Relationships between environmental factors and biological parameters of Asian wedge clam, Donax scortum, morphometric analysis, length-weight relationship and condition index: a first report in Asia

2016 ◽  
Vol 97 (8) ◽  
pp. 1617-1633 ◽  
Author(s):  
Yambem Tenjing Singh

Wedge clam, Donax scortum occurrence was studied from February 2009 to January 2010 in Padukere sandy beach, Karnataka (India). The following biological parameters were measured in 2367 individuals of the wedge clam, Donax scortum: length, breadth, width, total weight, shell weight, wet meat weight, dry meat weight and number of clams. The calculated linear equation of length-breadth and length-width relationships were B = 3.5968 + 0.5421L and W = 0.8191 + 0.4345L respectively. The length-total weight, length-wet meat weight, length-dry meat weight and length-shell weight relationships were 0.0001414L3.0224, W = 0.0000037L3.5204, W = 0.0000011L3.4513 and 0.0000852L2.9912 respectively. The values of correlation coefficient for different shell dimensional relationships were very close to unity. It was clear from the study that the most ideal period for clam harvest was April, June and December, especially when condition index was maximum. Length showed a strong correlation with silt and clay. Dry meat weight was negatively correlated with air temperature. Shell weight showed positive correlation with length, breadth, width and dry meat weight, and abiotic parameters, silt and clay. Condition index was positively correlated with electrical conductivity, whereas it was negatively correlated with dissolved oxygen. It showed a strong positive correlation with salinity. Seasonal fluctuation of condition index in D. scortum was probably related to reproductive activity. The harvesting of wedge clam could be carried out considering the maximum sustainable yield without over-exploitation

2021 ◽  
Vol 50 (1) ◽  
pp. 87-97
Author(s):  
Selcuk Yigitkurt

Abstract The present study was carried out to determine gonadal stages and quality of pearl oyster meat (Pinctada imbricata radiata, Leach, 1814) in Izmir Bay (Turkey). Pearl oyster samples were collected from the study area at a depth of ~5 m between February 2013 and January 2014. The highest and lowest temperature was measured in July and January as 27°C and 14.2°C, respectively. The maximum chlorophyll a value of 4.640 μg l−1 was calculated in May and the lowest value of 1.009 μg l−1 was recorded in April. Individuals reached their first maturity in April. Spawning activity was observed from June to September and the gonad index (GI) was at the highest level during those months. The development was observed from April to February. The overall female to male ratio was 1.32:1 (p < 0.05) and it did not affect the GI (p > 0.05). There is a strong positive correlation between the GI and temperature (p < 0.05). The highest condition index (CI) was recorded in May as 12.31 ± 0.51, whereas the lowest one in January as 7.37 ± 0.22. As a result, this study revealed that the pearl oyster population in the region is characterized by high reproductive activity, especially during the summer months.


Author(s):  
Packiam Paul ◽  
Chelladurai Stella ◽  
J Siva

n general, changes in biochemical components are closely linked to the state of sexual maturity of the mollusks and to energy supply, either directly from ingested food or from previously stored reserves. Carbohydrates are considered to be the main energy source in adult marine bivalves and are important for gamete formation and maintenance of adult condition during periods of nutritive stress or in winter. Many studies have related changes in the biochemical composition of bivalves with the reproductive cycle mostly in the natural environment. Energy storage and biochemical cycle are closely related to reproductive activity in marine bivalves. The present study indicates that major biochemical constituents in oyster Crassostrea madrasensis and Saccostrea cucullate are significantly influenced by environment condition such as quantity of food availability, temperature and salinity. The high contents of lipids, proteins, carbohydrates, and water content values, during summer are indicating this season as the best for harvesting this particular oyster species and the statistical analysis of the biochemical composition of the tissue sample of the oyster revealed positive correlation in both species of oyster Crassostrea madrasensis and Saccostrea cucullata. The strong Positive Correlation were observed in between the two stations and the highest value of protein, carbohydrate and lipids were observed in Crassostrea madrasensis rock and creek when it compare to Saccostrea cucullata. Keywords: Protein, Carbohydrate, Lipid , Crassostrea madrasensis, Saccostrea cucullata, oysters


2021 ◽  
Vol 26 (4) ◽  
pp. 620-629
Author(s):  
Ilham Zulfahmi ◽  
Kamaliah Helmi ◽  
Siti Rahmah ◽  
Neri Kautsari ◽  
Siti Maulida ◽  
...  

The blood clam, Tegillarca granosa (Linnaeus, 1758) is one of the economically important aquatic organisms. Therefore, information related to biometric conditions is crucial as preventive and responsive efforts to manage blood clams. This study aims to analyze the biometric condition of blood clams collected from the northern coast of Banda Aceh City. Blood-clam samples were collected from three locations, namely Alue Naga, Tibang, and Deah Raya. A total of 300 blood clams were observed. The biometric parameters included the distribution of length and weight classes, the relationship between length and weight, condition factors, ratios, and correlations between total weight, meat weight, and shell weight were measured. The results showed that the majority of blood clams found in Deah Raya were in the smaller length and weight classes (30-32 mm and 12,25-17,24 g) compared to those found in Alue Naga (33-35 mm and 17,25-22,24 g) and Tibang (42-44 mm and 22,25-27,24 g). Despite having identical growth patterns (negative allometric) and condition-factor values, the blood clams collected from Alue Naga had higher meat weight ratios than those collected from the other two locations. The correlation values between the weight of the meat and the total weight of the blood clams collected from Deah Raya tends to be lower than those of blood clams obtained from Alue Naga and Tibang, which are 0,55; 0,81; and 0,78, respectively.   Keywords: biometric, environmental factor, Deah Raya


Author(s):  
Yambem Tenjing Singh

Rock oysters of the genus Saccostrea are the dominating group of filter-feeding communities on rocky beaches worldwide. The edible rock oyster (Saccostrea cucullata) is used as food and fish bait along the Indian coast. Morphometric analyses of S. cucullata from Baindur, Karnataka (India) were performed from June 2010 to May 2011, aiming to establish relationships between length and weight (total weight, shell weight, meat wet weight and meat dry weight). Morphometric relationships between length (L)-breadth (B) and length (L)-width (W) were B = 6.4952 + 0.4619 L and W = 3.1806 + 0.3276L, respectively. The equations of the length (L)-total weight (TW), length (L)-shell weight (SW), length (L)-meat wet weight (WW) and length (L)-meat dry weight (DW) were TW = 0.001227L2.3973, SW = 0.001165L2.3164, WW = 0.000037L2.1327 and DW = 0.000030L2.3289, respectively. The allometric growth pattern revealed changes in shell shape and weight variation throughout ontogeny in rocky habitats. The condition index and meat yield of S. cucullata exhibited seasonality, with higher values recorded during the periods post-monsoon and pre-monsoon.


Author(s):  
Packiam Paul ◽  
Chelladurai Stella ◽  
J Siva

In general, changes in biochemical components are closely linked to the state of sexual maturity of the mollusks and to energy supply, either directly from ingested food or from previously stored reserves. Carbohydrates are considered to be the main energy source in adult marine bivalves and are important for gamete formation and maintenance of adult condition during periods of nutritive stress or in winter. Many studies have related changes in the biochemical composition of bivalves with the reproductive cycle mostly in the natural environment. Energy storage and biochemical cycle are closely related to reproductive activity in marine bivalves. The present study indicates that major biochemical constituents in oyster Crassostrea madrasensis and Saccostrea cucullate are significantly influenced by environment condition such as quantity of food availability, temperature and salinity. The high contents of lipids, proteins, carbohydrates, and water content values, during summer are indicating this season as the best for harvesting this particular oyster species and the statistical analysis of the biochemical composition of the tissue sample of the oyster revealed positive correlation in both species of oyster Crassostrea madrasensis and Saccostrea cucullata. The strong Positive Correlation were observed in between the two stations and the highest value of protein, carbohydrate and lipids were observed in Crassostrea madrasensis rock and creek when it compare to Saccostrea cucullata.Keywords: Protein, Carbohydrate, Lipid , Crassostrea madrasensis, Saccostrea cucullata, oysters


2015 ◽  
Vol 5 (1) ◽  
pp. 48-55
Author(s):  
S. Subba ◽  
V. K. Mahaseth

The sex ratio, Gonado Somatic Index and fecundity of the Copper Mahseer, Neolissochilus hexagonolepis were investigated. The sex ratio was 1:1.2 (Male to female). The gonado-somatic index ranged from 0.084 % to 16.47 % for female fish and 0.086% to 5.81 % for male fish. The highest mean GSI 9.037 % was recorded in July for female fishes and the highest 2.838 % was recorded in September for male fishes.  The total weight and total length of the fishes had strong positive correlation. Also, the correlation between the weight of gonad and GSI was positively correlated.  Absolute fecundity ranged from to 11424. Fecundity had strong positive correlation with total length (r = 0.98), total weight (r= 0.9) and total length (r= 0.88).


1995 ◽  
Vol 73 (03) ◽  
pp. 429-434 ◽  
Author(s):  
Kazuomi Kario ◽  
Takefumi Matsuo ◽  
Reiko Asada ◽  
Toshiyuki Sakata ◽  
Hisao Kato ◽  
...  

SummaryWe compared factor VII clotting activity (FVIIc) assays using different thromboplastins to determine which is the most sensitive for activated FVII (FVIIa) or for FVII antigen (FVIIag). FVIIc levels were measured using thromboplastins derived from bovine brain (FVIIc Bov), human placenta (FVIIc Hum), and rabbit brain (FVIIc Rab). FVIIa levels were measured by fluorogenic assays using human soluble tissue factor (rsTF) or bovine rsTF. We also measured FVII activity by an amidolytic assay (FVIIc:am Hum) using human thromboplastin and a chromogenic substrate for thrombin. FVIIag levels were determined by ELISA. In the FVIIa assay, the reaction time obtained from using bovine rsTF was shorter than that with human rsTF, suggesting that the interaction of plasma FVIIa with bovine rsTF was stronger than with human rsTF. The plasma FVIIa levels measured using human rsTF and bovine rsTF were almost the same (r=0.947, p<0.0001). Among the three FVIIc assays, FVIIc Bov had the strongest positive correlation with the plasma FVIIa level (r=0.886, p<0.000l), but had no correlation with FVIIag. An increase of 1 ng/ml in the plasma FVIIa level yielded a 27.9% increase of FVIIc Bov. Plasma FVIIc Hum and FVIIc:am Hum showed moderate correlations with both FVIIa (r=0.520, p<0.02 and r=0.569, p<0.01, respectively) and FVIIag (r=0.438, p<0.05 and r=0.468, p<0.05, respectively). FVIIc Rab had the lowest correlation with FVIIa (r=0.367, p<0.1), but had a moderate correlation with FVIIag (r=0.436, p<0.05). After in vitro cold activation, FVIIc Bov levels increased the most and FVIIc:am levels showed the least change. These findings indicate that consideration of the thromboplastin used for assay is necessary when assessing the clinical significance of FVII activity as a cardiovascular risk factor.


Genetics ◽  
2000 ◽  
Vol 156 (3) ◽  
pp. 1285-1298 ◽  
Author(s):  
Bret A Payseur ◽  
Michael W Nachman

Abstract Background (purifying) selection on deleterious mutations is expected to remove linked neutral mutations from a population, resulting in a positive correlation between recombination rate and levels of neutral genetic variation, even for markers with high mutation rates. We tested this prediction of the background selection model by comparing recombination rate and levels of microsatellite polymorphism in humans. Published data for 28 unrelated Europeans were used to estimate microsatellite polymorphism (number of alleles, heterozygosity, and variance in allele size) for loci throughout the genome. Recombination rates were estimated from comparisons of genetic and physical maps. First, we analyzed 61 loci from chromosome 22, using the complete sequence of this chromosome to provide exact physical locations. These 61 microsatellites showed no correlation between levels of variation and recombination rate. We then used radiation-hybrid and cytogenetic maps to calculate recombination rates throughout the genome. Recombination rates varied by more than one order of magnitude, and most chromosomes showed significant suppression of recombination near the centromere. Genome-wide analyses provided no evidence for a strong positive correlation between recombination rate and polymorphism, although analyses of loci with at least 20 repeats suggested a weak positive correlation. Comparisons of microsatellites in lowest-recombination and highest-recombination regions also revealed no difference in levels of polymorphism. Together, these results indicate that background selection is not a major determinant of microsatellite variation in humans.


Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1181
Author(s):  
Roma Durak ◽  
Jan Dampc ◽  
Monika Kula-Maximenko ◽  
Mateusz Mołoń ◽  
Tomasz Durak

Temperature, being the main factor that has an influence on insects, causes changes in their development, reproduction, winter survival, life cycles, migration timing, and population dynamics. The effects of stress caused by a temperature increase on insects may depend on many factors, such as the frequency, amplitude, duration of the stress, sex, or the developmental stage of the insect. The aim of the study was to determine the differences in the enzymatic activity of nymphs and adult aphids Aphis pomi, Macrosiphum rosae and Cinara cupressi, and changes in their response to a temperature increase from 20 to 28 °C. The activity of enzymatic markers (superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), β-glucosidase, polyphenol oxidase (PPO) and peroxidase (POD)) in aphid tissues was analysed for three constant temperatures. The results of our research showed that the enzymatic activity of aphids (measured as the activity of antioxidant, detoxifying and oxidoreductive enzymes) was mainly determined by the type of morph. We observed a strong positive correlation between the activity of the detoxifying and oxidoreductive enzymes and aphids’ development, and a negative correlation between the activity of the antioxidant enzymes and aphids’ development. Moreover, the study showed that an increase in temperature caused changes in enzyme activity (especially SOD, CAT and β-glucosidase), which was highest at 28 °C, in both nymphs and adults. Additionally, a strong positive correlation between metabolic activity (heat flow measured by microcalorimeter) and longevity was observed, which confirmed the relationship between these characteristics of aphids. The antioxidant enzyme system is more efficient in aphid nymphs, and during aphid development the activity of antioxidant enzymes decreases. The antioxidant enzyme system in aphids appears to deliver effective protection for nymphs and adults under stressful conditions, such as high temperatures.


2018 ◽  
Vol 3 (1) ◽  
pp. 381-384
Author(s):  
Hem Sagar Rimal ◽  
Shripad J Walavalkar

Introduction: Vitamin D is an important micronutrient having crucial role in calcium and phosphate homeostasis but there is emerging evidence to suggest its role in prevention of infectious, inflammatory and neoplastic diseases. The vitamin D insufficiency/deficiency is a widely recognized problem among children in developed as well as developing countries.Objective: To find out the prevalence of vitamin D deficiency/insufficiency among children aged 2 months to 13 yrs and its correlation with serum calcium, phosphate and demographic factors.Methodology: Prospective, cross sectional, hospital based study conducted at Birat Medical College Teaching Hospital for a period of one year among children presented to pediatric OPD in whom pediatrician had a suspicion of Vitamin D Insufficiency /Deficiency. Venous blood Samples were taken for the estimation of 25(OH) Vitamin D, Calcium and Phosphate. Statistical analysis was done using SPSS software version 16. Results Among 174 children aged 2 months to 13 years, the prevalence of vitamin D insufficiency at the cutoff of <30ng/ml was 82.75% where as no cases of vitamin D deficiency was noted at cut off level of < 10 ng/ml. Children residing in urban area, samples taken in the winter season had higher prevalence of vitamin D insufficiency (p value <0.05). Serum calcium and phosphate level were found positively correlated with Vitamin D level (p<.05). However the relationship was very strong between Vitamin D and Calcium (r=0.402, p-value <0.001) and weak positive correlation was noted with phosphate(r=0.155, p value <0.05).Conclusion: There is very high prevalence of Vitamin D insufficiency among children. The vitamin D insufficiency was significantly higher in winter season as compared to summer. Children living in the urban area are more prone to Vitamin D insufficiency. Moderately strong positive correlation was observed between Vitamin D level and calcium but weak correlation existed with phosphate. BJHS 2018;3(1)5 : 381-384


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