). Comparisons, adjusted for height, weight and age were made between sex, maturity, and BPAQ tertile groups. Few to no differences were observed between sexes or BPAQ tertiles prior to APHV, whereas marked sexual dimorphism and differences between BPAQ tertiles were observed after APHV. Cross-sectional location-specific differences between BPAQ tertiles were not evident prior to APHV, whereas clear location-specificity was observed after APHV. In conclusion, the skeletal benefits of physical activity are location-specific in the tibia. The present results indicate that the peri- or post-pubertal period is likely a more favourable window of opportunity for enhancing cross-sectional bone geometry than pre puberty. Increased loading during the peri-pubertal period may enhance the bone of both sexes.

Population structure and sexual maturity of the calico box crab Hepatus epheliticus Linnaeus (Brachyura, Hepatidae) from Yucatan Peninsula, Mexico

The calico box crab Hepatus epheliticus is an abundant species from shallow and continental shelf waters of the Atlantic coast of USA and Mexico. Information about population structure and sexual maturity is absent, even though this crab is caught to be used as bait for the octopus fishery in the Campeche Bank, Mexico. In order to achieve such information, a total of 768 individuals were collected from January to March 2010 through baited traps installed in the Yucatan Peninsula, Mexico. Our results showed that sex ratio is biased towards more males than females (1:0.55), contradicting to that reported in other brachyuran crabs. The absence of ovigerous females suggests that they did not enter into the traps during embryogenesis. Males reached a larger maximum size than females (64.0 +/- 6.15 and 58.4 +/- 5.60 mm carapace width, respectively). The general scheme of growth being positive allometric throughout ontogeny of both sexes. Males presented a transition phase from juveniles to adult corresponding to the puberty moult. The estimation of the onset of functional sexual maturity revealed a steady situation for the population, with 21.5 and 13.8% of males and females, respectively, morphologically immature at the time of catch. This study constitutes the first report on population structure and sexual maturity in a population of the calico box crab H. epheliticus.

Genetic associations between weight at maturity and maturation rate with ages and weights at first and second calving in Canchim beef cattle

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relative growth, morphological sexual maturity, and size of Macrobrachium amazonicum (Heller 1862) (Crustacea, Decapoda, Palaemonidae) in a population with an entirely freshwater life cycle

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Reproductive period and size at the onset of sexual maturity of mottled purse crab, Persephona mediterranea (Herbst, 1794) (Brachyura, Leucosioidea) on the southeastern Brazilian coast

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chromatic alteration in Arenaeus cribrarius (Lamarck) (Crustacea, Portunidae): an indicator of sexual maturity

Some individuals of the species Arenaeus cribrarius (Lamarck, 1818) bear a characteristic pink abdomen, which is notably different from the usual white coloration. The incidence of this chromatic alteration was determined for a single population and its relation with other individual variables were examined. The individuals were monthly collected from May, 1991 to April, 1993, in Ubatuba, São Paulo, with the aid of a shrimp fishery boat provided with double-rig trawling nets. All specimens were sexed, measured (CW = carapace width), distributed in 10-mm size classes and classified according to growth phase (juvenile and adult), molting condition and development stage of gonads. The occurrence of pink-colored morphs was also recorded. From a total of 2,096 collected individuals, only 60 females (nine of those ovigerous) presented a pink-colored abdomen, which represents 2.9% of the whole sample and 5.2% of the females. Almost all of them were intermolt individuals (96.6%) and 63.3% showed mature gonads. According to published data, size at the onset of functional maturity in A. cribrarius females is around 60 mm CW, from which the incidence of pink morphs and ovigerous crabs were recorded. The obtained results suggest that such a chromatic alteration is associated to sexual maturity in these females. This characteristic may enhance the attraction potential for mating, shortly after the puberty molt.

Physiological maturity and relationships of growth and reproduction in the red mangrove crab Goniopsis cruentata (Latreille) (Brachyura, Grapsidae) on the coast of São Paulo, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Morphometry and sexual maturity of the tropical hermit crab Calcinus tibicen (Crustacea, Anomura) from Brazil

Ontogenetic changes in relative growth were studied in the hermit crab Calcinus tibicen in order to determine its growth phases with sexual maturity. Specimens were collected at 2-month intervals for two consecutive years. A total of 570 individuals was collected and analysed. Total mean animal size in terms of shield length was 5.14±1.23mm for males, 4.23±0.79mm for females and 4.53±0.60mm for ovigerous females. Sexual dimorphism in chela dimensions was stronger in males than in females. Differences between males and females were found in left propodus length (LPL) and height (LPH) versus shield length (SL) and wet weight (WW) versus SL relationships. Males showed a high positive allometry, while juveniles and adult females were isometric for the LPL/SL relationship. Negative allometry was observed in adult females in the LPL/SL relationship. The size at which a differentiation occurred in the growth of the chelipeds and in the weight gain of males and females was between 3.0 and 3.2mm SL, suggesting that sexual maturity occurs in small-sized individuals in the life cycle of C. tibicen.

Age assessment based on dental calcification in individuals with Down syndrome

It is important to estimate both chronological age (CA) and maturational age of an individual, in order to perform orthopedic treatment or surgery, and in cases of lost documentation. Use of dental age (DA) for these purposes has been widely studied; however, the literature is scarce with regard to individuals with Down syndrome (DS), a prevalent condition worldwide. In this study the chronology of dental maturation was evaluated by analyzing the DA of individuals with DS based on the Chronological Mineralization Table proposed by Nolla (1960). Thus, second molars were evaluated in 57 panoramic radiographs of male and female individuals with DS, between 5 and 16 years-old. These data were compared with a control group of 191 nonsyndromic individuals of the same age group. Correlation between CA and DA was ascertained using Pearson's correlation coefficient (r), and the difference between these variables was measured using Student's t-test for paired samples and the method proposed by Bland and Altman. The difference between DA and CA was compared between the control and DS groups using Student's t-test for independent samples (α=0.05). DA was slightly lower than the CA; however, this difference was only significant for females. The difference between DA and CA was not significant between individuals with DS and control group (both genders, p=0.945; males, p=0.542; females, p=0.381). We concluded that dental maturation in individuals with DS occurs similarly to that of nonsyndromic individuals. © 2013 Elsevier Ltd.

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.

Brazilian soccer players and no-players adolescents: effect of the maturity status on the physical capacity components performance

The aim of this study was to compare the speed and the agility between Brazilian soccer players and non-players, regarding maturity status in adolescents 11-15 years old. Forty and two soccer players (age – 159.30±17.28 months old; weight – 48.45±9.96 kg; height – 1.53±0.10 m) and 45 non-players (age – 162.62±24.92 months old; weight – 48.30±8.35 kg; height – 1.54±0.12 m) participated of this study. Participants were classified by maturity status. On 2 different days with 1 week of differences between the assessments the participants were evaluated the agility, by Shuttle Run test, and the speed, by 30 m maximum speed test. The results showed that the maturity status was an influential factor in the performance with better results for individuals in a more advanced stage. The soccer practice does not seem to interfere in the performance of the physical capacity components analyzed, only effective when different maturity levels are involved in the analysis. It is also possible that late maturing boys selectively drop-out of soccer as age and sport specialization increase.