Mature Size Research Articles

Reproductive characteristics of malabar blood snapper \(\textit{Lutjanus malabaricus}\) (Bloch &Schneider, 1801) in coastal marine zone of Nghe An and Ha Tinh provinces, Vietnam

Malabar blood snapper Lutjanus malabaricus (Bloch & Schneider, 1801) inhabits in coastal marine waters of Nghe An and Ha Tinh provinces, Vietnam. An investigation of the reproductive characteristics of Lutjanus malabaricus in the coastal marine waters of Nghe An and Ha Tinh provinces was undertaken between June 2020 and May 2021. The spawning season of L. malabaricus occurred throughout the year, fish were in the ripe or spawning condition in most months; but spawning peaks from late March/April and August. Females matured at a smaller size than males, with total length (TL) at first maturity being 280–330 mm for males and 230–280 mm for females. The sex ratios of 365 individuals were approximately 1/1, and the total ratio G/W was approximately 0.08−5.65% with a mean of 0.32%. The highest GSI mean value in males was 0.77 (stage IV in July) and the lowest mean value 0.03−0.11 was recorded during stages I and II in November and December. Females had the highest mean value of 1.22−1.41 (stage IV in May) and the lowest mean value of 0.07 during stages I and II in January, and 0.20 at stages I and II in October. These show that fish (L. malabaricus) were ripe or spawning from March and August in the studied waters. The first maturity size was 280−330 mm for males and 230–280 mm for females. Absolute fecundity (Fa) ranged from 24.000 to 769.000 (the mean value 112.000) ova per ovaries for L. malabaricus. In the main spawning period, high gonadal index values were found around the time of the last quarter to the first quarter moon for each month from late March or early April to August. It is suggested that L. malabaricus is a lunar-synchronized spanner in the studied waters.

Ontogenetic changes in root and shoot respiration, fresh mass and surface area of Fagus crenata.

To date, studies on terrestrial plant ecology and evolution have focused primarily on the trade-off patterns in the allocation of metabolic production to roots and shoots in individual plants and the scaling of whole-plant respiration. However, few empirical studies have investigated the root : shoot ratio by considering scaling whole-plant respiration at various sizes throughout ontogeny. Here, using a whole-plant chamber system, we measured the respiration rates, fresh mass and surface area of entire roots and shoots from 377 Fagus crenata individuals, from germinating seeds to mature trees, collected from five different Japanese provenances. Non-linear regression analysis was performed for scaling of root and shoot respiration, fresh mass and surface area with body size. Whole-plant respiration increased rapidly in germinating seeds. In the seedling to mature tree size range, the scaling of whole-plant respiration to whole-plant fresh mass was expressed as a linear trend on the log-log coordinates (exponent slightly greater than 0.75). In the same body size range, root and shoot respiration vs. whole-plant fresh mass were modelled by upward-convex (exponent decreased from 2.35 to 0.638) and downward-convex trends (exponent increased from -0.918 to 0.864), respectively. The root fraction in whole-plant respiration, fresh mass and surface area shifted continuously throughout ontogeny, increasing in smaller seedlings during early growth stages and decreasing in larger trees. Our results suggest a gradual shift in allocation priorities of metabolic energy from roots in seedlings to shoots in mature trees, providing insights into how roots contribute to shoot and whole-plant growth during ontogeny. The models of root : shoot ratio in relation to whole-plant physiology could be applied in tree growth modelling, and in linking the different levels of ecological phenomena, from individuals to ecosystems.

The Evolution of tRNA Copy Number and Repertoire in Cellular Life.

tRNAs are universal decoders that bridge the gap between transcriptome and proteome. They can also be processed into small RNA fragments with regulatory functions. In this work, we show that tRNA copy number is largely controlled by genome size in all cellular organisms, in contrast to what is observed for protein-coding genes that stop expanding between ~20,000 and ~35,000 loci per haploid genome in eukaryotes, regardless of genome size. Our analyses indicate that after the bacteria/archaea split, the tRNA gene pool experienced the evolution of increased anticodon diversity in the archaeal lineage, along with a tRNA gene size increase and mature tRNA size decrease. The evolution and diversification of eukaryotes from archaeal ancestors involved further expansion of the tRNA anticodon repertoire, additional increase in tRNA gene size and decrease in mature tRNA length, along with an explosion of the tRNA gene copy number that emerged coupled with accelerated genome size expansion. Our findings support the notion that macroscopic eukaryotes with a high diversity of cell types, such as land plants and vertebrates, independently evolved a high diversity of tRNA anticodons along with high gene redundancy caused by the expansion of the tRNA copy number. The results presented here suggest that the evolution of tRNA genes played important roles in the early split between bacteria and archaea, and in eukaryogenesis and the later emergence of complex eukaryotes, with potential implications in protein translation and gene regulation through tRNA-derived RNA fragments.

Three-Year Closure of Fishing Seasons as a Management Tool for the Omani Abalone, Haliotis mariae, Fishery in the Sultanate of Oman

Data from underwater surveys conducted between 2009 and 2021 were analyzed to determine the effect of closed fishing seasons on the density and size composition of Omani abalone, in the main fishing areas (Mirbat, Sadah, Hadbin, and Hasik). The average density of abalones, the abundance of mature and legal size abalone, and the average abalone size increased significantly after a 3-year closure (2008-2010). From 2012 to 2021, abalone density and size decreased despite four 1-2 years of closed fishing seasons. The density of mature abalone after 2011 was below the minimum spawning density of Haliotidae. Abalone densities were found to be relatively high in Sadah and Hadbin but very low in Mirbat and critical conditions in Hasik. Lack in regulations’ enforcement, overlap between fishing and reproduction season, and the uncontrolled number of divers are probably the main reasons for the decline in abalone abundance and size. Future fishing closure must be extended for at least three years, and abalone harvest in Mirbat and Hasik should be banned for at least five years. The number of divers must be regulated, and changing the fishing season must be evaluated. It is necessary to identify if the population is sustainable, threatened, or recovering, by studying more biological aspects of the Omani abalone, including minimum spawning density, abalone aggregation, and recruitment levels at each fishing ground. These studies will help the authorities to decide when fishing must stop to avoid any further reduction in the abalone densities. It is important to understand the socioeconomic status of abalone diver’s communities in Oman for better management and development.

Diverse mangroves deviate from other angiosperms in their genome size, leaf cell size and cell packing density relationships.

While genome size limits the minimum sizes and maximum numbers of cells that can be packed into a given leaf volume, mature cell sizes can be substantially larger than their meristematic precursors and vary in response to abiotic conditions. Mangroves are iconic examples of how abiotic conditions can influence the evolution of plant phenotypes. Here, we examined the coordination between genome size, leaf cell sizes, cell packing densities and leaf size in 13 mangrove species across four sites in China. Four of these species occurred at more than one site, allowing us to test the effect of climate on leaf anatomy. We found that genome sizes of mangroves were very small compared to other angiosperms, but, like other angiosperms, mangrove cells were always larger than the minimum size defined by genome size. Increasing mean annual temperature of a growth site led to higher packing densities of veins (Dv) and stomata (Ds) and smaller epidermal cells but had no effect on stomatal size. In contrast to other angiosperms, mangroves exhibited (1) a negative relationship between guard cell size and genome size; (2) epidermal cells that were smaller than stomata; and (3) coordination between Dv and Ds that was not mediated by epidermal cell size. Furthermore, mangrove epidermal cell sizes and packing densities covaried with leaf size. While mangroves exhibited coordination between veins and stomata and attained a maximum theoretical stomatal conductance similar to that of other angiosperms, the tissue-level tradeoffs underlying these similar relationships across species and environments were markedly different, perhaps indicative of the unique structural and physiological adaptations of mangroves to their stressful environments.

Some Aspects of the Reproductive of Japanese Threadfin Bream (Nemipterus japonicus Bloch, 1791) Caught in the Area Around the Artificial Reef In the Pitu Sunggu Waters of the Makassar Strait

Japanese Threadfin Bream is a demersal fish commonly found around artificial reefs. Food availability in the artificial reef ecosystem is essential for the sustainability of this species. Hence, this research aimed to determine several aspects of bio-reproduction of Japanese Threadfin Bream caught in the artificial reef (bioreeftek). Samples were taken using handline fishing, twice a month (April-July 2020) in Pitu Sunggu Waters, Makassar Strait. The samples were observed for its reproduction aspects. The result showed that the Japanese Threadfin Bream fish caught have a balanced sex ratio between males and females, 1:1.03. The analysis of the gonad maturity stage obtained was II-IV, and the gonado somatic index ranged from 0.541-0.940 for males and 1.156-2.358 for females. The first mature Japanese Threadfin Bream size was 18.29 cm for males and 16.99 cm for females. The Japanese Threadfin Bream fish fecundity ranged between 35.042-42.061 eggs.

Low iron ameliorates the salinity-induced growth cessation of seminal roots in wheat seedlings.

Wheat plants are ubiquitously simultaneously exposed to salinity and limited iron availability caused by soil saline-alkalisation. Through this study, we found that both low Fe and NaCl severely inhibited the growth of seminal roots in wheat seedlings; however, sufficient Fe caused greater growth cessation of seminal roots than low Fe under salt stress. Low Fe improved the root meristematic division activity, not altering the mature cell sizes compared with sufficient Fe under salt stress. Foliar Fe spray and split-root experiments showed that low Fe-alleviating the salinity-induced growth cessation of seminal roots was dependent on local low Fe signals in the roots. Ionomics combined with TEM/X-ray few differences in the root Na+ uptake and vacuolar Na+ sequestration between two Fe levelsunder salt stress. Phytohormone profiling and metabolomics revealed salinity-induced overaccumulation of ACC/ethylene and tryptophan/auxin in the roots under sufficient Fe than under low Fe. Differential gene expression, pharmacological inhibitor addition and the root growth performance of transgenic wheat plants revealed that the rootward auxin efflux and was responsible for the low Fe-mediated amelioration of the salinity-induced growth cessation of seminal roots. Our findings will provide novel insights into the modulation of crop root growth under salt stress.

The growth, respiration, and reproduction of crustaceans: a synthesis through the Gill-Oxygen Limitation Theory (GOLT)

AbstractGill surface area (S) and respiration (R) in juvenile and adult crustaceans scale with their body weight (W) such that S ∝ R ∝ Wd, with d ranging mostly between 0.6 and 0.9, but always <1, as in other water-breathing ectotherms (WBE). The growth of adult crustaceans therefore approaches an asymptote, whether or not seasonal growth oscillations are explicitly considered in the model used to describe that growth (e.g., von Bertalanffy growth function). On the other hand, the variation in asymptotic size (L∞ or W∞) among crustaceans is primarily determined by water temperature, which impacts on the oxygen requirements of WBE. Through multiple examples, this and related aspects of the Gill-Oxygen Limitation Theory (GOLT), first developed for fishes and later extended to other WBE, are shown to also apply to the growth of a wide range of crustacean taxa. The GOLT also explains certain aspects of crustacean reproduction, such as the relationship between size at first maturity and maximum size, and, possibly, the feature that female crustaceans hold their eggs outside of their bodies instead of internally.

Invited Review: Genetic decision tools for increasing cow efficiency and sustainability in forage-based beef systems

The beef industry is experiencing pressure to increase the efficiency and sustainability of forage-based cow-calf production. Dozens of traits affect a cow’s ability to be biologically, economically, and environmentally efficient. Furthermore, in an increasingly volatile climate, an animal’s genetic merit must be considered in the context of its environment. This review discusses the complex problem of cow efficiency and how the industry can leverage genetic selection tools to improve these traits. I review currently available selection tools for increasing cow-calf production efficiency and discuss developing technologies and research that will drive future innovation. This review draws on primary literature from animal breeding, beef production, engineering, and agricultural sustainability to broadly discuss the challenges of genetically improving cow-calf efficiency and adaptability. Decision support tools allow breeders to select sires that will have more efficient daughters. Historically, these tools have focused on moderating mature cow size and milk production. They have recently expanded to include traits that directly measure feed efficiency and other related phenotypes such as longevity and fertility. Genetic selection tools also exist for adaptive traits to help producers select sires that produce offspring that respond better to environmental stressors such as heat stress or high elevation. Future work to develop genetic selection tools for forage-based beef systems will rely on integrating genomics, animal breeding, and precision livestock technologies. These developing technologies, coupled with existing tools, will enable producers to more directly make breeding decisions focused on cow efficiency and greenhouse gas emissions.

Modeling 3D geometric growth patterns and variations of Children's heads

To design high-quality head/face-related products for children, it is essential to be able to construct 3D geometric models of their head growth patterns and variations. However, compared to 3D anthropometric analysis of adults' heads, this is still an underexplored research area. This study developed a framework for modeling the 3D geometric growth patterns and sex-specific variations of children's heads. To analyze these variations, the entire heads of 793 children (395 females and 398 males) ages 5–17 were scanned, and one global and two sex-specific statistical shape models (SSMs) were constructed. The first principal component in these SSMs, contributing more than 65% to the total explained variations, was highly related to overall head sizes. To model growth patterns, expected average heads for different ages and per-vertex growth rates were computed. Our results showed that the entire female head basically reaches its mature size at age 13–14, whereas in males it continues to increase until age 16–17. This study therefore provides valuable references for children's head/face-related product design, including the development of a more accurate sizing system and improvements in product fit and function.

Environmental Friendliness Analysis of Purse Seine Operated by Km Sumber Baru, Belawan, North Sumatera

Purse Seine fishing gear is a fishing gear operated by several fishermen in the WPP NRI 571. Purse seine is a type of fishing gear that classified as surrounding nets, which is an active fishing gear to catch pelagic fish which who generally live in groups in large flocks. The main catch is Mackerel scad (Decapterus spp). The purpose of this study was to determine the level of environmental friendliness of the Purse seine fishing gear in PPS Belawan. The method used in this study is by using a score based on the Code of Conduct for Responsible Fisheries (CCRF) criteria, fish physiology analysis, and also analyze the suitability of fishing gear with the regulation of Permen KP.71 of 2016. Based on the results of the study, it can be concluded that physiologically fish include into fish fit for catching with a total length ranging from 19-24 cm, the average size of the first caught (Lc) at a length of 15 cmFL, the size of the first sentence gonads (Lm) 19.6 cmFL, Km. Sumber Baru does not meet the Regulations of the size of the vessel, and the Purse Seine fishing gear is very environmentally friendly with a score of 32 points.This Lc value is smaller than the Lm value. From this result, it is known that most of the scads caught have not passed the first gonadal maturity size (Lc<Lm), but in terms of the specifications of the fishing gear, they have adjusted to the applicable regulations

Fecundity, Female Maturation, and Nesting Season of Western Chicken Turtles (Deirochelys reticularia miaria) in Texas

The reproductive lifespans of turtles are consistently long, but reproductive cycles are under environmental control and thus can vary within species, populations, and individuals over time and space. Knowledge of turtle species' reproductive traits and their associated variances over time and space are critical to understanding the dynamics of turtle populations, especially those requiring management or conservation. Deirochelys reticularia is a species being considered for protection by the US Fish and Wildlife Service and contains 3 subspecies with some differences in reproductive characteristics of nesting season, annual nesting frequency, and egg retention. We collected ultrasound and x-radiograph data in Texas to identify the maturation size, nesting season, annual nesting frequency, and clutch size of female D. r. miaria in Texas. We observed no reproductive activity in individuals from 101 to 146 mm in plastron length (PL) and detected either unshelled eggs, shelled eggs, or both in individuals from 150 to 197 mm PL. Maturation sizes were similar to those in other regions and for other subspecies. We observed shelled clutches or nesting events from April to July, confirming a spring–summer nesting season in Texas consistent with other D. r. miaria sites and supporting the paradigm that the western subspecies does not follow the autumn–winter nesting season of the other subspecies. We found no evidence that individuals retain shelled eggs while aestivating or overwintering. Individuals nested up to 3 times/yr in Texas. Individuals laid 7–11 eggs and the mean clutch size was 9.2 eggs, similar to other regions and other subspecies. Nesting phenology is regionally variable, so management plans and policies for the species will need to consider that variation and potentially recognize management differences among D. reticularia subspecies.

Use of fermented spent coffee grounds as a substrate supplement for rearing black soldier fly larvae, Hermetia illucens (L), (Diptera: Stratiomyidae).

Spent coffee grounds (SCG), an increasingly abundant waste product with environmental disposal problems, has been used as a dietary supplement for many animals and have the potential to be used as a dietary supplement for black soldier fly (BSF) larvae; however, its effective use is still under scrutiny. To date, no studies have considered the use of SCG after microbial fermentation (fSCG) and its effects on BSF life history. A mixture of fruit and vegetable pulp residue supplemented with one of six different fSCG percentages (0%, 20%, 40%, 60%, 80%, and 100% by weight) were provided as a diet substrate in order to evaluate the effect of the fSCG quantity on BSF growth, yield, and conversion ability. The addition of fSCG to the pulp diet prolonged larval development times, while 100% fSCG affected the larval survival rate and resulted in a male-biased adult sex ratio. The 20-40% fSCG and 40-60% fSCG treatments supported the largest prepupal and mature larval sizes, respectively. The highest waste reduction efficiency and feed conversion rate by BSF larvae was found with 20% fSCG, similar to the control (0% fSCG). From the short rearing time, high yield, and high bioconversion efficiency, a 20% fSCG supplementation of the mixed pulp was recommended for rearing BSF larvae. These data are valuable for coffee by-product waste management in urban areas.

Sexual Maturity Scale of the Swimming Crab Callinectes pallidus (Rochebrune, 1883) from Lake Nokoué in South Benin, West Africa

Aims: Reproductive parameters are important tools for the sustainable management of halieutic species in the water bodies of its exploitation. This study intends to characterize the sexual maturity scale of swimming crab Callinectes pallidus, perform testicular and ovarian structures in order to develop a specific maturity scale.
 Study Design: This study was carried out with macroscopic and microscopic observations of 394 specimens of crabs including 206 females and 188 males.
 Place and Duration of Study: The specimens used in this study were collected monthly from March to July 2018 from small scale fisheries of Lake Nokoué (Benin).
 Methodology: At the laboratory, each crab specimen is identified and its sex determined. Grids for describing each sexual maturity stage of the crab C. pallidus were developed based on the Zairon et al. (2015) scale. Histological sections of female and male gonads were analyzed in order to certify the different stages of sexual development noted from the macroscopic study.
 Results: Macroscopic analysis of external and internal anatomy and histological study of male and female gonads of C. pallidus allowed to establish a sexual maturity scale with 5 stages in females and 4 stages in males respectively. Macroscopic observations made with a binocular magnifying glass allowed to describe the characteristic features of the sexual development cycle of the species. The histological study confirmed the results of the macroscopic analysis. Significant difference was recorded between the mean oocytes diameters of the different oocyte development stages (p<0.05).
 Conclusion: The outcomes of this constitute an important database for the assessment of the reproductive parameters of the species in the water bodies of its exploitation. The stages IV and V are the mature steps in the female development whereas the stages III and IV are that of the male. It is recommended to allow C. pallidus reach the sexual maturity size (5,95 cm for female and 6,38 cm for male) before their exploitation to ensure the sustainable management of the species.

Appraisal of a novel fishery of whelks (Buccinum undatum) in Danish waters

In 2016, a fishery for whelks (Buccinum undatum) was initiated in the Danish part of Kattegat and the Belt Sea. Until then the whelk had been a pristine resource in Danish fisheries. The inner Danish waters are not covered by EU regulations and very little is known about the whelk population characteristics in the area. Thus, the Danish whelk fishery is at present carried out without any administrative regulations or specific biological knowledge. This work gives novel information about the Danish whelk populations in the Southern Kattegat and Belt Sea. The stock size (shell length > 40 mm) in Kattegat was estimated to be in the range of 230,250–921,000 tons. The overall meat percentage in the three studied fishing zones ranged from 58.2–65.6 %. The size at maturity (sexes pooled) ranged from 62.9–70.3 mm corresponding to 4–4.5 years of age. The average shell length of the studied populations ranged from 64.1–73.2 mm and the asymptotic shell length was estimated to be 77.6–83.1 mm. Test fishery showed the CPUE quickly to decrease in a southern direction in the Belt Sea due to the prevailing salinity gradient. Commercial fishermen achieved an average CPUE of 1.3 kg pot-1 in the Southern Kattegat (January 2017–November 2018). Although the three zones studied are adjacent, significant differences were found in several of the measured parameters. This underlines the need of local monitoring of population characteristics in order to advice authorities on possible regulation of whelk fishery. The ongoing whelk fishery in the Southern Kattegat has at present an intensity not believed to cause recruitment overfishing. However, the Danish fishing authority is encouraged to implement a minimum conservation reference sizes (MCRS) based on locally determined size of maturity (SOM).

Parasites of Merluccius australis as biological tags to determine the hake ecological stocks in the sea channels of Chilean Patagonia

To manage fishery resources, defining the spatial distribution of biological populations is paramount. However, identification of populations can be controversial according to the methods used. The parasitofauna of the southern hake, Merluccius australis, in the Patagonian Fjord and Channel System of southern Chile, were analysed to determine if there was more than one ecological population. Samples were collected between spring 2004 and winter 2005 in three areas of the sea channels: in Chiloé (1); north of the Strait of Magellan (2); and south of the Strait of Magellan (3). In these areas, 219 hake specimens were collected, harbouring 26,071 parasites from 25 taxa. To determine whether any parasite taxon behaved as a biological tag, its abundance and prevalence was compared given body length, sex, and seasonality of the fish samples. The parasite communities among these areas were compared using GLM on the scores of the multivariate DECORANA analysis. The following criteria were used to select the taxa studied 1) taxa with a prevalence >5%, 2) parasites that accumulated through time (body length) in the fish, and 3) variability of their abundance among sites. The greatest variability in parasite abundance in these hakes was due to fish body length and sampling area, but not to fish sex and in general, not to seasonality to distinguish fish samples among the three areas. The digenean Aporocotyle australis characterized the samples from Chiloé that represented the smallest in body size. The nematode Anisakis sp. characterized the samples from south Magallanes that were the largest specimens. Fish from north Magallanes were similar in size to those of Chiloé but with smaller length range, and a transition of parasitofauna from Chiloé and south Magallanes samples. Statistical analyses of parasite taxa with a prevalence >5% and fish of all size classes (56–85 cm) showed significant differences in the parasitofauna abundance of southern hakes from the three sites. The analysis of fish length class 66–75 cm, the first maturity size, showed no significant differences among the Magallanes sites but both were different between the Chiloé sites. The parasitofauna of taxa with a prevalence >5% were useful as biological tags to discriminate between ecological stocks in the Magallanes areas compared to individual taxa but was time-consuming. Seven endoparasites and one ectoparasite are proposed as biological tags for future monitoring of ecological stocks in Chiloé and Magallanes.

Phenotypic and Chemotypic Relations among Local Andrographis paniculata (Burm. f.) Wall Landrace Collection

The relationship between the phenotypic and chemical composition of local Andrographis paniculata was evaluated in this study. Five seed collections were sourced from different regions of Thailand, namely Kamphaeng Saen (KS), Udon Thani (UT), Chiang Rai (CR), Chiang Mai (CM), and Ratchaburi (RB). They were cultivated in the same conditions, potted, and partially shaded (60%) in an open conventional greenhouse. The phenology and chemical composition of these plants were assessed at the commercial harvesting stage (ca. 90 days after planting). The results indicated that UT was morphologically distinctive, illustrating the highest edible biomass yield (aerial and mature leaf size). The above-ground parts (viz., leaves and stem) were then analyzed for bioactive compounds after maceration with 80% (w/w) ethanol. It was found that the highest lactone content (~14 mg/g extract) was obtained from leaf and stem extracts of all samples except KS. Nonetheless, total phenolics and flavonoids in the stem extract of KS were found to be the highest at 3.22 and 2.42 mg/g, respectively. Phytochemicals from both leaf and stem extracts were capable of high anti-oxidant activity (~70%) as determined by DPPH and ABTS assays. Chemically, RB contained the highest 14-deoxy-11,12-didehydroandrographolide (156.98 mg/g extract), while UT and CM contained up to 0.68 mg/g extract of neoandrographolide. Classification of the samples indicated a clear relationship between the morphological traits and chemical compositions. In conclusion, our findings suggest the variations in phenotypic and chemotypic relations across the different landraces of A. paniculata. In essence, the quantity of the consumable parts was essentially the marker to describe the quality of the phytochemical constituents. The overall outcome of this study was to select the physiological characteristics that could be used for further breeding programs of the ideal variety with high productivity and higher bioactive(s) content.

Size of maturity for blue king crab Paralithodes platypus in the northern part of the Sea of Okhotsk

We determined the size of sexual maturity of male and female blue crabs in the northwestern part of the sea (zone of cold core action), as well as in the northeastern part of the sea and the local cluster near the Iona bank (zone of comparatively warm waters). Morphological 50% maturation of males in the northwestern part of the Sea of Okhotsk was observed at the carapace width of 73.3 mm. Similar width were demonstrated for the northeastern part of the sea and for the Iona Bank area – respectively 88.5 mm and 91.0 mm. Females in samples from the northwestern part of the sea reached functional 50% maturity at the carapace width of 71.7 mm, from the northeastern part – of 79.4 mm, and from the Iona Bank – of 81.0 mm. Comparison with available literature data showed that blue crab in the northwestern part of the Sea of Okhotsk has probably the slowest growth rate, and the crabs have the smallest size at maturity compared to individuals in the other areas.

Reef crab population changes after oil spill disaster reach Brazilian tropical environments.

The oil spill that reached Brazilian Coast in 2019 was one of the most extensive disasters and its effects on distinct species are still under investigation. This study evaluated the effects of the oil spill on the crab Pachygrapsus transversus in four reef areas in Northeast of Brazil that are also under different levels of chronic anthropogenic impacts. Changes in population aspects were investigated including maturity, sex ratio, and relative growth considering periods before and after the oil spill. An acute decrease in the number of females captured in areas most affected by oil spill was evident and may be associated with the closure of burrows used for protection. Crabs from the most touristic area presented a decrease in the medium size of carapace and maturation compared to crabs from other less visited areas, which highlights the importance of studying the effects of impacts on marine fauna.

Radial growth, present status and future prospects of west Himalayan fir (Abies pindrow Royle) growing in the moist temperate forest of Himalayan mountains of Pakistan

Forests play a significant role for maintaining the biodiversity. In order to manage sustainable forests, tree species history, distribution, and their future prospects are vital. Using standardized quantitative approaches, the age, radial growth, and size class distribution of Abies pindrow (Himalayan fir) were determined from three different altitudinal sites (i.e. high, middle, and lower). The results indicate that Himalayan fir growing in the high-altitude site (Ayubia, 2 917 m a.s.l.) of moist temperate forests of the Himalayan mountains showed lower radial growth (0.13 cm) than in the middle (Bara Gali, 2 617 m a.s.l.; radial growth = 0.13 cm) and lower (Kuldana, 2 455 m a.s.l.; radial growth = 0.22 cm) altitude sites. Correlation analysis demonstrated that age showed a significant positive correlation (P < 0.001) with diameter at breast height. The tree-ring width chronology (totally 80 core samples) of Himalayan fir was developed from moist temperate forests of Himalayan mountains of Pakistan. At Ayubia site it possesses a long time-span (1703–2020 C.E.), followed by Bara Gali (1862–2020 C.E.) and Kuldana (1864–2020 C.E.). Further, the tree-ring width (TRW) chronology of Ayubia showed a significant positive correlation (P < 0.05) with May and June temperature, and a significant negative correlation (P < 0.05) with June and October precipitation, indicating that summer temperatures are the key factor for the radial growth of Himalayan fir. For the Kuldana site, the response of TRW chronology to temperature and precipitation was the same, however, it was significant only for June temperature at Bara Gali. The size class distribution of the high-altitude region (Ayubia) showed a higher number of individuals than the lower altitude region, indicating the lowest disturbance conditions. The absence of individuals in the early size classes and the gap in middle and mature size classes indicate a lower regeneration potential and anthropogenic impact. The pointer year analysis indicated that the Bara Gali forest is more sensitive to abnormal climate events than the other sites. Based on the present study, we suggest that proper attention and conservation strategy should be provided to Himalayan fir growing in the moist temperate forests of Pakistan.