Characterization of the species of genus Physa on the basis of typological species concept from Central Punjab

Physids belong to Class Gastropoda; Phylum Mollusca have important position in food web and act as bio indicators, pests and intermediate host. Being resistant these are called cockroaches of malacology. Physid snails were collected from different water bodies of Faisalabad (Punjab) and were identified up to species using morphological markers. The morphometry of the specimens was carried out with the help of a digital Vernier caliper in millimeters (mm) using linear measurement of shell characters. Linear regression analysis of the AL/SW ratio vs AL and SL/SW ratio vs AL indicated that allometric growth exists only in Physa acuta when compared with P.gyrina and P. fontinalis. This study will lead to assess the status of the Physid species in Central Punjab. The Principal component analysis shows that the Component 1 (Shell Length) and component 2 (Shell Width) are the most prolific components and nearly 80 percent of the identification. The distance between P. acuta and P. fontinalis is 5.4699, P. acuta and P. gyrina is 7.6411, P. fontinalis and P. gyrina is 16.6080 showing that P. acuta resembles with P. fontinalis, and both these specimens donot resemble with P. gyrina. P.acuta is an invasive species and shows bioactivity making it a potent candidate for bioactive substances.

Effect of replacing maize with plantain peels on the performance traits and haematological characteristics of African giant land snail

The study was carried out at the Niger Delta University, Faculty of Agriculture Teaching and Research Farm, Bayelsa State. A total of Ninety six (96) growing snails (Archachatina marginata). Using Plantain peel as an additive, four diets were formulated at the levels of 0%, 3%, 6%, and 9% to form the treatment diets. The experiment lasted for eight (8) weeks during which the weight gain, feed intake, shell width, shell length, shell thickness and hematological parameters were obtained. The weight gain, shell width, shell length and shell thickness are not significantly different (p<0.05) whereas, the feed intake differed significantly (p<0.05) for all the treatment diets in the experiment. From the results, it was concluded that concentrate with 0% inclusion of Plantain peel meal was suitable for snail diets as it gave the best performance. The hematological parameters measured in the African giant land snails are White blood cell, Neutrophile and Lymphocyte differed significantly (p<0.05). Plantain peel can serve as source of potassium for other animals, as the highest percentage of potassium was found in the hemolymph of snails fed with 9% inclusion of plantain peel. It is recommended that; there should be no inclusion of plantain peels in the diet of the African giant land snails in order to achieve higher weight gain and feed intake.

The world’s tiniest land snails from Laos and Vietnam (Gastropoda, Pulmonata, Hypselostomatidae)

Two new, extremely small land snail species, Angustopila coprologos Páll-Gergely, Jochum & Hunyadi n. sp. and Angustopila psammion Páll-Gergely, Vermeulen & Anker n. sp. are described from northern Vietnam and northern Laos, respectively. The former is characterized by a rough surface sculpture and bears tiny mud granules arranged in a pattern of radial lines on its shell surface. The latter species is the new global record-holder of the tiniest land snail title, with a shell width of 0.6–0.68 mm and a shell height of 0.46–0.57 mm. These measurements surpass the former records of Angustopila pallgergelyi and Acmella nana.

Chemical synthesis of nanopowder Nd2Fe14BаSiO2 of the nucleus-shell type

Nanoparticles of the alloy with the composition Nd-Fe-B were formed by the chemical method of co-precipitation reduction using a reducing agent sodium borohydride. The nanoparticle size was 35–95 nm. The silica coating was applied after stabilizing the nanoparticles with APTMS. The core of Nd-Fe-B alloy nanoparticles covered with a SiO2 shell, Nd2Fe14BаSiO2, the particle size was 35–125 nm with a shell width of 8–15 nm.

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

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.

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

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.

The structure of the ovotestis of the common African land snails found in Abeokuta, South Western Nigeria.

A comparative study of the structure of the ovotestis of African land snails found in Abeokuta was investigated. Of all the five snails species found and dissected, Archachatina marginata, Achatina achatina, A. fulica, Helix pomatia and Limcolaria aurora, only the ovotestis of H. pomatia could not be observed. The positioning, shape and arrangement of the ovotestis was the same for all the other four species. The ovotestis is embedded in the digestive gland at the anterior region of the coiled posterior end of the visceral mass. It is cream coloured and made up of sac-like lobes arranged on a single plane. It is differentiated into an ovariaon and testicular region. The number and size of the ovotestis differ significantly (P<0.05) in all the snails. Each lobe is made of several follicles and the number of which varied in the four species. Statistical analysis showed that live weight, shell length, shell width and shell circumference of the snails had no significant influence on the size on their ovotestis. Meiotic metaphase spreads of the ovotestis tissues revealed chromosome numbers 2n=56, 2n=44, 2n=54 and 2n=28 for A. marginata, A. achatina, A. fulica and L. aurora

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

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.

The addition of calcium oxide with different doses in the recirculation system to improve the abalone Haliotis squamata seed production

Information about abalone growth is necessary to overcome the abalone culture sustainability. Water quality parameters are aspects that need to be reviewed, one of which is the calcium level in the water. The aim of this study was to determine the optimal calcium dose in recirculation system for abalone (Haliotis squamata) growth. The study was conducted with an experimental method with four treatments (calcium oxide with doses of 0, 15, 30, 45 mg/L) and three times replications. Abalone with 2.3 g body weight, 2.3 cm shell length, and 1.2 cm shell width was reared for 60 days in recirculation system and fed with Gracilaria verrucosa. The results showed that the best abalone treatment medium with the addition of calcium oxide to increase the abalone seed production was 15 mg/L CaO with 100% survival rate, 31.57±2.82% feed efficiency, and 0.56±0.06%/day specific growth rate. Keywords: Abalone, calcium, organ composition, production, recirculation ABSTRAK Informasi tentang pertumbuhan abalon diperlukan untuk mengatasi keberlanjutan budidaya abalon. Parameter kualitas air merupakan aspek yang perlu ditinjau. Kadar kalsium dalam air menjadi salah satu aspek yang dapat ditinjau.Tujuan dari penelitian ini adalah menentukan dosis kalsium optimal melalui sistem resirkulasi untuk pertumbuhan abalon Haliotis squamata. Penelitian ini dilakukan dengan metode eksperimental dengan empat perlakuan 3 ulangan penambahan CaO dengan dosis 0, 15, 30, dan 45 mg/L. Secara singkat, abalon dengan bobot badan 2,3 g, panjang cangkang 2,3 cm dan lebar cangkang 1,2 cm dipelihara selama 60 hari dengan sistem resirkulasi dan diberi makan dengan Gracilaria verrucosa. Hasil penelitian menunjukkan bahwa media perlakuan abalon dengan penambahan kalsium oksida terbaik untuk meningkatkan produksi abalon adalah CaO 15 mg/L dengan tingkat kelangsungan hidup 100%, efisiensi pakan 31,57 ± 2,82 %, dan laju pertumbuhan spesifik harian 0.56 ± 0.06%/hari. Kata kunci: Abalon, kalsium, komposisi organ, produksi, resirkulasi

Influence of breeds and number of whorls on phenotypic traits and correlations among giant African land snails in Nigeria

Six hundred adult mature black-skinned snails with four and five whorls on the shellcomprising of 200 each of the breeds; Archachatina marginata, Achatina achatina and Achatina fulica were used for the study. Phenotypic traits measured from the snails included body weight (BDW), shell length (SHL), shell width (SHW), aperture length (APL), aperture width (APW), spiral length (SPL), spiral width (SPW), diagonal length (DAL), length between the aperture and first spiral (LAS). The data obtained were used to estimate simple statistics (mean, standard error and coefficient of variations) and correlation oefficients. The results showed high significant (p<0.01) breed effects on phenotypic traits as A.nmarginata snails with four (288.700g) and 5(394.500g) whorls were phenotypically and genotypically heavier, larger and wider than A. achatina (127.0g and 182.000g) and A. fulica (48.850g and 65.050g) with four and five whorls respectively. There were also high significant (p<0.01) disparity number of whorls effects on body weight and other phenotypic traits studied. There was only one strong, negative and significant (p<0.01) phenotypic correlation (r ) between SHL and LAS (r = – 0.650) recorded for A. achatina snails with four whorls while A. achatina snails with five whorls recorded few strong, negative and significant(P<0.01) phenotypic correlations between BDW and SHW (r = – 0.613), SHL and LAS (r = –0.641), SHW and APW (r = – 0.602). Similarly, A. fulica snails with four whorls recorded few strong, negative and significant (p<0.01) phenotypic correlations between BDW and SHW (r = – 0.627), SHL and APL (r = – 0.639), SHW and APW (r = – 0.657) and only one strong, negative and significant (p<0.01) phenotypic correlation between SHL and LAS (r = – 0.605) for A. fulica snails with five whorls. Again, Am snails with four whorls had only one strong, negative and significant(p<0.01) phenotypic correlation between BDW and SHL (r = – 0.720). The only two low, positive and significant (p<0.05) phenotypic correlations recorded in this study were between APL and APW ((r = 0.544) and between SPL and DAL (r = 0.583) for A. marginata snails with four and five whorls respectively. Thus, the breed type and number of whorls on snail shells strongly influenced estimates of phenotypic traits and correlation coefficients of giant African land snails in Nigeria. Also, that estimates of correlation coefficients of mature giant African land snails with higher whorls were (4 and 5) are scarcely strong, positive and significant. The study revealed and confirmed that A. marginata snails are phenotypically and genotypically heavier, larger and wider than A. achatina and A. fulica snails with 4 and 5 whorls. These estimates are recommended as strong and efficient tools for selection and up grading or improvement of giant African land snails genetic traits in Nigeria.