scholarly journals Relationship of Condition Index and Reproductive Status of Black Snail, Fannus ater in Merchang Lagoon

Author(s):  
Nurul Husna Hassan ◽  
Roslizawati Ab Lah

Black snail, Faunus ater is an abundant species in Malaysia yet not many research have focused on its physiological and biological activities. This research aimed to assess the condition index (CI) and reproductive status based on the gonadosomatic index (GSI) for short-term duration. Samples were collected monthly from Merchang Lagoon, from November 2018 to January 2019. Four different types of condition indices equation were applied in this study and the results revealed that there were significant differences between four equations for measuring the CI (P=0.000). However, the result for the GSI shows no significant difference between three month of sampling (P>0.05). CI based on fresh weight measurement (Fww/Tww x 100) and dry weight measurement (Fdw/Fww x 100) reached its peak when GSI decreased. The rest of the trend for CI fluctuated and CI was not affected by GSI. Overall, this study concluded that, there were trends observed in CI and GSI for the black snails. However, it is suggested that longer term observation in future research is needed have a better understanding on the black snails.

Parasitology ◽  
2012 ◽  
Vol 139 (3) ◽  
pp. 406-417 ◽  
Author(s):  
M. VANACKER ◽  
G. MASSON ◽  
J-N. BEISEL

SUMMARYSampling of the fish community was carried out for 20 years in the Mirgenbach reservoir, in North-Eastern France. The prevalence and the mean intensity of Ligula intestinalis (Cestoda) were analysed in roach (Rutilus rutilus) and silver bream (Blicca bjoerkna) populations, the main two infected species. The aim of this study was to investigate the host switch from roach to silver bream and the consequences of L. intestinalis infestation in silver bream, which is an unusual host for this parasite as Ligula parasitism in silver bream appears to be rare. We analysed in detail the relationships between parasitism index (PI), gonadosomatic index (GSI), perivisceral fat abundance (PFA) and condition index (CI) in the silver bream population. In 1998, prevalence of L. intestinalis highlighted a clear host switch from roach to silver bream. In the silver bream population, young fish were the most severely infected and the impact of plerocercoids appeared to be different depending on the host sex. In male silver bream, plerocercoids drew energy from fat reserves even if GSI was also slightly impacted. On the contrary, in females energy was diverted from gonad maturation rather than from perivisceral fat reserves. No significant difference was observed in terms of CI in either sex.


2019 ◽  
Vol 76 (6) ◽  
pp. 886-903 ◽  
Author(s):  
Mark J. Wuenschel ◽  
W. David McElroy ◽  
Kenneth Oliveira ◽  
Richard S. McBride

Measuring fish condition should link ecosystem drivers with population dynamics, if the underlying physiological basis for variations in condition indices are understood. We evaluated traditional (K, Kn, hepatosomatic index, gonadosomatic index, energy density, and percent dry weight of muscle (%DWM) and liver (%DWL)) and newer (bioelectrical impedance analysis (BIA) and scaled mass index (SMI)) condition indices to track seasonal cycles in three flatfishes — winter founder (Pseudopleuronectes americanus; three stocks), yellowtail flounder (Limanda ferruginea; three stocks), and summer flounder (Paralichthys dentatus; one stock) — with contrasting life histories in habitat, feeding, and reproduction. The %DWM and %DWL were good proxies for energy density (r2 > 0.96) and more strongly related to K, Kn, and SMI than to BIA metrics. Principal component analysis indicated many metrics performed similarly across species; some were confounded by size, sex, and maturity along PC1, while others effectively characterized condition along PC2. Stock differences were along PC1 in winter flounder, reflecting different sizes across stocks, whereas in yellowtail flounder differences occurred along PC2 related to condition. These comparisons, within and across species, highlight the broad applicability of some metrics and limitations in others.


1985 ◽  
Vol 63 (2) ◽  
pp. 331-333 ◽  
Author(s):  
G. Gauthier ◽  
J. Bédard

We evaluate several external condition indices as predictors of total fat reserves (TFR) in greater snow geese. In 1979 and 1980, we collected 373 adult geese during their spring staging halt along the St. Lawrence estuary, Québec, and determined their fat content by ether extraction. Body weight (BW) alone and BW divided by various morphometric measurements are relatively poor predictors of TFR (maximum r2 = 0.56). The thickness of subcutaneous fat (measured externally with an adiposimeter) combined with BW is the best predictor of TFR (R2 = 0.65). This condition index can be useful in predicting the average condition of living geese, provided a reasonable sample size is available. We also examined some internal condition indices. Of these, the dry weight of abdominal fat is the easiest to apply and one of the most reliable (r2 = 0.86).


Author(s):  
C.W. Oh ◽  
J.Y. Kim ◽  
I.J. Jeong ◽  
H.L. Suh ◽  
Y.K. Cho

Investigations were made on reproduction and population dynamics of Leptochela gracilis on the western coast of Korea, Yellow Sea, between May 2000 and October 2001. The egg volume was significantly larger at later egg stage than at early egg stage. Brood loss did not occur during the incubation period. Based on dry weight, the reproductive output (mass of incubating eggs/mass of female) averaged 0.18. The mature females first appeared in May, reached a peak in July and August, and then did not appear after September. The main breeding season was summer, although slightly different between the two years. A similar pattern could be found in monthly changes of gonadosomatic index (GSI), showing relatively higher GSI during the annual breeding season. A significant difference in ovarian dry weight between females with non-eyed eggs and eyed eggs indicates that ovarian maturation occurred during the embryonic development, suggesting that females were potentially consecutive breeders, capable of multiple spawning within a reproductive season. The size at which 50% of females were mature (CL50) was estimated as 7.63 mm carapace length. Females grew faster and reached a larger size at age than males (L∞=12.43 mm CL and K=0.90 y−1 for females, and L∞=12.22 mm CL and K=0.58 y−1 for males).


1996 ◽  
Vol 47 (2) ◽  
pp. 301 ◽  
Author(s):  
IM Suthers ◽  
JJ Cleary ◽  
SC Battaglene ◽  
R Evans

The RNA:DNA ratio for first-feeding larvae (12 days after hatching, 4-6 mm standard length, SL) of Australian bass (Percichthyidae, Macquaria novemaculeata) exposed to four different feeding regimes over 8 days was found to be insensitive to the level of starvation. An alternative condition index based on residuals derived from the regression of RNA on SL showed significant differences over the course of the experiment; these reflected the four feeding treatments. Field collections of juvenile monacanthids (Paramonacanthus otisensis, 10-30 mm SL) from a local estuary revealed no significant difference in RNA: DNA ratio at three sites over six weeks. A residual-based index (RNA on dry weight) showed parallel fluctuations at all sites; they were positively correlated with water temperature. The RNA : DNA ratio depends on the difference in fluorescence between total nucleic acids (TNA, using thiazole orange) and DNA (using Hoechst 33258) to calculate RNA, as there is no RNA-specific fluorescent dye. The numerator is thus dependent on the denominator, and measurement error may be compounded in the ratio, exacerbating potential variability in the index. Ratios may also be variably correlated with age or size and consequently may erroneously indicate condition or growth in larger and faster-growing fish.


2014 ◽  
Vol 1 (1) ◽  
pp. 25-29
Author(s):  
Rahim Mohammadian ◽  
Behnam Tahmasebpour ◽  
Peyvand Samimifar

A factorial experiment was conducted with a completely randomized design to evaluate the effects of planting date and density on calendula herbs and peppermint. It had 3 replicates and was done in Khosroshahr research farm, Tabriz in 2006. Under studied factors were: 3 planting dates (10 May, 25 May and 10 June) in 4 densities (25, 35, 45, 55) of the plant in square meters. The results of variance a nalysis showed that there was 1% probability significant difference between the effects of planting date and bush density on the leave number, bush height and the bush dry weight. But the mutual effect of the plant date in mentioned traits density was insignificant. Regarding the traits mean comparison, the total maximum dry weight was about the 55 bush density in mm. Also, the bush high density in mm causes the bush growth and its mass reduction. When there is the density grain, the flower number will increase due to bush grain in surface unit. Overall, we can conclude that 10 June planting and 45 bush density in mm is the most suitable items and results in favored production with high essence for these crops.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 485b-485
Author(s):  
Lisa M. Barry ◽  
Michael N. Dana

Nurse crops are often recommended in prairie restoration planting. This work investigated several alternative nurse crops to determine their utility in prairie planting. Nurse crops were composed of increasing densities (900, 1800, or 2700 seeds/m2) of partridge pea, spring oats, spring barley, Canada wild rye, or equal mixtures of partridge pea and one of the grasses. The experimental design was a randomized complete-block set in two sites with three blocks per site and 48 treatments per block. Each 3 × 3-m plot contained 1 m2 planted in Dec. 1995 or Mar. 1996 with an equal mix of seven prairie species. The nurse crops were sown over each nine square meter area in April 1996. Plots lacking nurse crops served as controls. Evaluated data consisted of weed pressure rankings and weed and prairie plant dry weight. Nurse crop treatments had a significant effect on weed pressure in both sites. Barley (1800 and 2700 seeds/m2) as well as partridge pea + barley (2700 seeds/m2) were most effective at reducing weed pressure. When weed and prairie plant biomass values were compared, a significant difference was observed for site quality and planting season. Prairie plant establishment was significantly greater in the poorly drained, less-fertile site and spring-sown plots in both sites had significantly higher prairie biomass values. Overall, after two seasons, there was no advantage in using nurse crops over the control. Among nurse crop treatments, oats were most effective in reducing weed competition and enhancing prairie plant growth.


2021 ◽  
Vol 14 ◽  
pp. 194008292110103
Author(s):  
Patrick Jules Atagana ◽  
Eric Moïse Bakwo Fils ◽  
Sevilor Kekeunou

We aimed to assess how bats are affected by habitat transformation by comparing bat assemblages in four habitat types: primary forest, secondary forest, cocoa plantations and human habitations in the Dja Biosphere Reserve of southern Cameroon. Bats were sampled in the four habitat types using mist nets. During 126 nights, a total of 413 bats were captured, belonging to four families, 16 genera and 24 species. Ninety three individuals (17 species) were captured in the primary forest, followed by plantations (105 individuals, 14 species), human habitations (159 individuals, 10 species), and secondary forest (55 individuals, eight species). Megaloglossus woermanni was recorded in all the four habitats, and was the most abundant species (105 individuals). The analysis of bat assemblage between habitat types showed a statistically significant difference in species composition. The distribution of the six most abundant species ( Epomops franqueti, Megaloglossus woermanni, Rousettus aegyptiacus, Dohyrina cyclops, Hipposideros cf. caffer and Hipposideros cf. ruber) was influenced by habitat types. Our results suggest that the decrease in species richness observed in disturbed habitats may be due to habitat perturbations of primary forest habitats. Therefore, it is important to examine the effects of habitat conversion at species level, as responses are often species-specific.


2021 ◽  
pp. jclinpath-2020-206927
Author(s):  
Maryam Ahmed Al Barashdi ◽  
Ahlam Ali ◽  
Mary Frances McMullin ◽  
Ken Mills

The leucocyte common antigen, protein tyrosine phosphatase receptor type C (PTPRC), also known as CD45, is a transmembrane glycoprotein, expressed on almost all haematopoietic cells except for mature erythrocytes, and is an essential regulator of T and B cell antigen receptor-mediated activation. Disruption of the equilibrium between protein tyrosine kinase and phosphatase activity (from CD45 and others) can result in immunodeficiency, autoimmunity, or malignancy. CD45 is normally present on the cell surface, therefore it works upstream of a large signalling network which differs between cell types, and thus the effects of CD45 on these cells are also different. However, it is becoming clear that CD45 plays an essential role in the innate immune system and this is likely to be a key area for future research. In this review of PTPRC (CD45), its structure and biological activities as well as abnormal expression of CD45 in leukaemia and lymphoma will be discussed.


2011 ◽  
Vol 142 ◽  
pp. 233-237
Author(s):  
Han Wen Yuan ◽  
Fang Chen ◽  
Qiao Qing Xu ◽  
Shi Yuan Gong ◽  
Zhang Jie Chu ◽  
...  

The effects of stocking density on various growth parameters and sex reversal in the rice field eel (Monopterus albus) were investigated by evaluating steroid hormone, the gonadosomatic index (GSI) and sex ratio. Fish (mean initial weight of 9.88 ± 0.70 g) were stocked to densities of 4, 20, 36, 52, 68, 84 or 100 fish/m2 in cages (2 m × 1 m × 1.5 m) in a pond, with five replicate cages for each density. Fish were fed for 420 days on a formulated isocaloric diet containing 40.22% crude protein and 12.86 MJ/kg. Serum E2 and T concentrations were determined by radioimmunoassays. There were no significant differences in final bodyweight (FBW) and daily weight gain (DWG) for fish in the groups containing less than 52 fish/m2, while FBW and DWG were significant lower in groups at 68 fish/m2 or more. Specific growth rate (SGR) differed significantly between the 84 and 100 fish/m2 groups compared with the 4, 20 and 36 fish/m2 groups. There was no significant difference in SGR in groups containing less than 84 fish/m2. There were no significant difference between the 4 and 20 fish/m2 groups in net yield (NY), but these groups did differ significantly from the other groups. The final condition factors of fish stocked at 84 or 100 fish/m2 were significantly lower than fish stocked at the other densities. E2 and T hormone concentrations declined as stocking density increased, while GSI values increased initially but then reduced with increasing stocking density. Female ratio and survival decreased with increasing stocking density. The proportion of male fish was significantly greater in the three highest stocking density groups. Therefore, high stocking density may promote sex change from female to male in M. albus.


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