An analysis of morphological variation in limpets of the genus Collisella

1978 ◽  
Vol 56 (4) ◽  
pp. 643-650 ◽  
Author(s):  
Paul A. Dehnel
Keyword(s):  
Morphological Variation ◽  
Shell Length ◽  
Shell Height ◽  
Shell Morphology ◽  
Shell Weight ◽  
Shell Width ◽  
Significant Relationships ◽  
Wet Weight ◽  
Animal Growth

Shell morphology, radular length, and wet weight of soft parts were compared between three species (Collisella pelta, Collisella persona, and Collisella scutum) from one geographic locality. Shell length vs. shell height, wet weight of soft parts vs. radular length, and shell length vs. radular length are statistically significant relationships to separate the three species. Shell weight vs. wet weight of soft parts, wet weight of soft parts vs. extravisceral space, and shell volume vs. wet weight of soft parts are statistically significant relationships to separate C. scutum from either C. pelta or C. persona. These comparisons do not separate C. pelta from C. persona. Shell length vs. shell width, shell length vs. shell volume, and shell length vs. shell weight were found not to be statistically significant relationships to separate the three species. The importance of using shell length and wet weight of soft parts as a measure of animal growth is discussed.

scholarly journals Prediction Accuracies of Genomic Selection for Nine Commercially Important Traits in the Portuguese Oyster (Crassostrea angulata) Using DArT-Seq Technology

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 210
Author(s):  
Sang V. Vu ◽  
Cedric Gondro ◽  
Ngoc T. H. Nguyen ◽  
Arthur R. Gilmour ◽  
Rick Tearle ◽  
...  
Keyword(s):  
Moisture Content ◽  
Genomic Selection ◽  
Shell Length ◽  
Prediction Accuracy ◽  
Genomic Information ◽  
Morphometric Traits ◽  
Shell Weight ◽  
Shell Width ◽  
Crassostrea Angulata ◽  
Selection For

Genomic selection has been widely used in terrestrial animals but has had limited application in aquaculture due to relatively high genotyping costs. Genomic information has an important role in improving the prediction accuracy of breeding values, especially for traits that are difficult or expensive to measure. The purposes of this study were to (i) further evaluate the use of genomic information to improve prediction accuracies of breeding values from, (ii) compare different prediction methods (BayesA, BayesCπ and GBLUP) on prediction accuracies in our field data, and (iii) investigate the effects of different SNP marker densities on prediction accuracies of traits in the Portuguese oyster (Crassostrea angulata). The traits studied are all of economic importance and included morphometric traits (shell length, shell width, shell depth, shell weight), edibility traits (tenderness, taste, moisture content), and disease traits (Polydora sp. and Marteilioides chungmuensis). A total of 18,849 single nucleotide polymorphisms were obtained from genotyping by sequencing and used to estimate genetic parameters (heritability and genetic correlation) and the prediction accuracy of genomic selection for these traits. Multi-locus mixed model analysis indicated high estimates of heritability for edibility traits; 0.44 for moisture content, 0.59 for taste, and 0.72 for tenderness. The morphometric traits, shell length, shell width, shell depth and shell weight had estimated genomic heritabilities ranging from 0.28 to 0.55. The genomic heritabilities were relatively low for the disease related traits: Polydora sp. prevalence (0.11) and M. chungmuensis (0.10). Genomic correlations between whole weight and other morphometric traits were from moderate to high and positive (0.58–0.90). However, unfavourably positive genomic correlations were observed between whole weight and the disease traits (0.35–0.37). The genomic best linear unbiased prediction method (GBLUP) showed slightly higher accuracy for the traits studied (0.240–0.794) compared with both BayesA and BayesCπ methods but these differences were not significant. In addition, there is a large potential for using low-density SNP markers for genomic selection in this population at a number of 3000 SNPs. Therefore, there is the prospect to improve morphometric, edibility and disease related traits using genomic information in this species.

scholarly journals Telaah morfometrik Pinctada margaritifera untuk pengembangan usaha budidaya

2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Karel Sumtaki ◽  
Ockstan J. J. Kalesaran ◽  
Cyska Lumenta
Keyword(s):  
Water Quality ◽  
Shell Length ◽  
Current Velocity ◽  
Quality Parameters ◽  
Morphometric Measurements ◽  
Shell Weight ◽  
Pinctada Margaritifera ◽  
Shell Width ◽  
Aquaculture Development ◽  
Quality Measurements

This study aimed to analyze the size of shell length, shell width and total weight of Pinctada margaritifera shells, and water quality parameters for the aquaculture development. Morphometric measurements include: shell length (PC), and shell width (LC), shell weight (BT). The results showed that PC size 8 - 11.99 cm, LC 8 - 9.99 cm and BT 80 - 99.99 gram dominate the Arakan waters  while PC size 6 - 9.99 cm, LC 6 - 7.99 cm and BT 60 - 79.99 gram dominate the Bahoi  waters. The results of water quality measurements in both locations are Bahoi waters, namely: 29-32oC, DO 7-8,5 mg/l, pH 7,8-7,9, salinity, 28-32 ppt, 4,5- 7 meters, 11 cm/sec. While in Arakan waters, the temperature was 30-30,8oC, DO 6,3-6,7 mg/l, pH 7,6-7,7 salinity 30 ppt, brightness 4-5 meter, current velocity 4,5 cm / second. Both locations were feasible for the development of pearl aquacultureKeywords: Morphometric, Pinctada margaritifera, Aquaculture

scholarly journals Spatial distribution and morphometry of the succineid snail Succinea baconi (Pfeiffer, 1854) in India

2021 ◽  
Author(s):  
Himangshu Barman ◽  
Soujita Pramanik ◽  
Gargi Nandy ◽  
Sampa Banerjee ◽  
Gautam Aditya
Keyword(s):  
Spatial Distribution ◽  
Vertical Distribution ◽  
Shell Length ◽  
Land Snail ◽  
Shell Morphology ◽  
Shell Shape ◽  
Regression Equations ◽  
Growth Strategies ◽  
Shell Weight ◽  
Significant Difference

The spatial distribution and morphological features of the land snail Succinea baconi (Pfeiffer, 1854) (Gastropoda: Succineidae) from India were evaluated. The survey performed in gardens and bushes in Coochbehar, West Bengal, India, has made it possible to assess the abundance of the snail S. baconi on the randomly selected lemon plants (n = 18). Logistic regressions were employed to judge differences in vertical distribution, resource association and size class variation in the snails under study. Variation in shell morphology was assessed by performing the regression analysis of the sampled shells of live snails (n = 258) and vacant shells of the deceased individuals (n = 100). An overall significant difference (p < 0.05) in the vertical distribution of snails in lemon plants was observed. As to their association with resources available, snails were found to be more abundant in detritus than on living parts of the plants. The performed logistic regression revealed that the relative abundance of different S. baconi size classes was significantly different (p < 0.001). Significant correlations (p < 0.001) were found among different body size variables, with the shell length (x)-body weight (y) relationship being: y = 0.232x2.524 (for live snails) and the shell length (x)-shell weight (y) relationship being: y = 0.358x2.537 (for shells of dead snails). Various parameters of the snail shell shape could be represented through regression equations. Although reproduction and growth strategies of snails need to be explored further, the presented observations improve our understanding of the ecology of S. baconi, which may prove useful for future conservation efforts.

scholarly journals Colour and Morphometric Variation of Donacid Bivalves from Nepa Beach, Madura Island, Indonesia

2017 ◽  
Vol 9 (3) ◽  
pp. 466 ◽  
Author(s):  
Reni Ambarwati ◽  
Ulfi Faizah
Keyword(s):  
Regression Analysis ◽  
Shell Length ◽  
Shell Height ◽  
Morphological Characteristics ◽  
Morphological Characters ◽  
Colour Pattern ◽  
Morphometric Variation ◽  
Shell Width ◽  
Northern Shore

<p class="IsiAbstrakIndo"><span lang="EN-GB">Donacid bivalves vary in colour, pattern, and the shape of the shells. A population of donacid bivalves had been found in the northern shore of Madura Island, Indonesia. This study aimed to identify the donacids found in northern shore of Madura Island as well as to describe their variation on morphometric and morphological characters. Colour and pattern of 215 shells were observed and carefully photographed. Morphometric of the shells including the shell height, shell length, shell width, dorsal length, and umbo-margin length were measured and then their patterns were analyzed using regression analysis. The results revealed that there were two species of donacid bivalves in Nepa Beach, namely </span><em><span lang="EN-GB">Donax cuneata</span></em><span lang="EN-GB"> and </span><em><span lang="EN-GB">Donax faba</span></em><span lang="EN-GB"> with different morphological characteristics, including twelve different patterns and colours of the shells. These variations were described completely in this paper. This study contributes to the research on bivalve taxonomy, and is useful for the identification of donacid bivalves based on morphological characteristics.</span></p>

Shell shape, dysodont tooth morphology, and hinge-ligament thickness in the bay mussel Mytilus trossulus correlate with wave exposure

2000 ◽  
Vol 78 (2) ◽  
pp. 240-253 ◽  
Author(s):  
Robert J Akester ◽  
André L Martel
Keyword(s):  
Shell Length ◽  
Shell Height ◽  
Wave Exposure ◽  
Shell Morphology ◽  
Shell Shape ◽  
Width Ratio ◽  
Mytilus Trossulus ◽  
Barkley Sound ◽  
High Wave Energy ◽  
Mussel Mytilus Trossulus

We examined the shell morphology of the bay mussel Mytilus trossulus (Gould) at six locations with various levels of wave exposure in Barkley Sound on the west coast of Vancouver Island, British Columbia, Canada. Young adult M. trossulus (29-35 mm shell length) collected from wave-exposed sites displayed striking differences in shell morphology from M. trossulus from sheltered sites. Mytilus trossulus from wave-exposed habitats had a lower shell height / shell width ratio and a thicker shell; they also had higher, more robust dysodont teeth, as well as a thicker hinge ligament. Examination of juveniles (12-14 mm shell length) collected from a wave-exposed shore and a sheltered shore separated by only a few hundred metres displayed similar differences in shell morphology and ligament thickness. These observations suggest that wave exposure is the cause of the observed differences in shell morphology and ligament thickness in M. trossulus. This is the first report of a correlation between wave exposure and morphology of the dysodont teeth and ligament in a bivalve. We discuss potential selective pressures that may favor characteristics of wave-exposed shells, including the probability of dislodgment and misalignment of valves in high wave energy areas.

Structure and growth of a high-level population of Cerastoderma edule (Lamellibranchiata)

1979 ◽  
Vol 59 (2) ◽  
pp. 277-287 ◽  
Author(s):  
A. M. Jones
Keyword(s):  
Growth Ring ◽  
Shell Height ◽  
Maximum Size ◽  
Dry Weight ◽  
Shell Weight ◽  
Cerastoderma Edule ◽  
Tissue Weight ◽  
Wet Weight ◽  
High Level ◽  
High Tidal Level

The allometric relationships between shell length and shell breadth, shell height, shell weight, wet tissue weight and dry tissue weight are described for a population of Cerastoderma edule living at a high tidal level in the Dovey Estuary, West Wales. Seasonal fluctuations in standard animal values for shell weight and dry weight are interpreted in terms of the cycles of reproduction and food availability; the dangers associated with the use of wet weight in growth studies are demonstrated. The population structure is described using a combination of length-frequency and growth ring analyses and comprised nine year-classes with overlapping size ranges. The growth of the population was very slow and the relative growth rate was almost constant; associated with this slow, atypical growth pattern was considerable longevity and a small maximum size. The reasons for these characteristics are discussed.

scholarly journals Prediction of body weight using morphometric indices in giant African land snail in three zones of Imo state

2021 ◽  
Vol 47 (6) ◽  
pp. 1-9
Author(s):  
S. I. Ahamba ◽  
C. U. Ekugba ◽  
O. E. Kadurumba ◽  
U. E. Ogundu
Keyword(s):  
Body Weight ◽  
Shell Length ◽  
Land Snail ◽  
Study Data ◽  
Shell Weight ◽  
Ecological Zones ◽  
Imo State ◽  
Shell Width ◽  
Poids Corporel ◽  
Significant Difference

Prediction of body weight using morphometric indices in giant African land snail (Achatina marginata) was studied for the three (3) agro-ecological zones in Imo State (Owerri, Okigwe and Orlu zones). One hundred and sixty (160) snails in Imo State were surveyed in course of this study. Data were generated through measurement of body weight, shell length, shell width, shell thickness, mouth length, weight of shell, weight of visceral, length of foot and thickness of foot. Data collected were subjected to regression analysis using SPSS statistical package. Results showed generally highly significant value (P<0.01) R2 value and R-value across the zoness. Highly significant difference (P<0.01) was observed in Owerri zone for the weight of shell, and the shell length. In Okigwe zone, only the weight of visceral showed a significant effect (P<0.01), whereas, in Orlu zone also, the shell width, shell mouth length and foot thickness showed a significant effect (P<0.01). The study therefore recommends that the linear model used, fits the data. Hence a comprehensive selection program for improvement of A. marginata in Imo State could be planned using the regressions coefficients obtained from the study.   La prédiction du poids corporel à l'aide d'indices morphométriques chez l'escargot terrestre géant africain (Achatina marginata) a été étudiée pour les trois (3) zones agro-écologiques de l'État d'Imo (zones Owerri, Okigwe et Orlu). Cent soixante (160) escargots de l'État d'Imo ont été étudiés au cours de cette étude. Les données ont été générées en mesurant le poids corporel, la longueur de la coquille, la largeur de la coquille, l'épaisseur de la coquille, la longueur de la bouche, le poids de la coquille, le poids du viscéral, la longueur du pied et l'épaisseur du pied. Les données collectées ont été soumises à une analyse de régression à l'aide du progiciel statistique SPSS. Les résultats ont montré une valeur R2 et une valeur R généralement très significatives (P <0,01) dans les zones. Une différence très significative (P <0,01) a été observée dans la zone d'Owerri pour le poids de la coquille et la longueur de la coquille. Dans la zone Okigwe, seul le poids des viscéraux a montré un effet significatif (P<0,01), alors que, dans la zone Orlu, la largeur de la coque, la longueur de la bouche de la coque et l'épaisseur du pied ont également montré un effet significatif (P <0,01) que le modèle linéaire utilisé, ajuste les données. Par conséquent, un programme de sélection complet pour l'amélioration d'A. Marginata dans l'État de l'Imo pourrait être planifié en utilisant les coefficients de régression obtenus à partir de l'étude.

scholarly journals Sexual dimorphism in shell morphology of mollusks of the genus Viviparus – important objects of water resources of Ukraine

2021 ◽  
Vol 280 ◽  
pp. 10011
Author(s):  
Olena Uvayeva ◽  
Tetiana Vakaliuk ◽  
Georgiy Shcherbina ◽  
Elena Shimkovich
Keyword(s):  
Sexual Dimorphism ◽  
Shell Height ◽  
Shell Morphology ◽  
Male And Female ◽  
Shell Width ◽  
Viviparus Viviparus ◽  
Body Whorl ◽  
Relationship Of ◽  
The Relationship ◽  
Mantle Section

Bioindication assessment of water bodies of Ukraine can be carried out using the ratio of males and females of mollusks of the genus Viviparus. In practice, it is very convenient to determine the sex of mollusks by the differences in their shell. Male and female freshwater snails Viviparus viviparus (Linnaeus, 1758) and V. contectus (Millet, 1813) are shown to have reliable differences in shell morphology depending on their age. There is almost no sexual dimorphism by shell morphometrics and indices in Viviparus snails aged one to three years. After three years of life, mature females have significantly larger shell width, higher body whorl, and size of the aperture. Females of V. viviparus at the age of two to five years may be differentiated from males by the relationship of mean shell width and shell height, which is statistically significant higher than in males. This difference is explained by the different size of the mantle section genital organs of mature male and female. The obtained results should be taken into consideration in establishing the sex of viviparid snails.

Ecophenotypic plasticity in shell growth direction of asari clam Ruditapes philippinarum

2021 ◽  
pp. 1-6
Author(s):  
Takeshi Tomiyama
Keyword(s):  
Growth Rate ◽  
Shell Growth ◽  
Shell Height ◽  
Growth Direction ◽  
Ruditapes Philippinarum ◽  
Shell Morphology ◽  
Individual Growth ◽  
Shell Size ◽  
Internal Factors ◽  
Suitable Habitats

Abstract Asari clam (or Manila clam) Ruditapes philippinarum is an important bivalve for local fisheries. This species exhibits a large variation in shell morphology, and the shell roundness tends to be greater in more unsuitable habitats. To test whether the increments in shell size parameters (length, height and width) were affected solely by environmental conditions or by internal factors such as initial shell shapes or growth rate, a field caging experiment was conducted at two different sites of unsuitable and suitable habitats in Matsukawaura Lagoon, Japan, where shell shapes of wild clams were significantly different between the habitats. In the experiment, clams were released from the two sites to the same site or to the other site and were re-collected after 3, 6 and 12 months of caging. Caged clams originating from unsuitable habitats and released to suitable habitats showed a reduction in shell height relative to shell length, while clams from suitable habitats introduced to unsuitable habitats showed marked increases in both shell height and width. Generalized linear mixed models suggested that the increase in shell height was affected largely by the release habitat (environment) whereas the increase in shell width was affected largely by the individual growth rate. These results suggest that marginal growths in shell height and width respond differently to external and internal factors of clams, resulting in plasticity in their shell shapes according to the environments to which they are translocated.

scholarly journals Effects of low-pH stress on shell traits of the dove snail, <i>Anachis misera</i>, inhabiting shallow-vent environments off Kueishan Islet, Taiwan

2015 ◽  
Vol 12 (9) ◽  
pp. 2631-2639 ◽  
Author(s):  
Y. J. Chen ◽  
J. Y. Wu ◽  
C. T. A. Chen ◽  
L. L. Liu
Keyword(s):  
Shell Length ◽  
Shell Thickness ◽  
Expression Profiles ◽  
Shell Shape ◽  
Natural Environments ◽  
Additional Information ◽  
Shell Width ◽  
T1 And T2 ◽  
Body Whorl ◽  
Protein Expression Profiles

Abstract. The effects of naturally acidified seawater on shell traits were quantified through the comparison of dove snails (Family: Columbellidae) Anachis misera from vent environments with Euplica sp. from non-vent sites in northeastern Taiwan. Samples of A. misera were collected around a shallow vent (24.8341° N, 121.96191° E), which included the east, south, southwest, and northwest sites. An absence of Anachis snails was found in the most acidic north site (pH 7.19–7.25). Based on the similarities of protein expression profiles, the Anachis snails were classified into two groups, i.e., V-South (pH 7.78–7.82) and V-Rest (pH 7.31–7.83). Comparing their shell traits to the non-vent Euplica sp. from Da-xi (DX) and Geng-fang (GF) (pH 8.1–8.2), a difference in shell shape (shell width : shell length) was found, with the populations having more globular shells than the non-vent ones. The means of shell width were significantly different among sites (p < 0.01), with a descending order of GF > DX > V-South and V-Rest. The relationships of shell length to total weight were curvilinear for both Anachis and Euplica snails. The logarithmically transformed slopes differed significantly among sites, and the mean body weight of the GF population was greater than that of the others (p < 0.01). Positive correlations between shell length and shell thickness of body whorl (T1) and penultimate whorl (T2) were only observed in non-vent GF and DX populations. Anachis snails from vent sites were thinner in T1 and T2 compared to the Euplica snails from non-vent sites (p < 0.05). Within each vent group, shell thickness between T1 and T2 was insignificantly different. Between vent groups, T1 and T2 from V-Rest showed a decrease of 10.6 and 10.2%, respectively, compared to V-South ones. The decrease of T1 and T2 between vent Anachis snails and non-vent Euplica snails was as great as 55.6 and 29.0%, respectively. This was the first study to compare snail's morphological traits under varying shallow-vent stresses with populations previously classified by biochemical responses. Overall, the shallow-vent-based findings provide additional information from subtropics on the effects of acidified seawater on gastropod snails in natural environments.

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