Growth and reproductive traits of endemic Anatolian khramulya Capoeta tinca (Heckel, 1843) (Teleostei: Cyprinidae) in the Devrez River, Türkiye

Understanding the biological characteristics of fishes is essential for conserving native, particularly endemic species and providing accurate recommendations for fisheries management. In Türkiye, studies on the endemic Ankara nase, Chondrostoma angorense, are rare, and no data are available on its reproductive biology. This study provides some biological parameters of C. angorense, including population age structure, growth, and reproductive characteristics, from the Devrez River. Fish specimens were sampled monthly from April 2020 to March 2021 using a cast net. The overall ratio of males to females was 0.98:1, with an age distribution of I–V age groups. The length–weight relationship and von Bertalanffy growth function were estimated as log W = −1.9586 + 3.0039 log (L) and Lt = 32.64 (1 − e−0.109 (t + 1.870)), respectively. The maturity ogives indicated that 50% of males and females reached sexual maturity at total lengths (TLs) of 14 cm and 16 cm and weights of 25 g and 34 g, respectively. C. angorense had a protracted spawning season lasting from March to June. The absolute fecundity ranged from 1015 to 10 664 oocytes, with an average of 5130. Fecundity was positively correlated with fork length, total weight, gonad weight, and age.

We compared the von Bertalanffy growth function (VBGF) and five polynomial functions (PF) in modelling fish growth for 16 populations comprising six species of freshwater fishes. Ranked results of the variance explained by each growth function indicated that VBGF described growth data better than three- and four-parameter polynomial functions. Log-transforming length and age greatly improved the goodness-of-fit of the three-parameter polynomial function. Statistical comparison of growth between populations or sexes was done using a general linear model for polynomial functions. An analysis of residual sum of squares was proposed to compare the resultant VBGFs because the nonlinear formulation of the VBGF prevented traditional analysis of covariance procedures. Fitting of different growth functions to the same growth data set yielded the same result in the intra-species growth comparisons for three species (eight populations) but different results for two species (seven populations). Where ages of the fish were less than the maximum age in the samples, dL/dt were similar for all growth functions except the parabola based on the log-transformation of length alone. The VBGF proved to be the best growth model for all 16 populations.

Two inshore and four shore localitites of Ligusticum scoticum in C Norway were studied regarding the growth and reproductive characteristics of the L. scoticum individuals, and the vegetation and ecology of the sites. L. scoticum showed a similar growth and reproductive characteristics at the inshore and the shore localities. The inshore localities were judged as relatively persistent on their basis of growth and reproductive characteristics and population size, and one of the inshore localities has with certainty maintained itself for at least 20 years. We suggest the inshore populations have established from seeds dispersed from the shore by birds. There were large differences in vegetation and ecological variables and cover between the inshore and the shore localities. At the inshore localities vegetation contained a large number of dwarf shrub and moss species which were almost entirely absent from the shore. Due to various physiological properties L. scoticum has a relatively better competitive ability and is better adapted to grow on inshore localities in the northern part of its distribution area. At the inshore localities L. scoticum occurred at two types of localitites: summits and rocky walls. The absence of inshore localitites in areas where conditions for further dispersal would appear to be ideal, indicate that specific conditions are required for successful establishment of L. scoticum at inshore localities. We suggest that the occurrence of L. scoticum at the summits depends to some extent promoted by the influence of birds, e.g. by nutrients in the excrements. However in the case of rocky walls this is an unlikely explanation, because individuals are often scattered over many hundreds of metres.

Silurus lanzhouensis is a large-sized commercial fish species endemic to the mid-upper reaches of the Yellow River, serving as a “Card of Aquatic Biological Species in the Yellow River”. However, due to factors such as overfishing and habitat changes, it has been listed as an endangered species. In order to protect and restore its wild resources, we conducted a detailed study for the first time from 2022 to 2024 on the age composition, growth characteristics, mortality rate, and current status of resource exploitation of the S. lanzhouensis population in the upper Yellow River. A total of 489 individuals underwent measurements for their total length (L) and body weight (W), with age determination conducted using lapillus otoliths. The collected samples exhibited a spectrum of total lengths spanning from 2.5 to 63.7 cm, body weights ranging from 0.11 to 1974.15 g, and ages ranging from 1 to 6 years. Further analysis of the length–weight relationships unveiled an allometric growth index (b) of 2.9562 for the overall samples, indicating an isometric growth pattern. Additionally, insights into the growth characteristics of S. lanzhouensis were provided by the von Bertalanffy growth function, revealing an asymptotic total length (L∞) of 119.30 cm and a growth coefficient (K) of 0.1278 yr−1. The growth characteristic index (φ) totaled 3.2598, suggesting a moderate growth rate in comparison to other Silurus species. The total mortality rate (Z) recorded for the population of S. lanzhouensis was found to be 0.5296 yr−1. Through the application of three distinct methodologies on exhaustive samples, the average natural mortality rate (M) was calculated to be 0.3105 yr−1. Consequently, the fishing mortality rate (F) for the entire sample set was determined to be 0.2191 yr−1, leading to an exploitation rate (E) of 0.4137. Based on the survey findings, it is evident that the population of S. lanzhouensis has not been subjected to over-exploitation, attributable to ongoing stock enhancement. These results also provide foundational data for the protection and restoration of S. lanzhouensis in the upper Yellow River.

Many environmental problems like dam construction, agricultural debris, flooding and industrial establishments threaten Iyidere stream (Rize, Turkey) on the southeastern coast of the Black Sea (Turkey). The trace element concentrations in water, fish and sediments in lyidere stream (Rize, Turkey) were investigated in this study. The concentration of six different elements in ten freshwater fish species and sediment was determined using energy dispersive X-ray fluorescence method. A radioisotope excited X-ray fluorescence analysis using the method of multiple standard addition is applied for the elemental analysis of fish and sediments. Water samples for trace metals were analyzed using standard spectrophotometry methods. A qualitative analysis of spectral peaks showed that ten different freshwater fish samples (Chondrostoma colchicum, Chalcalburnus chalcoides, Salmo trutta labrax, Alburnoides bipunctatus, Leuciscus cephalus, Barbus taurus escherichia, Capoeta tinca, Neogobius kessleri, Rutilus frisii, Lampetra lanceolata) and sediment contained phosphorus (P), sulphur (S), chlorine (Cl), potassium (K), calcium (Ca) and titanium (Ti). Heavy metals as toxic elements for biota (Pb, Cd, Hg, Zn and Mn etc.) were not detected in fish, water and sediments. Thus, It can be declared that freshwater fish of Iyidere does not contains health risks for consumers in terms of metal pollution.

Divergent age and growth characteristics can reduce deleterious competitive interactions between taxonomically related species facilitating coexistence. Five platycephalid fish species, Platycephalus caeruleopunctatus, Platycephalus longispinis, Platycephalus richardsoni, Ambiserrula jugosa and Ratabulus diversidens, inhabit inner continental shelf habitats along the east coast of Australia. We tested the hypothesis that the age and growth characteristics of these five species are unique. The age of each species was estimated by counting the number of opaque zones in sectioned otoliths. The maximum observed age ranged from 4 years for A. jugosa to 16 years for P. longispinis. von Bertalanffy growth functions were fitted to length-at-age data for each combination of species, sex and location and compared using likelihood ratio tests. The age and growth characteristics of each species were unique and each species displayed sexually dimorphic growth, with females growing larger than males. The unique species-specific growth characteristics may assist length-based partitioning of resources, reducing competitive interactions and facilitate coexistence between these platycephalid species.

Dinolestes lewini (longfin pike) is a common, but little studied, fish species endemic to temperate marine-dominated waters below ~31°S on the east, south and west coasts of the Australian mainland and around Tasmania. Samples of longfin pike collected in Lake Macquarie, a large coastal lagoon in south-eastern Australia, were examined for age, growth and reproductive characteristics. Spawning occurred over an extended period between at least October and March (austral spring to autumn), and although spent individuals occurred in samples, spawning location could not be ascertained. Examination of otolith edge condition provided strong support that opaque and translucent zones were deposited annually and that counts of opaque zones on otoliths can be used to estimate ages. Sex-related differences in mean length at age and projected growth based on the von Bertalanffy growth function were evident. Growth trajectories diverged at ~1.5 years of age, after which females grew faster than males for a longer period, eventually attaining greater observed maximum lengths and ages. Observed longevity was 5+ and 9+ years for males and females, respectively. The data provide an initial knowledge-platform for incorporation in species assessments and for further comparative investigations of variation in biological traits across the species’ distribution.

OBSOLETE: Trends in biodiversity: freshwater

Acetolactate synthase–- (ALS-) inhibiting herbicides are frequently used to control annual bluegrass in managed turfgrass systems. Recently, the number of annual bluegrass populations resistant to these herbicides has increased on golf courses. Previous research involving annual bluegrass resistance to ALS inhibitors has included elucidating the mechanism of resistance and in vivo response of ALS to ALS-inhibiting herbicides. The purpose of this research was to generate baseline information on enzymatic parameters of resistant (R) and susceptible (S) annual bluegrass biotypes and further distinguish these biotypes by comparing vegetative growth and reproductive characteristics. The R biotype contained a mutation in the ALS gene resulting in a Trp574to Leu amino acid substitution. Compared to the S biotype, the R biotype exhibited a 27- and 10-fold resistance to trifloxysulfuron at the whole-plant level and under in vitro conditions, respectively. No significant differences were observed in substrate concentration at one-half maximum rate of enzyme activity (pyruvate) or extractable ALS activity between biotypes, but the maximum rate of enzyme activity was higher for the R biotype. The feedback inhibition of ALS activity by the branched-chain amino acids was higher for the R biotype than the S biotype, with leucine, valine, and isoleucine inhibiting ALS activity 20, 6, and 4% more in the R biotype, respectively. The R biotype produced more inflorescences and seeds per plant in comparison with the S biotype, but relative growth rates between biotypes were similar at all harvest intervals. Our research provides baseline information regarding ALS enzyme response, vegetative growth, and reproductive characteristics of annual bluegrass biotypes resistant and susceptible to ALS-inhibiting herbicides.

This study aimed at estimating genetic and phenotypic correlations among traits in local Guinea fowl in Ghana. Animal farm of Akenten Appiah-Menka University of Skills Training and Entrepreneurial Development Mampong-Ashanti campus was where the study took place, from 2015 to 2018. Data for the experiment was obtained from keets made up of 300 males and 300 females. Parents of the keets consisted of 110 dams and 22 sires. Arithmetic method and Pearson’s product moment correlation were used for the estimates. In male Guinea fowl, the values of genetic correlations among growth characteristics ranged from -0.63 to 0.93. Between growth and other characteristics, estimates of genetic correlation ranged from 0.29 to 0.97, -0.67 to 0.43, -0.62 and 0.94 respectively. Values of phenotypic correlations among growth parameters were between -0.32 and 0.49. Range of figures of phenotypic correlations recorded between growth characteristics and survival, docility, and dressing percentage were between -0.28 and 0.28, -0.46 and 0.18, and -0.41 and 0.36 correspondently. In female Guinea fowl on the other hand, range of genetic correlations among growth traits was between -0.80 and 0.95. Range of figures of genetic correlation between growth traits and survival, docility, dressing percentage and reproductive characteristics of were from -0.47 to 0.9, -0.52 to 0.58, -0.58 to 0.82 and -0.59 to 0.9 respectively. The values of phenotypic correlations among growth characteristics fell between -0.39 and 0.46. Phenotypic correlations recorded between growth traits and survival, docility, dressing percentage and reproductive characteristics were from -0.26 to 0.47, -0.47 to 0.19, -0.35 to0.47 and -0.33 to 0.47 respectively. Values of genetic correlations higher than one (1) among some traits in male Guinea fowl were recorded. To conclude, discoveries of this study are in general agreement of what pertains to Guinea fowl and other farm livestock species.

Age, growth and mortality of Mactra chinensis were investigated during the period from October 2012 to September 2013 in Busan, South Korea. The monthly variation of the marginal index (MI) of the shell and chondrophore showed that the ring of this species was formed once a year during July. We estimated the age of M. chinensis by reading the external rings on the shell and the growth bands of the chondrophore to compare growth parameters between the two growth characters. The age of this species ranged from 0 to 8 years (shell-based age reading) and from 0 to 10 years (chondrophore-based age reading). Based on external rings and growth bands of chondrophore for the same period, the von Bertalanffy growth functions were expressed by the equation, Lt = 101.53[1-exp {-0.15(t + 0.75)}] and Lt = 90.03[1-exp {-0.20(t + 0.50)}], respectively. The likelihood test showed that there was a significant difference in L∞ (P < 0.001), K (P < 0.001), to (P < 0.001) estimated from non-linear regression between the two growth characters.

Using occupancy estimation to assess the effectiveness of a regional multiple-species conservation plan: Bats in the Pacific Northwest

Pterygoplichthys spp. is an invasive alien species distributed in most water bodies of southern Vietnam. Pre-matured fish (70 - 188 mm in length) were sampled from Am Chua canal (12o17.436' N, 109o6.063' E) in Khanh Hoa province, Vietnam and analyzed for reproductive and growth characteristics. Morphology analysis of gonad of these fish indicated that sex of small fish (≈ 8 cm in length, 4 g in weight) could be distinguished using naked eyes. Male to female ratio for the population was 1:1. Weight of gonad at stage I was significantly smaller those at stage II (both collected at the same and different sampling period). Fish at pre-matured stage tended to grow in length more than in weight (b&lt;3). Research results indicated that this species had diverse reproductive characteristics and well adapted to water bodies in south Vietnam.

It is widely recognized that there are basic conflicts between the resource needs of a plant for paternal versus maternal functions. In dioecious species, these divergent demands, and the selection pressures they impose, can lead to the evolution of sexual dimorphism. The present study was conducted to assess the potential for the evolution of sexual dimorphism in Silene latifolia by evaluating the genetic variation and genetic correlation between characters and between the sexes for a range of growth and reproductive characters. Sexual dimorphism is largely restricted to reproductive characters, particularly flower number and flower size. A canonical correlation analysis revealed considerable intercorrelation between growth characters, such as germination date, height, and leaf size, and reproductive characters; plants that grow fast early on also flower earlier, and plants that produce big leaves also produce big flowers. There was genetic variation for several sexually dimorphic characters; much of the focus in this analysis was on flower size, particularly calyx diameter. Finally, genetic correlations within and between the sexes were found that limit the rate of evolutionary divergence between the sexes. The genetic results suggest that S. latifolia has been subject to divergent selection on the two sexes for a long period of time, bringing about a gradual fixation of sex-limited gene effects, so that the remaining genetic effects are expressed in both sexes. Genetic correlations between the sexes that arise from this residual variation impose limits on further evolutionary change.

River sediments, functioning as sink and source for nutrients, are one of the most diverse bacteria habitats in freshwater ecosystems. Recently, more attention has been paid to the sediment bacteria because of their important roles in biogeochemical cycling. Our study addresses the question of how sediment bacterial community varies taxonomically and functionally along one of the largest plateau river in the world (the Yarlung Tsangpo River) subject to anthropogenic pressures, including wastewater discharge and river damming, as they may lead to adverse impacts on river ecosystems. The results indicated that river damming retained biogeochemical nutrients of carbon, silica and nitrogen in the reservoir, while phosphorus was more sensitive to wastewater discharge. Besides, wastewater discharge resulted in asynchronous change of biomass and diversity in sediment bacteria while they were both inhibited by the construction of dam. Moreover, significant alterations in the community composition were observed in dam-associated sites, while according to exploratory bioinformatics prediction tool of PICRUSt, functional variation was not detected between upstream and downstream of the dam due to functional redundancy. In addition, revealed by General Additive Model (GAM) and Mantel test results, elevation was the endemic driver shaping the sediment bacterial community diversity and composition along with pH, while nutrient concentrations were responsible for functional variation. Furthermore, little synchronized dynamics of co-occurrence was exhibited in the sediment bacteria in the Yarlung Tsangpo River. Therefore, our study proposed that sediment bacterial community should be defined taxonomically and functionally when studying its variation in river ecosystems.