Condition Index Values Research Articles

Relationship between soil conditions and road quality degradation

Abstract Roads are one of the infrastructures that are greatly needed by the community. One component of the road pavement structure is the subgrade. Road damage may be caused by a decrease in the quality of the subgrade. Therefore, this study aims to explain the relationship between soil conditions and the decline in road quality. The location of the study is on Jalan Lampur-Munggu, Lampur Village, Sungai Selan District, Central Bangka Regency. This study was conducted at STA 0+000 to STA 1+285 which were divided into 52 segments where the length of each segment was 25 m. Soil condition data was taken at 10 points. The results of the study showed that the road pavement condition index value obtained was 44.7, which is in the poor category. Furthermore, the California Bearing Ratio value for the soil conditions obtained was 8.08%, which is classified as quite good. It can be concluded for this case that the degradation in road quality is not affected by the California Bearing Ratio value of the subgrade. However, it is better to still consider other factors of soil conditions that can accelerate road damage.

Functional assessment of pavements on a university campus

With the constant increase in traffic volume at the Darcy Ribeiro Campus of the University of Brasília (UnB), attention to the preservation of road infrastructure is necessary. The implementation of an Urban Pavement Management System (UPMS) emerges as a strategy. This study aims to evaluate the functional condition of the pavements at the UnB University Campus by observing distresses on their surfaces, using the Fixed Value Matrix for 5 Distress method by Zanchetta (2017). A total of 161 road segments were evaluated, and both Objective and Subjective Pavement Condition Index (PCI) values were obtained, along with the recommended intervention for each segment. The most common types of defects found in the pavements were Raveling and Fatigue Cracks. The most suggested interventions were Preventive Maintenance (23.60%) and Corrective Maintenance (22.98%). Statistical analysis led to the conclusion that there were no significant differences between the Objective and Subjective PCI data. Thematic maps were generated for the Objective PCI, Subjective PCI, and maintenance activities in order to make georeferenced spatial information available.

Spatial and Seasonal Variations in the Size-Weight Relationship and Condition Index of the Mangrove Oyster Crassostrea tulipa (Lamarck, 1819) in the Saloum Delta, Senegal

In the Saloum delta in Senegal, the mangrove oyster Crassostrea tulipa is under increasing human pressure, leading to a decline in wild stocks, a decrease in the quality of the marketed oysters and the degradation of mangrove tree roots. Previous studies have pinpointed some of these disturbances and yet, there is little information available on the structure of the population and the condition index of the species. The aim of this study was to document these aspects in order to support a sustainable management of the resource. From January 2021 to December 2022, monthly sampling was carried out at five stations to study the size-weight relationship and the condition index (CI) of oysters. A total of 26,790 individuals ranging in size from 0.23 to 93.19 mm with an average of 33.86±16.38 mm shell height were collected. The species was found to have a minority allometry (b = 2.54 <3), with a strong correlation between individual weight and oyster shell height (r = 0.88). CI showed seasonal and inter-site variations over the two years, with an overall mean value of 11.17±2.72%. The highest CI values were observed during the hot season and the lowest during the hot-cold transition period.

Extreme Body Condition Index Values in Small Mammals.

The body condition index (BCI) values in small mammals are important in understanding their survival and reproduction. The upper values could be related to the Chitty effect (presence of very heavy individuals), while the minimum ones are little known. In this study, we analyzed extremes of BCI in 12 small mammal species, snap-trapped in Lithuania between 1980 and 2023, with respect to species, animal age, sex, and participation in reproduction. The proportion of small mammals with extreme body condition indices was negligible (1.33% with a BCI < 2 and 0.52% with a BCI > 5) when considering the total number of individuals processed (n = 27,073). When compared to the expected proportions, insectivores and herbivores were overrepresented, while granivores and omnivores were underrepresented among underfit animals. The proportions of granivores and insectivores were higher, while those of omnivores and herbivores were lower than expected in overfit animals. In several species, the proportions of age groups in underfit and overfit individuals differed from that expected. The male-female ratio was not expressed, with the exception of Sorex araneus. The highest proportion of overfit and absence of underfit individuals was found in Micromys minutus. The observation that individuals with the highest body mass are not among those with the highest BCI contributes to the interpretation of the Chitty effect. For the first time in mid-latitudes, we report individuals of very high body mass in three shrew species.

Heat hardening improves thermal tolerance in abalone, without the trade-offs associated with chronic heat exposure

Marine animals are challenged by chronically raised temperatures alongside an increased frequency of discrete, severe warming events. Exposure to repeated heat shocks could result in heat hardening, where sub-lethal exposure to thermal stress temporarily enhances thermotolerance, and may be an important mechanism by which marine species will cope with future thermal challenges. However, we have relatively little understanding of the effects of heat hardening in comparison to chronic exposure to elevated temperatures. Therefore, we compared the effects of heat hardening from repeated exposure to acute heat shocks and chronic exposure to elevated temperatures on thermal tolerance in the European abalone, Haliotis tuberculata. Adult abalones were exposed to either control temperature (15 °C), chronic warming (20 °C) or a regime of two events of repeated acute heat shock cycles (23–25 °C) during six months, and their thermal tolerance and performance, based upon cardiac activity, compared using a dynamic ramping assay. The cost associated with each treatment was also estimated via measurements of condition index (CI). Abalone exposed to both temperature treatments had higher upper thermal limits than the control, but heat-hardened individuals had significantly higher CI values, indicating an enhancement in condition status. Differences in the shape of the thermal performance curve suggest different mechanisms may be at play under different temperature exposure treatments. We conclude that heat hardening can boost thermal tolerance in this species, without performance trade-offs associated with chronic warming.

Assessing Multifaceted Effects of Speed Humps and Bumps: Travel Time, Safety, and Environmental Considerations

This study focuses on investigating the significant impacts of speed breakers on various parameters, including travel time delays, vehicle speeds, fuel consumption, pavement maintenance costs, and vehicular exhaust emissions. Field data was collected and analyzed to assess the effects of different types of traffic calming measures on these parameters. The findings provide valuable insights into the implications of speed breakers on road safety, environmental pollution, and overall road infrastructure management. The results reveal that the implementation of speed humps, speed bumps, and triple bumps effectively slows down vehicles, as evidenced by considerable reductions in the 85th percentile speeds. The reduction percentages were 41.65% for speed humps, 73.52% for speed bumps, and 86.27% for triple bumps. This indicates the effectiveness of these traffic calming measures in improving road safety by reducing vehicle speeds. However, the presence of speed breakers also leads to increased travel time delays. On average, traversing stretches with speed humps, speed bumps, and triple bumps resulted in delays of 9.31, 16.42, and 29.51 seconds, respectively. While the individual delay times may appear relatively short, the cumulative effect of multiple speed obstacles along a road needs to be considered. Another significant impact observed is the increased fuel consumption associated with speed breakers. The study found that for every 100 km of travel, motorcycles and passenger cars consumed approximately 12.07 km and 27.37 km of additional fuel, respectively, when the density of speed breakers was 1.33/km. This translates to a fuel consumption increase of 13.73% for motorcycles and 37.74% for passenger cars. Furthermore, the presence of speed humps was found to contribute to pavement deterioration, as indicated by decreased Pavement Condition Index (PCI) values. The study also revealed that sections with speed humps incurred significantly higher maintenance costs compared to sections without speed humps. The increase in maintenance cost ranged from 100 to 264% across different road sections, with higher traffic volumes leading to greater cost escalation. Additionally, the study confirms that lower vehicle speeds, particularly between 0-15 km/hr, are associated with higher emissions of pollutants, including carbon monoxide (CO) and other pollutants. This highlights the environmental implications of speed breakers and their contribution to urban air pollution. Doi: 10.28991/CEJ-2024-010-07-07 Full Text: PDF

Effect of selected environmental factors on the growth and survivability of the larvae of the Chinese sleeper Perccottus glenii Dybowski 1877

The aim of this study was to determine the influence of the temperature (range 15 to 25°C), pH (6 to 9) and salinity of water (between 0 to 10‰) on the growth, condition and survival of larvae of the Chinese sleeper. During the 28‐day experimental rearing, the highest average body weight of 81.3 ± 16.3 mg was reached in fish from the group maintained at a water temperature 25°C, and was almost five times higher than the weight at the temperature of 15°C (15.6 ± 2.2 mg). A significantly higher body weight of Chinese sleeper larvae was also recorded in the group reared in alkaline water (pH 9), compared to those kept in acidic and neutral water. Statistically significant differences between the groups (p≤0.05) were recorded for the condition index (K) values and relative body weight (SGR) only in the experiment with different water temperatures of fish rearing. The highest number (16% of the initial stock) of abnormal larvae, associated with a lower jaw and vertebral structure deformities, was recorded in the group reared at 5‰ salinity (Z5). Simultaneously, 100% mortality of the stock was noted by the 10th day of rearing in the 10‰ salinity. The cumulative mortality of the Chinese sleeper larvae related to cannibalism Types I and II in all the experimental rearing was low, oscillating between 0.5% and 11.5% in the groups bred in water with a pH 9 and 0‰ salinity, respectively. The study results may help determine the critical values of water parameters that promote or limit development in the early stages of the Chinese sleeper and could be used in activities related to eradicating or significantly reducing the increasing abundance of this alien invasive fish species in freshwater ecosystems.

FOOD AVAILABILITY ON INFLUENCE MUSSEL Mytilus galloprovincialis (Lamarck, 1819) ON PHYSIOLOGICAL AND BIOCHEMICAL STATUS

Phytoplankton, as the primary food source for suspension-feeding bivalves, can significantly impact the growth and survival of bivalves. To investigate the influence of food availability on the condition index and biochemical composition of mussels Mytilus galloprovincialis from the Romanian Black Sea coast, phytoplankton and mussels samples were collected from four sites between November 2017 and November 2018. The phytoplankton quality and quantity varied across locations and seasons. The ports had the highest diversity and abundance of phytoplankton, while the area with low trophic conditions had the lowest. The most dominant phytoplankton groups observed were diatoms and dinoflagellates. The condition index values were higher in sites with greater food availability, reaching the peak in spring. The lipid and carbohydrate content peaked in spring when the food availability was high. The protein content was higher in winter and autumn. Condition index was positively correlated with phytoplankton abundance and biomass (p 0.05). Several significant correlations were found between the biological parameters of mussels, such as proteins, lipids, carbohydrates, tissue dry weight, moisture, ash free dry weight, and ash. In conclusion, the results indicated that higher food availability and increasing seawater temperatures led to greater condition index and reserve accumulation, primarily in the form of proteins, carbohydrates, and lipids, providing mussels with enough energy to withstand stressful conditions.

Reproductive Biology and Spawning Pattern of Oyster Magallana bilineata in Mengkabong Bay, Sabah, Malaysia

Abstract Magallana bilineata is a commercially important oyster species in Malaysia. Despite its economic significance, the biology and ecology of this species, particularly its reproductive cycle, are poorly understood in the region. Therefore, this study aimed to investigate the reproductive cycle of M. bilineata in Mengkabong Bay, Tuaran, Sabah and its correlation with environmental factors. A total of 105 oyster specimens were collected and examined to determine the sex ratio, gonad developmental stages, maturity index (MI), and condition index (CI). The results revealed a sex ratio of 1:2.36 (♂:♀) in the oyster population of the bay, with a significantly higher proportion of females (P &lt; 0.05). Hermaphroditism was detected in 1.90% of the samples. M. bilineata was found to spawn throughout most months in the bay, with the highest MI and CI values recorded in November 2019 when most oysters were in mature or maturing stages. Salinity was found to be the primary factor influencing male gonad maturation, while temperature was the primary factor influencing female gonad maturation. Understanding the reproductive biology of this species is crucial for predicting its future survival and facilitating assisted spawning and hatchery spat production, thereby ensuring the conservation and sustainability of the oyster fishery in Malaysia.

ROAD DAMAGE EVALUATION ON RIGID PAVEMENT WITH PAVEMENT CONDITION INDEX METHOD IN KLAKAH REJO-BENOWO ROAD, SURABAYA CITY, EAST JAVA

The research objective was to analyze the level and type of damage from every kind of damage on the Klakah Rejo Benowo road by calculating the rigid pavement condition index value and providing solutions. This study took the location of the Klakah Rejo-Benowo road section, Surabaya City—data analysis by calculating the Deduct Value, m, TDV, CDV, and PCI. The research results state it was concluded that five types of damage occurred in Jalan Klakah Rejo-Benowo, Surabaya City. The types of damage are Grooves, Patches, Alligator Cracks, Weathering and Loose Granules, and Pits. Damage caused by high rainfall conditions (&gt; 900mm/year) &amp; Daily Traffic Volume exceeds the provisions of the Binamarga. After analysis, it shows that the road pavement is in Moderate/Fair condition; field analysis results and values calculated using the PCI (Pavement Index Condition) method for damaged road conditions can provide recommendations for road repairs using the Asphalt Institute MS-17 method, namely patching and resurfacing. Based on the analysis of the road condition values obtained, the solution must be patched and re-coated so that water does not quickly seep into the road layer, which causes more severe road damage.

Reproductive cycle of the mangrove oyster Crassostrea rhizophorae (Guilding, 1828) in Delta do Parnaíba, Brazil

This study describes some aspects of the reproductive biology of the native oyster Crassostrea rhizophorae in the Delta do Parnaíba estuary, located between the states of Maranhão and Piauí, Brazil. The oysters were acquired from landings at Porto dos Tatus (Ilha Grande - PI) between June 2017 and May 2018. Approximately 50 individuals per month (n=611) with an average total shell length of 74.44 mm (±14.31 SD) were collected for analysis of gonadal development and condition index and correlated with temporal variations in local rainfall. The C. rhizophorae population in the Parnaíba Delta estuary showed a sex ratio of 2.18 females to 1 male and continuous reproduction. The condition index (CI) values in the dry period were higher, coinciding with a greater proportion of individuals in the gametogenesis and pre-spawning stages. In the rainy season, there was a reduction in the CI as a result of animals in the gamete release stage.

Evaluation of building condition index, repair, and maintenance priority order (Case study: Lecture room of engineering faculty, Syiah Kuala University)

The Engineering Faculty building at Syiah Kuala University was constructed in 1963 and completed in 1998. Visible damages can be observed on the components. Therefore, this study aimed to evaluate the damages to these components, the condition index (CI) value, as well as the priority order for repairing and maintaining the building. The process commenced by evaluating the physical condition of the lecture hall. Questionnaires were also distributed and the data were then analysed using the Analytical Hierarchy Process (AHP) method to determine the weights of the component. These weights were combined with the volume of component damage to obtain the building’s CI values. The results showed that the majority of the damage in the Faculty of Engineering at Syiah Kuala University was related to architectural components. The Building Condition Index (BCI) classified all structures were in Zone 1 where indicated a very good condition with values ranging from 87.09% to 97.83%. Building A, received the highest priority for repair and maintenance, followed by the PPI and the D3 Civil Engineering structure. Regarding the building elements, columns were given the highest priority with a weight of 0.226, whereas carpet floor coverings were assigned the lowest with a mass of 0.003.

Evaluation of Pavement Condition Based on the Value of Surface Distress Index and Pavement Condition Index on the Road Section of Gedong Tataan - Kedondong, Pesawaran

Good road infrastructure conditions can stimulate the economic growth of an area. Therefore, routine road maintenance is carried out by its administrators. One of the road sections that needs improvement is the Gedong Tataan - Kedondong road section. The Gedong Tataan - Kedondong section is a provincial road with a length of 16.67 kilometers. To predict the pavement condition on the road section, an assessment method is required for identification. This method is used as one of the tools to assess pavement damage on a road section, and the methods used are the Surface Distress Index (SDI) and the Pavement Condition Index (PCI). The research results show a PCI (Pavement Condition Index) value of 73%, indicating that the road pavement condition is very good, and routine maintenance is required. Meanwhile, with the SDI (Surface Distress Index) method, a value of 65 is obtained, indicating that the road falls into the fair category, and the appropriate treatment options include patching and overlay. Another implication is to allocate the budget wisely for road maintenance. Information from these two indices helps in determining improvement priorities. Routine maintenance can be a better investment in the long term than letting road conditions deteriorate.

Modelling and testing forest ecosystems condition account

We developed an application model based on the System of Environmental Economic Accounting-Ecosystem Accounting (SEEA-EA) framework, endorsed by the United Nations Statistical Commission in 2021. This model enables mapping condition accounts for forest ecosystems using automated computation. We applied the model nationally in Spain between 2000 and 2015 to test its effectiveness. Our model follows five methodological steps to generate forest condition accounts: (i) definition and spatial delimitation of forest ecosystem types; (ii) selection of variables using the ecosystem condition typology encompassing physical, chemical, compositional, structural, functional, and landscape characteristics; (iii) establishment of reference levels, including lower (collapse) and upper (high ecosystem integrity) thresholds; (iv) aggregation of variables into condition index; and (v) calculation of a single condition index by rescaling the aggregated indicators between 0 and 1. The results obtained from the model provide valuable insights into the status and trends of individual condition indicators, as well as aggregated condition index values for forest ecosystems, in a spatially explicit manner. Overall, the condition of the forest ecosystems in Spain showed a slight increase, from 0.56 in 2000 to 0.58 in 2015. However, distinct trends were observed for each ecosystem type. For example, mixed Alpine and Macaronesia forests exhibited a significant improvement, while the continental Mediterranean coniferous forests did not show any change. This innovative approach to monitoring forest condition accounts has important potential applications in policy and decision-making processes. It can contribute to effective evidence-based nature conservation, ecosystem service management, and identifying restoration areas.

Penanganan Kerusakan Jalan dengan Menggunakan Metode Pavement Condition Index

Highways are one of the land transportation infrastructures that are very important in aspects of human activity, so that road conditions are expected to provide a sense of security and comfort for users of highway infrastructure. However, along with the increasing population in the Medan City area, the need for transportation facilities has also increased, causing a decrease in the quality of the highways which has an impact on road damage caused by roads that are burdened with high volumes of traffic repeatedly. In this study, each type of damage was measured directly in the field and analyzed using the Pavement Condition Index method and the Bina Marga method as an alternative for damage management. Based on the results of this study, the level of damage to the flexible pavement that occurred on Jalan Willem Iskandar, was that there were 7 types of damage, namely crocodile skin cracks, longitudinal cracks, transverse cracks, patches, holes, subsidence, and overturns. The overall average pavement condition index (PCI) value on the Williem Iskandar road is 64.08% with good conditions so that an alternative repair that is appropriate to the damaged conditions is to carry out maintenance per unit segment with reference to the Directorate General of Highways Standard Repair Method.

Analysis of Physical Condition of First-Year Military Higher Education Institution Cadets

The purpose of the study was to determine the dynamics of anthropometric and functional indicators of the physical condition of first-year cadets over three years (from 2019 to 2021). Materials and methods. 152 cadets from Ivan Kozhedub Air Force National University were involved in the experiment. The age of participants was from 17 to 22 years. All cadets were informed about the experiment and gave their consent. Anthropometric (measurement of anthropometric data) and medical-biological (rhythm inversion, electromanometry) methods of investigation were used to determine the assessment of the cadets’ physical condition. A highly informative method – the assessment of O. Pirogova index was used for analysis of the cadets’ physical condition. Pirogova physical condition index is a complex indicator based on the heart rate, systolic and diastolic blood pressure, age, body weight, and body height. Statistical analysis of the results was carried out using the EXCEL tables. The data was analyzed using Student’s test, p less than 0.05 was considered the level of significance. Results and discussion. The results of the study showed that the mean values of the anthropometric and functional indicators of the first-year cadets have not been changed statistically significant over three years. The exception is the difference in the average value of systolic blood pressure of control group 1 and control group 3 representatives, which is statistically reliable (p &lt;0.05). Current anthropometric indicators of cadets obtained during the experiment confirmed the data available in the scientific and methodological literature about the anthropometric indicators of candidates for training in higher military educational institutions of Ukraine. The Pirogova physical condition index calculating showed the following average values of the Pirogova physical condition index: control group 1 – 0.704 points, control group 2 – 0.688 points, control group 3 – 0.671 points. However, the results of the study show a statistically significant deterioration of the Pirogova physical condition index of the 2021 recruitment cadets by 4.7% compared to the representatives of 2019. The comparative analysis of the first-year cadets' physical condition assessments demonstrates a gradual, significant decrease in the number of “high” physical condition ratings: 12% among control group 1 cadets (2019 year of recruitment); 9% among control group 2 representatives (2020 year of recruitment) and only 3% among control group 3 cadets (2021 year of recruitment). However, over three years, the percentage of representatives with physical condition assessment rating “Lower than average” has increased significantly: 1% among cadets of control group 1 (2019 year of recruitment); 7% among cadets of control group 2 (2020 year of recruitment); 7% among representatives of control group 3 (2021 year of recruitment). Conclusion. Over the last 3 years, there has been a deterioration of the general physical condition of higher military educational institution cadets

Morphological variations in blood cockle Tegillarca granosa (L, 1758) populations collected from the south-east and south-west coasts of Bangladesh

Morphology helps in studying the external features of an individual, including the size, shape, structure of the animals and in determining the evolutionary relationships among organisms. Current study was undertaken to investigate the morphological variations between the two populations of blood cockle, Tegillarca granosa collected from the south-east (west coast of Maheshkhali Island, Cox’s Bazar; S1) and south-west (Jamuna River Estuary near Ishawrypur, Shemnagar, Shatkhira; S2) coasts of Bangladesh. Samples were drawn from the intertidal region during low-tide by hand-picking with the aid of local people in March 2020 from both sites. Fifteen primary parameters, and 27 secondary parameters obtained from the ratios of different primary parameters were studied to compare the values between the two populations. Out of 15 primary morphological parameters, there was no significant difference (p&gt;0.05) between the populations. Among the 27 secondary morphological parameters, only 4 parameters were significantly different (p&lt;0.05) between the two populations. The statistically different parameters were shell length (SL)/wet tissue weight (TWW), shell height (SH)/wet tissue weight (TWW), shell thickness (ST)/wet tissue weight (TWW) and condition index (CI). The ratios of shell dimensions and wet tissue weight were significantly higher (p&lt;0.05) in S2 when compared with S1 indicated that S1 population could be more economically viable due to their relatively higher edible meat content. The CIs were significantly higher (p&lt;0.05) in S1 population than the CIs of S2 population. The values of CIs reflected that S1 population had better health condition than S2 population. The ratios of different shell measurements did not vary significantly implied that both populations were homogenous in size, shape and structure. Morphological analyses of different populations of T. granosa revealed that habitat could play a vital role in morphological variations.

Evaluation of functional and structural conditions on flexible pavements using pavement condition index (PCI) and international roughness index (IRI) methods

Road quality degradation affecting on safety and comfort of road users. It is necessary to carry out regular assessments of the functional and structural condition of the pavement. Evaluation of functional and structural conditions is carried out to maintain the good quality of road services. This research aims to evaluate the functional and structural conditions using the Pavement Condition Index (PCI) method and the functional condition of the road using the International Roughness Index (IRI) method. The tool used in testing functional conditions is the Hawkeye 2000 car which generates Pavement Condition Index data for each road segment, then calculates the average PCI value and the conditions on the road segment. From the analysis of the functional condition of the road pavement, the Pavement Condition Index value was obtained for Kudus East Ring Road Section at 57.05 (Fair), Pati Ring Road Section at 60.57 (Fair), and Wangon-Menganti Road Section at 78.35 (Satisfactory). From the results of the analysis of the functional condition of the road pavement, the International Roughness Index value was obtained for Kudus East Ring Road Section at 5.16 (Medium), Pati Ring Road Section at 4.94 (Medium), and Wangon-Menganti Road Section at 4.64 (Medium). The results of the correlation of the 2 parameters using SPSS on each successive road section show "weak correlation" with r = 0.2754; "moderate correlation" with r = 0.5534; and "no correlation" with r = 0.0435.

Growth and condition index of pokea clams (Batissa violacea var. celebensis, von Martens 1897) in Lasolo River Mouth, Southeast Sulawesi

The somatic growth and condition index (CI) of pokea population aren’t yet fully known in the Lasolo river. This research aims to decide the somatic growth relationship between length and weight as well as the condition factor of pokea population. This research was carried out in the Lasolo river from January-December 2014. Pokea clams were taken from the river bed with traditional tool (tangge). The length and total weight of the clams were determined by employing a caliper with a precision of 0.5 cm and a digital scale with an accuracy of 0.01g. Meat and shells were then dried in an oven at 70°C about 48 hours. The dry weight of the meat and the shells of the pokea clams were weighed using a digital scale with an accuracy of 0.0001 g. Calculations obtained average b parameter values of the males and females about 2.52 and 2.70, respectively. The b values for both sex of clams were 2.37-3.05 and 2.24-3.15, respectively, which were within the negative allometric category. The CI values of the male (3.98±1.44) and female (4.27±1.52) putting them in the fat category. The condition index experienced three local peak periods in February-March, June, and November-December.

Relationship between Condition Index Values and Expression Levels of Gene and Protein in the Adductor Muscle of Diploid and Triploid Oysters Crassostrea gigas

Three proteins [myosin heavy chain (MHC), filamin-C fragment (FIL-C), and actin 2 (ACT2)] were identified in adductor muscle from diploid and triploid Pacific oysters (Crassostrea gigas) and the relationship between the condition index (CI) and mRNA expression of these genes was investigated, together with the mRNA expression of molluscan insulin-related peptide (MIP), C. gigas insulin receptor-related receptor (CIR), and insulin-like growth factor binding protein complex acid labile subunit (IGFBP-ALS). Monthly changes in the CI were similar to the changes in the tissue weight rate in both groups. ACT2 and MHC mRNA expression was statistically higher in the triploid than the diploid, while FIL-C mRNA expression was significantly higher in the diploid (p<0.05). The MIP, CIR, and IGFBP-ALS mRNA expression of the diploid oysters were all significantly higher in July than in other months (p<0.05). The MIP, CIR, and IGFBP-ALS mRNA expression in the triploid oysters was high in July, but there were no significant differences (p>0.05). Changes in the expression levels of the genes investigated in this study could be used as intrinsic indicators of the annual growth, maturity, and spawning period of cultured diploid and triploid C. gigas in Tongyeong, Korea.