scholarly journals Growth and morphometric characteristics of the scallop Flexopecten glaber (Bivalvia: Pectinidae) reared in cages off the coast of Crimea (Black Sea)

2021 ◽  
Vol 31 (3) ◽  
pp. 127-138
Author(s):  
N. K. Revkov ◽  
A. V. Pirkova ◽  
V. A. Timofeev ◽  
L. V. Ladygina ◽  
S. V. Schurov

The spat of the scallop Flexopecten glaber were collected in cages with the Pacific oyster Crassostrea gigas cultured on a mussel-and-oyster farm (outer roadstead of Sevastopol Bay). For two years they were reared in plastic cages at a depth of 2-3 m. The cages were periodically withdrawn to measure the size and weight parameters of the molluscs: the length (L, mm), height (H, mm), and width (D, mm) of shells and the total live weight (W, g). The correlations among the parameters under study are presented. The changes in the indices of the frontal (D/L) and sagittal (H/L) curvatures, convexity ((H+D)/L) and conditional volume (H×D×L/1000) of the shells in ontogenesis are shown. Upon reaching a shell length of 30-35 mm, the allometry of the volumetric and weight growth of molluscs changed from positive to negative. The largest values of the shell convexity index were registered in thesame length range. A conclusion about the interval-type growth of F. glaber in linear size and weight is made. It is suggested that the optimal strategy of shell formation in F. glaber in ontogenesis implies the ripening and the first reproduction of the molluscs occurring at the highest volumetric characteristics of the shell. The relationships for the linear size and weight growth ofF. glaber in the first two years of life are obtained. It is concluded that the scallop F. glaber should be considered as a possible element for the diversification of the existing aquaculture of molluscs (mussels and oysters) off the coast of Crimea.

Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 526
Author(s):  
Barbara Mikac ◽  
Alessandro Tarullo ◽  
Marina Antonia Colangelo ◽  
Marco Abbiati ◽  
Federica Costantini

Oyster shells are substratum for different epibiontic and endobiontic organisms, including pests and parasites. Rocellaria dubia is endolithic and facultative tube-dwelling bivalve, boring in different calcareous substrates, including the shells of bivalves. In 2020, R. dubia was found as endolithic in the shells of the Pacific oyster Magalana gigas, from an oyster farm off the Sacca di Goro lagoon (Emilia-Romagna region, Northern Adriatic Sea, Italy). The purpose of this study was to describe this newly recorded association. Altogether, 136 specimens of R. dubia were found in 15 oysters, photographed under a stereoscope, and their length was measured. Heavily infested oysters hosted tens of R. dubia borers, which were perforating the whole thickness of the oyster valves. The flesh of these oysters was heavily damaged, suggesting parasitic association. R. dubia specimens were categorized into three age classes (0–1, 1–2, and 2–3 years old). M. gigas/R. dubia might be a widespread association, overlooked due to the very scarce research on macrofauna associated with M. gigas. Considering the negative effects of R. dubia endobiosis on oyster fitness, and possible impacts on oyster aquaculture, further research should be conducted in order to elucidate the distribution and ecological characteristics of this parasitic association.


2017 ◽  
Vol 53 ◽  
pp. 115-119
Author(s):  
A. V. Dymchuk ◽  
O. I. Lyubynskyy

The studies of the dynamics results of body weight, absolute and daily average, relative increases averaging bulls of Ukrainian black-and-white and Ukrainian red-and-white dairy cattle. Researches are conducted in the conditions of POSP «Napadivske» Kalyinivka district of the Vinnytsya area after materials of primary pedigree account. In an economy use the whole-year of the same type feeding. In the structure of ration 40% make the concentrated sterns and also high-quality silage and soilage. Average daily increases of bulls for period of age to realization for a slaughter made over 1000 grammes. The dynamics of growth of living mass, absolute, average daily and relative increases of bulls, is analysed Ukrainian black-and-white and Ukrainian red-and-white dairy cattle. Living mass and weight gain researches of age to 12-monthly age with an interval in 3 months after the generally accepted methods. Materials of researches are worked out the methods of mathematical statistics with the use of programmatic package of Statistica 8.0. Living mass of bulls of the second group at birth made 36,3 kg, that anymore on 0,8 kg by comparison to new-born bulls of the first group. In all next periods living mass of animals of the second group was greater as compared to the animals of the same age of the first. In 3 months advantage made 1,7 kg, in 6 months – 4,6 kg (P>0,95), in 9 months – 8,8 kg (P>0,95), in 12 months – 12,5 kg (P>0,99). Difference of absolute increases of bulls of the second group above the bulls of the same age of the first of age to to 3-monthly age made 0,8 kg in behalf of animals of the second group. In a period 3-6 months a difference is after this index between the first and second groups made 2,9 kg in behalf of the last. In periods 6-9 and reliable advantage of animals of the second group is 9-12 months set above the bulls of the same age of the first on 4,1 kg (P>0,95) and 3,7 kg (P>0,95) accordingly. In a period of age to 18-monthly age absolute increases of bulls of the second group were greater by comparison to bulls first on 12,5 kg (R>0,99). Average daily increases of bulls of the second group of age to 3-monthly age made 763,0 grammes, that anymore on 8,9 grammes by comparison to bulls of the first group. In periods 3-6 months the average daily increases of animals of the second group prevailed the bulls of the same age of the first on 32,6 grammes. In a period 6-9 months the average daily increases of animals of the second group were made by 1045,9 grammes, that for certain anymore on 45,9 grammes (P>0,95) by comparison to the bulls of the same age of the first. Maximal increases of bulls were in a period 9-12 months and made 1210,4 grammes in the animals of the second group and 1168,9 grammes – for the bulls of the same age of the first, that for certain anymore on 41,5 grammes (P>0,95). In a period of age to 12-monthly age the average daily increases of bulls of the second group were made by 970,6 grammes, that was for certain anymore on 31,8 grammes (R>0,99) by comparison to the bulls of the same age of the first group. Relative increases of bulls of both groups were high. From birth to 3-monthly age greater increases had bulls of the first group – 97,8%, and in periods 3-6, 6-9 and 9-12 months greater were increases of bulls of the same age of the second group – 56,4; 40,1 and 32,4% accordingly. For all probed periods of reliable advantage it is not discovered between the compared groups. It is set researches, that at the identical terms of feeding and maintenance more rapid bulls grow Ukrainian red-and-white dairy cattle. In all age-old periods they prevailed the bulls of the same age of the Ukrainian black-and-white dairy cattle, in a that number, beginning from 9-monthly age, advantage was reliable (P>0,95–0,99). Average daily increases of bulls of two breeds were the least in a period of age to to 3-monthly age – 754,1-763,0 grammes, and most in a period 9-12 months – 1168,9–1210,4 grammes.


2016 ◽  
Vol 113 ◽  
pp. 31-38 ◽  
Author(s):  
Perrine Gamain ◽  
Patrice Gonzalez ◽  
Jérôme Cachot ◽  
Patrick Pardon ◽  
Nathalie Tapie ◽  
...  

Aquaculture ◽  
2021 ◽  
pp. 736923
Author(s):  
Roberto Arredondo-Espinoza ◽  
Ana M. Ibarra ◽  
Steven B. Roberts ◽  
Maria Teresa Sicard-Gonzalez ◽  
Cristina Escobedo-Fregoso

Sign in / Sign up

Export Citation Format

Share Document