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This study investigates the reproductive seasonality variation in Indian Major Carps (IMC), specifically Rohu (Labeo rohita) and Catla (Labeo catla). Utilizing field observations and analysis of gonadosomatic index (GSI), distinct reproductive patterns were observed among these species. The findings highlight that, in the absence of scientific interventions such as photoperiod manipulation and feeding management, a significant portion of Rohu and Catla fish reach maturity and breed after and before monsoon period (December and March). Understanding these reproductive variations is crucial for the identification of genetically distinct stocks suitable for line development that can reproduce during the winter seasons. This knowledge contributes to the strategic management of year-round seed availability. By elucidating the natural reproductive cycles of these economically important species, researchers can optimize breeding programs to align with environmental conditions, potentially identifying genetically different stock for line development, which can breed during winter seasons. [ABSTRACT FROM AUTHOR]

Flatback turtles (Natator depressus) are endemic to northern Australia, but their movements at sea have remained understudied. Here, we compiled one of the world's largest single‐species satellite tracking datasets (n = 280 transmitters, deployed between 2005 and 2020) to investigate the movements and level of spatial protection afforded to five flatback genetic stocks across Western Australia during different behavioral phases (i.e., inter‐nesting, migration, and foraging). Flatbacks spent 99.5% of their time in Australian waters and are provided with a very high level of spatial protection (>98% overlap with Biologically Important Areas) during the inter‐nesting phase of their life cycle. Up to 85.6% and 59.1% overlap between marine reserves and the foraging and migratory ranges for flatback stocks, respectively, was found. However, our results identified additional foraging and migratory areas where protective measures would benefit multiple stocks at once. The detailed flatback distribution maps produced here will be key resources for managers and researchers and highlight the benefits of collaborative multi‐agency studies. Additionally, this work provides a useful analytical framework for future studies endeavoring to complete large‐scale, multi‐stock spatial distributions and overlap assessments for populations of conservation concern. [ABSTRACT FROM AUTHOR]

Abstract Flatback turtles (Natator depressus) are endemic to northern Australia, but their movements at sea have remained understudied. Here, we compiled one of the world's largest single‐species satellite tracking datasets (n = 280 transmitters, deployed between 2005 and 2020) to investigate the movements and level of spatial protection afforded to five flatback genetic stocks across Western Australia during different behavioral phases (i.e., inter‐nesting, migration, and foraging). Flatbacks spent 99.5% of their time in Australian waters and are provided with a very high level of spatial protection (>98% overlap with Biologically Important Areas) during the inter‐nesting phase of their life cycle. Up to 85.6% and 59.1% overlap between marine reserves and the foraging and migratory ranges for flatback stocks, respectively, was found. However, our results identified additional foraging and migratory areas where protective measures would benefit multiple stocks at once. The detailed flatback distribution maps produced here will be key resources for managers and researchers and highlight the benefits of collaborative multi‐agency studies. Additionally, this work provides a useful analytical framework for future studies endeavoring to complete large‐scale, multi‐stock spatial distributions and overlap assessments for populations of conservation concern.

Background: Butter catfish (Ompok bimaculatus) is a preferred species in South East Asia, with huge aquaculture potential. However, there is limited information about genetic stock composition due to insufficient markers. The goal of this study was to develop de novo microsatellite markers. Methods and results: For sequencing, genomic SMRT bell libraries (1.5 Kbp size) were prepared for O. bimaculatus. A total of 114 SSR containing sequences were used for primer designing. Polymorphic loci were validated by genotyping 83 individuals from four distant riverine populations, viz., Brahmaputra, Bichiya, Gomti and Kaveri. A total of 30 microsatellite loci were polymorphic, of which five were found to be associated with functional genes and eight (four positive and four negative) loci were found to be under selection pressure. A total of 115 alleles were detected in all loci and PIC ranged from 0.539 to 0.927 and pair-wise FST values from 0.1267 to 0.26002 (p < 0.001), with an overall FST value of 0.17047, indicating the presence of population sub-structure. Cross-species transferability of 29 loci (96.67%) was successful in congener species, Ompok pabda. Conclusion: The novel SSR markers developed in this study would facilitate stock characterization of natural populations, to be used in future selection breeding programs and planning conservation strategies in these species. Identified non-neutral markers will give insights into the effect of local adaptation on genetic differentiation in the natural population of this species. [ABSTRACT FROM AUTHOR]

This study investigated the genetic structure, diversity, and migratory patterns of hawksbill turtles (Eretmochelys imbricata) from two nesting locations in Papua New Guinea (PNG) using mitochondrial DNA (mtDNA) sequencing and satellite telemetry. Tissue samples collected from nesting female hawksbill turtles (n=75) in PNG revealed a total of 6 haplotypes from the Conflict Group site and 5 haplotypes from Kavieng site, with the Conflict Group and Kavieng samples significantly differing from one another and all other known Asia-Pacific stocks. This finding expands our understanding of the genetic stock structure of hawksbill turtles in the Asia-Pacific region, resulting in 9 Management Units (MUs) now published. Satellite tracking of 15 hawksbill turtles revealed that all individuals migrated from the Conflict Group westerly towards foraging areas in eastern Australia (93%) and PNG (7%). With a mean migration path distance of 1241 ± 108 km, three distinct migration strategies were used by the 10 hawksbill turtles that made it to their foraging grounds in the I) eastern Torres Strait, II) Far North Queensland, and III) western PNG waters. A broad scope of home-range strategies and sizes (95% UD) were used, and in comparison to other studies further postulates that hawksbills are connected to non-specific foraging grounds associated with food source availability. This study provides for the first time in PNG essential insights into hawksbill turtle population structure and connectivity in the western Pacific region, highlighting the importance of effectively conserving and managing this critically endangered species as distinct population stocks. Furthermore, we make recommendations for national and regional conservation strategies and transboundary management to ensure the long-term survival and recovery of western Pacific’s hawksbill turtle populations.

This paper investigates the morphological and productive characteristics of two Tsigaie ecotypes belonging to the red variety. They represent genetic stock and semen, oocytes and embryos will be harvested from them in order to be cryopreserved. The sheep belong to the hill ecotype (Jucu farm and SCD Turda) and the mountain ecotype (SCDCOC Reghin). Body dimensions and weight are characteristic for the breed and prove the superiority of the hill ecotype over the mountain ecotype. The differences between populations from the hill ecotype are an effect of the keeping and feeding, the measurements being higher for animals from the Jucu farm. Wool production of sheep from the mountain ecotype is close to that of animals form the Jucu farm. Characteristics list the sheep as part of the breeds having semi-fine wool. Milk production increases until the thirs lactation and then decreases. It is higher for the hill ecotype. Milk quality, expressed through fat and protein percentages is similar for the two ecotypes and characteristic for the breed.

The scalloped hammerhead shark Sphyrna lewini is a migratory shark species, highly valued commercially for its meat and fins. Although this species has been listed on the CITES Appendix II, its genetic structure in the West Pacific is still little known. In this study, shotgun sequencing technique was used to sequence millions of small fragmented DNA sequences simultaneously. Nine novel polymorphic microsatellite markers were isolated from sequencing reads and then tested on 54 individuals collected from the western North Pacific. The number of alleles detected in each locus ranged from seven to 21. Observed and expected heterozygosity of these loci were from 0.370 to 0.870 and from 0.505 to 0.724, respectively. These nine novel polymorphic loci can further be used to reveal genetic connectivity patterns among S. lewini in the West Pacific. [ABSTRACT FROM AUTHOR]

Gymnogobius isaza is a freshwater goby endemic to ancient Lake Biwa, the largest lake in Japan. The species is now listed as ‘Critically Endangered’ in the Red Data Book of Japan. Nevertheless, it remains subject to fishing without any specific management strategies. Previous studies using mitochondrial DNA markers showed that this fish species has two cryptic lineages. However, little is known about spatial genetic structure and ecological differences across the broad lakescape. In this study, we collected fish samples at nine locations along the lakeshore during the breeding season and tested for the presence of spatial heterogeneity in the lineage’s composition while measuring body size as the most fundamental biological trait. The results showed that the major lineage dominated all the sampling locations whereas the minor lineage consisted of only 11% (16/143) of samples. Furthermore, although their spatial distributions overlapped (i.e. the two lineages may be well mixed), we found it possible that the minor lineage may have a potentially narrower distribution than the major lineage. In addition, we found that the two lineages differ in body size; specifically, the minor lineage is smaller in size. From the viewpoint of genetic diversity conservation and sustainable resource use, this fish should be managed as two genetic stocks and spatial and/or body size-based fishery management is desirable, with particular attention to the minor (smaller sized) lineage. [ABSTRACT FROM AUTHOR]

Abstract: Estuarine habitats provide rearing opportunities for the juvenile life stage of anadromous fishes. Because survival is positively correlated with juvenile performance, these estuarine habitats play an important role in population abundance and productivity. To provide information for the recovery of several depressed stocks of Chinook salmon in the Columbia River Basin, we sought to identify the factors that explain variability in performance. Using otolith‐derived estimates of juvenile somatic growth rate as an index of recent performance, we observed a negative nonlinear relationship between growth rate and day of year, and a decreasing and increasing trend of growth rate over the 8 years of this study and distance from the river mouth respectively. Using a generalised linear modelling approach, we found that variability in juvenile somatic growth rate was best explained by where and when individuals were collected, their body size, contaminant loads, stock of origin, and whether a fish was hatchery produced or unmarked. Lastly, we argue that a considerable improvement to the growth rate of juveniles in estuarine habitats is physiologically possible. The results of this 8‐year study provide a baseline of the performance of juvenile Chinook salmon to evaluate habitat restoration programs and to compare against future anthropogenic conditions. [ABSTRACT FROM AUTHOR]

Octopus minor (Sasaki, 1920) is an important economic fishery resource in China. In order to explore the stock information and the phylogeographic status of O. minor, mitochondrial DNA cytochrome c oxidase subunit I (COI, 565 bp) and 16S rRNA (493 bp) genes were amplified from 11 different sampling locations. Genetic diversity evaluated by haplotypic and nucleotidic diversity implied high diversity in Lianjiang, and relatively low diversity in Rongcheng, which suggests that effective measures to protect the O. minor resource in this area are urgently required. Private haplotypes and remarkable higher pairwise ΦST in Yilan are responsible for the deep genetic divergence between Yilan and the 10 other populations. Haplotypes networks and two clusters’ topological structure also support the distinct subgroups (lineages A and lineages B), which apparently possess smaller genetic variation than mean interspecies distance. Taiwan island and its strait may act as a natural barrier that restricts the gene flow from the mainland. Deep genetic divergence between mainland and Taiwanese east coasts suggests different genetic stock, indicating that different management strategies are required. [ABSTRACT FROM AUTHOR]

Bread wheat ( Triticum aestivum ) ranks as one of our most important staple crops. However, its hexaploid nature has complicated our understanding of the genetic bases underlying many of its traits. Historically, functional genetic studies in wheat have focused on identifying natural variations and have contributed to assembling and enriching its genetic stock. Recently, mold-breaking advances in whole genome sequencing, exome-capture based mutant libraries, and genome editing have revolutionized strategies for genetic research in wheat. We review new trends in wheat functional genetic studies along with germplasm conservation and innovation, including the relevance of genetic stocks, and the application of sequencing-based mutagenesis and genome editing. We also highlight the potential of multiplex genome editing toolkits in addressing species-specific challenges in wheat. [ABSTRACT FROM AUTHOR]

Sandy beach surf zones serve as alternative nursery habitats for juvenile Chinook salmon (0 age) during their early marine residency, a period considered critical due to high and variable mortality rates. Despite the importance of early marine residence, the extent of juvenile salmon surf zone use and movement along sandy beaches is not well understood. Juvenile Chinook salmon distribution and movement were studied in shallow surf zone habitats by sampling from 2006 to 2010 with a beach seine 11 beaches adjacent and distant to four estuary mouths in Oregon and Washington, USA. The estuary of origin of each juvenile was determined using genetic stock identification methods and coded wire tags. Surf zones sampled were within littoral cells, which are stretches of the coastline bordered by rocky headlands, and included estuaries with and without Chinook salmon populations. Juvenile salmonids were only collected at littoral cells with Chinook-inhabited watersheds. Most juveniles (95 %) were present at sandy beaches adjacent (<500 m from estuary mouth) to their estuary of origin. Few Chinook salmon (5 %) were collected at littoral cells that contained non-natal estuaries. These results indicate that juvenile Chinook salmon inhabiting surf zones mostly use beaches adjacent to their estuaries of origin, but some juveniles may reside in beaches distant from their point of ocean entry. [ABSTRACT FROM AUTHOR]

Galaxias maculatus (Pisces: Galaxiidae) commonly known as "puye" has a disjunct distribution along the Southern Hemisphere including landlocked and migratory populations at latitudes over 30°S in South America, Australia, Tasmania, and New Zealand. Chilean artisanal fishery of G. maculatus has become less important as a resource due to multiple factors including overexploitation, pollution, introduction of predators, and competitors. At the same time, the current conservation status of the species in Chile is still uncertain. Here, we used mtDNA control region sequences (925 bp) to investigate main patterns of genetic diversity and structure in populations from 2 biogeographic areas along the Chilean coast. Extremely high levels of genetic diversity characterize the species, suggesting a low amount of influence of the last glacial cycle over its demography compared with other studies in freshwater and marine South American fishes. However, we recognized contrasting genetic patterns between the Intermediate Area (between 30°S and 42°S) and the Magellanic Province (between 42°S and 56°S). On the one hand, over a narrow geographical range (<200 km) each Intermediate Area estuarine population constitutes a different genetic unit. On the other hand, the Magellanic populations of the species exhibited low levels of differentiation in an area extending for more than 500 km. Such differences may be a consequence of different coastal configurations, oceanographic regimes, and Quaternary glacial histories. Finally, our results support the existence of different stock units for G. maculatus and this information should be integrated in future management strategies and aquaculture programs for this species. [ABSTRACT FROM AUTHOR]

In this study, we have reviewed the population genetic structure of eleven tuna species (albacore, bigeye, yellowfin, Pacific bluefin, Atlantic bluefin, southern bluefin, blackfin, longtail, skipjack, frigate, and little tuna) with a global perspective. Based on the studies using molecular markers, there are 50 genetically distinct populations of tuna species worldwide (12 albacore, 4 bigeye, 9 yellowfin, 4 bluefin, 2 blackfin, 2 longtail, 12 skipjack, 2 little tuna, and 3 frigate tuna). It is evident that some tunas (albacore, bigeye, yellowfin, bluefin, and skipjack) have got more attention of researchers than the others (longtail tuna, blackfin tuna, little tuna, and frigate tuna), possibly because of their higher commercial importance. So, the larger number of studies on some species of tuna might be the reason for the higher number of population structure observed. Also, relying on the results of a single molecular marker, which were used in some studies, may produce misleading conclusions. Therefore, complementary sets of markers should be used in assessing population structure. Still, the number of to date revealed genetically distinct populations in some tunas species (albacore, yellowfin, and skipjack) is higher than number of stocks managed by authorities grouped in tuna regional fisheries management organizations. It might be a signal for reevaluation of fishery management of such tunas. [ABSTRACT FROM AUTHOR]

Body measurements and certain reproductive indexes were computed for a Bazna population kept at SCDA Turda as genetic stock. Values were compared to those reported in 1999 when this population was last analyzed. The data has induced us to conclude that breeding and selection have lead to an increase in both height at withers and rump proving that this breed has been improved toward meat production. Prolificacy and piglet weight at birth are within breed standards but closer to the lower limit. The weight of piglets weaned at 56 days is above 11 kg, which represents a good start for their growth. A negative element is the high piglet mortality before weaning. [ABSTRACT FROM AUTHOR]

The objective of this research is to characterize the morphological traits and sow reproductive performance in a red Mangalitsa swine population kept as genetic stock at SCDA Turda. Body length, height at withers and rump height are larger than the ones reported by in 1999 for the same population, but they are within breed standards. Prolificacy is above breed standard but high piglet mortality until the age of 21 days proves the sows are not good mothers. Lactating ability is high and together with piglet ability to use the ingested feed leads to a doubling of animal weight at weaning (56 days) when compared to the breed standard. [ABSTRACT FROM AUTHOR]

In parts of the Indo-Pacific, large-scale exploitation of the green turtle Chelonia mydas continues to pose a serious threat to the persistence of this species; yet very few studies have assessed the pattern and extent of the impact of such harvests. We used demographic and genetic data in an age-based model to investigate the viability of an exploited green turtle stock from Aru, south-east Indonesia. We found that populations are decreasing under current exploitation pressures. The effects of increasingly severe exploitation activities at foraging and nesting habitat varied depending on the migratory patterns of the stock. Our model predicted a rapid decline of the Aru stock in Indonesia under local exploitation pressure and a shift in the genetic composition of the stock. We used the model to investigate the influence of different types of conservation actions on the persistence of the Aru stock. The results show that local management actions such as nest protection and reducing harvests of adult nesting and foraging turtles can have considerable conservation outcomes and result in the long-term persistence of genetically distinct management units. [ABSTRACT FROM AUTHOR]

Parapenaeopsis stylifera (H. Milne Edwards, 1837), popularly known as Kiddi shrimp, constitutes an important fishery resources along the Indian coast with wide geographical distribution. Despite its economic importance, the genetic stock structure of the species is not investigated so far. Knowledge on genetic structure is essential for formulating sustainable management and conservation measures. Present study is carried out to characterize the five geographically isolated stocks of P. stylifera along the Indian coast using microsatellite markers. Eleven polymorphic microsatellites were developed in P. stylifera and used for genetic stock characterization. Including all the stocks, a total of 174 alleles were observed with a mean of 15.81 alleles per locus. Mean observed (H o) and expected (H e) heterozygosity values ranged from 0.641 to 0.692 and 0.710–0.743, respectively. Six loci shown deviation from Hardy-Weinberg equilibrium and no significant linkage disequilibrium between loci pairs were detected. Pair-wise F ST, AMOVA and Structure analyses indicated low genetic structure between the stocks of east (Bay of Bengal) and west (Arabian Sea) coasts of India. Based on the present study, P. stylifera stocks of east and west coast of India can be proposed as single management units (MUs), which require single monitoring and management practices. [ABSTRACT FROM AUTHOR]

Influences of dietary levels of vitamin E fed to hens and their progeny, and routes of SRBC inoculation on antibody responses of diverse populations of chickens were studied. Populations were a commercial broiler sire line (C), 2 commercial broiler dam lines (A and B), and Leghorn lines selected for high (H) or low (L) antibody response to SRBC. Dams from lines A and B were fed diets supplemented with either 10 or 300 IU/kg of vitamin E, whereas dams from lines H and L received only the diet with 10 IU of vitamin E/kg. Progeny from matings of C males with A and B females as well as H and L females mated to males from their respective lines were hatched on the same day and fed diets supplemented with either 10 or 300 IU/kg of vitamin E. Breeders were the same age and eggs were incubated in the same machine. Chicks were inoculated on d 14 intravenously with 0.1 mL of a 0.5% suspension of SRBC or intramuscularly with 0.1 mL of a 25% suspension of SRBC. Antibody response was measured 6 and 14 d later. Chicks received a booster i.m. inoculation of 0.1 mL of 25% SRBC on d 28. Titers were again measured 6 and 14 d later. Level of vitamin E fed to dams did not affect progeny BW or plasma vitamin E levels. Although titers were higher following i.v. than i.m. inoculation, the degree of difference varied among stocks. Dietary vitamin E level interacted with inoculation route with a greater response to the higher than lower level of vitamin E for i.v., but there was no difference for i.m. There were stock ⊗ level of vitamin E and stock ⊗ route of inoculation interactions for secondary responses to SRBC inoculation. Stock rankings after the first inoculation were not predictive of the rankings after the second inoculation. The 30-fold increase in dietary level of vitamin E resulted in >12-fold differences in plasma levels of vitamin E. Overall, there was a stock-dependent influence of dietary vitamin E on growth and humoral antibody response. [ABSTRACT FROM AUTHOR]

Tree species in the arid and semi-arid regions use various strategies to combat drought stress. Ziziphus nummularia (Burm. f.) Wight et Arn., native to the Thar Desert in India, is highly drought-tolerant. To identify the most drought-tolerant ecotype of Z. nummularia, one ecotype each from semi-arid (Godhra, annual rainfall >750 mm), arid (Bikaner, 250-350 mm) and hyper-arid (Jaisalmer, <150 mm) regions was selected along with two other Ziziphus species, Ziziphus mauritiana Lamk. and Ziziphus rotundifolia Lamk., and screened for parameters contributing to drought tolerance. Among these, Z. nummularia (Jaisalmer) (CIAHZN-J) was the most drought - tolerant. The tolerance nature of CIAHZN-J was associated with increased membrane stability, root length and number, length of hairs and thorns, root dry/fresh weight ratio, seed germination (at -0.5 MPa), proline content (31-fold), catalase and sugar content (two- to three-fold). Apart from these characteristics, it also exhibited the longest duration to reach highest cumulative drought stress rating, maintained higher relative water content for a longer period of time with reduced leaf size, leaf rolling and falling of older leaves, and displayed sustained shoot growth during drought stress. To determine drought tolerance in Ziziphus, we developed a morphological symptom-based screening technique in this study. Additionally, transcriptome profiling of CIAHZN-J in response to drought revealed the up-regulation of genes involved in sugar metabolism and transport, abscisic acid biosynthesis, osmoregulation, reactive oxygen species homeostasis and maintaining water potential. Expression profiles and semi-quantitative reverse transcription PCR results further correlated with the physiological and biochemical mechanisms. In conclusion, CIAHZN-J is an excellent genetic stock for the identification of drought-responsive genes and can also be deployed in crop improvement programs for drought tolerance., (© The Author(s) 2021. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.)

Presented is an overview of the thesis of this symposium with a snapshot summation of the papers presented, including modest critiques and suggestions for future efforts. [ABSTRACT FROM AUTHOR]